Document:

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                                                                   Exhibit 10.17

Nortel Networks plc                    LambdaNet Communications Gesellschaft mbH
                 Frame Contract to Supply DWDM and SDH Equipment
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TABLE OF CONTENTS

TERMS AND CONDITIONS

APPENDIX 1: PRICE

APPENDIX 2: TECHNICAL DESCRIPTION OF THE SYSTEMS

         CHAPTER 1: GUARANTEED ATTRIBUTES

         CHAPTER 2: WORKAROUND - AGREEMENTS

         CHAPTER 3: SYSTEM FEATURE DESCRIPTIONS

                  SYSTEM FEATURE DESCRIPTIONS DWDM SYSTEMS
                  Optical Line Terminal
                  Optical Add/Drop Multiplexer
                  Optical Line Amplifier

                  SYSTEM FEATURE DESCRIPTIONS SDH SYSTEMS
                  ADM-64/4 (TN-64X)
                  ADM-16/1 (TN-16XE / TN-4XE)
                  DXC-N/1 (TN-16XE / TN-4XE))
                  TM-N/1 (TN-4XE)
                  TM-N/1 (TN-1X)
                  TN-1C
                  TN-16X

                  SYSTEM FEATURE DESCRIPTIONS NETWORK MANAGEMENT SYSTEMS
                  Path Management System
                  Element Management System

APPENDIX 3: SPECIFICATION OF SERVICES

APPENDIX 4: SITE DOCUMENTATION

APPENDIX 5: IMPLEMENTATION GUIDELINES

            Guidelines for the Layout of Signal Distribution Frames
            Technical Guidelines on Cable Lengths

APPENDIX 7: DATA PROTECTION AND NON-DISCLOSURE AGREEMENT

APPENDIX 8: LIST OF AFFILIATES ACCORDING TO SECTION 15

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                               FRAMEWORK AGREEMENT*

                                     between

                    LambdaNet Communications Gesellschaft mbH
                             Gunther-Wagner-Allee 13
                                 30 177 Hannover

                     hereinafter referred to as "LambdaNet"

                                       and

                               Nortel Networks plc
                             Maidenhead Office Park
                                  Westacott Way
                                   Maidenhead
                                    SL6 3QH.

                  hereinafter referred to as "Nortel Networks"

   concerning the purchase of the transmission systems and associated services

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* Portions of this agreement are confidential and have been omitted and filed
  separately with the Securities and Exchange Commission pursuant to a
  request for confidential treatment in accordance with Rule 406 under the
  Securities Act of 1933, as amended. Asterisks, for example "*****," have
  been inserted to indicate that information has been deleted.

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TABLE OF CONTENTS

<TABLE>
<S>                                                                                     <C>
1     Scope of supply....................................................................3

2     Usufruct...........................................................................4

3     Integration of third party systems.................................................5

4     Liability for the violation of third party rights..................................5

5     Informational obligations of the Contractor........................................6

6     Products of third party producers..................................................7

7     Prices / Terms of payment..........................................................7

8     Ordering...........................................................................8

9     Type acceptance....................................................................9

10       Field acceptance...............................................................10

11       Taking back defective products / parts, complete disposal......................10

12       System documentation...........................................................11

13       Site documentation.............................................................11

14       Investigation and reporting obligation.........................................12

15       Delivery times.................................................................12

16       Development milestones.........................................................12

17       Repair times...................................................................13

18       MTBF- Guarantee................................................................14

19       Warranty.......................................................................14

20       Liability for claims to compensation for damages...............................15

21       Transfer of risk and transfer of ownership.....................................16

22       Permits........................................................................17

23       Availability of spare parts....................................................17

24       Confidentiality and data protection............................................17

25       Training.......................................................................18

26       Term of contract...............................................................18

27       Year 2000 compatibility........................................................18

28       Force majeure..................................................................19

29       Other..........................................................................19
</TABLE>

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PREAMBLE

LambdaNet (formerly Carriers` Carrier Gesellschaft mbH) and Nortel Dasa Networks
Systems GmbH & Co. KG on February 21, 1999 executed a frame contract regarding
the purchase of transmission systems and services related thereto, which applies
to Germany. LambdaNet now plans to also build and operate transmission lines for
telecommunications services (telecommunications transport networks) in several
countries of Europe. LambdaNet plans to order the transmission systems required
therefor and the services related thereto from Nortel Networks and its
affiliates. This agreement shall be the base for the cooperation of the parties
in Europe except for Germany

On the basis of the aforesaid premises, the parties agree to the following.

1        SCOPE OF SUPPLY

1.1       This frame contract sets out the terms and conditions according to
          which LambdaNet, or its affiliates within the meaning of section 15
          ff. AktG, may purchase transmission systems and services related
          thereto from Nortel Networks or its affiliates within the meaning of
          section 15 ff. AktG. If required LambdaNet or its affiliates shall
          place orders for deliveries and services under this frame contract
          with Nortel Networks or its affiliates. Contractual relationships
          arising from the respective orders shall come into existence between
          the company which places the order (,,Purchaser") and the company
          which accepts the order (,,Contractor").A list of such Nortel Networks
          affiliates which may act as Contractor besides Nortel Networks is
          enclosed as Annex 8. Annex 8 also contains a survey of the countries
          in which the respective affiliates operate. A list of LambdaNets
          affiliates which besides LambdaNet are entitled to place orders under
          this frame contract with Nortel Networks or its affiliates is enclosed
          as Annex 8.

1.2       The scope of supply to be provided by the Contractor consists of the
          delivery, installation and commissioning of the transmission system
          described in Appendix 2 (referred to below as "system"). These include
          the network elements such as multiplexers and repeaters and the items
          needed to control the network elements - management software,
          accompanying platforms for computer, operating system and database -
          and other hardware and software required to link the network elements
          to the management system.

1.3       The Contractor shall also provide the regular and optional services
          described in Appendix 4 for all systems supplied within the context of
          this contract. Services that differ on a national level will be agreed
          upon by LambdaNet and Nortel Networks and included as a national
          appendix.

1.4       The functions and services specified in Appendix 2 and Appendix 4
          shall be guaranteed by the Contractor. Moreover, the Contractor shall
          guarantee the properties listed in Appendix 2, Section 1.

1.5       Components of this contract shall be the text of this contract and the
          Appendices attached to this contract:

                  Appendix 1:       Prices

                  Appendix 2:       System Feature Descriptions

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                  Appendix 4:       Specifications of Services

                  Appendix 3:       Scope of supply location documentation

                  Appendix 4:       Construction guidelines

                  Appendix 5:       Confidentiality agreement

                  Appendix 7:       Data protection and confidentiality
                                    obligation

                  Appendix 8:       List of Nortel Networks' and Lambdanet's
                                    affiliates, within the meaning of section
                                    15 ff. AktG.

1.6       No claim to the conclusion and performance of individual purchase
          contracts shall exist on the basis of this framework contract.
          LambdaNet is planning a DWDM backbone network in France and Spain and
          will ensure that LambdaNet or one of its affiliates, as described in
          Appendix 8, orders its system technology from Nortel Networks.

2         USUFRUCT

2.1       The Contractor shall guarantee to the Purchaser the non-exclusive
          right, and unlimited in terms of time, for companies connected with
          the Purchaser in accordance with the provisions of Sections 15 ff.
          of AktG [Law on Limited Liability Companies], to use the software of
          the system with the accompanying documentation or allow third parties
          to use it. The Right to use is limited to those countries in which the
          System is delivered or from which the network is operated.

2.2       The Purchaser shall not be permitted to modify, disassembly,
          decompile, back-translate or in any other way decode the software
          supplied by the Contractor. This prohibition shall not apply to the
          extent that there is an enforceable provision of law opposed to it.
          The Purchaser must obligate its subcontractors to comply with these
          license conditions. However, the Contractor shall guarantee to the
          Purchaser the right to modify and to translate the system
          documentation in accordance with Section 12 and the site documentation
          in accordance with Section 13 for the Purchaser's own purposes.

2.3       The Contractor shall guarantee to the Purchaser the right to integrate
          the supplied system wholly or in part into the software programs of
          third parties. In this respect, the Contractor shall, without
          additional compensation, make available for inspection the information
          necessary for such integration requested by the Purchaser concerning
          the external interfaces to his system. This includes in particular the
          following information:

          -    Description of the communication protocol used on the interface
               (description of the protocol for each layer),

          -    Description of the protocol data units used in the protocol for
               each layer,

          -    Description of the rules applied for the coding of the
               information,

          -    Description of the information model,

          -    Explicit list of the alarms supplied through the interface.

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          Furthermore, the Contractor shall prepare information on the databases
          of the supplied management system that are needed for the integration.
          These include in particular:

          -    List of the DB table names,

          -    Description of the DB table fields,

          -    Description of the coding rules of the DB table entries,

          -    Description of the DB triggers used,

          -    Description of the DB functions used,

          -    Description of the DB procedures used.

          The information about the databases shall be submitted to the
          Purchaser upon their written request. After submission of the
          information, the Contractor shall immediately and comprehensively
          instruct the Purchaser concerning planned modifications in the
          databases on which the supplied management system is based.

2.4       The Contractor shall also guarantee to the Purchaser the right to have
          a third party perform the integration of its systems into the software
          programs of third parties, if the Purchaser so chooses. In this
          respect, the Purchaser shall have the right to distribute the
          information obtained concerning interfaces and databases to third
          parties, whereby this information must only be distributed to third
          parties within the context of and for the purposes of integrating the
          Contractor's system into the software programs of third parties. If
          the third party is a company that produces hardware and software of
          the same type as the subject matter of the contract, the distribution
          of information shall require the prior consent of the Contractor, who
          shall refuse such a request only for important reasons. In any event,
          before distributing information to a third party, the Purchaser shall
          conclude an information protection agreement with such party. The
          Contractor shall support the Purchaser in the integration of his
          system into the software programs of third parties to an appropriate
          extent. The support shall be offered without additional compensation
          unless the services he is to provide demonstrably exceed the
          information obligation described in 2.3. Services that exceed this
          shall be compensated on the basis of the labour cost at the agreed per
          diem rates.

3         INTEGRATION OF THIRD PARTY SYSTEMS

          The Contractor hereby declares himself ready to integrate systems of
          third parties into the management system in accordance with Appendix
          2. Upon request by the Purchaser, the Contractor shall present a
          quotation for this. The integration shall be done on the basis of the
          interfaces available on the systems of third parties. The Purchaser
          shall arrange for the third party in question to make available for
          inspection the information needed on the interfaces involved. In this
          respect, the Contractor, by his signature of the Agreement on Secrecy
          vis-a-vis Third Parties, declares his agreement to abide by this
          provision.

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4         LIABILITY FOR THE VIOLATION OF THIRD PARTY RIGHTS

4.1       The Contractor shall be responsible to assure that the subject matter
          of the contract is free from third party patent rights that exclude or
          limit its use. The Contractor shall assume the sole responsibility,
          unlimited by amount, in relation to any party that asserts a claim
          that patent rights have been violated and shall release the Purchaser
          from all legally enforceable third party claims of this type to the
          full extent of such claims, in so far as the Purchaser fulfils its
          obligations according to paragraph 4.3.

4.2       If the contractually stipulated use by the Purchaser of the system
          supplied by the Contractor or parts thereof is affected or prohibited
          by an asserted violation of third party patent rights, the Contractor
          shall be authorised and obligated at his own expense to exercise
          whichever of the following two options he prefers:

          a)   to procure for the Purchaser the right to use the system without
               limitation and without additional expense for the Purchaser, or

          b)   to modify or replace the system, or the parts of it in question,
               such that it no longer falls under the patent rights of third
               parties, yet still corresponds to the contractual specifications.

                  In addition, the Contractor shall be liable under 20.4 b).

4.3      The Purchaser shall:

          a)   give notice to the Contractor of any actual or threatened action
               or claim forthwith upon becoming aware of the same;

          b)   give the Contractor the sole conduct of the defence to any actual
               or threatened action or claim in respect of an alleged
               intellectual property infringement and shall not at any time
               admit liability or otherwise attempt to settle or compromise the
               said action or claim except upon the express written instructions
               of the Contractor;

          c)   act in accordance with the reasonable instructions of the
               Contractor and shall give to the Contractor such assistance as it
               shall reasonably require in respect of the conduct of the said
               defence including, without prejudice to the generality of the
               foregoing, the filing of all pleadings and other court process
               and the provision of all relevant documents.

4.4       All claims by the Purchaser based on violation of third party patent
          rights shall be asserted with the aforesaid provision.

5         INFORMATIONAL OBLIGATIONS OF THE CONTRACTOR

5.1       The Contractor shall undertake to instruct the Purchaser immediately
          of foreseeable and actual delays in completing the performance of the
          contract.

5.2       The Contractor shall undertake to inform the Purchaser concerning
          changes of the status of science and technology, particularly with
          regard to new products of the Contractor that have become known on the
          market, that have possible repercussions on the subject matter of the
          contract, and concerning new technical knowledge.

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5.3       If the Contractor recognises that he cannot satisfy an agreed
          performance requirement according to Appendix 2 or Appendix 4, he must
          immediately communicate this to the Purchaser in writing including the
          reasons for it and the consequences of it that are recognisable to him
          and at the same time make corresponding proposals for modifications,
          which, insofar as the Contractor himself is not in the position to
          complete the modification proposal himself, must also consist in the
          delivery of OEM equipment. The parties shall jointly determine whether
          the modification proposal can be accepted by the Purchaser, whereby
          the Purchaser shall not be permitted to refuse acceptance of the
          modification proposal within reasonable parameters. If the Purchaser
          accepts the modification proposal, then the additional expenses that
          may result shall not be charged to the Purchaser. If the Purchaser
          refuses the modification proposal, then the Purchaser shall be
          authorised to request a deduction from the price, or, if the entire
          system is affected in more than a minor way by the failure to fulfil
          the performance requirement, even at this point in time the Purchaser
          shall be entitled to demand withdrawal (cancellation) from the
          individual purchase contracts or indemnification for damages because
          of non-performance according to reasonable judgement.

6         PRODUCTS OF THIRD PARTY PRODUCERS

          If standard application software is a part of the subject matter of
          the contract and this standard application software is purchased by
          the Purchaser on its own volition, or if the Purchaser purchases
          additional hardware, operating system software and other software for
          the operation of the subject matter of the contract, the following
          shall apply:

          The Contractor shall communicate to the Purchaser which standard
          application software, hardware, operating system software and other
          software is needed for the operation of the subject matter of the
          contract. The Contractor shall guarantee that this standard
          application software operates fault-free as a part of the subject
          matter of the contract and that the hardware, operating system
          software and other software operates fault-free together with the
          subject matter of the contract, unless a merely insignificant fault is
          present. Furthermore, the Contractor shall assure that no additional
          hardware, operating system software or other software is necessary for
          the operation of the devices described in Appendix 2.

          If the Purchaser would like to use different hardware or operating
          system software, then the Contractor shall undertake to communicate to
          the Purchaser whether this hardware and operating system software is
          likewise suited to operate fault-free together with the subject matter
          of the contract. If this is the case, the Contractor shall issue an
          guarantee of this.

7         PRICES / TERMS OF PAYMENT

7.1       The prices cited in Appendix 1 are fixed prices in DM with the
          statutorily mandated locally prevailing value added tax to be added.
          They shall apply for all orders according to the provisions of this
          framework agreement and are to be understood as f.o.b. to the site of
          use (DDP in accordance with ICC-Incoterms 1990), including packing and
          disposal of packing materials. For delivery to countries outside of
          the EU, the Contractor can invoice the Purchaser for the associated
          import duties. In the event that payments have to be made in local
          currency according to law, the DM prices shall be converted into Euro
          prices at the exchange rate prevailing at the time of presentation of
          invoice by the Contractor.

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7.2       A partial invoice for 25% of the entire order shall be presented upon
          the successful delivery of the ordered goods to their destination. The
          invoice for the remaining 75% shall be presented subject to prior
          successful field acceptance testing and signature of the corresponding
          field acceptance certificate (FAC). With the exception of the
          aforementioned partial invoice, there shall be no further partial
          invoices unless the field acceptance cannot be performed as a result
          of acts or ommissions of the Purchaser. A copy of the corresponding
          FAC shall be attached to the invoice. If the Purchaser, neither issues
          the FAC and sends it to the Contractor, nor complains about any
          defects within 5 business days after completion of the acceptance
          test, the acceptance shall be considered declared and the FAC shall be
          considered as issued. The Contractor can present quarterly invoices
          for existing and ongoing services.

7.3       Each invoice amount shall be payable within 30 days net after the
          invoice is received.

7.4       The agreed prices for hardware, software and services are maximum
          prices (not to exceed prices) and shall not be exceeded in any add-on
          orders. Should price reductions result because of a change in the
          overall price structure, they shall be taken into account in any
          add-on orders.

7.5       For commercial goods (third party products), the Contractor shall
          guarantee that his prices for the Purchaser are calculated on the
          basis of his purchase prices plus a maximum mark-up 20%. If the
          Contractor at the point in time of the procurement attains favourable
          purchase prices, then he shall pass the attained price advantage on to
          the Purchaser.

7.6      Invoices shall be sent to the respective Purchaser.

8         ORDERING

8.1       Depending on its needs, the Purchaser shall call for the Contractor's
          supplies and services included in the scope of supply within the
          parameters of the particular agreed delivery and performance times
          individually or jointly - possibly separated according to location -
          in the form of a written order on the respective Contractor.

8.2       Along with the name of the supply or service to be provided, the
          orders shall include the place and time the performance is to be
          provided, as well as further details where needed.

8.3       Modifications of orders that have already been placed are legally
          binding only if they are made in writing by the Purchasing and
          Logistics Section of the Purchaser or from a representative expressly
          empowered for this.

8.4       If the Contractor, upon receiving an order, determines that he for any
          reason cannot complete the required supplies and services within
          established deadlines, then he shall immediately make this known to
          the Purchaser in writing.

8.5       The Contractor shall assume the risk of accidental destruction of the
          system components during storage by the Contractor. This provision
          shall not apply if the storage is done by the Purchaser in areas made
          available by the Purchaser or its customers.

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8.6       The order shall be considered accepted if it conforms with the
          provisions of this Frame Agreement and a complaint has not been filed
          with the Purchaser within 5 business days of receipt of the order by
          the Purchaser. This also applies if the order deviates in only an
          insignificant manner from the provisions of this Frame Agreement.

8.7       The Purchaser purchase order number must always be indicated in
          correspondence related to the order.

8.8       The positioning of the order shall not be altered in order
          confirmations, delivery notes and invoices. Additional items shall
          be placed at the end.

8.9       Additional agreements on ordering of supplies and services are
          described in Appendix 4, Section "Ordering".

8.10      For administrative convenience, this Frame Agreement will be centrally
          administered by Nortel Networks , and the Purchaser shall accordingly
          issue all purchase orders and submit to the Contractor with a copy to
          Nortel Networks. This lies outside the scope of the agreements of the
          individual contracts according to paragraph 1.1 and the production of
          contractual fulfillment by the Purchaser and the Contractor.

8.11      All purchase orders will be raised by LambdaNet, either on its own
          behalf or in the name of LambdaNet`s affiliate in the country of
          deployment, or by the respective affiliate itself, on the Nortel
          Networks affiliate in the country in which the System is to be
          provided.

          All purchase orders are to be sent to the Contractor with a copy to
          Nortel Networks at the following address:

                  NORTEL NETWORKS plc
                  MAIDENHEAD OFFICE PARK

                  WESTACOTT WAY
                  MAIDENHEAD
                  SL6 3QH.
                  FOR THE ATTENTION OF MR. STEVE ILLMAN, LAMBDANET ACCOUNT TEAM

          The Nortel Networks Contract Administrator will ensure that all
          purchase orders are directed to the correct Nortel Networks affiliate.

9         TYPE ACCEPTANCE

9.1       All types of systems and system components shall be subject to a type
          acceptance test. The type acceptance test shall be conducted by the
          Purchaser according to the procedure/conditions described in Appendix
          4, Section "Type Acceptance". The Contractor shall undertake to
          support the Purchaser on an uncompensated basis in the type acceptance
          testing to the extent defined in Appendix 3. In particular, the
          Contractor must provide the equipment adjustment and support services
          described in Appendix 4 on an uncompensated basis. The Purchaser shall
          confirm the type acceptance to the Contractor with a Type Acceptance
          Certificate (TAC).

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9.2       In the event of non-acceptance of the type, the term of default of the
          Contractor shall be calculated retroactively from the time the "Ready
          for Type Acceptance" was communicated, in accordance with the
          provisions of Appendix 3, Section 2.1, unless the Purchaser is to
          blame for delaying the start and execution of the type acceptance
          test. The parties hereby agree that the initiation of the type
          acceptance test shall be regarded as timely if it occurs within one
          calendar week after the communication of "ready for type acceptance".
          The Purchaser shall undertake to commence the testing within this
          period. The parties to the contract shall employ qualified personnel
          to conduct the test.

9.3       Unless the Purchaser requests otherwise in writing, the Contractor
          shall supply to the Purchaser only the hardware and software versions
          for which the Purchaser has conducted a successful type acceptance
          test. Modifications in the version of hardware and software after the
          initial type acceptance of a system or a system component shall
          require prior testing and approval by the Purchaser. This shall be
          performed according to the procedure described in Appendix 4, Section
          "Type Modification".

9.4       The type acceptance shall not release the Contractor from his warranty
          obligations.

10        FIELD ACCEPTANCE

10.1      The acceptance of the particular supplies and services shall be
          carried out at each place of destination by means of a field
          acceptance test conducted by the Purchaser. The Contractor shall
          undertake to support the Purchaser in the field acceptance testing on
          an uncompensated basis to the extent defined in Appendix 3. The field
          acceptance for each individual order shall be completed if all of the
          required hardware and software has been completely supplied to the
          designated site of use and the order based on the specifications of
          the Purchaser is completely installed, cabled, connected to the power
          grid and the management system, tested, documented and delivered to
          the Purchaser or to a representative expressly empowered for this. The
          Purchaser shall confirm the field acceptance to the Contractor by a
          Field Acceptance Certificate (FAC). The signing of the field
          acceptance certificate shall proceed immediately after the successful
          completion of the field acceptance.

10.2      The installation of the system shall be performed according to the
          construction guidelines attached as Appendix 4.

10.3      The field acceptance shall be performed according to the procedure and
          conditions described in Appendix 3, Section "Field Acceptance".

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10.4      The field acceptance shall be considered declared, notwithstanding the
          specifications cited in Appendix 3, if the system or parts thereof
          have been placed in actual operation. This provision does not apply if
          the Contractor is late with his supplies or services and the Purchaser
          places the system or parts thereof in actual operation in order to
          satisfy demonstrable existing obligations to the customers of the
          Purchaser (so-called "provisional actual operation"). In this case,
          the Contractor shall obtain a part of the compensation agreed for the
          system or parts thereof as a monthly use compensation even before the
          field acceptance test. The amount of the use compensation shall be
          calculated according to the sum of the agreed prices for the hard and
          software supplied up until the provisional operational commissioning
          in consideration of a depreciation time of years (calculation example:
          sum of the prices for supplied hard and software: 5 (years) : 12
          (months) = monthly use compensation). The use compensation shall be
          due at the beginning of each month for the preceding month. It is to
          be credited against the compensation to be paid by the Purchaser for
          the system or parts thereof after the field acceptance. The payment of
          the use compensation shall not represent a waiver by the Purchaser of
          possible claims for default or of payment of a contract penalty;
          Section 341 BGB [German Civil Code] shall not apply. If the
          provisional actual operation lasts longer than 2 months, then the
          system or parts thereof that were commissioned shall be considered as
          accepted.

10.5      In the event the acceptance is denied, the term of default of the
          Contractor shall be counted retroactively from the time "Site Ready
          for Acceptance" was communicated in accordance with the provisions of
          Appendix 3, Section 2.1 " (RfA), unless the Purchaser is to blame for
          delays in the commencement and execution of the acceptance test. The
          parties hereby agree that commencement of the acceptance test within
          one calendar week of the communication "Ready for Field Acceptance"
          shall be regarded as timely. The Purchaser shall undertake to commence
          the test within this time period. The parties shall employ qualified
          personnel for the execution of the tests.

11        TAKING BACK DEFECTIVE PRODUCTS / PARTS, COMPLETE DISPOSAL

11.1      The Contractor shall take back transport packing without compensation
          and bear the costs for disposal.

11.2      The Contractor shall be obligated to take back system components that
          are defective or no longer needed and dispose of them in a proper
          manner without compensation. The sender shall bear the delivery costs.
          If the statutory situation changes during the term of the contract,
          both parties shall jointly come to agreement on the resulting
          additional costs of the disposal.

11.3      Upon request of the Purchaser, the Contractor shall present proof of
          the properly conducted disposal.

12        SYSTEM DOCUMENTATION

12.1      The Contractor shall make available to the Purchaser one complete set
          of paper form system documentation in triplicate copy for each unit
          supplied. If the Purchaser so desires, the system documentation or
          parts thereof can also be supplied in software form (e.g. CD-ROM). The
          Purchaser shall be authorised to copy it to use for the production of
          its own manuals and specifications. The copyrights to the system
          documentation shall in any case remain with the Contractor.

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12.2      The system documentation shall describe in a comprehensive and
          comprehensible way the operation, the mode of functioning, the
          characteristics and the technical structure of the system components.
          It shall include, among other things, installation instructions,
          repair instructions, operating instructions and technical
          specifications.

12.3      Installation instructions and operating instructions shall be composed
          in the respectively agreed language. The technical specification can
          be composed in the English language.

12.4      The review of the system documentation is an item subject to type
          acceptance testing.

12.5      The Contractor shall immediately instruct the Purchaser concerning
          faults and defects in the system documentation subsequently recognised
          and correct the system documentation accordingly. In particular, the
          Contractor shall adapt the system documentation to modifications of
          the hardware and software versions. Individual changes can be made
          with adequately referenced modification pages. With multiple or
          extensive modifications, the Contractor shall supply a reworked
          version of the system documentation. The services performed to make
          the corrections shall in any case be on an uncompensated basis.

13        SITE DOCUMENTATION

13.1      The Contractor shall compile a complete set of site documentation and
          shall deliver it to the Purchaser at the time of the field acceptance.
          Structure and contents of the site documentation are described in
          Appendix 4. The composition and supply of the site documentation shall
          in any case be made on an uncompensated basis.

13.2      The review of the site documentation is an item subject to field
          acceptance testing.

13.3      The Contractor shall instruct the Purchaser immediately concerning
          faults and defects in the site documentation subsequently discovered
          and shall correct the site documentation accordingly. Subsequent
          installations at a site shall be recorded in the site documentation
          that has already been composed. The Contractor in these cases shall
          modify or supplement the existing site documentation to the extent
          required. Individual modifications or supplements can be made with
          adequately referenced modification pages. With multiple or extensive
          modifications, the Contractor shall supply a reworked version of the
          site documentation. The documentation services of the Contractor shall
          be provided in any case on an uncompensated basis.

14        INVESTIGATION AND REPORTING OBLIGATION

14.1      Apart from an extensive review, the Purchaser can satisfy itself of
          the suitability of the supply by a random sampling review.

14.2      The Contractor shall waive any additional right to file a claim of
          violation of the obligation to conduct immediate review and reporting
          in accordance with Section 377, 378 HGB.

<PAGE>

15        DELIVERY TIMES

15.1      The delivery times are established in Appendix 4, Section "Delivery
          Times" and shall be indicated with the corresponding orders.

15.2      If the Contractor is late in the delivery of the system ready for
          acceptance or parts thereof, then the Contractor shall be obligated to
          pay a contract penalty in the amount of 0.25% per calendar day of the
          price of the network elements delivered late, plus the price of any
          network elements that cannot be used commercially because of the late
          delivery, up to a maximum amount of 15% of this reference amount.
          According to the provisions of this Item 15.2, commercially usefulness
          shall mean that the usefulness of the network elements must neither be
          completely disabled nor substantially limited in terms of the
          telecommunications services or the administration of them (network
          management) - whereby a substantial limitation of the administration
          is present even if the Purchaser has an increased operational expense.
          In addition, the Contractor shall be liable under 20.4 b) in the event
          that the Purchaser is prevented, as a direct result of the delay, from
          providing contracted services to its customers The Contractor can
          avoid the payment of the contract penalty and liability under clause
          20.4 b), if he completes the overdue delivery within a grace period of
          two weeks of notification of default. All claims of the Purchaser
          because of default in the delivery of the system or parts thereof
          shall be compensated according to this provision. The right of the
          Purchaser to withdraw from the purchase order according to item 26.2
          in the event the above 15% maximum penalty is reached shall remain
          unaffected by this provision.

15.3      No proviso according to Section 341 Par. 3 BGB shall needed to assert
          a claim for the contract penalty; this can be asserted up to six (6)
          months after receipt of the final invoice.

16        DEVELOPMENT MILESTONES

16.1      Nortel Networks shall undertake to develop the system components
          further in relation to the characteristics and functions specified in
          Appendix 2 and to make them available to LambdaNet for the type
          acceptance test on the dates listed below, unless LambdaNet determines
          a later date for the acceptance test:

          T2:      **

          T3:      **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

                  *:     **

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                  *:     **

16.2      If Nortel Networks is late in readying the system and characteristics
          cited in Appendix 2, Section 1, or parts of said system, for the type
          acceptance test, then Nortel Networks shall be obligated to pay a
          contract penalty in the weekly amount of 2 % of the penalty amount
          cited in Appendix 2, Chapter 1, up to the entire penalty amount,
          unless LambdaNet has accepted a modification proposal according to the
          terms of the provisions under item 5.3. The contract penalty will be
          calculated from the respective milestone date, in any case no earlier
          than the date of signature of the Frame Agreement. Nortel Networks can
          avoid the payment of the contract penalty if he makes the system and
          characteristics cited in Appendix 2, Section 1 available for type
          acceptance testing within a grace period of two weeks after
          notification of default. Nortel Networks shall also not be obligated
          to pay the contract penalty, if LambdaNet, in spite of the delay, can
          completely fulfil its obligations to its customers to provide
          telecommunications services. The preceding sentence shall apply
          accordingly, if, in spite of the systems or characteristics that turn
          out to be late, no significant effects result for the conduct of
          operations. The payment of this contract penalty can be claimed by
          LambdaNet in addition to the contract penalty according to Item 15.2
          of this contract. In this case, the contract penalty according to Item
          15.2 shall be credited against the contract penalty according to this
          paragraph. If LambdaNet asserts the existing claim for payment of the
          contract penalty according to Item 16.2, a deduction shall be made
          against the purchase price. The contract penalty to be paid by Nortel
          Networks according to this Item 16.2 shall be limited to an overall
          total amount of ********. All claims by LambdaNet based on
          default in making the systems and characteristics cited in Appendix 2,
          Section 1 available for type acceptance testing shall be asserted with
          the aforesaid provision.

16.3      No proviso in accordance with Section 341 Par. 3 BGB shall be required
          in asserting a claim for the contract penalty; on the contrary, it can
          be asserted up to 6 months after receipt of the final invoice.

17        REPAIR TIMES

17.1      If the Purchaser requires the repair and maintenance services
          according to Appendix 4, Section "Maintenance Services", the
          Contractor shall undertake to adhere to the repair times (Time to
          Repair, TTR) according to Appendix 4, Chapter "Corrective Maintenance
          Service".

17.2      If the Contractor is late in completing a repair order or parts
          thereof, then the Contractor shall be obligated to pay the following
          contract penalties:

                      *** **                if up to 6 h late
                      *** **                if from 6 h to 12 h late
                      *** **                if from 12 h to 18 h late
                      *** **                if from 18 h to 36 h late

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

          For each additional 24 hour period that the Contractor's default
          continues, the Contractor shall be obligated to pay an additional
          contract penalty of ****** up to an additional total amount of
          ****** per repair. Further claims for compensation of damages in
          the event that the Contractor is late in completing a repair order or
          parts thereof shall not apply. The Purchaser's right to fulfilment of
          performances shall remain unaffected by the aforesaid provision. In
          the event that the above maximum penalty is reached, the Purchaser may
          perform itself or have a third party perform the repair order or part
          thereof, and claim the costs incurred. No proviso in accordance with
          Section 341 Par. 3 BGB shall be required in asserting a claim for the
          contract penalty; on the contrary, it can be asserted up to 6 months
          after receipt of the final invoice.

18        MTBF- GUARANTEE

18.1      Notwithstanding his other warranty obligations the Contractor shall be
          responsible to guarantee in particular the MTBF (Mean Time Between
          Failures) values listed in Appendix 2 for the system components. The
          Contractor shall immediately conduct a technically documented and
          comprehensive review of any atypically frequent occurrences of system
          failures observed by the Purchaser and instruct the Purchaser in
          detail on the results of the review. Any design, production or
          material faults coming to light shall be reported immediately to the
          Purchaser. The repair of the defect on the installed systems shall be
          carried out immediately by the Contractor in co-ordination with the
          Purchaser on an uncompensated basis within the warranty period.

18.2      Independent of 18.1 the Contractor shall be responsible to inform the
          Purchaser immediately if risks become known to him which could
          endanger adherence to the agreed MTBF values.

19        WARRANTY

19.1      The contract shall guarantee that the system according to Appendix 2
          corresponds to the contractual requirements, in particular that it has
          the guaranteed characteristics and is not encumbered with defects that
          negate or reduce the value or fitness for the standard or
          contractually stipulated use.

19.2      The Contractor shall guarantee that the system components he is to
          supply correspond to the currently valid and applicable safety
          standards, the manadatory provisions of the applicable regulatory
          authorities and the currently valid and applicable standards regarding
          EMC (Electro Magnetic Compatibility). The Contractor shall further
          guarantee compliance with all trade association health and safety
          requirements and all other standards for telecommunications equipment.

19.3      The warranty period for functional utility and freedom of the system
          components and the system from faults shall amount to a total of 24
          months from the issuance of the corresponding Field Acceptance
          Certificate. Refer to the provision under item 7.2, second paragraph
          regarding the issuance of the FAC.

19.4      For all components of the system that, because of the interruption in
          operation that becomes necessary for improvement repairs or deliveries
          of spare parts, cannot be used as stipulated by contract, the warranty
          period shall be extended by the duration of the interruption.

19.5      The Contractor must repair defects in the supplies and services
          discovered during the warranty period immediately upon demand within 5
          calendar days on an uncompensated basis, including incidental costs..

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

          If a repair is not possible or if the acceptance of repaired parts is
          not appropriate for the Purchaser, then the Contractor must replace
          the defective parts with new ones. If the fault is not repaired in
          spite of three deliveries of spare parts, the Purchaser can return the
          entire system and demand a refund of the purchase price, provided that
          the fault is of Class A according to Appendix 3. The Contractor shall
          guarantee a repair or spare parts just as he does for the original
          delivery, and specifically either until expiration of the warranty for
          the originally supplied part or after 6 (six) months have passed,
          whichever is later.

19.6      If this involves not just defects in individual devices, but more
          serious systemic faults or a series of serious faults, the Purchaser
          can set an appropriate deadline period for the repair of these
          defects. If this period expires before the defect is repaired, the
          Purchaser can, at its own discretion, withdraw wholly or in part from
          the individual purchase contracts, return the devices that have
          already been delivered and demand a refund for the part of the
          purchase price that has already been remitted and demand compensation
          for damages.

          The costs (shipping, labour, and material costs) for any recall
          measures arranged by the Contractor that may become necessary shall be
          borne by the Contractor.

19.7      The failure to fulfil the technical specifications according to
          Appendix 2, the lack of required permits and the deviation from
          specifications according to 19.2 shall be considered defects, unless
          specific specifications according to this contract are expressly
          declared non-essential according to this contract.

19.8      In the event of software defects, the Contractor must remedy the
          faults as rapidly as possible. Recourse to a provisional solution that
          is reasonable for the Purchaser can be made in this situation to avoid
          down times in the interim. If the defect cannot be remedied within an
          appropriate time, the Contractor must install a completely new version
          of the affected software. If this does not remedy the defect
          completely, the Purchaser shall have the right to refuse the entire
          system and withdraw entirely from the contract.

19.9      If the Contractor ends up being late in fulfilling his obligation to
          remedy the defect, the Purchaser can itself take the required
          measures, notwithstanding the warranty obligation of the Contractor,
          provided that this measure is harmony with the repair instructions of
          the Contractor submitted to the Purchaser. The Purchaser can bill the
          Contractor for the resulting costs. Except in urgent cases, the
          Contractor shall be informed before execution of such measures; after
          the execution of the repair work, the Contractor shall receive a
          report on the type and scope of the defects and the work performed.

19.10     The right to withdrawal or price deduction shall remain unaffected by
          the aforesaid provision. Further claims for damages are excluded.

20        LIABILITY FOR CLAIMS TO COMPENSATION FOR DAMAGES

20.1      For claims by the Purchaser to compensation for damages, no matter
          what type and no matter on which legal grounds, the Contractor, his
          employees and his resource personnel in the performance of the
          contract shall be liable according to mandatory statutory regulations,
          unless a specific provision of this contract stipulates otherwise.

20.2      The Contractor shall be completely liable within the context of and
          according to the regulations of the Product Liability Law.

20.3      Subject to clause 20.4, neither party shall be liable to the other for
          indirect or consequential damages or lost profits, save in the case of
          premeditated behaviour.

<PAGE>

20.4      If parties contracting with the Purchaser assert claims for
          compensation of damages against the Purchaser that are related to the
          fact that said parties are required by their end customers to provide
          compensation for material damages within the limits of the TKV, or the
          limits of the respective applicable regulation:

          a)   the Contractor shall be liable without limit for the compensation
               of these damages to the extent that they are attributable to
               premeditated behaviour of the Contractor in relation to the
               Purchaser;

          b)   the Contractor will reimburse the Purchaser

     1.)  50% of the damages, insofar as these are the result of a delivery
          delay according to paragraph 15.2, and

     2.)  99% of the damages, insofar as these lead back to a breach of the
          rights of a third party according to paragraph 4.

     The liability for the damages according to paragraph 20.4b) is subject to
     limits per event of ***** and in aggregate of *****.

20.5      For negligence, the Contractor's liability, on whatever legal grounds,
          shall be limited to direct damages typical for contracts, excluding
          liability for indirect or consequent damages, such as lost profit or
          operational failure. Moreover, this liability shall be limited to 4
          million DM per instance and overall to 15 million DM. Any contract
          penalties paid by the Contractor as well as the liability according to
          Item 20.4 shall be taken into account with the aforesaid liability
          limit.

21        TRANSFER OF RISK AND TRANSFER OF OWNERSHIP

21.1      The transfer of risk shall be completed upon delivery of the
          individual system components in accordance with ICC INCOTERM (1990)
          DDP.

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

21.2      The Contractor shall retain ownership of the delivered system
          components until the purchase price is completely paid off.

          Until the purchase price is completely paid off, the Purchaser shall
          not acquire ownership of the delivered system components by virtue of
          their installation in other devices. The Contractor shall perform any
          servicing of the system components he has supplied. In the event of
          installation in outside products by the Purchaser, the Contractor
          shall become a co-owner of the resulting product in the same
          proportion as the ratio of the value of his system components to the
          value of the outside products used with it. The resulting products
          shall be regarded as reserved property of the Contractor.

          Until cancellation of the reservation of title, the Purchaser,
          provided that it meets its payment obligations toward the Contractor,
          shall be entitled to resell the supplied system components or the
          products resulting by connection in the manner referred above in the
          normal course of business operations only under reservation of title.
          If third parties tamper with the reserved property, the Purchaser
          shall advise them of the Contractor's ownership of it and shall notify
          the Contractor immediately. The Purchaser shall assign to the
          Contractor even at this point for safety sake all claims accruing to
          him from a resale or leasing with additional rights in the amount of
          the value of the supplied system components. The Purchaser shall
          provisionally be entitled and obligated to collect on the assigned
          claims in its own name. The Contractor shall not notify the parties
          contracting with the Purchaser of the assignment as long as the
          Purchaser satisfies its payment obligations toward the Contractor, is
          not in arrears with payment and especially if there has been no filing
          for bankruptcy and no suspension of payments.

          If the Purchaser does not satisfy its payment obligations to the
          Contractor in accordance with the contract, the Contractor shall be
          entitled at any time to take back the reserved property; this does not
          constitute a withdrawal from the contract. The Contractor shall
          release the the Purchaser guarantee amounts to the extent that their
          value exceeds all claims to be secured by more than 20 %.

22        PERMITS

          The Contractor shall undertake to obtain in a timely manner the
          permits necessary for the delivery of the subject matter of the
          contract. The lack of necessary permits as such does not constitute a
          case of force majeure.

23        AVAILABILITY OF SPARE PARTS

          The Contractor shall guarantee the availability of spare parts or
          compatible parts, as well as service support, for a time period of 10
          years, calculated from the time of the field acceptance of the
          particular system component.

24        CONFIDENTIALITY AND DATA PROTECTION

          Both parties to the contract shall undertake to comply with the
          confidentiality agreement attached as Appendix 6 and the data
          protection and confidentiality obligation attached.

<PAGE>

25        TRAINING

          The Contractor shall undertake to conduct training sessions in
          accordance with Appendix , Section "Training" if the Purchaser so
          requires. The training sessions shall be conducted in the German
          language to the extent possible. If the training sessions are held in
          English, the Contractor shall provide an interpreter.

26        TERM OF CONTRACT

26.1      This framework agreement shall have a term of 24 months commencing
          with the signature of the contract. The term of the contract can be
          extended on the part of the Purchaser with a notification period of 2
          months before expiration of the contract period in effect and be
          extended each time by one year. The Contractor shall be authorised to
          cancel this framework agreement after the expiration of 5 years with a
          notification period of 6 months. For the optional repair and
          maintenance services according to Appendix , Section "Maintenance
          Services" the term shall amount to 6 months. It can be extended on the
          part of the Purchaser by an additional 6 months each time with a
          notification period of 2 months before expiration of the service
          contract period in effect.

26.2      Cancellation for important reasons shall remain unaffected by this
          provision. An important reason for the cancellation shall exist if one
          of the parties violates essential obligations of this contract and
          does not provide a remedy within an appropriate period even after a
          written request of the other party. An important reason for both
          parties shall exist, for example, in the event of application for or
          commencement of a bankruptcy proceeding involving the assets of the
          other party or in the event of a denial of such a proceeding for lack
          of assets. In the event of a cancellation for important reasons, the
          Contractor's services provided up until the cancellation becomes
          effective shall be compensated to the extent that they can be used by
          the Purchaser for the overall system.

27        YEAR 2000 COMPATIBILITY

27.1      The Contractor shall guarantee the year-2000 compatibility of the
          contractual performances.

          Year-2000 compatibility shall be understood as performance such that
          neither performance nor functionality of a system shall be influenced
          by the year numbering before, during and after the year 2000
          (definition of the British Standards Institution), unless the
          performance or functionality is influenced in a merely insignificant
          way.

          In particular this means:

          -    No current date value shall create a system interruption.

          -    Functions based on dates must perform consistently for a date
               before during and after the year 2000.

          -    In all interfaces and data memories, the date indication must be
               specified in all date fields either explicitly or by unambiguous
               algorithms.

          -    The year 2000 must be recognised by the system as a leap year.

27.2     Any claims of the Purchaser in connection with this guarantee must not
         expire before 3/31/2001.

<PAGE>

28       FORCE MAJEURE

         Cases of force majeure that hinder the parties wholly or in part from
         fulfilling their obligations release both parties from the fulfilment
         of the contract to the extent the performance is hindered until the
         force majeure is no longer present. The party for which the force
         majeure has occurred must instruct the other party immediately when
         this occurs and later when it ends. If, because of a force majeure, a
         delay in the performance of more than 30 calendar days occurs, then the
         party other than the one effected can cancel the contract without
         benefit of a notification period by written communication to the other
         party. The performances completed up to this point in time shall be
         compensated to the extent that they are economically useful to the
         Purchaser and actually used by the Purchaser.

29       OTHER

29.1     General terms and conditions of the parties shall not be applicable.
         Collateral agreements shall not be made. Revisions and addenda must be
         in written form in order to be valid. This shall also apply for
         agreements through which the requirement for written form is supposed
         to be limited or nullified.

29.2     The place of performance for supplies and services is the site of use
         for each particular supply and service.

29.3     This contract is subject to German law with the exception of the rules
         of international civil law. The UN Convention on the International Sale
         of Goods shall not apply. The place of jurisdiction for disputes
         arising from this contract shall be Hannover.

29.4     Should individual parts of this contract be or become invalid, the
         validity of the remaining contractual provisions shall remain
         unaffected thereby. In such a case, invalid provisions shall be
         replaced by provisions that come as close as possible to the invalid
         provisions in terms of their economic purpose. The same shall be true
         in the case of an omission.

29.5     Claims of one party arising from this contract can only be assigned
         with the written consent of the other. Such an assignment shall not be
         denied by the other party except for good reason.

Hannover, date 10-04-00                               , date 12-04-00
              --------------              ------------       ----------
----------------------------              -----------------------------
 /s/
----------------------------              -----------------------------

LambdaNet                                 Nortel Networks
<PAGE>

PRODUCT PRICING FOR LAMBDANET PAN-EUROPE NETWORK BUILD

For the European Frame Agreement, the following prices apply on top of the
prices and commercial arrangements as has been defined for the Pan-German
Network build. These prices are applicable for all new orders for equipment not
yet delivered to site.

1. REVISED PRICES ON UNIT LEVEL

1.1      EQUIPMENT PRICES

-    2.5GBit/s transponder      ***

-    10GBit/s transponder       ***

-    10GBit regen: Until a 2 card version of the STM-64 4 fibre regeneraor
     function is ready for deployment, Nortel Network will deliver a 4 card
     version. Nortel Network will charge *** for this 4 card regenerator
     solution. As soon as the 2 card based regenerator functions is available
     for bulk deployment, Nortel Networks will charge *** for this
     function.

-    TX-16 prices have not been included into the pan-German Contract. The
     corresponding TN-16 price list is attached.

-    For non (a) OEM hardware and software unit prices as listed in the attached
     pan-German pricing, (b) for TN-16X pricing as attached and (c) for unit
     prices as listed above, a discount of 10% is to be applied. This discount
     does not apply to non per network element priced centralised management
     rights to use.

-    OPTera Unit Prices are subject to further agreement based on dark fibre vs.
     Leased lambda cost trade off calculations.

-    All of the price agreements will be incorporated into the pan-German frame
     contract by formal amendment.

-    These prices are applicable for all new orders.

2. PRICES FOR SERVICES

Prices for Services as defined in the attached price list from pan-German
Network Build are reflecting the German cost level. Prices for Services will be
agreed on a National basis taking into account the National cost level in the
corresponding country.

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>
<CAPTION>

       ITEM                                                                       ORDER CODE                     PRICE
                                                                                                                   DM
<S>                                                                           <C>                 <C>
TN-64X
CORE AND TRANSPORT SHELF
BREAKER MODULE                                                                NTCA40AA                               ***
SC060 SHELF CONTROLLER                                                        NTCA41BA                               ***
32M SHELF CONTROLLER                                                          NTCA41CA                               ***
MESSAGE TRANSFER CARD                                                         NTCA48AA                               ***
PARALELL TELEMETRY CARD                                                       NTCA45AA                               ***
MAINTENANCE INTERFACE CARD                                                    NTCA42AA                               ***
MAINTENANCE INTERFACE CARD (120 MBYTES)                                       S0000300S0000581                       ***
MAINTENANCE INTERFACE CARD (120 MBYTES)                                       S0000300S0000545                       ***
EUROPEAN 2 MHZ EXTERNAL SYNCHRONIZATION INTERFACE                             NTCE44BA                               ***
TRANSPORT SHELF FILLER CARD                                                   NTCA49AA                               ***
TRANSPORT SHELF SWITCH FILLER CARD                                            NTCA49AB                               ***
COMMON EQUIPMENT FILLER CARD (1 IN.)                                          NTCA59AA                               ***
OC192/STM64 4FR SWITCH ASSY                                                   NTCA24AA                               ***
OC192/STM64 DEMULTIPLIER (TMUX)                                               NTCA05BA                               ***
ADM AGGREGATES
OC-192/STM64 ADM 1533.47NM +/- CHIRP ADAPTERLESS                              NTCA01FK                               ***
OC-192/STM64 ADM 1528.77NM +/- CHIRP ADAPTERLESS                              NTCA01MK                               ***
OC-192/STM64 ADM 1535.04NM +/- CHIRP ADAPTERLESS                              NTCA01GK                               ***
OC-192/STM64 ADM 1530.33NM +/- CHIRP ADAPTERLESS                              NTCA01EK                               ***
OC-192/STM64 ADM 1539.77NM +/- CHIRP ADAPTERLESS                              NTCA01RK                               ***
OC-192/STM64 ADM 1538.19NM +/- CHIRP ADAPTERLESS                              NTCA01QK                               ***
OC-192/STM64 ADM 1536.61NM +/- CHIRP ADAPTERLESS                              NTCA01PK                               ***
OC-192/STM64 ADM 1531.90NM +/- CHIRP ADAPTERLESS                              NTCA01NK                               ***
OC-192/STM64 ADM 1555.75NM +/- CHIRP ADAPTERLESS                              NTCA01XK                               ***
OC-192/STM64 ADM 1550.92NM +/- CHIRP ADAPTERLESS                              NTCA01VK                               ***
OC-192/STM64 ADM 1557.36NM +/- CHIRP ADAPTERLESS                              NTCA01LK                               ***
OC-192/STM64 ADM 1552.52NM +/- CHIRP ADAPTERLESS                              NTCA01KK                               ***
OC-192/STM64 ADM 1547.72NM +/- CHIRP ADAPTERLESS                              NTCA01UK                               ***
OC-192/STM64 ADM 1558.98NM +/- CHIRP ADAPTERLESS                              NTCA01YK                               ***
OC-192/STM64 ADM 1549.32NM +/- CHIRP ADAPTERLESS                              NTCA01JK                               ***
OC-192/STM64 ADM 1554.13NM +/- CHIRP ADAPTERLESS                              NTCA01WK                               ***
REGENERATOR AGGREGATES
OC-192/STM64 REGEN 1533.47NM +/- CHIRP ADAPTERLESS                            NTCA03FK                               ***
OC-192/STM64 REGEN 1528.77NM +/- CHIRP ADAPTERLESS                            NTCA03MK                               ***
OC-192/STM64 REGEN 1535.04NM +/- CHIRP ADAPTERLESS                            NTCA03GK                               ***
OC-192/STM64 REGEN 1530.33NM +/- CHIRP ADAPTERLESS                            NTCA03EK                               ***
OC-192/STM64 REGEN 1539.77NM +/- CHIRP ADAPTERLESS                            NTCA03RK                               ***
OC-192/STM64 REGEN 1538.19NM +/- CHIRP ADAPTERLESS                            NTCA03QK                               ***
OC-192/STM64 REGEN 1536.61NM +/- CHIRP ADAPTERLESS                            NTCA03PK                               ***
OC-192/STM64 REGEN 1531.90NM +/- CHIRP ADAPTERLESS                            NTCA03NK                               ***
OC-192/STM64 REGEN 1555.75NM +/- CHIRP ADAPTERLESS                            NTCA03XK                               ***
OC-192/STM64 REGEN 1550.92NM +/- CHIRP ADAPTERLESS                            NTCA03VK                               ***
OC-192/STM64 REGEN 1557.36NM +/- CHIRP ADAPTERLESS                            NTCA03LK                               ***
OC-192/STM64 REGEN 1552.52NM +/- CHIRP ADAPTERLESS                            NTCA03KK                               ***
OC-192/STM64 REGEN 1547.72NM +/- CHIRP ADAPTERLESS                            NTCA03UK                               ***
OC-192/STM64 REGEN 1558.98NM +/- CHIRP ADAPTERLESS                            NTCA03YK                               ***
OC-192/STM64 REGEN 1549.32NM +/- CHIRP ADAPTERLESS                            NTCA03JK                               ***
OC-192/STM64 REGEN 1554.13NM +/- CHIRP ADAPTERLESS                            NTCA03WK                               ***
</TABLE>

20 September 1999

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>
<S>                                                                           <C>                 <C>
RECEIVERS
OC-192/STM64 SHORT REACH RECEIVER ADAPTERLESS BULK                            NTCA02BK                              ***

QUAD-OC12 T/R 1310NM SC                                                       NTCA36BC                              ***

LICENSES AND SOFTWARE
TN-64X APPLICATION - 4F SPRING                                                NTQJ93TC                              ***
FEC Licence                                                                   NTQJ93TF                              ***
TN-64X APPLICATION - REGENERATOR / MOR                                        NTQJ93TD                              ***
TN-64X INM RTU
INM Core Management RTU                                                       NTNM23BAAG                            ***
INM Performance Management RTU                                                NTNM23BCAG                            ***
INM Inventory  Management RTU                                                 NTNM31BDAG                            ***
INM Trail Management RTU                                                      NTNM12BAAG                            ***
INM Trail Advisor RTU                                                         NTNM12BBAG                            ***
INM Trail Scheduler                                                           NTNM12BCAG                            ***
INSTALLATION AND COMMISSIONING
Inst. STM-4 quad (4*port) card on TN-64X                                                                            ***
Inst. TN-64X Core system with aggregates                                                                            ***
CORRECTIVE MAINTENANCE
TN-64X FLM and TAS                                                                                        See commercial
                                                                                                  agreement for Yr. 2000

OPTera LH
MOR PLUS (BLUE PRE/RED POST) WITH OSC                                         NTCA11NK                              ***
MOR PLUS (RED PRE/BLUE POST) WITH OSC                                         NTCA11PK                              ***
1625NM OPTICAL SERVICE CHANNEL (SC)                                           NTCA11CC                              ***
C/L Band Splitter with 1625nm for OSC                                         NTCA15GH                              ***
100GHZ 8+2W MB/DR, VOA, SC                                                    NTCA10CC                              ***
100GHZ 8+2W MR/DB, VOA, SC                                                    NTCA10DC                              ***
100GHZ 16W UPGRADE MB/DR, VOA, SC                                             NTCA10EC                              ***
100GHZ 16W UPGRADE MR/DB, VOA, SC                                             NTCA10FC                              ***
SC-SC ADAPTER KIT                                                             NTCC99AC                              ***
DWDM SHELF ASSY - 4 POS (STD ETSI)                                            NTFW88DA                              ***
DWDM ADM 33/55,SC                                                             NTCA13MC                              ***
DWDM ADM 35/57,SC                                                             NTCA13NC                              ***

LICENSES AND SOFTWARE
MOR RTU                                                                       NTCA62DA                              ***
TN-64X APPLICATION - REGENERATOR / MOR                                        NTQJ93TD                              ***
MOR+ INM RTU
INM Core Management RTU - MOR                                                 NTNM23BAAN                            ***
INM Inventory Management RTU - MOR                                            NTNM31BDAN                            ***
INSTALLATION AND COMMISSIONING
Install MOR/DWDM Plus                                                                                               ***
CORRECTIVE MAINTENANCE
MOR+ FLM and TAS                                                                                          See commercial
                                                                                                  agreement for Yr. 2000

DWDM FLM  and TAS per site                                                                                See commercial
                                                                                                  agreement for Yr. 2000

TN-16XE
CORE
SATURN MULTIPLEXER ASSEMBLY                                                   NTEU70AA                              ***
</TABLE>

20 September 1999

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>
<S>                                                                           <C>                 <C>
INSTALLATION KIT (ETSI)                                                       NTEU57AA                              ***
SATURN 1" FILLER CARD ASSEMBLY                                                NTEU30AA                              ***
AGGREGATES
STM-16o AGG 1310 (FC/PC)                                                      NTEU25AA                              ***
TRIBUTARIES
SATURN STM10 DUAL PORT TRIB ASSEMBLY                                          NTEU10AA                              ***
STM1E/140MBIT TRIB                                                            NTEU13AA                              ***
STM-4O                                                                                                              ***
CABLES AND CONNECTORS
CABLE ASSY (RACK ALARM-SATURN)                                                NTEU4520                              ***
TN-16XE INM RTU
INM Core Management RTU                                                       NTNM23BAAM                            ***
INM Performance Management RTU                                                NTNM23BCAM                            ***
INM Inventory  Management RTU - TN-16XE                                       NTNM31BDAM                            ***
INM TRAIL MANAGER                                                             NTNM12BAAM                            ***
INM TRAIL ADVISOR RTU                                                         NTNM12BBAM                            ***
INM TRAIL SCHEDULER RTU                                                       NTNM12BCAM                            ***
INSTALLATION AND COMMISSIONING
Inst. TN-16XE core system with aggregates                                                                           ***
Inst. STM-1e single port trib card on TN-16XE                                                                       ***
Inst. STM-1o dual port (2*) trib card on TN-16XE                                                                    ***
INST. STM-4O TRIB CARD                                                                                              ***
CORRECTIVE MAINTENANCE
TN-16XE FLM and TAS                                                                                       See commercial
                                                                                                  agreement for Yr. 2000

TN-4XE
CORE
SATURN MULTIPLEXER ASSEMBLY                                                   NTEU70AA                              ***
INSTALLATION KIT (ETSI)                                                       NTEU57AA                              ***
SATURN 1" FILLER CARD ASSEMBLY                                                NTEU30AA                              ***
SATURN 3" FILLER CARD ASSEMBLY                                                NTEU30AB                              ***
AGGREGATES
SATURN STM140 AGGREGATE ASSEMBLY                                              NTEU20AA                              ***
TRIBUTARIES
SATURN STM10 DUAL PORT TRIB ASSEMBLY                                          NTEU10AA                              ***
CABLES AND CONNECTORS
Cable assy (Rack Alarm - Saturn)                                              NTEU4520                              ***
TN-4XE INM RTU
INM Core Management RTU                                                       NTNM23BAAD                            ***
INM Performance Management RTU                                                NTNM23BCAD                            ***
INM Inventory  Management RTU - TN-4XE                                        NTNM31BDAD                            ***
INM TRAIL MANAGER                                                             NTNM12BAAD                            ***
INM TRAIL ADVISOR RTU                                                         NTNM12BBAD                            ***
INM TRAIL SCHEDULER RTU                                                       NTNM12BCAD                            ***
INSTALLATION AND COMMISSIONING
Inst 4XE with aggs                                                                                                  ***
Inst. STM-1o dual port (2*) trib card on TN-4XE                                                                     ***
CORRECTIVE MAINTENANCE
TN-4XE FLM and TAS                                                                                        See commercial
                                                                                                  agreement for Yr. 2000

TN-1X
CORE
TN-1X Synchronous Access Multiplexer Subrack                                  25GMU00750GWV                          ***
Shelf Kit                                                                     25SKM00750HFN                          ***
</TABLE>

20 September 1999

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>
<S>                                                                           <C>                 <C>
TN-1X Installation Kit                                                        25SKM00807ABL                          ***
Local Craft Access Panel Type 1                                               25UEP00750GXB                          ***
Service Interface Module Type 10 (Misc)                                       25UJJ00750GXC                          ***
Service Interface Module Type 40 (LCAP)                                       25UJJ00750GWX                          ***
Subrack Cover Kit                                                             25SKM00750HFL                          ***
Kit -Installation                                                             25SKM00750KAD                          ***
Dummy Front Panel 1"                                                          25RBN00021AAB                          ***
Dummy Front Panel 1.6"                                                        25RBN00021AAC                          ***
Dummy Front Panel 1.8"                                                        25RBN00021AAD                          ***
Dummy SIA Panel 1"                                                            25RBN00021AAA                          ***
Power Supply Unit                                                             25UPW00750HAY                          ***
Subrack Control Unit                                                          25UMN00750GXD                          ***
Payload Manager (mixed payloads)                                              NTKD10AA                               ***
AGGREGATES
STM-1 Optical Aggregate CR                                                    NTKD20AA                               ***
TRIBUTARIES
16 x 2 Mbit/s G.703 Tributary Card 120 Ohm                                    25UJU00750HVQ                          ***
Traffic Interface Module (TIM) Type 22                                        25UJJ00750HLV                          ***
TN-1X INM RTU
INM Core Management RTU                                                       NTNM23BAAC                             ***
INM Performance Management RTU                                                NTNM23BCAC                             ***
INM Inventory Management RTU                                                  NTNM31BDAC                             ***
INM TRAIL MANAGER                                                             NTNM12BAAC                             ***
INM TRAIL ADVISOR RTU                                                         NTNM12BBAC                             ***
INM TRAIL SCHEDULER RTU                                                       NTNM12BCAD                             ***
INSTALLATION AND COMMISSIONING
Inst 1X with aggs                                                                                                    ***
CORRECTIVE MAINTENANCE
TN-1X FLM and TAS                                                                               See commercial agreement
                                                                                                            for Yr. 2000

TN-1C
CORE
TN-1C 8x2/16x2 turbo ADM                                                      NTFT52BD                               ***
TN-1C INSTALLATION KIT (RACK)                                                 NTFT06AA                               ***
TN-1C INM RTU
INM Core Management RTU                                                       NTNM23BAAB                             ***
INM Performance Management RTU                                                NTNM23BCAB                             ***
INM Inventory Management RTU                                                  NTNM31BDAB                             ***
INM TRAIL MANAGER                                                             NTNM12BAAB                             ***
INM TRAIL ADVISOR RTU                                                         NTNM12BBAB                             ***
INM TRAIL SCHEDULER RTU                                                       NTNM12BCAB                             ***
INSTALLATION AND COMMISSIONING
Inst 1C with aggs                                                                                                    ***
CORRECTIVE MAINTENANCE
TN-1C FLM and TAS                                                                               See commercial agreement
                                                                                                            for Yr. 2000
EQUIPMENT PRACTICE
TN-64X
MECH BAY ASSY ETSI TRIB SH (2.0 MHZ SATT)                                     NTCE89BB                               ***
Mech bay Assy ETSI                                                            NTCE89GB                               ***
MECH BAY ASSY, ETSI 2.0MHZ (W/LINE EXTENSION SH)                              NTCE89BD                               ***
ETSI EQUIPMENT PRACTICE
2.2M ETSI RACK, STEEL UPRIGHTS, NO SIDE PANELS                                NTKD70AB                               ***
NT ETSI Rack Standard Inst.Kit                                                25SKM00807ABE                          ***
</TABLE>

20 September 1999

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>
<S>                                                                           <C>                 <C>
ETSI Rack 48V DC Distrib Panel with Rack Alarm Unit                           25SKM00807AAN                         ***
Fan Installation kit (ETSI 3 shelf)                                           NTEU59AA                              ***
Lower Vent Cover (75mm)                                                       P0890340                              ***

INTEGRATED NETWORK MANAGEMENT
EC-1 HARDWARE
HP B180                                                                                                             ***
TN-1X Release 8.2 software download (from EC)                                 NTQJ31HE                              ***
HP-UX 10.20 Y2K Patches, 8 May 98                                             NTQJ30MC                              ***
EC-1 RELEASE 13.1 SERVICE PACK 2                                              NTQJ30MH                              ***
HP-UX 10.20 Y2K Patches, 8 May 98                                             NTQJ01EC                              ***

CORBA INTERFACE RTU
Trail Management feature                                                                                            ***
Inventory Management feature                                                                                        ***
Performance Management feature                                                                                      ***
Fault Management feature                                                                                            ***
Consultancy for above (per day)                                                                                     ***

POPC HARDWARE
PARTITIONED OPC CONTROLLER                                                    NTCA50AA                              ***
PARTITIONED OPC STORAGE MODULE                                                NTCA51AA                              ***
PARTITIONED OPC IO MODULE                                                     NTCA52AA                              ***
PARTITIONED OPC STORAGE MODULE (for TN-64X)                                   S0000600S0000514                      ***
PARTITIONED OPC STORAGE MODULE (for OPTera LH)                                S0000600S0000583                      ***
OPC Flash Cartridge (122M) for OPTera LH                                      S0000700S0000580                      ***
OPC Flash Cartridge (122M) for TN-64X                                         S0000700S0000515                      ***

SOFTWARE CERTIFICATE                                                          NTNM51AD                              ***
INM APPLICATION RTU
INM Broadband RTU                                                             NTNM51AA                              ***
INM Resilient platform RTU
(per resilient platform)                                                      NTNM51AB                              ***
INM External Alarm Interface RTU                                              NTNM23AG                              ***
Netscape for Unix (Fastrack Server and Navigator)                             NTQJ81AA                              ***

INM HARDWARE
HP C3000 workstation                                                               No longer required               ***
INSTALLATION AND COMMISSIONING
Inst.l hardware for INM (HP)                                                                                        ***
CORRECTIVE MAINTENANCE
INM FLM and TAS                                                                                           See commercial
                                                                                                  agreement for Yr. 2000
INTEGRATION
Site survey per site                                                                                                ***
Integration of Network into the INM                                                                       See commercial
                                                                                                  agreement for Yr. 2000
Integration of Racks  (per Rack)                                                                                    ***

DCM
DCM-60 module assy                                                            NTCC14CC                              ***
</TABLE>

20 September 1999

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>
<S>                                                                           <C>                 <C>

DCM-80 module assy                                                            NTCC14DC                               ***

DCM-100 module assy                                                           NTCC14EC                               ***

DCM-100N module assy                                                          NTCC14HC                               ***
DCM-300N module assy                                                          NTCC14JC                               ***
FIXED ATTENUATOR, IN-LINE, SC, 5 DB +/- 0.5 DB, 15                            FOP-ATT-SC-SMF-FXD-3-A                 ***

DCN
ROUTER 2514 0SI DC                                                            NTJM01MA                               ***
ROUTER 2514 0SI, Interfaces: 2 serial & 2 LAN, Protocols: IP & OSI,           NTJM01KA                               ***
Power 110-220 VAC, 50-60Hz, IOS Enterprise Software
BAYSTACK 106 10 BASE T HUB 12 PORT RJ-45-48 VDC                               NTJM02JA
10Base-T Hub with 12 ports, RJ45 Connectors, -48VDC Power                                                            ***
DCN Router Configuration                                                      NTJM99xx                               ***
CAB-X21MT/CAB-X21FC                                                           NTJM02DA                               ***
HS MODEM SP-1-AR,DC                                                           NTJM01TA                               ***
SHELF CANTELEVER 19IN MOUNTING                                                P0878672                               ***
TRANSCEIVER 10BASET                                                           NTJM01VA                               ***
Cable assy (OC192 Ethernet to terminal)                                       NTCC90CA                               ***
Cable Assy LAN RJ45 - RJ45 h/e                                                32YCN00727AFA                          ***
CABLE ASSY (OC192 ETHERNET TO LAN 20M)                                        NTCC90BA                               ***
MECHANICAL ASSEMBLY, RACK, 37U                                                A0726261                               ***
DISTRIBUTION BLOCK FUSED -48VDC              A0729324                                                                ***

GPS
TimeSource 3100 10 E1                        990-72020-02                                                            ***
RG59 (200 foot) 60 meter cable                                                060-72010-20                           ***

TRAINING
Per student per day                                                                                                  ***
</TABLE>

COMMERCIAL ARRANGEMENTS;
Prices above are cash price, as negotiated for third party project financing for
an initial order in 1999 of >***
When a full working 4F TN-64X ADM is ordered, two of the four aggregates and
two of the receivers are to be included in the total price at ***
Price of workarounds to be covered by Nortel as per agreed commitments
Corrective maintenance - review of services cost will take place on annual
basis, discount structure as follows;
Total network build < *** corrective maintenance prices as above
Network build >*** < *** 10% price reduction on this portion
Network build >*** further 10% on this portion
Non-OEM prices are subject to a price decay of 7% p.a, starting 12 months
from contract signature date
Prices are based on finance arranged between CCG and Nortel through a third
party (i.e. not Nortel vendor financing)
FLM and TAS - Yr. 2000 charge for network ***. After a period of one year a
review of use and efficiency will take place in order to align price.
Integration of network into INM - a flat charge of *** to be paid for
initial 1999 build, price per element to be agreed for subsequent orders.

20 September 1999 CAE

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

              FUTURE FEATURE AND PRODUCT PRICING FOR PAN-GERMAN NETWORK BUILD,
                                         LAMBDANET

<TABLE>
<CAPTION>

  ----------------------------------------------------------------------------------------------------
                                  ITEM                                      ORDER CODE       PRICE
                                                                                               DM
<S>                                                                     <C>                   <C>
  TN-64X STM-16 TRIB CARD 1310NM SC                                     NTCA30LC                  ***
  I&C for STM-16 trib card                                                                        ***

  TN-16XE quad 1e trib                                                  NTEU16KA                  ***
  I&C for STM-1e quad card                                                                        ***

  TN-64X Quad STM-1                                                                               ***
  I&C for STM-1e quad card                                                                        ***

  TN-64X 16*STM-1e trib card                                                                      ***
  I&C for 16*STM-1e trib card                                                                     ***

  OPTERA 1600G

  Dual 2.5Gbit/s transponder card for use with channel combiner         NTCA30CK                  ***
  I&C for dual 2.5Gbit/s transponder card                                                         ***
  FLM for dual port 2.5Gbit/s transponder card                                                    ***
  TAS for dual port 2.5Gbit/s transponder card                                                    ***

  10Gbit/s Channel combiner                                             NTCA06xK                  ***
  I&C for 10Gbit/s channel combiner                                                               ***
  FLM for 10Gbit/s channel combiner                                                               ***
  TAS for 10Gbit/s channel combiner                                                               ***

  10Gbit/s regen card                                                   NTCA04xK                  ***
  I&C for 10Gbit/s regen card                                                                     ***
  FLM for 10Gbit/s regen card                                                                     ***
  TAS for 10Gbit/s regen card                                                                     ***

  10G Wavelength Translator                                             NTCA07xx                  ***
  I&C for 10Gbit/s Wavelength Translator                                                          ***
  FLM for 10Gbit/s Wavelength Translator                                                          ***
  TAS for 10Gbit/s Wavelength Translator                                                          ***

  Wavelength Combiner Timing card                                       NTCA21AA                  ***

  C BAND
  Module 1  Pre Amp (8 wavelengths)                                     NTCA15CA                  ***
  Module 2  Booster   (20 wavelengths)                                  NTCA15CE                  ***
  Module 3 Booster   (40 wavelengths)                                   NTCA15CH                  ***
  C Band RTU                                                                                      ***
  I&C for Module 1-3 Pre Amp                                                                      ***
  FLM  for Module 1 Pre Amp                                                                       ***
  TAS for Module 1 Pre Amp                                                                        ***
  FLM  for Module 2 Booster                                                                       ***
  TAS for Module 2 Booster                                                                        ***
  FLM  for Module 3 Booster                                                                       ***
  TAS for Module 3 Booster                                                                        ***

  L BAND

</TABLE>
-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>
<S>                                                                     <C>                    <C>
  Module 1  Pre Amp (8 wavelengths)                                                               ***
  Module 2  Booster   (20 wavelengths)                                                            ***
  Module 3 Booster   (40 wavelengths)                                                             ***
  L Band RTU                                                                                      ***
  I&C for Module 1-3 Pre Amp                                                                      ***
  FLM  for Module 1 Pre Amp                                                                       ***
  TAS for Module 1 Pre Amp                                                                        ***
  FLM  for Module 2 Booster                                                                       ***
  TAS for Module 2 Booster                                                                        ***
  FLM  for Module 3 Booster                                                                       ***
  TAS for Module 3 Booster                                                                        ***

  INTERLEAVING FILTER 300/150 (28 WAVELENGTH)
  C-Band                                                                NTCA15FA                  ***
  L-Band                                                                                          ***

  INTERLEAVING FILTER 100/50 (80 WAVELENGTH)
  C-Band                                                                                          ***
  L-Band                                                                                          ***

  Bi-directional OSC 1510/1480nm                                        NTCA15BK                  ***
  C/L splitter  (SC)                                                    NTCA15GH                  ***

  CONSULTANCY/POST CONTRACT
  Man hour price for technician (including travel within Germany) *** Man hour
  price for engineer (including travel within Germany) ***

  ----------------------------------------------------------------------------------------------------

</TABLE>

Exact codes and descriptions of cards subject to change
Above prices subject to final negotiation

Consultancy prices dependant upon total number of hours required

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

             PRICE LIST FOR PAN-GERMAN NETWORK BUILD CAE, LAMBDANET

<TABLE>
<CAPTION>

<S>                                                                           <C>                                 <C>
       ITEM                                                                              ORDER NUMBER                   PRICE
                                                                                                                          DM

CABLES, DDF, ODF
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on FC/PC                                        1m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on FC/PC                                        2m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on FC/PC                                        5m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on FC/PC                                       10m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on FC/PC                                       15m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on FC/PC                                       20m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on E2000                                        1m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on E2000                                        2m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on E2000                                        5m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on E2000                                       10m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on E2000                                       15m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on E2000                                       20m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on SC/PC                                        1m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on SC/PC                                        2m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on SC/PC                                        5m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on SC/PC                                       10m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on SC/PC                                       15m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. FC/PC on SC/PC                                       20m                           ***

Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on SC/PC                                        1m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on SC/PC                                        2m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on SC/PC                                        5m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on SC/PC                                       10m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on SC/PC                                       15m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on SC/PC                                       20m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on E2000                                        1m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on E2000                                        2m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on E2000                                        5m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on E2000                                       10m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on E2000                                       15m                           ***
Optical fibre cable 9/125 1 E1V(ZN) H Simpl. SC/PC on E2000                                       20m                           ***
Coaxial cable Type 43/Type 1.6_5.6 75 OHM for 155 Mbit                                             1m                           ***
Coaxial cable Type 43/Type 1.6_5.6 75 OHM for 155 Mbit                                             2m                           ***
Coaxial cable Type 43/Type 1.6_5.6 75 OHM for 155 Mbit                                             5m                           ***
Coaxial cable Type 43/Type 1.6_5.6 75 OHM for 155 Mbit                                            10m                           ***
Coaxial cable Type 43/Type 1.6_5.6 75 OHM for 155 Mbit                                            15m                           ***
Coaxial cable Type 43/Type 1.6_5.6 75 OHM for 155 Mbit                                            20m                           ***

TN-16XE STM-1e cable                                                          32YCN00752BFA                                     ***
TN-1X 2Mbs TX cable                                                           P0874820                                          ***
TN-1X 2Mbs RX cable                                                           P0874814                                          ***
TN-1C 2Mbs TX cable                                                           P0874821                                          ***
TN-1C 2Mbs RX cable                                                           P0874815                                          ***

Optical fibre cable adjustable attenuator. With test line for electrical                                                        ***
adjustment including mounting of connectors, optionally SC,FC/PC
attenuation factor >/- 20dB. Version  9/125
</TABLE>

20 September 1999 CAE

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>
<TABLE>
<CAPTION>

<S>                                                                           <C>                                 <C>
DDF/ODF
Distribution frame                                                                                                             ***
Distribution frame section 2-row 1800 mm                                                                                       ***
Distribution frame section 2-row 1000 mm                                                                                       ***
Coupler unit panel electrical 4x2 Type  1.6/5.6 (DDF 75 OHM)                                                                   ***
Coupler unit panel optical 6x2 E2000/APC (ODF)                                                                                 ***
Splice box                                                                                                                     ***
LSA section for shielded routing 8xabs 2Mbit                                                                                   ***
LSA section 8 DA for alarm cabling                                                                                             ***

Subrack 19"/ 4HM or 7SU with sectional bars and integrated patch                        6690 1 371-00                          ***
cable routing, H = 175 mm, D = 183 mm
Mounting dimensions: metric = 515 mm or 19-inch = 465

Vt COM - 2 Mbit/coax/Gf  -  basic frame as wall-mounted upright distribution            6971 1 201-00                          ***
frame, B x D x H = 540 x 300 x 2.200 mm consisting of 2 rows of sectional bars.
For mounting LSA modules and/or assemblies SubD/coax/ Gf. The basic frames can
be mounted next to each other or back-to-back. Delivered partly preassembled.

Back-to-back - threaded connection                                                      6971 2 420-00                          ***
1x per upright frame - two-sided (2 basic frames)

Frame end assembly kit  Vt COM - one-sided                                              6971 2 210-00                          ***
required 1x per one-sided row of frames

Frame end assembly kit  Vt COM - two-sided                                              6971 2 212-00                          ***
required 1x per two-sided row of frames

Coaxial module 4x2 - 1.6/5.6                                                            7013 2 001-00                          ***
for max. 8x coaxial coupler units Type 1.6/5.6 DIN 47 295, for snap-on
mounting on sectional bars, distribution frame, snap-on dimension = 100 mm

Coax housing coupler unit Type  1.6/5.6  DIN 47 295, 75Ohm straight, with               7013 2 906-00                          ***
threaded connection for cable type 02Y (St)CY - 0.45/2.0, crimping of outer
conductor and Loters of inner conductor, partly assembled

Gf-module 6 x 2 for max. 12 Gf-coupler units SC / E2000                                 7013 2 300-04                          ***
for snap mounting on sectional bar of
distribution frame, snap-on dimension = 100 mm,

Gf-connection coupler unit Type : E2000/APC colour green                                6824 2 300-20                          ***
(with DTAG approval)

</TABLE>

COMMERCIAL ARRANGEMENTS;

Items above are priced at a unit level for a high volume order. BofQ to be
provided with exact number of units required by CCG
Prices quoted cost of OEM + mark-up by Nortel - Nortel accepts no
responsibility for changes in prices or incorrect information or inaccuracy
by supplier

20 September 1999 CAE

-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

PRODUCT PRICING TN-16X

<PAGE>

<TABLE>

<S>                                                                 <C>              <C>        <C>

SDH EQUIPMENT                                                       ALL IN DM                                         MODEL PRICE

TN-16X

MODEL 1 TN16X RACK                                                                                                        ***
NTE-STM16 RACK(2200 X 600 X 300)                                     NTFW70EA        1            ***
TN-16X Installation Kit                                           25SKM00807ABM      1            ***
Rack Side Cover - Left Hand                                          P0725173        1            ***
Rack Side Cover - Right Hand                                         P0725175        1            ***

MODEL 2 TN16X DWDM ADM CORE                                                                                               ***
CORE
STM16 LTE/ADM/RING SHELF                                             NTFW50EA        1            ***
SH PROCESSOR FOR SDH (DCC HUBBING)                                   NT7E20GC        1            ***
Maintenance Interface Unit                                           NT7E23AA        1            ***
OC-48/STM-16 Ring Demux                                              NT8E06AB        2            ***
AGGREGATES                                                                                             -
OC-48 DWDM 1535.04 NM RING TX                                        NT8E11MS        1            ***
OC-48 DWDM 1557.36 NM RING TX                                        NT8E11TT        1            ***
OC-48/STM16 LR SAW Rx Interface (SC)                                 NT8E02DE        2            ***
SYNCHRONISATION                                                                                        -
External synchronisation interface carrier                           NT7E19AA        1            ***
External Synchronisation Interface (2 M Hz)                          NTFW27AA        2            ***
CABLES AND CONNECTORS
Optical Patch Cord SC (20m)                                          NT7E46FD        4            ***
KIT, SC OPTICAL CONNECTOR. INITIAL USE NTN401AA.                     NTN459SC        2            ***
SOFTWARE
TN-16X Shared Protection Ring Software Licence  (Release 7)          NTQJ93HG        1            ***
MANAGEMENT (LICENCES)
LICENSES DEALT WITH SEPARATELY

MODEL 3 TN-16X POST AMP SUBRACK                                                                                           ***
AGGREGATES
18dBm OPTICAL AMPLIFIER ETSI SUBRACK                                 NTW048AB        1            ***
OPTICAL AMPLIFIER INSTALLATION KIT (1 AMP)                           NTFW72XX        2            ***
CABLES AND CONNECTORS
D.C . DISTRIBUTION PANEL ASSY                                        NTFW62AA        1            ***
Optical Patch Cord SC (20m)                                          NT7E46FD        2            ***
ALARM CABLE OP-AMP (4) 15 WAY D TYPE                                 NTFW5748        1            ***
LOCKING POWER CABLE ADAPTER (OPTICAL AMPLIFIER)                      NTFW56EA        1            ***

MODEL 4 TN-16X POST & PRE AMP SUBRACK                                                                                     ***
AGGREGATES
FILTER - FIBRE OPTIC 1557nm (OP-AMP CONN)                            NTFW57PB        1            ***
18dBm OPTICAL AMPLIFIER ETSI SUBRACK                                 NTW048AB        1            ***
TYPE 119 SUB RACK EDFA 9DBM (C33 FC/SPC CONNECTORS                   NTW048FB        1            ***
OPTICAL AMPLIFIER INSTALLATION KIT (1 AMP)                           NTFW72XX        1            ***
CABLES AND CONNECTORS
D.C . DISTRIBUTION PANEL ASSY                                        NTFW62AA        1            ***
Optical Patch Cord SC (20m)                                          NT7E46FD        4            ***
ALARM CABLE OP-AMP (4) 15 WAY D TYPE                                 NTFW5748        1            ***
LOCKING POWER CABLE ADAPTER (OPTICAL AMPLIFIER)                      NTFW56EA        1            ***

MODEL 5 TN-16X STM-1O TRIBUTARY                                                                                           ***
TRIBUTARIES
STM1o IR 1310 Tributary I/F (SC)                                     NTFW11CD        1            ***
STM1 Optical Carrier Assembly                                        NTFW19BA        1            ***
CABLES AND CONNECTORS
Fibre Optic Cable  Assy STM1 Duplex SC-SC 20M                        NTFW5753        2            ***

MODEL 6 TN-16X STM-4 TRIBUTARY                                                                                            ***
TRIBUTARIES
OC-12 IR INTERFACE                                                   NT7E02PB        1            ***
CABLES AND CONNECTORS
Optical Patch Cord SC (20m)                                          NT7E46FD        2            ***
KIT, SC OPTICAL CONNECTOR. INITIAL USE NTN401AA.                     NTN459SC        1            ***

MODEL 7 TN-16X OPC                                                                                                        ***
MANAGEMENT (HARDWARE)

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

<TABLE>

<S>                                                                  <C>             <C>          <C>
OPC with tape drive                                                  NT7E24BC        1            ***
MANAGEMENT (SOFTWARE)
PHOENIX SUPERSET CODE FOR REL 7.1                                    NTFW97HB        1            ***
CABLES
***Ethernet kit for OPC hub (20m,OC-48)                              NT7E44JE        1            ***

MODEL 8 TN-16X DWDM REGEN                                                                                                  ******
SH PROCESSOR (ETHERNET,SYNC MSG 24M)                                 NT7E20KA         1           ***
Maintenance Interface Unit                                           NT7E23AA         1           ***
*** OPTICAL PATCH CORD 20M (SC-SC)                                   NT7E46FD         4           ***
OC-48/STM16 LR SAW Rx Interface (SC)                                 NT8E02DD         2           ***
OC-48 DWDM 1535.04 NM REGEN TX                                       NT8E13ML         1           ***
OC-48 DWDM 1557.36 NM REGEN TX                                       NT8E13TM         1           ***
TN-16X Regenerator Subrack Kit                                       NTFW51AA         1           ***
KIT, SC OPTICAL CONNECTOR. INITIAL USE NTN401AA.                     NTN459SC         2           ***
TN-16X Regenerator Software Licence  (Release 7)                     NTQJ93GG         1           ***
FW TN-16X Rel 7 NTPS (CD-ROM)                                        NTFW64AH         1           ***
RACKS
-----
TN-16X Installation Kit                                           25SKM00807ABM       1           ***
REGEN RACK ASSY.                                                     NTFW71AA         1           ***

MODEL 28 INM LICENCES TN-16X ADM                                                                                           ******

INMCORE INCL FM-NE_TN16X RTU                                         NTNM23BAAE       1           ***
INVENTORY MANAGEMENT - NE_TN-16X RTU                                 NTNM31BDAE       1           ***
PERFORMANCE MANAGEMENT - NE_TN-16X RTU                               NTNM23BCAE       1           ***
TRAIL MANAGEMENT - NE_TN-16X RTU                                     NTNM12BAAE       1           ***
TRAIL ADVISOR - NE_TN-16X RTU                                        NTNM12BBAE       1           ***
TRAIL SCHEDULE - NE_TN-16X RTU                                       NTNM12BCAE       1           ***

MODEL 29 INM LICENSES TN-16X REGEN                                                                                         ******
INMCORE INCL FM-NE_TN16X RTU                                         NTNM23BAAE       1           ***
INVENTORY MANAGEMENT - NE_TN-16X RTU                                 NTNM31BDAE       1           ***
PERFORMANCE MANAGEMENT - NE_TN-16X RTU                               NTNM23BCAE       1           ***

</TABLE>
-----------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

  ANNEX 2, CHAPTER 1       LIST OF GUARANTEED TECHNICAL FEATURES
<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------------
        FEATURES                                                                              READY FOR       PENALTY
                                                                                                TYPE
                                                                                             ACCEPTANCE
---------------------------------------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------------------------------------
<S>  <C>                                                                                     <C>           <C>
1.   DWDM REGENERATOR CARDS for initial implementation DWDM systems regenerate the                 Te1     2 million DM
     optical line signals of transmission rate 10 Gbit/s by opto-electrical conversion
---------------------------------------------------------------------------------------------------------------------------
2.   CHANNEL COMBINER for initial implementation DWDM systems multiplex up to four STM-16          Te2     5 million DM
     signals in an optical line channel and vice versa.
---------------------------------------------------------------------------------------------------------------------------
3.   TRIBUTARY INTERFACES for the TN-64X system permit the setup, transfer and monitoring          Te3     5 million DM
     of four bi-directional STM-4 signals (without trib.- trib. interconnection).
---------------------------------------------------------------------------------------------------------------------------
4.   The INM CORBA INTERFACE permits the export of performance data, trail routing data,           Te4     2 million DM
     network inventory data and alarm data from the network management system
     INM to a third-party system.
---------------------------------------------------------------------------------------------------------------------------
5.   STM-16 TRANSLATOR INTERFACES for initial implementation DWDM systems fulfil the               Te5     5 million DM
     technical requirements in accordance with Annex 2 - System Feature
     Description Optical Line Terminal (16 wave lengths)
---------------------------------------------------------------------------------------------------------------------------
6.   STM-16 TRANSLATOR INTERFACES for initial implementation DWDM systems fulfil the               Te6     5 million DM
     technical requirements in accordance with Annex 2 - System Feature
     Description Optical Line Terminal (32 wave lengths)
---------------------------------------------------------------------------------------------------------------------------
7.   UNITS INTERFACES FOR TN-16XE permit the transmission of an optical STM-16 signal and          Te7     5 million DM
     non-blocking setup, transmission and monitoring of bi-directional
     connections between units interfaces as well as between units and
     tributary interfaces.
---------------------------------------------------------------------------------------------------------------------------
8.   TRIBUTARY INTERFACES for TN-16XE and TN-4XE systems permit the transmission of an             Te8     2 million DM
     optical STM-4 signal and non-blocking setup, transmission and monitoring of
     bi-directional connections between tributary interfaces as well as
     between units and tributary interfaces.
---------------------------------------------------------------------------------------------------------------------------
9.   TRIBUTARY INTERFACES for TN-64XE systems permit the transmission of FOUR OPTICAL              Te9     1 million DM
     STM-1 signals and non-blocking setup, transmission and monitoring of bi-directional
     connections between tributary interfaces as well as between units and
     tributary interfaces on VC-4 level.
---------------------------------------------------------------------------------------------------------------------------
10.  TRIBUTARY INTERFACES for TN-64XE systems permit the transmission of FOUR ELECTRICAL           Te10    1 million DM
     STM-1 signals and non-blocking setup, transmission and monitoring of bi-directional
     connections between tributary interfaces as well as between units and
     tributary interfaces on VC-4 level.
---------------------------------------------------------------------------------------------------------------------------
11.  TRIBUTARY INTERFACES for TN-64XE AND TN-4XE systems permit the transmission of FOUR           Te11    5 million DM
     ELECTRICAL STM-1 signals and non-blocking setup, transmission and monitoring of
     bi-directional connections between tributary interfaces as well as
     between units and tributary interfaces on VC-4, VC-3 and VC-12 levels.
---------------------------------------------------------------------------------------------------------------------------
12.  A 40-CHANNEL NORTEL DWDM SYSTEM can be set up in parallel to the 16-channel system            Te12    5 million DM
     used for initial implementation and can be operated in parallel for transmission via
     the same fibres.
---------------------------------------------------------------------------------------------------------------------------
13.  STM-64 TRANSPONDER INTERFACES permit the connection of systems of other                       Te13    5 million DM
     manufacturers via S-64 interface (STM-64)
---------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                                    ANNEX 2

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

-------------------------------------------------------------------------------
Supplier: NORTEL DASA                       Reference No.: 1
                                            otel.o Document No.: ST-rfx-0012
                                            Chapter: 4.1
                                            Item No.: 1,2,3,4,5,10,11,12

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Graphical User Interface for EMS

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
The element managers for the proposed SDH multiplexer equipment, OPC and EC-1,
are used according to the TMN modell to manage the Nes efficiently and providing
the element specific managmentcapabilities an upper layer pathmanagement system,
the INM system, makes use of. All operational actions and information is
accessible from the Pathmanagement platform INM. Hence, there is no need for the
operator to use the Element Controller directly as the INM provides a common
English GUI for all integrated equipment to be managed. Out of this reason the
EC-1 and OPC themselves provide UNIX-based textual user-interfaces.

As all the systems are Unix-based the keyboard doesn't support the special
German characters and consonants. Therefore it is not possible to enter German
characters.

The GUI of INM allows hierarchical views on the network including background
graphics icons and easy-to-use point-and click operation. Alarms are graphically
visible and counters for acknoledged, non-acknoledged and alarm severity are
available at the INM GUI.

As conclusion the usage of the element controllers in the absence of the
pathmanagement system INM doesn't is possible but only in combination with the
INM GUI all available and required functionality can be provided. Therefore
refer also to the compliance statements provided for the NMS-Pathmanagement
questions representing the capabilities of the INM system.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.

<PAGE>

<TABLE>
<CAPTION>

LICENSES AND SOFTWARE                                       PEC                   DESCRIPTION
<S>                                                         <C>                   <C>
MOR RTU                                                     NTCA62DA              1 per Network Element with MOR+ units
                                                                                  & 1 per Maintaince Interface
TN-64X APPLICATION - 4F SPRING                              NTQJ93TC              1 per TN-64X Network Element in ADM configuration
TN-64X APPLICATION - REGENERATOR / MOR                      NTQJ93TD              1 per Regenerator or Network Element housing
                                                                                  MOR+ units
INM Core Management RTU - MOR                               NTNM23BAAN            One per MOR+ when using INM
INM Inventory Management RTU - MOR                          NTNM31BDAN            One per MOR+ when using INM
INM Core Management RTU - TN-64X                            NTNM23BAAG            One per TN-64X when using INM
INM Performance Management RTU - TN-64X                     NTNM23BCAG            One per TN-64X when using INM
INM Inventory Management RTU - TN-64X                       NTNM31BDAG            One per TN-64X when using INM
INM Trail Manager RTU - TN-64X                              NTNM12BAAG            One per TN-64X when using INM

INM CORE MANAGEMENT RTU TN-16XE                             NTNM23BAAM            Always required. One per NE when using EC-1
INM Performance MANAGEMENT RTU TN-16XE                      NTNM23BCAM            Always required. One per NE when using EC-1
INM Inventory MANAGEMENT RTU TN-16XE                        NTNM31BDAM            Always required. One per NE when using EC-1
INM Trail Manager RTU TN-16XE                               NTNM12BAAM            Always required. One per NE when using EC-1

INM CORE MANAGEMENT RTU TN-4XE                              NTNM23BAAD            Always required. One per NE when using EC-1
INM Performance MANAGEMENT RTU TN-4XE                       NTNM23BCAD            Always required. One per NE when using EC-1
INM Inventory MANAGEMENT RTU TN-4XE                         NTNM31BDAD            Always required. One per NE when using EC-1
INM Trail Manager RTU TN-4XE                                NTNM12BAAD            Always required. One per NE when using EC-1

INM Core Management RTU - TN-1X                             NTNM23BAAC            Always required. One per NE when using EC-1
INM Performance Management RTU - TN-1X                      NTNM23BCAC            Always required. One per NE when using EC-1
INM Inventory Management RTU - TN-1X                        NTNM31BDAC            Always required. One per NE when using EC-1
INM Trail Manager RTU - TN-1X                               NTNM12BAAC            Always required. One per NE when using EC-1

INM Core Management RTU - TN-1C                             NTNM23BAAB            Always required. One per NE when using EC-1
INM Performance Management RTU - TN-1C                      NTNM23BCAB            Always required. One per NE when using EC-1
INM Inventory Management RTU - TN-1C                        NTNM31BDAB            Always required. One per NE when using EC-1
INM Trail Manager RTU - TN-1C                               NTNM12BAAB            Always required. One per NE when using EC-1

INM Broadband RTU                                           NTNM51AA              One per Network utilising INMs
INM External Alarm Interface RTU                            NTNM51AB              One per Network if external alarm interfaces
                                                                                  are used with INM
INM Resilient Platform RTU                                  NTNM23AG              One per additional resilent INM platform

</TABLE>

20 September 1999

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier:                                              Reference No.: 07.1
Nortel Dasa
Network Systems GmbH & Co. KG                          Document No.: ST-rfx-0007
Hahnstrasse 37 - 39
60528 Frankfurt / Main                                 Chapter: 1

                                                       Item No.: 1
--------------------------------------------------------------------------------

                              With Regard to TN-64X

--------------------------------------------------------------------------------
1. Item
--------------------------------------------------------------------------------

STM-1 e

--------------------------------------------------------------------------------
2. Description
--------------------------------------------------------------------------------

Quad card currently e/0 2000, potential improvement under investigation

<PAGE>

-------------------------------------------------------------------------------

                SYSTEM FEATURE DESCRIPTION OPTICAL LINE TERMINAL

-------------------------------------------------------------------------------

ID                        ST-RFX-0006
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

-------------------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description Optical Line Terminal-10

-------------------------------------------------------------------------------

DESCRIPTION

-------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

-------------------------------------------------------------------------------

-------------------------------------------------------------------------------

<PAGE>

1        ABBREVIATIONS

-------------------------------------------------------------------------------

INTRODUCTION This section lists abbreviation used throughout the entire
             document.

-------------------------------------------------------------------------------

                          AUI          Attachment Unit Interface
                          BBE          Background Block Error
                          EBER         Excessive Bit Error Rate

                          EMS          Element Management System
                          ES           Errored Second
                          ES-IS        End System - Intermediate System routing
                          IP           Internet Protocol
                          IS-IS        Intermediate System routing
                          ITU-T        International Telecommunications Union -
                                       Telecommunications Sector
                          LAPD         Link Access Protocol D-channel
                          LCT          Local Craft Terminal
                          LED          Light Emitting Diode
                          LOF          Loss Of Frame
                          LOS          Loss Of Signal
                          MAU          Media Attachment Unit
                          MDI          Miscellaneous Discrete Input
                          MDO          Miscellaneous Discrete Output
                          MIB          Management Information Base
                          NE           Network Element
                          NMS          Network Management System
                          NSAP         Network Service Access Point
                          OADM         Optical Add/Drop Multiplexer
                          ODBC         Open DataBase Connectivity
                          OLA          Optical Line Amplifier
                          OSC          Optical Service Channel
                          OSI          Open Systems Interconnection
                          OSS          Operation Support System
                          OTM          Optical Terminal Multiplexer
                          PSTN         Public Switched Telephone Network
                          RS           Regenerator Section
                          SDH          Synchronous Digital Hierarchy
                          SES          Severely Errored Second
                          SNMP         Simple Network Management Protocol
                          SQL          Structured Query Language
                          TCP          Transmission Control Protocol
                          UAS          Unavailable Second
                          UDP          User Datagram Protocol

-------------------------------------------------------------------------------

<PAGE>

2        REQUESTED FEATURES

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
1             TRANSMISSION FEATURES
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier provides a link/hop          NC
              planning tool allowing to simulate and
              design the DWDM network (Attenuation,
              Dispersion,..).
------------------------------------------------------------------------------------------------------------------------
         2.   The supplier provides a released          C - This can be  IR              IR
              document containing system planning and   made available
              engineering rules based on standard       if required
              single mode fibres.
------------------------------------------------------------------------------------------------------------------------
1.1           TRANSMISSION INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Connector Type E2000 APC                  FC & SC
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.1.1         INTERFACES CARRYING N X LAMBDAS
------------------------------------------------------------------------------------------------------------------------
         1.   Maximum output power of the interfaces    50W              IR              IR
------------------------------------------------------------------------------------------------------------------------
         1.   link/hop limits (attenuation,             5 hops, total    IR              IR
              dispersion,..) as function of number and  combined
              lengths of hops between terminals.        distance of
                                                        380km with
                                                        maximum overall
                                                        Db loss of 95Db
------------------------------------------------------------------------------------------------------------------------
         2.   Automatic output power adjustment         C
              depending on the number of
              received channels
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.1.2         TRANSPONDERS AND TRIBUTARY INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Optical interface I-16.1                  C
------------------------------------------------------------------------------------------------------------------------
         1.   Optical interface S-16.1                  C
------------------------------------------------------------------------------------------------------------------------
         2.   Optical interface L-16.1                  C
------------------------------------------------------------------------------------------------------------------------
         3.   Optical interface L-16.2                  C
------------------------------------------------------------------------------------------------------------------------
         4.   Bitrate independent interface             NC, however it
                                                        is possible to
                                                        multiplex any
                                                        bitrate signal
                                                        presented to
                                                        the optical
                                                        layer using
                                                        Nortel's ADM
                                                        equipment
------------------------------------------------------------------------------------------------------------------------
         5.   Optical Power Budget without              1 span = 27      IR              IR
              transponders                              2 spans = 25 Db
                                                        3 spans = 23 Db
                                                        4 spans = 21 Db
                                                        5 spans = 19 Db
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
         6.   Active wavelength control                 C
              (not only via chip temperature)
------------------------------------------------------------------------------------------------------------------------
         7.   Transmit transponders optional for        NC - Nortel's
              tributary channels                        SDH ADMs feed
              (option to use output signals from        their signal
              coloured transmitters without need to     directly into
              implement transponders)                   the OADM
                                                        without need
                                                        for transponders
------------------------------------------------------------------------------------------------------------------------
         8.   Receive transponders optional for         NC - see above
              tributary channels
              (option to apply DEMUX output signal to
              SDH-receiver)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.2           SYSTEM CONNECTIVITY
------------------------------------------------------------------------------------------------------------------------
         1.   IN CASE OF OPTICAL CHANNEL SPACING 100 GHZ:
------------------------------------------------------------------------------------------------------------------------
         2.   Max. number of optical channels           16 channels      IR              IR
                                                        supporting 32
                                                        wavelengths
------------------------------------------------------------------------------------------------------------------------
         1.   Min. number of optical channels           2 supporting 4   IR              IR
                                                        wavelengths
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
              IN CASE OF OPTICAL CHANNEL SPACING 50
              GHZ:
------------------------------------------------------------------------------------------------------------------------
         1.   Max. number of optical channels           Nortel's         IR              IR
                                                        Optical equipment
                                                        follows the ITU-T
                                                        recommended 200Ghz grid
                                                        with 100Ghz spacing as
                                                        defined in G.692
------------------------------------------------------------------------------------------------------------------------
         1.   Min. number of optical channels           See above        IR              IR
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.3           STM-64 COMPATIBILITY
------------------------------------------------------------------------------------------------------------------------
         1.   It is possible to upgrade channels from   Equipment will
              STM-16 to STM-64 without need to change   initially be
              hardware.                                 provisioned to
                                                        support STM-64
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.4           OTHER TRANSMISSION FEATURES
------------------------------------------------------------------------------------------------------------------------
         1.   Dispersion compensation                   C
------------------------------------------------------------------------------------------------------------------------
         1.   Automatic gain control                    C
         -------------------------------------------------------------------------------------------------
         2.   A channel upgrade is not traffic          See response to
              affecting to all                          1.3.1
              channels already in service
------------------------------------------------------------------------------------------------------------------------
         3.   Forward error correction                  C
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
2             ENGINEERING ORDERWIRE
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
2.1           INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   2 wire i/f (towards PSTN)                 C
------------------------------------------------------------------------------------------------------------------------
         1.   2 wire  i/f (towards standard handset)    C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
2.2           FUNCTIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Selective Call                            C
------------------------------------------------------------------------------------------------------------------------
         1.   Conference Call (up to four participants) C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
3             MANAGEMENT COMMUNICATION
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
3.1           COMMUNICATION INTERFACES
------------------------------------------------------------------------------------------------------------------------
         -    F- Interface   (RS 232)                   C
------------------------------------------------------------------------------------------------------------------------
         -    Q- interface as gateway to the EMS        C
------------------------------------------------------------------------------------------------------------------------
         -    Qecc Routing (2 level IS-IS)              C
------------------------------------------------------------------------------------------------------------------------
         -    Q I/F (Ethernet)                          C
------------------------------------------------------------------------------------------------------------------------
         1.   Optical Supervisory Channel               C
------------------------------------------------------------------------------------------------------------------------
         2.   OSC                                       Integrated OSC   IR              IR
              -        wavelength                       at 1510nm or
              -        bitrate                          separate module
              -        optical span limit               operating at
              -        transmission protocol            1625nm
                                                        operating at
                                                        10Gbit/s with a
                                                        limit of 5 spans
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
3.2           O & M INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   8 x Remote Control Inputs                 NC
------------------------------------------------------------------------------------------------------------------------
         1.   Remote Control Outputs                    C - However
                                                        Management
                                                        Performance may
                                                        be reduced
------------------------------------------------------------------------------------------------------------------------
         2.   Card LED support                          C
------------------------------------------------------------------------------------------------------------------------
         2.   Subrack LED support                       C
------------------------------------------------------------------------------------------------------------------------
         3.   Rack Alarm support                        C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
4             PERFORMANCE MANAGEMENT
------------------------------------------------------------------------------------------------------------------------
         1.   B1 Performance Monitoring on Transponder  Transponder
              Unit                                      Unit not used
                                                        in this solution
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
         2.   15 min Performance History Data           C - extensive
              Collection from each Regenerator          performance
              Section Monitoring Point (ES, SES and     monitoring is
              UAT).                                     available as
                                                        part of
                                                        Nortel's INM
                                                        network
                                                        management
                                                        platform
------------------------------------------------------------------------------------------------------------------------
         3.   24 h Performance History Data Collection  See response to
              from each Regenerator Section Monitoring  4.2 above
              Point (ES, SES and UAT).
------------------------------------------------------------------------------------------------------------------------
         1.   15 min Performance History Log for more   See response to
              than 100 intervals                        4.2 above
------------------------------------------------------------------------------------------------------------------------
         2.   24 h Performance History Log for more     See response to
              than 30 intervals                         4.2 above
------------------------------------------------------------------------------------------------------------------------
         4.   Performance Monitoring Threshold          See response to
              Crossing Notification                     4.2 above
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5             FAULT AND STATUS MANAGEMENT
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.1.1         ALL OPTICAL INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Laser Restart for Test                    C
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of Laser Shutdown               C - alarms are
                                                        raised if for
                                                        whatever reason
                                                        a loss of
                                                        signal occurs.
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of disabled ALS on any          See response to
              optical interface                         6.2.1.9
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of Optical Source Power         C
              High on any optical interface
------------------------------------------------------------------------------------------------------------------------
         5.   Detection of LOS, LOS status change       C - Loss of
              hysteresis                                Signal is
                                                        reported
                                                        through the use
                                                        of alarms based
                                                        upon input and
                                                        output signal
                                                        thresholds.
------------------------------------------------------------------------------------------------------------------------
         6.   Insertion of AIS upon detection of LOS    C
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of number of received channels  C
------------------------------------------------------------------------------------------------------------------------
         2.   Monitoring of laser current for pump      C
              laser 1
------------------------------------------------------------------------------------------------------------------------
         7.   Monitoring of laser current for pump      C
              laser 2
------------------------------------------------------------------------------------------------------------------------
         3.   Monitoring of temperature for pump laser  C
              1
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
         4.   Monitoring of temperature for pump        C
              laser 2
------------------------------------------------------------------------------------------------------------------------
         5.   Monitoring of laser temperature           C
------------------------------------------------------------------------------------------------------------------------
         6.   Monitoring of transmitted wavelength      C
------------------------------------------------------------------------------------------------------------------------
         8.   Monitoring of received input power        C
------------------------------------------------------------------------------------------------------------------------
         7.   Monitoring of transmitted output power    C
------------------------------------------------------------------------------------------------------------------------
         8.   Detection of coupler temperature high     C
------------------------------------------------------------------------------------------------------------------------
         9.   Detection of grating temperature high     C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.1.2         ALL REGENERATOR SECTION MONITORING POINTS
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of OOF                             NC - At an
                                                            Optical
                                                         Terminal site,
                                                         regen section
                                                        is monitored by
                                                          the SDH ADM
                                                           equipment
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of LOF                          See response to
                                                        5.1.2.1 above
-----------------------------------------------------------------------------------------------------------------------
         2.   Detection of RS EBER (10E-3) based on     See response to
              B1 BIP-8 parity calculation               5.1.2.1 above
              on demux unit
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of RS EBER (10E-3) based on     See response to
              B1 BIP-8 parity calculation on            5.1.2.1 above
              transponder unit
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of Section Trace Mismatch       See response to
              based on J0 Byte monitoring on demux unit 5.1.2.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of Section Trace Mismatch       Transponder
              based on J0 Byte monitoring on            Unit not used in
              transponder unit                          this solution
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.1.3         MANAGEMENT COMMUNICATION FUNCTION
------------------------------------------------------------------------------------------------------------------------
              Detection of Remote Control Input Active  C
------------------------------------------------------------------------------------------------------------------------
              Detection of OSC Comms Fail (LAPD Alarm)  C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.1.4         SYSTEMS MANAGEMENT FUNCTION
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of Secondary Power Fail         See response to
                                                        8.3.2
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of Primary Power Low            See response to
                                                        8.3.2
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of Primary Power Fail per       See response to
              each single power feed                    8.3.2
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of Re-Boot Fail                 C
------------------------------------------------------------------------------------------------------------------------
         5.   Detection of Configuration Data           C
              Integrity Check Failure
------------------------------------------------------------------------------------------------------------------------
         6.   Detection of System Software Integrity    C
              Check Failure
------------------------------------------------------------------------------------------------------------------------
         7.   Detection of Network Element Controller   C
              Fail
------------------------------------------------------------------------------------------------------------------------
         8.   Detection of Card Protection Switch       C
              Failure
------------------------------------------------------------------------------------------------------------------------
         9.   Detection of Card Out                     C
------------------------------------------------------------------------------------------------------------------------
         10.  Detection of Card Fail (upon detection    C
              of internal parity mismatch etc.)
------------------------------------------------------------------------------------------------------------------------
         11.  Detection of Wrong Card                   C
------------------------------------------------------------------------------------------------------------------------
         12.  Network Protection Switch Failure
------------------------------------------------------------------------------------------------------------------------
         13.  Optical Layer Protection Switch Active
------------------------------------------------------------------------------------------------------------------------
         14.  Card Protection Switch Active             C
------------------------------------------------------------------------------------------------------------------------
         1.   Fault / Status Log Capacity Exceeded      C
------------------------------------------------------------------------------------------------------------------------
         15.  Configuration Data Transaction Log        C
              Capacity Exceeded
------------------------------------------------------------------------------------------------------------------------
         16.  Performance Monitoring Log Capacity       C
              Exceeded
------------------------------------------------------------------------------------------------------------------------
         17.  Access  Log Capacity Exceeded             C
------------------------------------------------------------------------------------------------------------------------
         2.   Software Download in Progress             C
------------------------------------------------------------------------------------------------------------------------
         18.  Software Download Failure                 C
------------------------------------------------------------------------------------------------------------------------
         19.  Software Download Failure - Retry in      C
              Progress
------------------------------------------------------------------------------------------------------------------------
         20.  Software Download Complete                C
------------------------------------------------------------------------------------------------------------------------
         21.  Card Restoration Complete                 C
------------------------------------------------------------------------------------------------------------------------
         22.  Re-Boot Restoration Complete              C
------------------------------------------------------------------------------------------------------------------------
         23.  Electronic Label Update                   C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.2           ALARM EVENT HANDLING
------------------------------------------------------------------------------------------------------------------------
         1.   Alarm Persistence Filter (filtering of    C - It is
              toggling alarms)                          possible to
                                                        filter alarms
                                                        using the
                                                        functionality
                                                        of INM,
                                                        Nortel's
                                                        Network
                                                        Management
                                                        System
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
         2.   Alarm Correlation Filter (F3 filter,    C
              suppression of consequent alarms)
------------------------------------------------------------------------------------------------------------------------
         3.   Alarm Inversion Facility                     C - It is
                                                          possible to
                                                         invert alarms
------------------------------------------------------------------------------------------------------------------------
         4.   Performance of the alarm throughput     C
              greater than 10 alarms per second
------------------------------------------------------------------------------------------------------------------------
         5.   Indication of Alarm Event Forwarding    NC
              Suppression per functional unit (e.g.
              Regenerator Section ...)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6             CONFIGURATION MANAGEMENT
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.1           GENERAL
------------------------------------------------------------------------------------------------------------------------
         1.   Upload of Configuration Data - on single  C
              command
------------------------------------------------------------------------------------------------------------------------
         1.   Upload of Configuration Data - on bulk    C
              command
------------------------------------------------------------------------------------------------------------------------
         2.   Download of Configuration Data - on bulk  C
              command
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.2           CONFIGURATION OF FUNCTIONAL BLOCKS
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.2.1         ALL OPTICAL INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Set of transmitted output power           C
------------------------------------------------------------------------------------------------------------------------
         2.   Set of input power warning thresholds     C
------------------------------------------------------------------------------------------------------------------------
         3.   Set input power switch off thresholds     C
------------------------------------------------------------------------------------------------------------------------
         4.   Set output power warning thresholds       C
------------------------------------------------------------------------------------------------------------------------
         5.   Set output power switch off thresholds    C
------------------------------------------------------------------------------------------------------------------------
         6.   Set laser current alarm thresholds        C
------------------------------------------------------------------------------------------------------------------------
         7.   Set of laser temperature alarm thresholds C
------------------------------------------------------------------------------------------------------------------------
         1.   Set of transmitted wavelength alarm       C
              thresholds
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
         2.   Enable / Disable Automatic Laser          NC - The OPTera
              Shutdown according to ITU-T G.958         LH is a Class
                                                        3A system. Whilst not
                                                        advised, a Class 3A
                                                        system is deemed to be
                                                        safe for long term
                                                        viewing without optical
                                                        aids and with the
                                                        supplied warning labels
                                                        and procedural
                                                        precautions, ALS is not
                                                        necessary for this
                                                        equipment
------------------------------------------------------------------------------------------------------------------------
         3.   Enable / Disable Laser                    C - it is
                                                        possible to
                                                        enable/disable
                                                        the laser both
                                                        manually and
                                                        remotely
------------------------------------------------------------------------------------------------------------------------
         4.   Enable Laser for Test Purposes
              (2s / NC 90s)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.2.2         ALL REGENERATOR SECTION MONITORING POINTS
------------------------------------------------------------------------------------------------------------------------
         1.   Set Threshold B1-EBER                     NC -At an
                                                        Optical
                                                        Terminal site,
                                                        regen section
                                                        is monitored by
                                                        the SDH ADM
                                                        equipment
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
7             NETWORK PROTECTION
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
7.1           OPTICAL MULTIPLEX SECTION PROTECTION
              (OMSP)
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
         1.   OMSP function                             NC - Nortel      However,
                                                        believes that    Nortel also
                                                        in today's       believes that
                                                        networks where   optical
                                                        SDH              protection
                                                        multiplexers     switching
                                                        are already      offers
                                                        required for     benefits for
                                                        traffic          demands
                                                        aggregation and  carried on
                                                        bandwidth        individual
                                                        management it    optical
                                                        is more cost     channels,
                                                        effective to     Optical
                                                        put the          protection
                                                        protection       switching of
                                                        switching in     this type is
                                                        the SDH layer    only viable if
                                                                         deployed with
                                                                         appropriate
                                                                         solutions for
                                                                         the monitoring
                                                                         and management
                                                                         of the optical
                                                                         domain
------------------------------------------------------------------------------------------------------------------------
         2.   Switch-Over Completion Time less         See response to
              than 50ms                                7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Enable / Disable Automatic Switching      See response to
                                                        7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         4.   Manual Switching via Management           See response to
              Interface                                 7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         5.   Configurable Wait Time to Restore         See response to
                                                        7.1.1 above
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
7.2           WAVELENGTH SELECTIVE PROTECTION SWITCHING
------------------------------------------------------------------------------------------------------------------------
         1.   Wavelength selective Subnetwork           See response to
              Connection Protection                       7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         2.   Switch-Over Completion Time less          See response to
              than 50ms                                   7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Enable / Disable Automatic Switching      See response to
                                                          7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         4.   Manual Switching via Management           See response to
              Interface                                   7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         5.   Configurable Wait Time to Restore         See response to
                                                          7.1.1 above
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
8             OPERATION AND MAINTENANCE
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
8.1           GENERAL
------------------------------------------------------------------------------------------------------------------------
         1.   Event buffer                              C
------------------------------------------------------------------------------------------------------------------------
         2.   Heart Beat Function for all processes     NC
------------------------------------------------------------------------------------------------------------------------
         1.   Automatic Re-boot after power failure
------------------------------------------------------------------------------------------------------------------------
         3.   Real time clock function                  C
------------------------------------------------------------------------------------------------------------------------
         4.   Automatic synchronization of NE real      C
              time clock on EMS real time clock
------------------------------------------------------------------------------------------------------------------------
         5.   It is possible to set the NE time and     C
              date via EMS/LCT
------------------------------------------------------------------------------------------------------------------------
         6.   NSAP Address modification                 C
------------------------------------------------------------------------------------------------------------------------
         7.   Local Software Download                   C
------------------------------------------------------------------------------------------------------------------------
         8.   Remote Software Download                  C
------------------------------------------------------------------------------------------------------------------------
         9.   Upload of configuration data to EMS/LCT   C
------------------------------------------------------------------------------------------------------------------------
         2.   Download of configuration data from       C
              EMS/LCT
------------------------------------------------------------------------------------------------------------------------
         10.  Manager Decision Process for equipment    C
              access control
------------------------------------------------------------------------------------------------------------------------
         11.  Display of Optical Transmit Power Level   C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
8.2           LOGS
------------------------------------------------------------------------------------------------------------------------
         1.   Alarm / Status Log                        C
------------------------------------------------------------------------------------------------------------------------
         1.   Performance Log (storage capacity at      C
              least 8 x 15 min intervals and 30 x 24 h
              interval for each monitoring point)
------------------------------------------------------------------------------------------------------------------------
         2.   Configuration Log (storage capacity at    C
              least 24 h)
------------------------------------------------------------------------------------------------------------------------
         3.   Access Control Log (storage capacity at   C
              least 10 days)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
8.3           REDUNDANCY
------------------------------------------------------------------------------------------------------------------------
         1.   Dual Power Feed                           C - standard 2
                                                        power feeds,
                                                        optional 6
                                                        power feeds
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
------------------------------------------------------------------------------------------------------------------------
         2.   1+1 Protection of Power Supply            The OPTera
                                                        system is
                                                        powered by
                                                        redundant
                                                        feeds. Failure
                                                        of one of the
                                                        power feeds due
                                                        to an open or
                                                        short circuit
                                                        does not affect
                                                        the system. Two
                                                        breaker/filter
                                                        modules provide
                                                        power for the
                                                        OPtera shelves.
------------------------------------------------------------------------------------------------------------------------
         3.   Redundancy of pump lasers                 C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
8.4           EQUIPMENT TESTING FUNCTIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Integrity Check of Configuration Data     C - managed
                                                        via the
                                                        functionality
                                                        of the NE OPC
------------------------------------------------------------------------------------------------------------------------
         1.   Integrity Check of System Software        See response to
                                                        8.4.1
------------------------------------------------------------------------------------------------------------------------
         2.   Configuration of Loop Back on all         NC
              optical Interface Cards
------------------------------------------------------------------------------------------------------------------------
         3.   Optical monitoring port on each           Transponder
              transmit transponder (output signal)      Unit not used
                                                        in this solution
------------------------------------------------------------------------------------------------------------------------
         4.   Optical monitoring port on each receive   Transponder
               transponder (input signal)               Unit not used
                                                        in this solution
------------------------------------------------------------------------------------------------------------------------
         2.   Optical monitoring port on each           C - managed
              pre-amplifier (input signal)              via the
                                                        functionality
                                                        of the NE OPC
------------------------------------------------------------------------------------------------------------------------
         5.   Optical monitoring port on each           C - managed
              booster-amplifier (output signal)         via the
                                                        functionality
                                                        of the NE OPC
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
8.5           INVENTORY DATA
------------------------------------------------------------------------------------------------------------------------
         1.   Electronic Label Read Access via          Nortel's INM Network
              Management Interfaces                     Management system offers
                                                        the option of
                                                        centralised inventory
                                                        management, which is
                                                        accessed via the GNB and
                                                        allows the user to
                                                        retrieve an inventory of
                                                        the remotely located
                                                        NEs. The retrieved
                                                        information can be
                                                        displayed and saved to a
                                                        file suitable for
                                                        further processing
------------------------------------------------------------------------------------------------------------------------
         1.   Automatic Electronic Label Upgrade        See response to
                                                        8.5.1 above
------------------------------------------------------------------------------------------------------------------------
         2.   Compatibility Check of Equipment          See response to
              Hardware Releases                         8.5.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Compatibility Check of Equipment          See response to
              Firmware Releases                         8.5.1 above
------------------------------------------------------------------------------------------------------------------------
         2.   Compatibility Check of Equipment          Management by release
              Software Releases                         automatically defines a
                                                        set of compatible
                                                        software loads (called
                                                        the software lineup) for
                                                        all downloadable CPs in
                                                        a span of control and
                                                        enforces strict software
                                                        configuration management
                                                        among these loads.
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
         4.   Compatibility Check of Equipment          Management by release
              Software Releases to the Management       automatically
              System                                    defines a set of
                                                        compatible software
                                                        loads (called the
                                                        software lineup) for all
                                                        downloadable CPs in a
                                                        span of control and
                                                        enforces strict software
                                                        configuration management
                                                        among these loads.
------------------------------------------------------------------------------------------------------------------------
         5.   Electronic Label contents:                See response to
              - Unit hardware release / version         8.5.1 above
              - Unit hardware serial number
              - Unit firmware release / version
              - Unit software release / version
              - Unit installation date of unit/NE
              - Production date of unit/NE
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
9             ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL
              COMPATIBILITY AND SAFETY
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
9.1           CLIMATIC CONDITIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Compliance with Stationary Use            C
              Conditions acc. to prETS 300 019-2-3
              Class T 3.2
------------------------------------------------------------------------------------------------------------------------
         2.   No need for air conditioning via          C
              elevated ground floor
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
9.2           ELECTROMAGNETIC COMPATIBILITY
------------------------------------------------------------------------------------------------------------------------
         1.   Compliance with EN 55022                  C
------------------------------------------------------------------------------------------------------------------------
         2.   Compliance with EN 50082                  C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
9.3           SAFETY
------------------------------------------------------------------------------------------------------------------------
         1.   CE certification available                C
------------------------------------------------------------------------------------------------------------------------
         1.   Electrical safety according to EN 41003   C
------------------------------------------------------------------------------------------------------------------------
         2.   General requirements according to         C
              EN 60950 A1, A2
------------------------------------------------------------------------------------------------------------------------
         3.   Fire and heat safety according to ETS     C
              300 019-2
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
10            PHYSICAL CONSTRUCTION
------------------------------------------------------------------------------------------------------------------------
         1.   Rack size according to ETSI 300 119,      C
              600 mm x 300 mm
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                    T1               T2              T3               Comment
------------------------------------------------------------------------------------------------------------------------
<S>     <C>                                          <C>                <C>            <C>              <C>
         1.   Rack size according to ETSI 300 119,      N/A
              600 mm x 600 mm
------------------------------------------------------------------------------------------------------------------------
         2.   System installation and h/w upgrade via   C
              front access possible
------------------------------------------------------------------------------------------------------------------------
         2.   Number of required Racks in minimum       1                1               1
              configuration
------------------------------------------------------------------------------------------------------------------------
         3.   Number of required Racks in maximum       1                IR              IR
              configuration
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
11            POWER SUPPLY
------------------------------------------------------------------------------------------------------------------------
         1.   Nominal input voltage -48V                C
------------------------------------------------------------------------------------------------------------------------
         1.   Minimum accepted input voltage            -38V             IR              IR
------------------------------------------------------------------------------------------------------------------------
         2.   Maximum accepted input voltage            -75V             IR              IR
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
12            AVAILABILITY
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier shall provide MTBF figures   C - see Annex 1  IR              IR
              for each functional unit of the offered
              equipment based on his statistical
              evaluations according to the template as
              attached in Annex 1
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
13            POWER CONSUMPTION
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier shall provide worst case     C - see Annex 1  IR              IR
              power consumption figures for each
              functional unit of the offered equipment
              according to the template as attached in
              Annex 1
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
14            SYSTEM MANUALS
------------------------------------------------------------------------------------------------------------------------
         1.   System Description in Hypertext Format    C -
              on CD                                     documentation
                                                        is available in
                                                        Adobe Acrobat
                                                        format
------------------------------------------------------------------------------------------------------------------------
         2.   System O&M Manuals in Hypertext Format    C -
              on CD                                     documentation
                                                        is available in
                                                        Adobe Acrobat
                                                        format
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------
UNIT NAME/TYPE                         UNIT ID           UNIT FIT FIGURE         MAXIMUM POWER
                                                                                  CONSUMPTION
----------------------------------------------------------------------------------------------------
<S>                                    <C>                     <C>                  <C>
MANDATORY CONTROL
----------------------------------------------------------------------------------------------------
Shelf Controller                       NTCA41BA                1125                 13W/20W
----------------------------------------------------------------------------------------------------
Half Height Breaker                    NTCA40CA                 256                  5W/8W
----------------------------------------------------------------------------------------------------
Maintenance Interface                  NTCA42AA                1139                 7.5W/10W
----------------------------------------------------------------------------------------------------
Message Transfer                       NTCA48AA                 677                  8W/10W
----------------------------------------------------------------------------------------------------
OPTIONAL CONTROL
----------------------------------------------------------------------------------------------------
Parallel Telemetry Interface           NTCA45AA                 703                  2W/5W
----------------------------------------------------------------------------------------------------
AMPLIFIER/FILTER OPTIONS
----------------------------------------------------------------------------------------------------
MOR+ Red Pre/ Blue Post with OSC       NTCA11PK                4499                 35W/50W
----------------------------------------------------------------------------------------------------
MOR+ Blue Pre/Red Post with OSC        NTCA11NK                4499                 35W/50W
----------------------------------------------------------------------------------------------------
OSC                                    NTCA11CA                1024                 25W/40W
----------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

--------------------------------------------------------------------------------

            SYSTEM FEATURE DESCRIPTION OPTICAL ADD/DROP MULTIPLEXER

          ----------------------------------------------------------------------

ID                        ST-rfx-0005
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

          ----------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description Optical Add Drop Mux- 10

          ----------------------------------------------------------------------

DESCRIPTION

          ----------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

          ----------------------------------------------------------------------

--------------------------------------------------------------------------------

<PAGE>

1 ABBREVIATIONS

          ----------------------------------------------------------------------

INTRODUCTION   This section lists abbreviation used throughout the entire
               document.

          ----------------------------------------------------------------------
<TABLE>

               <S>            <C>
                AUI            Attachment Unit Interface
                BBE            Background Block Error
                EBER           Excessive Bit Error Rate

                EMS            Element Management System
                ES             Errored Second
                ES-IS          End System - Intermediate System routing
                IP             Internet Protocol
                IS-IS          Intermediate System routing
                ITU-T          International Telecommunications Union -
                               Telecommunications Sector
                LAPD           Link Access Protocol D-channel
                LCT            Local Craft Terminal
                LED            Light Emitting Diode
                LOF            Loss Of Frame
                LOS            Loss Of Signal
                MAU            Media Attachment Unit
                MDI            Miscellaneous Discrete Input
                MDO            Miscellaneous Discrete Output
                MIB            Management Information Base
                NE             Network Element
                NMS            Network Management System
                NSAP           Network Service Access Point
                OADM           Optical Add/Drop Multiplexer
                ODBC           Open DataBase Connectivity
                OLA            Optical Line Amplifier
                OSC            Optical Service Channel
                OSI            Open Systems Interconnection
                OSS            Operation Support System
                OTM            Optical Terminal Multiplexer
                PSTN           Public Switched Telephone Network
                RS             Regenerator Section
                SDH            Synchronous Digital Hierarchy
                SES            Severely Errored Second
                SNMP           Simple Network Management Protocol
                SQL            Structured Query Language
                TCP            Transmission Control Protocol
                UAS            Unavailable Second
                UDP            User Datagram Protocol
          ----------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>

2 REQUESTED FEATURES
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
1             TRANSMISSION FEATURES
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier provides a link/hop           NC
              planning tool allowing to simulate and
              design the DWDM network (Attenuation,
              Dispersion,..).
------------------------------------------------------------------------------------------------------------------------
         2.   The supplier provides a released           C - This can be
              document containing system planning and    made available
              engineering rules based on standard        if required
              single mode fibres.
------------------------------------------------------------------------------------------------------------------------
1.1           TRANSMISSION INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Connector Type E2000 APC                   FC & SC
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.1.1         INTERFACES ACCYING N X LAMBDAS
------------------------------------------------------------------------------------------------------------------------
         1.   Maximum output power of the interfaces     50W
------------------------------------------------------------------------------------------------------------------------
         2.   OADM link/hop limits (attenuation,         5 hops. total
              dispersion,..) as function of number       combined
              and lengths of hops between terminals.     distance of
                                                         380km with
                                                         maximum
                                                         overall Db
                                                         loss of 95Db
------------------------------------------------------------------------------------------------------------------------
         3.   Automatic output power adjustment          C
              depending on the number of
              received channels
------------------------------------------------------------------------------------------------------------------------
         4. N x lambda interface on tributary side       C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.1.2         TRANSPONDERS AND TRIBUTARY INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Optical interface I-16.1                   C
------------------------------------------------------------------------------------------------------------------------
         2.   Optical interface S-16.1                   C
------------------------------------------------------------------------------------------------------------------------
         3.   Optical interface L-16.1                   C
------------------------------------------------------------------------------------------------------------------------
         4.   Optical interface L-16.2                   C
------------------------------------------------------------------------------------------------------------------------
         5.   Bitrate independent interface              NC, however it
                                                         is possible to
                                                         multiplex any
                                                         bitrate signal
                                                         presented to
                                                         the optical
                                                         layer using
                                                         Nortel's ADM
                                                         equipment
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         6.   Optical Power Budget without transponders  1 span = 27 Db     IR              IR
                                                         2 spans = 25 Db
                                                         3 spans = 23 Db
                                                         4 spans = 21 Db
                                                         5 spans = 19 Db

------------------------------------------------------------------------------------------------------------------------
         7.   Active wavelength control (not only via    C
              chip temperature)
------------------------------------------------------------------------------------------------------------------------
         8.   Transmit transponders optional for         NC - Nortel's
              tributary channels                         SDH ADMs feed
              (option to use output signals from         their signal
              coloured transmitters without need to      directly into
              implement transponders)                    the OADM
                                                         without need
                                                         for
                                                         transponders
------------------------------------------------------------------------------------------------------------------------
         9.   Receive transponders optional for          NC - see above
              add/drop channels
              (option to apply DEMUX output signal to
              SDH-receiver)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.2           SYSTEM CONNECTIVITY
------------------------------------------------------------------------------------------------------------------------
         1.   IN CASE OF OPTICAL CHANNEL SPACING 100 GHZ:
------------------------------------------------------------------------------------------------------------------------
         2.   Max. number of optical channels            8 channels         IR              IR
              aggregate east to agg. west                supporting 16
                                                         wavelengths
------------------------------------------------------------------------------------------------------------------------
         3.   Min. number of optical channels            2 supporting 4     IR              IR
              aggregate west to agg. east                wavelengths
------------------------------------------------------------------------------------------------------------------------
         4.   Max. number of optical channels            2 channels         IR              IR
              added/dropped to/from direction east       (2(lambda)
                                                         added,
                                                         2(lambda)
                                                         dropped)
------------------------------------------------------------------------------------------------------------------------
         5.   Min. number of optical channels            1 channel          IR              IR
              added/dropped to/from direction east       (1(lambda)
                                                         added,
                                                         1(lambda)
                                                         dropped)
------------------------------------------------------------------------------------------------------------------------
         6.   Max. number of optical channels            2 channels         IR              IR
              added/dropped to/from direction west       (2(lambda)
                                                         added,
                                                         2(lambda)
                                                         dropped)
------------------------------------------------------------------------------------------------------------------------
         7.   Min. number of optical channels            1 channel          IR              IR
              added/dropped to/from direction west       (1(lambda)
                                                         added,
                                                         1(lambda)
                                                         dropped)
------------------------------------------------------------------------------------------------------------------------
         8.
------------------------------------------------------------------------------------------------------------------------
              IN CASE OF OPTICAL CHANNEL SPACING 50
              GHZ:
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         9.   Max. number of optical channels            Nortel's
              aggregate east to agg. west                Optical
                                                         equipment
                                                         follows the
                                                         ITU-T
                                                         recommended
                                                         200Ghz grid
                                                         with 100Ghz
                                                         spacing as
                                                         defined in G.692
------------------------------------------------------------------------------------------------------------------------
         10.  Min. number of optical channels            See response to
              aggregate west to agg. east                1.2.9 above
------------------------------------------------------------------------------------------------------------------------
         11.  Max. number of optical channels            See response to
              added/dropped to/from direction east       1.2.9 above
------------------------------------------------------------------------------------------------------------------------
         12.  Min. number of optical channels            See response to
              added/dropped to/from direction east       1.2.9 above
------------------------------------------------------------------------------------------------------------------------
         13.  Max. number of optical channels            See response to
              added/dropped to/from direction west       1.2.9 above
------------------------------------------------------------------------------------------------------------------------
         14.  Min. number of optical channels            See response to
              added/dropped to/from direction west       1.2.9 above
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.3           STM-64 COMPATIBILITY
------------------------------------------------------------------------------------------------------------------------
         1.   It is possible to upgrade aggregate -      Equipment will
              aggregate channels from STM-16 to STM-64   initially be
              without need to change hardware.           provisioned to
                                                         support STM-64
------------------------------------------------------------------------------------------------------------------------
         2.   It is possible to upgrade specific         Equipment will
              aggregate tributary channels from          initially be
              STM-16 to STM-64 is possible               provisioned to
              without affecting other channels.          support STM-64

------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.4           OTHER TRANSMISSION FEATURES
------------------------------------------------------------------------------------------------------------------------
         1.   Dispersion compensation for aggregate -    C
              aggregate channels
------------------------------------------------------------------------------------------------------------------------
         2.   Automatic gain control                     C
        ----------------------------------------------------------------------------------------------------------------
         3.   A aggregate - aggregate channel            See
              upgrade is not traffic affecting           response to
              to all channels already                    1.3.1 & 1.3.2
              in service
------------------------------------------------------------------------------------------------------------------------
         4.   A aggregate - tributary channel upgrade    See
              is not traffic affecting to all            response to
              channels already                           1.3.1 & 1.3.2
              in service
------------------------------------------------------------------------------------------------------------------------
         5.   Forward error correction                   C
------------------------------------------------------------------------------------------------------------------------

2             ENGINEERING ORDERWIRE
------------------------------------------------------------------------------------------------------------------------
2.1           INTERFACES
------------------------------------------------------------------------------------------------------------------------

         1.   2 wire i/f (towards PSTN)                  C
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
<TABLE>

------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         2.   2 wire  i/f (towards standard handset)     C
------------------------------------------------------------------------------------------------------------------------
2.2           FUNCTIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Selective Call                             C
------------------------------------------------------------------------------------------------------------------------
         2. Conference Call (up to four participants)    C
------------------------------------------------------------------------------------------------------------------------
3             MANAGEMENT COMMUNICATION
------------------------------------------------------------------------------------------------------------------------
3.1           COMMUNICATION INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   F- Interface   (RS 232)                    C
------------------------------------------------------------------------------------------------------------------------
         2.   Q- interface as gateway to the EMS         C
------------------------------------------------------------------------------------------------------------------------
         3.   Qecc Routing (2 level IS-IS)               C
------------------------------------------------------------------------------------------------------------------------
         4.   Q I/F (Ethernet)                           C
------------------------------------------------------------------------------------------------------------------------
         5.   Optical Supervisory Channel                C
------------------------------------------------------------------------------------------------------------------------
         6.   OSC                                        Integrated OSC     IR              IR
              -        wavelength                        at 1510nm or
              -        bitrate                           separate module
              -        optical span limit                operating at
              -        transmission protocol             1625nm
                                                         operating at
                                                         10Gbit/s with a
                                                         limit of 5 spans

------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
3.2           O & M INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   8 x Remote Control Inputs                  NC
------------------------------------------------------------------------------------------------------------------------
         2.   Remote Control Outputs                     C - However
                                                         Management
                                                         Performance may
                                                         be reduced
------------------------------------------------------------------------------------------------------------------------
         3.   Card LED support                           C
------------------------------------------------------------------------------------------------------------------------
         4.   Subrack LED support                        C
------------------------------------------------------------------------------------------------------------------------
         5.   Rack Alarm support                         C

------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
4             PERFORMANCE MANAGEMENT
------------------------------------------------------------------------------------------------------------------------

         1.   B1 Performance Monitoring on Transponder   Transponder
              Unit                                       Unit not used
                                                         in this solution
------------------------------------------------------------------------------------------------------------------------
         2.   15 min Performance History Data            C - extension
              Collection from each Regenerator           performance
              Section Monitoring Point (ES, SES and      monitoring is
              UAT).                                      available as
                                                         part of
                                                         Nortel's INM
                                                         network
                                                         management
                                                         platform
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         3.   24 h Performance History Data Collection   See response to
              from each Regenerator Section Monitoring   4.2 above
              Point (ES, SES and UAT).
------------------------------------------------------------------------------------------------------------------------
         4.   15 min Performance History Log for more    See response to
              than 100 intervals                         4.2 above
------------------------------------------------------------------------------------------------------------------------
         5.   24 h Performance History Log for more      See response to
              than 30 intervals                          4.2 above
------------------------------------------------------------------------------------------------------------------------
         6.   Performance Monitoring Threshold           See response to
              Crossing Notification                      4.2 above

------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
5             FAULT AND STATUS MANAGEMENT
------------------------------------------------------------------------------------------------------------------------
5.1.1         ALL OPTICAL INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Laser Restart for Test                     C
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of Laser Shutdown                C - alarms are
                                                         raised if for
                                                         whatever reason
                                                         a loss of
                                                         signal occurs.
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of disabled ALS on any optical   See response to
              interface                                  6.2.1.9
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of Optical Source Power High     C
              on any optical interface
------------------------------------------------------------------------------------------------------------------------
         5.   Detection of LOS, LOS status change        C - Loss of
              hysteresis                                 Signal is
                                                         reported
                                                         through the use
                                                         of alarms based
                                                         upon input and
                                                         output signal
                                                         thresholds.
------------------------------------------------------------------------------------------------------------------------
         6.   Insertion of AIS upon detection of LOS     C
------------------------------------------------------------------------------------------------------------------------
         7.   Detection of number of received channels   C
------------------------------------------------------------------------------------------------------------------------
         8.   Monitoring of laser current for pump       C
              laser 1
------------------------------------------------------------------------------------------------------------------------
         9.   Monitoring of laser current for pump       C
              laser 2
------------------------------------------------------------------------------------------------------------------------
         10.  Monitoring of temperature for pump         C
              laser 1
------------------------------------------------------------------------------------------------------------------------
         11.  Monitoring of temperature for pump         C
              laser 2
------------------------------------------------------------------------------------------------------------------------
         12.  Monitoring of laser temperature            C
------------------------------------------------------------------------------------------------------------------------
         13.  Monitoring of transmitted wavelength       C
------------------------------------------------------------------------------------------------------------------------
         14.  Monitoring of received input power         C
------------------------------------------------------------------------------------------------------------------------
         15. Monitoring of transmitted output power      C
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         16.  Detection of coupler temperature high      C
------------------------------------------------------------------------------------------------------------------------
         17.  Detection of grating temperature high      C
------------------------------------------------------------------------------------------------------------------------
5.1.2         ALL REGENERATOR SECTION MONITORING POINTS
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of OOF                           NC - At an OADM
                                                         site, regen
                                                         section is
                                                         monitored by
                                                         the SDH ADM
                                                         equipment
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of LOF                           See response to
                                                         5.1.2.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of RS EBER (10E-3) based on      See response to
              B1 BIP-8 parity calculation on demux unit  5.1.2.1 above
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of RS EBER (10E-3) based on      See response to
              B1 BIP-8 parity calculation on             5.1.2.1 above
              transponder unit
------------------------------------------------------------------------------------------------------------------------
         5.   Detection of Section Trace Mismatch        See response to
              based on J0 Byte monitoring on demux unit  5.1.2.1 above
------------------------------------------------------------------------------------------------------------------------
         6.   Detection of Section Trace Mismatch        Transponder Unit
              based on J0 Byte monitoring on             not used in this
              transponder unit                           solution
------------------------------------------------------------------------------------------------------------------------
5.1.3         MANAGEMENT COMMUNICATION FUNCTION
------------------------------------------------------------------------------------------------------------------------
              Detection of Remote Control Input Active   C
------------------------------------------------------------------------------------------------------------------------
              Detection of OSC Comms Fail (LAPD Alarm)   C
------------------------------------------------------------------------------------------------------------------------
5.1.4         SYSTEMS MANAGEMENT FUNCTION
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of Secondary Power Fail          See response to
                                                         8.3.2
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of Primary Power Low            See response to
                                                        8.3.2
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of Primary Power Fail per       See response to
              each single power feed                    8.3.2
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of Re-Boot Fail                  C
------------------------------------------------------------------------------------------------------------------------
         5.   Detection of Configuration Data            C
              Integrity Check Failure
------------------------------------------------------------------------------------------------------------------------
         6.   Detection of System Software Integrity     C
              Check Failure
------------------------------------------------------------------------------------------------------------------------
         7.   Detection of Network Element Controller    C
              Failure
------------------------------------------------------------------------------------------------------------------------
         8.   Detection of Card Protection Switch        C
              Failure
------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         9.   Detection of Card Out                      C
------------------------------------------------------------------------------------------------------------------------
         10.  Detection of Card Fail (upon detection     C
              of internal parity mismatch etc.)
------------------------------------------------------------------------------------------------------------------------
         11.  Detection of Wrong Card                    C
------------------------------------------------------------------------------------------------------------------------
         12.  Network Protection Switch Failure
------------------------------------------------------------------------------------------------------------------------
         13.  Optical Layer Protection Switch Active     See response to
                                                         7.1.1
------------------------------------------------------------------------------------------------------------------------
         14.  Card Protection Switch Active              C
------------------------------------------------------------------------------------------------------------------------
         15.  Fault / Status Log Capacity Exceeded       C
------------------------------------------------------------------------------------------------------------------------
         16.  Configuration Data Transaction Log         C
              Capacity Exceeded
------------------------------------------------------------------------------------------------------------------------
         17.  Performance Monitoring Log Capacity        C
              Exceeded
------------------------------------------------------------------------------------------------------------------------
         18.  Access Log Capacity Exceeded               C
------------------------------------------------------------------------------------------------------------------------
         19.  Software Download in Progress              C
------------------------------------------------------------------------------------------------------------------------
         20.  Software Download Failure                  C
------------------------------------------------------------------------------------------------------------------------
         21.  Software Download Failure - Retry in       C
              Progress
------------------------------------------------------------------------------------------------------------------------
         22.  Software Download Complete                 C
------------------------------------------------------------------------------------------------------------------------
         23.  Card Restoration Complete                  C
------------------------------------------------------------------------------------------------------------------------
         24.  Re-Boot Restoration Complete               C
------------------------------------------------------------------------------------------------------------------------
         25.  Electronic Label Update                    C
------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
5.2           ALARM EVENT HANDLING
------------------------------------------------------------------------------------------------------------------------
         1.   Alarm Persistence Filter (filtering of     C - It is
              toggling alarms)                           possible to
                                                         filter alarms
                                                         using the
                                                         functionality
                                                         of INM,
                                                         Nortel's
                                                         Network
                                                         Management
                                                         System
------------------------------------------------------------------------------------------------------------------------
         2.   Alarm Correlation Filter (F3 filter,       C
              suppression of consequent alarms)
------------------------------------------------------------------------------------------------------------------------
         3.   Alarm Inversion Facility                   C - It is possible
                                                         to invert alarms
------------------------------------------------------------------------------------------------------------------------
         4.   Performance of the alarm throughput        C
              >10 alarms per second
------------------------------------------------------------------------------------------------------------------------
         5.   Indication of Alarm Event Forwarding       NC
              Suppression per functional unit
              (e.g. Regenerator Section ...)
------------------------------------------------------------------------------------------------------------------------
6             CONFIGURATION MANAGEMENT
------------------------------------------------------------------------------------------------------------------------
6.1           GENERAL
------------------------------------------------------------------------------------------------------------------------
         1.   Upload of Configuration Data - on single   C
              command
------------------------------------------------------------------------------------------------------------------------
         2.   Upload of Configuration Data - on bulk     C
              command
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         3. Download of Configuration Data - on bulk     C
            command
------------------------------------------------------------------------------------------------------------------------
6.2           CONFIGURATION OF FUNCTIONAL BLOCKS
------------------------------------------------------------------------------------------------------------------------
6.2.1         ALL OPTICAL INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Set of transmitted output power            C
------------------------------------------------------------------------------------------------------------------------
         2.   Set of input power warning thresholds      C
------------------------------------------------------------------------------------------------------------------------
         3.   Set input power switch off thresholds      C
------------------------------------------------------------------------------------------------------------------------
         4.   Set output power warning thresholds        C
------------------------------------------------------------------------------------------------------------------------
         5.   Set output power switch off thresholds     C
------------------------------------------------------------------------------------------------------------------------
         6.   Set laser current alarm thresholds         C
------------------------------------------------------------------------------------------------------------------------
         7.   Set of laser temperature alarm thresholds  C
------------------------------------------------------------------------------------------------------------------------
         8.   Set of transmitted wavelength alarm        C
              thresholds
------------------------------------------------------------------------------------------------------------------------
         9.   Enable / Disable Automatic Laser           NC -
              Shutdown according to                      The OPTera
              ITU-T G.958                                LH OADM is a
                                                         Class 3A system.
                                                         Whilst
                                                         not advised,
                                                         a Class 3A
                                                         system is deemed
                                                         to be safe for
                                                         long term viewing
                                                         without optical
                                                         aids and with the
                                                         supplied warning
                                                         labels and
                                                         procedural
                                                         precautions, ALS
                                                         is not necessary
                                                         for this equipment
------------------------------------------------------------------------------------------------------------------------
         10.  Enable / Disable Laser                     C - it is
                                                         possible to
                                                         enable/disable
                                                         the laser both
                                                         manually and
                                                         remotely
------------------------------------------------------------------------------------------------------------------------
         11. Enable Laser for Test Purposes               NC
             (2s / 90s)
------------------------------------------------------------------------------------------------------------------------
6.2.2         ALL REGENERATOR SECTION MONITORING POINTS
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>

------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         1.   Set Threshold B1-EBER                      NC -At an OADM
                                                         site, regen
                                                         section is
                                                         monitored by
                                                         the SDH ADM
                                                         equipment

------------------------------------------------------------------------------------------------------------------------
7             NETWORK PROTECTION
------------------------------------------------------------------------------------------------------------------------
7.1           OPTICAL MULTIPLEX
              SECTION PROTECTION (OMSP)
------------------------------------------------------------------------------------------------------------------------
         1.   OMSP function                              NC - Nortel        However,
                                                         believes that      Nortel also
                                                         in today's         believes that
                                                         networks where     optical
                                                         SDH                protection
                                                         multiplexers       switching
                                                         are already        offers
                                                         required for       benefits for
                                                         traffic            demands
                                                         aggregation and    carried on
                                                         bandwidth          individual
                                                         management it      optical
                                                         is more cost       channels,
                                                         effective to       Optical
                                                         put the            protection
                                                         protection         switching of
                                                         switching in       this type is
                                                         the SDH layer      only viable if
                                                                            deployed with
                                                                            appropriate
                                                                            solutions for
                                                                            the monitoring
                                                                            and management
                                                                            of the optical
                                                                            domain
------------------------------------------------------------------------------------------------------------------------
         2.   Switch-Over Completion Time LESS THAN      See response to
              50ms                                       7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Enable / Disable Automatic Switching       See response to
                                                         7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         4.   Manual Switching via                       See response to
              Management Interface                       7.1.1 above

------------------------------------------------------------------------------------------------------------------------
         5.   Configurable Wait Time to Restore          See response to
                                                         7.1.1 above
------------------------------------------------------------------------------------------------------------------------
7.2           WAVELENGTH SELECTIVE PROTECTION SWITCHING
------------------------------------------------------------------------------------------------------------------------
         1.   Wavelength selective Subnetwork            See response to
              Connection Protection                      7.1.1 above
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>

------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         2.   Switch-Over Completion Time LESS THAN      See response to
              50ms                                       7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Enable / Disable Automatic Switching       See response to
                                                         7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         4.   Manual Switching via Management            See response to
              Interface                                   7.1.1 above
------------------------------------------------------------------------------------------------------------------------
         5.   Configurable Wait Time to Restore          See response to
                                                         7.1.1 above
------------------------------------------------------------------------------------------------------------------------
8             OPERATION AND MAINTENANCE
------------------------------------------------------------------------------------------------------------------------
8.1           GENERAL
------------------------------------------------------------------------------------------------------------------------
         1.   Event buffer                               C
------------------------------------------------------------------------------------------------------------------------
         2.   Heart Beat Function for all processes      NC
------------------------------------------------------------------------------------------------------------------------
         4.   Real time clock function                   C
------------------------------------------------------------------------------------------------------------------------
         5.   Automatic synchronization of NE real       C
              time clock on EMS real time clock
------------------------------------------------------------------------------------------------------------------------
         6.   It is possible to set the NE time and      C
              date via EMS/LCT
------------------------------------------------------------------------------------------------------------------------
         7.   NSAP Address modification                  C
------------------------------------------------------------------------------------------------------------------------
         8.   Local Software Download                    C
------------------------------------------------------------------------------------------------------------------------
         9.   Remote Software Download                   C
------------------------------------------------------------------------------------------------------------------------
         10. Upload of configuration data to EMS/LCT     C
------------------------------------------------------------------------------------------------------------------------
         11.  Download of configuration data from        C
              EMS/LCT
------------------------------------------------------------------------------------------------------------------------
         12. Manager Decision Process for equipment      C
             access control
------------------------------------------------------------------------------------------------------------------------
         13.  Display of Optical Transmit Power Level    C
------------------------------------------------------------------------------------------------------------------------
8.2           LOGS
------------------------------------------------------------------------------------------------------------------------
         1.   Alarm / Status Log                         C
------------------------------------------------------------------------------------------------------------------------
         2.   Performance Log (storage capacity at       C
              least 8 x 15 min intervals and 30 x 24 h
              interval for each monitoring point)
------------------------------------------------------------------------------------------------------------------------
         3.   Configuration Log (storage capacity at     C
              least 24 h)
------------------------------------------------------------------------------------------------------------------------
         4.   Access Control Log (storage capacity at    C
              least 10 days)
------------------------------------------------------------------------------------------------------------------------
8.3           REDUNDANCY
------------------------------------------------------------------------------------------------------------------------
         1.   Dual Power Feed                            C - standard 2
                                                         power feeds,
                                                         optional 6
                                                         power feeds
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         2.   1+1 Protection of Power Supply             The OPTera OADM
                                                         system is
                                                         powered by
                                                         redundant
                                                         feeds. Failure
                                                         of one of the
                                                         power feeds due
                                                         to an open or
                                                         short circuit
                                                         does not affect
                                                         the system. Two
                                                         breaker/filter
                                                         modules provide
                                                         power for the
                                                         OPtera OADM
                                                         shelves.
------------------------------------------------------------------------------------------------------------------------
         3.   Redundancy of pump lasers                  C
------------------------------------------------------------------------------------------------------------------------
8.4           EQUIPMENT TESTING FUNCTIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Integrity Check of Configuration Data      C - managed via
                                                         the
                                                         functionality
                                                         of the NE OPC
------------------------------------------------------------------------------------------------------------------------
         2.   Integrity Check of System Software         See response to
                                                         8.4.1
------------------------------------------------------------------------------------------------------------------------
         3.   Configuration of Loop Back on all          NC
              optical Interface Cards
------------------------------------------------------------------------------------------------------------------------
         4.   Optical monitoring port on each transmit   Transponder
              transponder (output signal)                Unit not used
                                                         in this solution
------------------------------------------------------------------------------------------------------------------------
         5.   Optical monitoring port on each receive    Transponder
              transponder (input signal)                 Unit not used
                                                         in this solution
------------------------------------------------------------------------------------------------------------------------
         6.   Optical monitoring port on each            C - managed via
              pre-amplifier (input signal)               the
                                                         functionality
                                                         of the NE OPC
------------------------------------------------------------------------------------------------------------------------
         7.   Optical monitoring port on each            C - managed via
              booster-amplifier (output signal)          the
                                                         functionality
                                                         of the NE OPC
------------------------------------------------------------------------------------------------------------------------
8.5           INVENTORY DATA
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         1.   Electronic Label Read Access via           Nortel's INM
              Management Interfaces                      Network
                                                         Management system
                                                         offers the option
                                                         of centralised
                                                         inventory
                                                         management, which
                                                         is accessed via
                                                         the GNB and
                                                         allows the user to
                                                         retrieve an
                                                         inventory of
                                                         the remotely
                                                         located
                                                         NEs. The retrieved
                                                         information can be
                                                         displayed and saved
                                                         to a file suitable
                                                         for further
                                                         processing
------------------------------------------------------------------------------------------------------------------------
         2.   Automatic Electronic Label Upgrade         See response to
                                                         8.5.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Compatibility Check of Equipment           See response to
              Hardware Releases                          8.5.1 above
------------------------------------------------------------------------------------------------------------------------
         4.   Compatibility Check of Equipment           See response to
              Firmware Releases                          8.5.1 above
------------------------------------------------------------------------------------------------------------------------
         5.   Compatibility Check of Equipment           Management by
              Software Releases                          release
                                                         automatically
                                                         defines a
                                                         set of compatible
                                                         software loads
                                                         (called the
                                                         software lineup)
                                                         for all
                                                         downloadable CPs
                                                         in a span of
                                                         control and
                                                         enforces strict
                                                         software
                                                         configuration
                                                         management
                                                         among these loads.
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         6.   Compatibility Check of Equipment           See response to
              Software Releases to the Management        8.5.5 above
              System
------------------------------------------------------------------------------------------------------------------------
         7.   Electronic Label contents:                 See response to
              - Unit hardware release / version          8.5.1 above
              - Unit hardware serial number
              - Unit firmware release / version
              - Unit software release / version
              - Unit installation date of unit/NE
              - Production date of unit/NE
------------------------------------------------------------------------------------------------------------------------
9             ENVIRONMENTAL CONDITIONS,
              ENVIRONMENTAL COMPATIBILITY
              AND SAFETY
------------------------------------------------------------------------------------------------------------------------
9.1           CLIMATIC CONDITIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Compliance with Stationary Use             C
              Conditions acc. to prETS 300 019-2-3
              Class T 3.2
------------------------------------------------------------------------------------------------------------------------
         2.   No need for air conditioning via           C
              elevated ground floor
------------------------------------------------------------------------------------------------------------------------
9.2           ELECTROMAGNETIC COMPATIBILITY
------------------------------------------------------------------------------------------------------------------------
         1.   Compliance with EN 55022                   C
------------------------------------------------------------------------------------------------------------------------
         2.   Compliance with EN 50082                   C
------------------------------------------------------------------------------------------------------------------------
9.3           SAFETY
------------------------------------------------------------------------------------------------------------------------
         1.   CE certification available                 C
------------------------------------------------------------------------------------------------------------------------
         2.   Electrical safety according to             C
              EN 41003
------------------------------------------------------------------------------------------------------------------------
         3.   General requirements according to          C
              EN 60950 A1, A2
------------------------------------------------------------------------------------------------------------------------
         4.   Fire and heat safety according to ETS      C
              300 019-2
------------------------------------------------------------------------------------------------------------------------
10            PHYSICAL CONSTRUCTION
------------------------------------------------------------------------------------------------------------------------
         1.   Rack size according to ETSI 300 119, 600   C
              mm x 300 mm
------------------------------------------------------------------------------------------------------------------------
         2.   Rack size according to ETSI 300 119, 600   N/A
              mm x 600 mm
------------------------------------------------------------------------------------------------------------------------
         3.   System installation and h/w upgrade via    C
              front access possible
------------------------------------------------------------------------------------------------------------------------
         4.   Number of required Racks in minimum        1                  1               1
              configuration
------------------------------------------------------------------------------------------------------------------------
         5.   Number of required Racks in maximum        1                  IR              IR
              configuration
------------------------------------------------------------------------------------------------------------------------
11            POWER SUPPLY
------------------------------------------------------------------------------------------------------------------------
         1.   Nominal input voltage -48V                 C
------------------------------------------------------------------------------------------------------------------------
         2.   Minimum accepted input voltage             -38V
------------------------------------------------------------------------------------------------------------------------
         3.   Maximum accepted input voltage             -75V
------------------------------------------------------------------------------------------------------------------------
12            AVAILABILITY
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier shall provide MTBF figures    C - see Annex 1
              for each functional unit of the offered
              equipment based on his statistical
              evaluations according to the template as
              attached in Annex 1
------------------------------------------------------------------------------------------------------------------------
13            POWER CONSUMPTION
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier shall provide worst case      C - see Annex 1
              power consumption figures for each
              functional unit of the offered equipment
              according to the template as attached in
              Annex 1
------------------------------------------------------------------------------------------------------------------------
14            SYSTEM MANUALS
------------------------------------------------------------------------------------------------------------------------
         1.   System Description in Hypertext Format     C -
              on CD                                      documentation
                                                         is available in
                                                         Adobe Acrobat
                                                         format
------------------------------------------------------------------------------------------------------------------------
         2.   System O&M Manuals in  Hypertext           C-
              Format on CD                               documentation
                                                         is available in
                                                         Adobe Acrobat
                                                         format
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

--------------------------------------------------------------------------------
<TABLE>
------------------------------------------------------------------------------------------------------------------------
<S>                                                      <C>                <C>             <C>           <C>
Para                                                     AVAILABLE NOW      AVAILABLE       AVAILABLE     Comment
                                                                             12/1999         12/2000
------------------------------------------------------------------------------------------------------------------------
UNIT NAME/TYPE                         UNIT ID           UNIT FIT FIGURE    MAXIMUM POWER
                                                                            CONSUMPTION
----------------------------------------------------------------------------------------------------
MANDATORY CONTROL
----------------------------------------------------------------------------------------------------
Shelf Controller                       NTCA41BA                1125           13W/20W
----------------------------------------------------------------------------------------------------
Half Height Breaker                    NTCA40CA                 256           5W/8W
----------------------------------------------------------------------------------------------------
Maintenance Interface                  NTCA42AA                1139           7.5W/10W
----------------------------------------------------------------------------------------------------
Message Transfer                       NTCA48AA                 677           8W/10W
----------------------------------------------------------------------------------------------------
OPTIONAL CONTROL
----------------------------------------------------------------------------------------------------
Parallel Telemetry Interface           NTCA45AA                 703           2W/5W
----------------------------------------------------------------------------------------------------
AMPLIFIER/FILTER OPTIONS
----------------------------------------------------------------------------------------------------
MOR+ Red Pre/ Blue Post with OSC       NTCA11PK                4499           35W/50W
----------------------------------------------------------------------------------------------------
MOR+ Blue Pre/Red Post with OSC        NTCA11NK                4499           35W/50W
----------------------------------------------------------------------------------------------------
OSC                                    NTCA11CA                1024           25W/40W
----------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

PARA. 1.1

1.1      INTER-SHELF INTERCONNECTIONS

The various I/O of the OMX module, shown in Figure 1 is connectorized to provide
the interconnection flexibility required to support the various configurations
of OPTera. The OTS In and OTS Out interfaces generally interface the outside
plant fiber, although in some configurations they connect to other co-located
OPTera shelves. The Thru Out and Thru In interfaces carry all of the wavelength
bands except for the band being added/dropped by the module. These interfaces
can be accessed via a connector or a pigtail. The Channel 1-4 Drop and Add
pigtails carry the Drop and Add channels and are connected to the OCLD cards.

All connectors are SC/PC. The pigtail connectors to the OCLDs are FC/PC.

FIGURE 1. OMX I/O

When configured for a hubbed ring remote, the OPTera shelf is provisioned with
two OMX modules as shown in Figure 2. The wavelengths that are not added/dropped
by the node must be passed through optically. This is accomplished by connecting
the Thru Out pigtail from each OMX to the Thru In connector of the other OMX.
The pigtail is used in this case to avoid an additional connector loss.

FIGURE 2. HUBBED RING REMOTE CONFIGURATION

                                    Page 1 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

The hubbed ring hub and the point-to-point terminal are configured the same way.
These nodes typically consist of multiple nodes, each accessing a different
wavelength band. Figure 3 shows the intershelf interconnections. The incoming
facility fiber is connected to the OTS In port of the OMX on the first shelf,
which drops its band of wavelengths. The Thru Out is connected, via a patchcord,
to the OTS In of the OMX on the next shelf, which drops its band of wavelengths.
This continues until the last shelf has dropped its band of wavelengths. This
interconnection is identical on both the West and East sides of the shelves.

The OTS Out of the OMX on the first shelf, which contains the band of
wavelengths added by that shelf, is connected, via a patchcord, to Thru In port
of the OMX on the next shelf. This daisychain continues until the last shelf has
added its band of wavelengths. The OTS Out of the last shelf connects to the
outgoing fiber facility. This interconnection is identical on both the West and
East sides of the shelves.

This style of interconnection minimizes the add/drop insertion loss of the
point-to-point terminal and the hubbed ring hub. The main alternative is to
connect the East OTS In/Out to the West OTS Out/In of the next shelf; however,
the 8th shelf would experience the insertion loss of 7 additional OMX modules in
this case.

This style of interconnection does not have an optical passthrough path. This is
not required in the point-to-point terminal or the hubbed ring hub.

FIGURE 3. POINT-TO-POINT TERMINAL OR HUBBED RING HUB

                                    Page 2 of 14
<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

To configure a point-to-point system, the OTS Out of the last shelf (`last'
referring to the daisy-chained interconnection described above) is connected to
the OTS In of the first shelf. This interconnection is identical for the A and B
sides.

FIGURE 4. POINT-TO-POINT SYSTEM INTERCONNECTION

To configure a hubbed ring system, the West OTS Out of the last shelf in the hub
(`last' referring to the daisy-chained interconnection described above) is
connected to the West OTS In of the first remote. The West OTS Out of the first
remote is connected to the West OTS In of the first shelf in the hub. The East
OTS Out of a remote is connected to the West OTS In of the next remote and the
West OTS Out of that remote is connected to the East OTS In of the previous
remote.

In summary, the West side of the hub is connected to the West side of the first
remote and the East side of the hub is connected to the East side of the last
remote. The remotes are daisy-chained East side to West side.

FIGURE 5. HUBBED RING SYSTEM INTERCONNECTION

                                    Page 3 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

PARA. 1.1.1

1.2      WAVELENGTH PLAN

OPTera wavelengths are organized into bands as shown in Figure 6 to facilitate
cost-effective add/drop/passthrough. Each band encompasses 4 wavelengths based
on a 200GHz spacing with central frequencies selected from the ITU 100GHz grid.
The center wavelength tolerance for OPTera lasers is +/- 0.25nm. This covers all
operating conditions, including the full ambient temperature range, laser aging,
and laser line broadening.

FIGURE 6. OPTERA WAVELENGTH ORGANIZATION

[GRAPHIC OMITTED]

TABLE 1. CHANNEL CENTRAL WAVELENGTHS

<TABLE>
<CAPTION>
----------------------- --------------------- -------------------- --------------------- --------------------
WAVELENGTH BAND         CHANNEL 1             CHANNEL 2            CHANNEL 3             CHANNEL 4
----------------------- --------------------- -------------------- --------------------- --------------------
<S>                     <C>                   <C>                  <C>                   <C>
1                       1528.77               1530.33              1531.90               1533.47
----------------------- --------------------- -------------------- --------------------- --------------------
2                       1538.19               1539.77              1541.35               1542.94
----------------------- --------------------- -------------------- --------------------- --------------------
3                       1547.72               1549.32              1550.92               1552.52
----------------------- --------------------- -------------------- --------------------- --------------------
4                       1557.36               1558.98              1560.61               1562.23
----------------------- --------------------- -------------------- --------------------- --------------------
5                       1567.13               1568.77              1570.42               1572.06
----------------------- --------------------- -------------------- --------------------- --------------------
6                       1577.03               1578.69              1580.35               1582.02
----------------------- --------------------- -------------------- --------------------- --------------------
7                       1587.04               1588.73              1590.41               1592.10
----------------------- --------------------- -------------------- --------------------- --------------------
8                       1597.19               1598.89              1600.60               1602.31
----------------------- --------------------- -------------------- --------------------- --------------------
</TABLE>

1.3      CLIENT INTERFACES

The first release of OPTera includes 2 OCI circuit card types. The first is
optimized for 1310nm client signals up to 622Mb/s and meets the optical
parameter specifications for OC-3 and OC-12 short and intermediate reach
applications. The second is optimized for 1310nm client signals up to 1.25Gb/s
and meets the optical parameter specifications for Gigabit Ethernet, however
this card can also interface SONET OC-3 and OC-12 signals.

                                    Page 4 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

TABLE 2. OPTICAL CHANNEL INTERFACE TYPES

<TABLE>
<CAPTION>
------------- ------------ --------------- ---------------- ---------------- ------------------
OCI           MAX BIT      FIBER TYPE      CONNECTOR        PROTOCOL         NOMINAL
              RATE                                                           WAVELENGTH
------------- ------------ --------------- ---------------- ---------------- ------------------
<S>           <C>          <C>             <C>              <C>              <C>
622M          622Mb/s      SMF             SC               Transparent      1310nm
------------- ------------ --------------- ---------------- ---------------- ------------------
1.25G         1.25Gb/s     SMF & MMF       SC               Transparent      1310nm
------------- ------------ --------------- ---------------- ---------------- ------------------

</TABLE>

OPTera is optimized for carrying OC-3 and OC-12 trunks between switching devices
and between end-users in metropolitan environments. OC-48 rates will be
supported in the future. There are currently no plans to support OC-192 rates,
however, such a rate is not precluded by the architecture.

The OPTera system will be transparent to subtending SONET equipment. All SONET
section, line and path layer overhead is passed through without modification.
SONET DCC channels, orderwire, APS signaling, pointers, etc., will all pass
through transparently such that the subtending SONET equipment will function as
if it is directly connected, including protection switching and synchronization
functions.

The following OCI cards are available in the first release of OPTera. Async FOTS
interfaces that are compatible with these specifications can be handled. Other
specifications can be considered based on the needs of the network provider.

TABLE 3. OPTICAL CHANNEL INTERFACE SPECIFICATIONS

<TABLE>
<CAPTION>
------------- ------------ --------------- -------------- -------------- -------------- ---------------------
OCI           MAX BIT      TX PWR MAX      TX PWR MIN     RX SENS (MIN)  RX OVERLOAD    WAVELENGTH
              RATE
------------- ------------ --------------- -------------- -------------- -------------- ---------------------
<S>           <C>          <C>             <C>            <C>            <C>            <C>
622M          622Mb/s      -15dBm          -8dBm          -28dBm         -7dBm          1274nm-1356nm
------------- ------------ --------------- -------------- -------------- -------------- ---------------------
1.25G         1.25Gb/s     -13dBm          -3dBm          -20dBm         -3dBm          1270nm-1335nm
------------- ------------ --------------- -------------- -------------- -------------- ---------------------
</TABLE>

TABLE 4. EXAMPLE CLIENT SIGNALS

<TABLE>
<CAPTION>
------------------------------------------- -------- -------------------------- -----------------------------
CUSTOMER EQUIPMENT INTERFACE TYPE           FIBER    OCI 622M DISTANCE          OCI 1.25G DISTANCE (ASSUMES
                                            TYPE     (ASSUMES .5DB/KM)          .5DB/KM)
------------------------------------------- -------- -------------------------- -----------------------------
<S>                                         <C>      <C>                        <C>
OC-3/12 SR (155-622Mb/s)                    SMF      15km                       8km
------------------------------------------- -------- -------------------------- -----------------------------
OC-3/12 IR (155-622Mb/s)                    SMF      25km                       10km
------------------------------------------- -------- -------------------------- -----------------------------
ATM OC-3/12 (155-622Mb/s)                   MMF      N/a                        230m (dispersion limited)
------------------------------------------- -------- -------------------------- -----------------------------
Fast Ethernet (100Mb/s)                     SMF      15-30km                    Up to 22km
------------------------------------------- -------- -------------------------- -----------------------------
Gigabit Ethernet (1.25Gb/s)                 SMF      N/a                        3km (dispersion limited)
------------------------------------------ -------- -------------------------- -----------------------------
Fiber Channel  (up to 531Mb/s)              SMF      10-20km                    12-22km
------------------------------------------- -------- -------------------------- -----------------------------
Fiber Channel (1.06Gb/s)                    SMF      N/a                        3km (dispersion limited)
------------------------------------------- -------- -------------------------- -----------------------------
ESCON/SBCON (200Mb/s)                       SMF      25km                       24km
------------------------------------------- -------- -------------------------- -----------------------------
FDDI (100Mb/s)                              SMF      15-30km                    Up to 22km
------------------------------------------- -------- -------------------------- -----------------------------
Other                                       MMF      N/a                        230m (dispersion limited)
------------------------------------------- -------- -------------------------- -----------------------------
</TABLE>

                                    Page 5 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

PARA. 1.1.3 (3)

1.3.1    PERFORMANCE MANAGEMENT

OPTera performance management includes the monitoring of Optical Power Received
(OPR), Optical Power Transmitted (OPT), and Signal-to-Noise Ratio (SNR) on a per
wavelength basis. This information is used to derive threshold crossing alerts
that can be used to trigger pre-emptive maintenance action and recorded for
subsequent trend analysis. Reports of these events are available at the network
element through the SMI/EMS. Active TCAs are reported in the Alarm Browser of
the System Manager Interface. TCAs events are timestamped and recorded in the
Event Log of the System Manager Interface.

There are two thresholds defined for each parameter. The first threshold is a
Degrade Threshold, indicating that the parameter being monitored is degraded and
potentially experiencing bit errors. This TCA is reported, however, it does not
trigger protection switching. The second threshold is a Fail Threshold,
indicating that the parameter being monitored is severely degraded and traffic
is being impacted. This TCA is reported and triggers protection switching, if
available.

The TCA thresholds are not currently user settable. The thresholds are
calibrated to client signal BERs, and different thresholds are required for
different client signal bit-rates. Since OPTera offers the flexibility to carry
any bit-rate, Cambrian Systems believes that it would be unwieldy for the user
to have to set the thresholds for each bit-rate. However, a method of supporting
user adjustment of these thresholds is planned.

It is also planned to support end-to-end optical channel performance monitoring
using protocol-specific integrity mechanisms. For example, OPTera will monitor
on an end-to-end basis, the SONET Section Layer BIP-8 and provide performance
parameters and binning as requested. This includes Code Violations, Errored
Seconds, Severely Errored Seconds and Severely Errored Frame Seconds. Although
far-end parameters are not available at the SONET section layer, OPTera will
monitor these parameters on both incoming and outgoing clients signals in both
directions and report these via the OPTera EMS.

                                    Page 6 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

PARA 1.1-4

STM-16 TX/RX OPTICAL INTERFACE SPECIFICATIONS

                                  GENERAL

                                           1310 nm            1557 nm
Circuit pack PEC
  FC connection                           NTCA20LA            NTCE30KA
  ST connector                            NTCA30LB            NTCA20KB
  SC connector                            NTCA30LC            NTCA30KC
Line rate                                 2488.32 Mbit's      2488.32 Mbit's
Line code                                 NRZ                 NRZ
ITU-T G.957 application code              S-16.1              L-16.2
Altonuination range (see Note 4)          ? dB to ? dB        ? dB to ? dB

                                 RECEIVER
GENERAL
  Detector                                Avalanche photo-detector (APD)
  Pigtail                                 Single-mode

                                           1310 nm             1557 nm
SPECTRAL CHARACTERISTICS
  Wavelength of operation                  1310 nm             1557 nm
OPTICAL SIGNAL
  Guaranteed receiver sensitivity          -25.6 dBm           -25.6 dBm
  Receiver overload level (see Note 1)     -15.0 dBm           -15.0 dBm
  Receiver damage level (see Note 2)       0 dBm               0 dBm

                                 TRANSMITTER
GENERAL
  Transmitter                              DFB semi-conductor laser
  Pigtail                                  Single-mode

                                           1310 nm             1557 nm
SPECTRAL CHARACTERISTICS
  Central wavelength                       1310 nm             1310 nm
  Central wavelength range                 1310 nm             1557 nm
                                           (plus or minus)     (plus or minus)
                                           10 nm               3.5 nm
  Spectral width                           0.65 nm             0.65 nm
  Single-mode suppression ratio (SSR)      33.0 dB             33.0 dB
OPTICAL SIGNAL
  Maximum tolerated optical reflection     20.0 dB             20.0 dB
  Guaranteed maximum launch power
    (see Note 3)                           ? dBm               ? dBm
  Guaranteed maximum launch power
    (see Note 3)                           -0.5 dBm            -0.5 dBm

NOTE 1: The overload level level is the maximum optical power for which a bit-
error rate 10(-10) and all filter tolerance specifications are met.

NOTE 2: Damage level is the maximum optical power for which no damage to
components is occurred.

NOTE 3: These are worst-case parameters and included connector losses, aging,
equipment impairment due to implementation and temperature degradation. This
represents the power level measured at the station fibre on the link side of
connectors.

NOTE 4: Including aging, temperature-connector losses and optical path
penalties. Excludes customer link margin as that depends upon the customer's
maintenance budgets (number of splices expected during service life).

NOTE 5: SC connections are recommended for TN-64X applications.

                                    Page 7 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

PARA. 1.2(4)-1.2.(7)

2        NETWORK CONFIGURATIONS

2.1      HUBBED RING

The Hubbed Ring configuration is optimized for hubbed traffic flows, such as in
access networks and many interoffice networks. The configuration consists of a
ring of remote shelves and the hub. Each remote shelf supports up to 4 protected
or 8 unprotected optical channel interfaces that are connected to corresponding
interfaces at the hub site. More than one remote shelf can be installed at a
given site in order to provide more than 4 (or 8) channel interface drops at
that site. Up to 8 remote shelves are supported for a maximum total of 32
protected or 64 unprotected optical channel interfaces.

FIGURE 7. HUBBED RING CONFIGURATION

[OBJECT OMITTED]

2.2      DISTRIBUTED ATM

A key objective in the development of the equipment has been to provide
value-added transport for ATM switch trunks within a metropolitan network
environment.

The Hubbed Ring is optimized for backhauling trunks from ATM edge switches to an
ATM core or tandem switch because this application involves a hubbed traffic
pattern. The trunks in these applications are currently OC-3, but are quickly
evolving to OC-12. OPTera will handle the upgrade with no additional investment
in the transport infrastructure because the OCI circuit cards are bit-rate
independent. Cambrian believes the economics and scalability of OPTera offers
the network provider the option to provide ATM trunking at the photonic layer
rather than through SONET.

                                    Page 8 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

FIGURE 8. DISTRIBUTED ATM CONFIGURATION

[OBJECT OMITTED]

In this application, all the elements will be managed by the Newbridge 46020,
providing simplified overall management.

2.3      POINT-TO-POINT

The point-to-point system can be configured as either protected or unprotected.
In the protected configuration, all optical channels can be bridged onto both a
working fiber and a protection fiber such that in the event of a failure of the
working fiber, the channels can be restored via the protection fiber. Both
protected and unprotected connections can be established over this
configuration, with the protection being optional on a per connection basis. For
example, two unprotected connections can be established over a single
wavelength, one on the working fiber pair, and one on the protection fiber pair,
in place of one protected connection.

For point-to-point applications where the protection capabilities are not
required, an unprotected point-to-point configuration is supported that allows
up to 4 unprotected interfaces to be supported per shelf.

                                    Page 9 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

FIGURE 9. POINT-TO-POINT CONFIGURATION - PROTECTED

[OBJECT OMITTED]

FIGURE 10. POINT-TO-POINT CONFIGURATION - UNPROTECTED

[OBJECT OMITTED]

2.4

                                    Page 10 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

2.5 CONNECTION TYPES

The equipment is designed to complement SONET networks by providing increased
capacity per fiber while leaving protection functions to the SONET network
elements. These applications may use the Unprotected Connections illustrated in
Figure 11 and Figure 13. However, the equipment is also designed to be deployed
in place of a SONET transport layer where appropriate. In order to be capable of
both these options, the equipment incorporates optical layer protection
switching functionality as illustrated in Figure 12. These different connections
options can be provisioned on the same system on a per connection basis.

Figure 11 illustrates a basic unprotected ring connection with an unprotected
client interface. Such a connection may be used when the client signal does not
require any protection, or it is protected via some other network. Note that the
same wavelength on the unused arc of the ring is available for another
connection.

FIGURE 11. UNPROTECTED CONNECTION WITH UNPROTECTED CLIENT INTERFACE

[OBJECT OMITTED]

Figure 12 illustrates a protected connection with an unprotected client
interface. This connection offers survivability against fiber cuts and node
failures, however, the client interface remains unprotected, perhaps because it
is an intra-office connection that is not expected to fail. This mechanism uses
a permanent head-end bridge performed by the OCMs in the two terminating nodes.
The drop node monitors the integrity of both received optical channels and uses
this information to select the better channel.

FIGURE 12. PROTECTED CONNECTION WITH UNPROTECTED CLIENT INTERFACE

[OBJECT OMITTED]

Figure 13 illustrates a high survivability connection where the protection
switching is provided by the subtending equipment, such as a SONET terminal.
Fiber cuts, node failures and channel interface failures are all survived.
Because the optical channel connections are completely transparent, the
subtending equipment protection mechanism operates as if it is directly
connected. In order for this method to work, the optical channel connection must
be transparent to failures. For example, if an OCI detects an incoming LOS from
the subtending equipment, the condition will be alarmed and a LOS will also be
generated at the other end of the connection to the subtending equipment so that
the failure will be detected and the protection switch performed.

                                    Page 11 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

FIGURE 13. UNPROTECTED CONNECTIONS WITH EXTERNALLY PROTECTED CLIENT INTERFACE

[OBJECT OMITTED]

2.5      OPTICAL LINK BUDGETS (SYSTEMS WITHOUT OPTICAL AMPLIFIERS)

The following link budgets apply across the entire operating range of 0-50
degrees centigrade and regardless of fiber type (NDSF, DSF, NS-DSF). A 1.5dB
penalty is included to cover all sources of distortion, including chromatic
dispersion on NDSF, and four-wave mixing on DSF and NZ-DSF. No allocation has
been made for connector losses at a Fiber Distribution Frame nor is there any
unallocated margin.

In the OPTera Hubbed Ring configuration, add/drop/passthrough functionality is
provided optically, such that the optical power budget must be calculated on a
ring basis; node to node distances are unimportant. In order to ensure that each
optical channel experiences the same passthrough losses, the wavelength bands
are allocated to the remotes as illustrated in Figure 25. With this allocation
of bands, the following link budgets apply regardless of which remote is
terminating the channel.

FIGURE 14. BAND ALLOCATION IN HUBBED RING CONFIGURATION

[OBJECT OMITTED]

                                    Page 12 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

TABLE 5. LINK BUDGET FOR HUBBED RING CONFIGURATIONS (UP TO 1.25GB/S)

---------------------------------------- --------------------------------------
        NUMBER OF REMOTE OPTER SHELVES     MAXIMUM LOSS FOR RING CIRCUMFERENCE
---------------------------------------- --------------------------------------
                     1                                   21.7 dB
---------------------------------------- --------------------------------------
                     2                                   19.9 dB
---------------------------------------- --------------------------------------
                     3                                   18.3 dB
---------------------------------------- --------------------------------------
                     4                                   16.8 dB
---------------------------------------- --------------------------------------
                     5                                   15.2 dB
---------------------------------------- --------------------------------------
                     6                                   13.7 dB
---------------------------------------- --------------------------------------
                     7                                   12.1 dB
--------------------------------------- ---------------------------------------
                     8                                   10.6 dB
--------------------------------------- ---------------------------------------

OPTera can be configured for point-to-point applications. These applications
involve slightly different configurations of the OMX modules that take advantage
of the topology to increase the system reach. The optical path loss shown in the
tables does not have any allowance for connector loss at Fiber Distribution
Frames nor any unallocated margin.

FIGURE 15. BAND ALLOCATION IN POINT-TO-POINT CONFIGURATION

[OBJECT OMITTED]

                                    Page 13 of 14

<PAGE>

CCG RFQ - ST-RFX-0005 - COMMENTS
------------------------------------------------------------------------------

TABLE 6. LINK BUDGET FOR POINT-TO-POINT CONFIGURATIONS  (UP TO 1.25 GB/S)

------------------------------------ -----------------------------------------
NUMBER OF REMOTE OPTERA SHELVES      MAXIMUM LOSS
------------------------------------ -----------------------------------------
1                                    21.7 dB
------------------------------------ -----------------------------------------
2                                    20.6 dB
------------------------------------ -----------------------------------------
3                                    19.6 dB
------------------------------------ -----------------------------------------
4                                    18.7 dB
------------------------------------ -----------------------------------------
5                                    17.8 dB
------------------------------------ -----------------------------------------
6                                    16.9 dB
------------------------------------ -----------------------------------------
7                                    15.9 dB
------------------------------------ -----------------------------------------
8                                    15.0 dB
------------------------------------ -----------------------------------------

                                    Page 14 of 14

<PAGE>

                SYSTEM FEATURE DESCRIPTION OPTICAL LINE AMPLIFIER

<TABLE>
-------------------------------------------------------------------------------
<S>                       <C>                            <C>
ID                        ST-RFX-0004
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

-------------------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description Optical Line Amplifier-10

-------------------------------------------------------------------------------

DESCRIPTION

-------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

-------------------------------------------------------------------------------
</TABLE>

<PAGE>

1        ABBREVIATIONS

-------------------------------------------------------------------------------

INTRODUCTION This section lists abbreviation used throughout the entire
             document.

-------------------------------------------------------------------------------
<TABLE>
                          <S>            <C>
                          AUI            Attachment Unit Interface
                          BBE            Background Block Error
                          EBER           Excessive Bit Error Rate

                          EMS            Element Management System
                          ES             Errored Second
                          ES-IS          End System - Intermediate System routing
                          IP             Internet Protocol
                          IS-IS          Intermediate System routing
                          ITU-T          International Telecommunications Union - Telecommunications Sector
                          LAPD           Link Access Protocol D-channel
                          LCT            Local Craft Terminal
                          LED            Light Emitting Diode
                          LOF            Loss Of Frame
                          LOS            Loss Of Signal
                          MAU            Media Attachment Unit
                          MDI            Miscellaneous Discrete Input
                          MDO            Miscellaneous Discrete Output
                          MIB            Management Information Base
                          NE             Network Element
                          NMS            Network Management System
                          NSAP           Network Service Access Point
                          OADM           Optical Add/Drop Multiplexer
                          OLA            Optical Line Amplifier
                          ODBC           Open DataBase Connectivity
                          OLA            Optical Line Amplifier
                          OSC            Optical Service Channel
                          OSI            Open Systems Interconnection
                          OSS            Operation Support System
                          OTM            Optical Terminal Multiplexer
                          PSTN           Public Switched Telephone Network
                          RS             Regenerator Section
                          SDH            Synchronous Digital Hierarchy
                          SES            Severely Errored Second
                          SNMP           Simple Network Management Protocol
                          SQL            Structured Query Language
                          TCP            Transmission Control Protocol
                          UAS            Unavailable Second
                          UDP            User Datagram Protocol

-------------------------------------------------------------------------------
</TABLE>

<PAGE>

2 REQUESTED FEATURES

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
1             TRANSMISSION FEATURES
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier provides a link/hop planning      NC
              tool allowing to simulate and design the
              DWDM network (Attenuation, Dispersion,..).
------------------------------------------------------------------------------------------------------------------------
         2.   The supplier provides a released document      C - This can
              containing system planning and engineering     be made
              rules based on standard single mode fibres.    available if
                                                             required
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.1           TRANSMISSION INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Connector Type E2000 APC                       FC/SC
------------------------------------------------------------------------------------------------------------------------
         2.   Maximum output power of the interfaces         50W
------------------------------------------------------------------------------------------------------------------------
         1.   OLA link/hop limits (attenuation,              5 hops, total    IR            IR
              dispersion,..) as function of number and       combined
              lengths of hops between terminals.             distance of
                                                             380km with
                                                             maximum
                                                             overall Db
                                                             loss of 95Db
------------------------------------------------------------------------------------------------------------------------
         3.   Automatic output power adjustment depending    C
              on the number of received channels
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.2           SYSTEM CONNECTIVITY
------------------------------------------------------------------------------------------------------------------------
1.2.1         SYSTEM CAPACITY
------------------------------------------------------------------------------------------------------------------------
         1.   IN CASE OF OPTICAL CHANNEL SPACING 100 GHZ:
------------------------------------------------------------------------------------------------------------------------
         2.   Max. number of optical channels                16 channels      IR            IR
                                                             providing
                                                             32(lambda)
------------------------------------------------------------------------------------------------------------------------
         3.   Min. number of optical channels                4 channels       IR            IR
                                                             providing
                                                             8(lambda)
------------------------------------------------------------------------------------------------------------------------
              IN CASE OF OPTICAL CHANNEL SPACING 50 GHZ:
------------------------------------------------------------------------------------------------------------------------
         1.   Max. number of optical channels                Nortel's         IR            IR
                                                             Optical
                                                             equipment
                                                             follows the
                                                             ITU-T
                                                             recommended
                                                             200Ghz grid
                                                             with 100Ghz
                                                             spacing as
                                                             defined in
                                                             G.692
------------------------------------------------------------------------------------------------------------------------
         2.   Min. number of optical channels                See response     IR            IR
                                                             above
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
1.2.2         SYSTEM UPGRADE TOWARDS OPTICAL ADD/DROP MUX
------------------------------------------------------------------------------------------------------------------------
         1.   System Upgrade towards Add/Drop Muliplexer     Nortel's
              possible                                       Optical Line
                                                             Amplifier can
                                                             be easily
                                                             upgraded to
                                                             an OADM
                                                             system by the
                                                             addition of
                                                             the Optical
                                                             Add Drop
                                                             Module
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.2.2.1       OPTICAL ADD/DROP, IN CASE OF OPTICAL CHANNEL
              SPACING 100 GHZ:
------------------------------------------------------------------------------------------------------------------------
         1.   Max. number of optical channels aggregate      8 channels       IR            IR
              east to agg. west                              supporting 16
                                                             wavelengths
------------------------------------------------------------------------------------------------------------------------
         1.   Min. number of optical channels aggregate      2 supporting     IR            IR
              west to agg. east                              4 wavelengths
------------------------------------------------------------------------------------------------------------------------
         1.   Max. number of optical channels added/dropped  2 channels       IR            IR
              to/from direction east                         (2(lambda)
                                                             added,
                                                             2(lambda)
                                                             dropped)
------------------------------------------------------------------------------------------------------------------------
         2.   Min. number of optical channels added/dropped  1 channel        IR            IR
              to/from direction east                         (1(lambda)
                                                             added,
                                                             1(lambda)
                                                             dropped)
------------------------------------------------------------------------------------------------------------------------
         3.   Max. number of optical channels added/dropped  2 channels       IR            IR
              to/from direction west                         (2(lambda)
                                                             added,
                                                             2(lambda)
                                                             dropped)
------------------------------------------------------------------------------------------------------------------------
         4.   Min. number of optical channels added/dropped  1 channel        IR            IR
              to/from direction west                         (1(lambda)
                                                             added,
                                                             1(lambda)
                                                             dropped)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.2.2.2       OPTICAL ADD/DROP, IN CASE OF OPTICAL CHANNEL
              SPACING 50 GHZ:
------------------------------------------------------------------------------------------------------------------------
         1.   Max. number of optical channels aggregate      Nortel's         IR            IR
              east to agg. west                              Optical
                                                             equipment
                                                             follows the
                                                             ITU-T
                                                             recommended
                                                             200Ghz grid
                                                             with 100Ghz
                                                             spacing as
                                                             defined in
                                                             G.692
------------------------------------------------------------------------------------------------------------------------
         2.   Min. number of optical channels aggregate      See response     IR            IR
              west to agg. east                              to 1.2.2.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         3.   Max. number of optical channels added/dropped  See response     IR            IR
              to/from direction east                         to 1.2.2.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
         4.   Min. number of optical channels added/dropped  See response     IR            IR
              to/from direction east                         to 1.2.2.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
         5.   Max. number of optical channels added/dropped  See response     IR            IR
              to/from direction west                         to 1.2.2.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
         6.   Min. number of optical channels added/dropped  See response     IR            IR
              to/from direction west                         to 1.2.2.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.2.2.3       OPTICAL ADD/DROP, TRANSPONDERS AND TRIBUTARY
              INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Optical interface I-16.1                       C
------------------------------------------------------------------------------------------------------------------------
         2.   Optical interface S-16.1                       C
------------------------------------------------------------------------------------------------------------------------
         3.   Optical interface L-16.1                       C
------------------------------------------------------------------------------------------------------------------------
         4.   Optical interface L-16.2                       C
------------------------------------------------------------------------------------------------------------------------
         1.   Bitrate independent interface                  NC, however
                                                             it is
                                                             possible to
                                                             multiplex any
                                                             bitrate
                                                             signal
                                                             presented to
                                                             the optical
                                                             layer using
                                                             Nortel's ADM
                                                             equipment
------------------------------------------------------------------------------------------------------------------------
         2.   Optical Power Budget without transponders      1 span = 27 Db   IR            IR
                                                             2 spans = 25 Db
                                                             3 spans = 23 Db
                                                             4 spans = 21 Db
                                                             5 spans = 19 Db

------------------------------------------------------------------------------------------------------------------------
         5.   Active wavelength control (not only via chip   C
              temperature)
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         6.   Transmit transponders optional for             NC - Nortel's
              tributary channels (option to use              SDH ADMs feed
              output signals from coloured                   their signal to
              transmitters without need to implement         the MOR+ via the
              transponders)                                  couplers
                                                             without need
                                                             for transponders
------------------------------------------------------------------------------------------------------------------------
         7.   Receive transponders optional for add/drop     NC - see above
              channels (option to apply DEMUX output
              signal to SDH-receiver)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.3           STM-64 COMPATIBILITY
------------------------------------------------------------------------------------------------------------------------
         1.   It is possible to upgrade channels from        Equipment
              STM-16 to STM-64 without need to change        will
              hardware.                                      initially be
                                                             provisioned
                                                             to support
                                                             STM-64
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
1.4           OTHER TRANSMISSION FEATURES
------------------------------------------------------------------------------------------------------------------------
         1.   Dispersion compensation                        C
------------------------------------------------------------------------------------------------------------------------
         2.   Automatic gain control                         C
         ---------------------------------------------------------------------------------------------------------------
         3.   A channel upgrade is not traffic affecting to  C
              all channels already in service
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
2             ENGINEERING ORDERWIRE
------------------------------------------------------------------------------------------------------------------------
2.1           INTERFACES
------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------
         1.   2 wire i/f (towards PSTN)                      C
------------------------------------------------------------------------------------------------------------------------
         2.   2 wire  i/f (towards standard handset)         C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
2.2           FUNCTIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Selective Call                                 C
------------------------------------------------------------------------------------------------------------------------
         2.   Conference Call (up to four participants)      C
------------------------------------------------------------------------------------------------------------------------
3             MANAGEMENT COMMUNICATION
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
3.1           COMMUNICATION INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   F- Interface   (RS 232)                        C
------------------------------------------------------------------------------------------------------------------------
         2.   Q- interface as gateway to the EMS             C
------------------------------------------------------------------------------------------------------------------------
         3.   Qecc Routing (2 level IS-IS)                   C
------------------------------------------------------------------------------------------------------------------------
         4.   Q I/F (Ethernet)                               C
------------------------------------------------------------------------------------------------------------------------
         5.   Optical Supervisory Channel                    C
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         6.   OSC                                            Integrated       IR             IR
              o        wavelength                            OSC at 1510nm
              o        bitrate                               or separate
              o        optical span limit                    module
              o        transmission protocol                 operating at
                                                             1625nm
                                                             operating at
                                                             10Gbit/s with
                                                             a limit of 5
                                                             spans
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
3.2           O & M INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   8 x Remote Control Inputs                      NC
------------------------------------------------------------------------------------------------------------------------
         2.   Remote Control Outputs                         C - However
                                                             Management
                                                             Performance
                                                             may be reduced
------------------------------------------------------------------------------------------------------------------------
         3.   Card LED support                               C
------------------------------------------------------------------------------------------------------------------------
         4.   Subrack LED support                            C
------------------------------------------------------------------------------------------------------------------------
         5.   Rack Alarm support                             C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
4             FAULT AND STATUS MANAGEMENT
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
4.1.1         ALL OPTICAL INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Laser Restart for Test                         C

------------------------------------------------------------------------------------------------------------------------
         2.   Detection of Laser Shutdown                    C - alarms
                                                             are raised if
                                                             for whatever
                                                             reason a loss
                                                             of signal
                                                             occurs.
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of disabled ALS on any optical       See response
              interface                                      to 5.2.1.9
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of Optical Source Power High on any  C
              optical interface
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of LOS, LOS status change hysteresis C - Loss of
                                                             Signal is
                                                             reported
                                                             through the
                                                             use of alarms
                                                             based upon
                                                             input and
                                                             output signal
                                                             thresholds.
------------------------------------------------------------------------------------------------------------------------
         5.   Insertion of AIS upon detection of LOS         C
------------------------------------------------------------------------------------------------------------------------
         6.   Detection of number of received channels       C
------------------------------------------------------------------------------------------------------------------------
         7.   Monitoring of laser current for pump laser 1   C
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         8.   Monitoring of laser current for pump laser 2   C
------------------------------------------------------------------------------------------------------------------------
         9.   Monitoring of temperature for pump laser 1     C
------------------------------------------------------------------------------------------------------------------------
         10.  Monitoring of temperature for pump laser 2     C
------------------------------------------------------------------------------------------------------------------------
         11.  Monitoring of laser temperature                C
------------------------------------------------------------------------------------------------------------------------
         12.  Monitoring of transmitted wavelength           C
------------------------------------------------------------------------------------------------------------------------
         13.  Monitoring of received input power             C
------------------------------------------------------------------------------------------------------------------------
         14.  Monitoring of transmitted output power         C
------------------------------------------------------------------------------------------------------------------------
         15.  Detection of coupler temperature high          C
------------------------------------------------------------------------------------------------------------------------
         16.  Detection of grating temperature high          C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
4.1.2         ALL REGENERATOR SECTION MONITORING POINTS
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of OOF                               Regen section
                                                             is monitored
                                                             by the SDH
                                                             ADM equipment
                                                             at regen site
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of LOF                               See response
                                                             to 4.1.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of RS EBER (10E-3) based on B1       See response
              BIP-8 parity calculation on demux unit         to 4.1.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
         3.   Detection of RS EBER (10E-3) based on B1       See response
              BIP-8 parity calculation on transponder unit   to 4.1.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of Section Trace Mismatch based on   See response
              J0 Byte monitoring on demux unit               to 4.1.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------
         5.   Detection of Section Trace Mismatch based on   Transponder
              J0 Byte monitoring on transponder unit         Unit not used
                                                             in this
                                                             solution
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
4.1.3         MANAGEMENT COMMUNICATION FUNCTION
------------------------------------------------------------------------------------------------------------------------
              Detection of Remote Control Input Active       C
------------------------------------------------------------------------------------------------------------------------
              Detection of OSC Comms Fail (LAPD Alarm)       C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
4.1.4         SYSTEMS MANAGEMENT FUNCTION
------------------------------------------------------------------------------------------------------------------------
         1.   Detection of Secondary Power Fail              See response
                                                             to 6.3.2
------------------------------------------------------------------------------------------------------------------------
         2.   Detection of Primary Power Low                 See response
                                                             to 6.3.2
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         3.   Detection of Primary Power Fail per each       See response
              single power feed                              to 6.3.2
------------------------------------------------------------------------------------------------------------------------
         4.   Detection of Re-Boot Fail                      C
------------------------------------------------------------------------------------------------------------------------
         5.   Detection of Configuration Data Integrity      C
              Check Failure
------------------------------------------------------------------------------------------------------------------------
         6.   Detection of System Software Integrity Check   C
              Failure
------------------------------------------------------------------------------------------------------------------------
         7.   Detection of Network Element Controller Fail   C
------------------------------------------------------------------------------------------------------------------------
         8.   Detection of Card Protection Switch Failure    C
------------------------------------------------------------------------------------------------------------------------
         9.   Detection of Card Out                          C
------------------------------------------------------------------------------------------------------------------------
         10.  Detection of Card Fail (upon detection of      C
              internal parity mismatch etc.)
------------------------------------------------------------------------------------------------------------------------
         11.  Detection of Wrong Card                        C
------------------------------------------------------------------------------------------------------------------------
         12.  Card Protection Switch Active                  C
------------------------------------------------------------------------------------------------------------------------
         13.  Fault / Status Log Capacity Exceeded           C
------------------------------------------------------------------------------------------------------------------------
         14.  Configuration Data Transaction Log Capacity    C
              Exceeded
------------------------------------------------------------------------------------------------------------------------
         15.  Access  Log Capacity Exceeded                  C
------------------------------------------------------------------------------------------------------------------------
         16.  Software Download in Progress                  C
------------------------------------------------------------------------------------------------------------------------
         17.  Software Download Failure                      C
------------------------------------------------------------------------------------------------------------------------
         18.  Software Download Failure - Retry in Progress  C
------------------------------------------------------------------------------------------------------------------------
         19.  Software Download Complete                     C
------------------------------------------------------------------------------------------------------------------------
         20.  Card Restoration Complete                      C
------------------------------------------------------------------------------------------------------------------------
         21.  Re-Boot Restoration Complete                   C
------------------------------------------------------------------------------------------------------------------------
         22.  Electronic Label Update                        C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
4.2           ALARM EVENT HANDLING
------------------------------------------------------------------------------------------------------------------------
         1.   Alarm Persistence Filter (filtering of         C - It is
              toggling alarms)                               possible to
                                                             filter alarms
                                                             using the
                                                             functionality
                                                             of INM,
                                                             Nortel's
                                                             Network
                                                             Management
                                                             System
------------------------------------------------------------------------------------------------------------------------
         2.   Alarm Correlation Filter (F3 filter,            C
              suppression of consequent alarms)
------------------------------------------------------------------------------------------------------------------------
         3.   Alarm Inversion Facility                        C
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         4.   Performance of the alarm throughput
              greater than 10 alarms per second
------------------------------------------------------------------------------------------------------------------------
         5.   Indication of Alarm Event Forwarding
              Suppression per functional unit (e.g.
              Regenerator Section ...)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5             CONFIGURATION MANAGEMENT
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.1           GENERAL
------------------------------------------------------------------------------------------------------------------------
         1.   Upload of Configuration Data - on single       C
              command
------------------------------------------------------------------------------------------------------------------------
         2.   Upload of Configuration Data - on bulk command C
------------------------------------------------------------------------------------------------------------------------
         3.   Download of Configuration Data - on bulk       C
              command
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.2           CONFIGURATION OF FUNCTIONAL BLOCKS
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.2.1         ALL OPTICAL INTERFACES
------------------------------------------------------------------------------------------------------------------------
         1.   Set of transmitted output power                C
------------------------------------------------------------------------------------------------------------------------
         2.   Set of input power warning thresholds          C
------------------------------------------------------------------------------------------------------------------------
         3.   Set input power switch off thresholds          C
------------------------------------------------------------------------------------------------------------------------
         4.   Set output power warning thresholds            C
------------------------------------------------------------------------------------------------------------------------
         5.   Set output power switch off thresholds         C
------------------------------------------------------------------------------------------------------------------------
         6.   Set laser current alarm thresholds             C
------------------------------------------------------------------------------------------------------------------------
         7.   Set of laser temperature alarm thresholds      C
------------------------------------------------------------------------------------------------------------------------
         8.   Set of transmitted wavelength alarm thresholds C
------------------------------------------------------------------------------------------------------------------------
         9.   Enable / Disable Automatic Laser Shutdown      NC - The
              according to ITU-T G.958                       OPTera LH OLA
                                                             is a Class 3A
                                                             system. Whilst not
                                                             advised, a Class 3A
                                                             system is deemed to
                                                             be safe for long
                                                             term viewing
                                                             without optical
                                                             aids and with the
                                                             supplied warning
                                                             labels and
                                                             procedural
                                                             precautions, ALS is
                                                             not necessary for
                                                             this equipment
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         10.  Enable / Disable Laser                         C - it is
                                                             possible to
                                                             enable/disable
                                                             the laser
                                                             both manually
                                                             and remotely
------------------------------------------------------------------------------------------------------------------------
         11. Enable Laser for Test Purposes (2s / 90s)       C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
5.2.2         ALL REGENERATOR SECTION MONITORING POINTS
------------------------------------------------------------------------------------------------------------------------
         1.   Set Threshold B1-EBER                          See response
                                                             to 4.1.2.1
                                                             above
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6             OPERATION AND MAINTENANCE
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.1           GENERAL
------------------------------------------------------------------------------------------------------------------------
         1.   Event buffer                                   C
------------------------------------------------------------------------------------------------------------------------
         2.   Heart Beat Function for all processes          NC
------------------------------------------------------------------------------------------------------------------------
         3.   Automatic Re-boot after power failure          C
------------------------------------------------------------------------------------------------------------------------
         4.   Real time clock function                       C
------------------------------------------------------------------------------------------------------------------------
         5.   Automatic synchronization of NE real time      C
              clock on EMS real time clock
------------------------------------------------------------------------------------------------------------------------
         6.   It is possible to set the NE time and date     C
              via EMS/LCT
------------------------------------------------------------------------------------------------------------------------
         7.   NSAP Address modification                      C
------------------------------------------------------------------------------------------------------------------------
         8.   Local Software Download                        C
------------------------------------------------------------------------------------------------------------------------
         9.   Remote Software Download                       C
------------------------------------------------------------------------------------------------------------------------
         10.  Upload of configuration data to EMS/LCT        C
------------------------------------------------------------------------------------------------------------------------
         11.  Download of configuration data from EMS/LCT    C
------------------------------------------------------------------------------------------------------------------------
         12.  Manager Decision Process for equipment access  C
              control
------------------------------------------------------------------------------------------------------------------------
         13.  Display of Optical Transmit Power Level        C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.2           LOGS
------------------------------------------------------------------------------------------------------------------------
         1.   Alarm / Status Log                             C
------------------------------------------------------------------------------------------------------------------------
         2.   Performance Log (storage capacity at least     C
              8 x 15 min intervals and 30 x 24 h interval
              for each monitoring point)
------------------------------------------------------------------------------------------------------------------------
         3.   Configuration Log (storage capacity at least   C
              24 h)
------------------------------------------------------------------------------------------------------------------------
         4.   Access Control Log (storage capacity at        C
              least 10 days)
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.3           REDUNDANCY
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>

         1.   Dual Power Feed                                C - standard
                                                             2 power
                                                             feeds,
                                                             optional 6
                                                             power feeds
------------------------------------------------------------------------------------------------------------------------
         2.   1+1 Protection of Power Supply                 The OPTera
                                                             OLA system is
                                                             powered by
                                                             redundant
                                                             feeds.
                                                             Failure of
                                                             one of the
                                                             power feeds
                                                             due to an
                                                             open or short
                                                             circuit does
                                                             not affect
                                                             the system.
                                                             Two
                                                             breaker/filter
                                                             modules
                                                             provide power
                                                             for the
                                                             OPtera OLA
                                                             shelves.
------------------------------------------------------------------------------------------------------------------------
         1.   Redundancy of pump lasers
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.4           EQUIPMENT TESTING FUNCTIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Integrity Check of Configuration Data          C - managed
                                                             via the
                                                             functionality
                                                             of the NE OPC
------------------------------------------------------------------------------------------------------------------------
         2.   Integrity Check of System Software             See response
                                                             to 6.4.1
------------------------------------------------------------------------------------------------------------------------
         3.   Configuration of Loop Back on all optical      NC
              Interface Cards
------------------------------------------------------------------------------------------------------------------------
         4.   Optical monitoring port on each transmit       Transponder
              transponder (output signal)                    Unit not used
                                                             in this
                                                             solution
------------------------------------------------------------------------------------------------------------------------
         5.   Optical monitoring port on each receive        Transponder
              transponder (input signal)                     Unit not used
                                                             in this
                                                             solution
------------------------------------------------------------------------------------------------------------------------
         6.   Optical monitoring port on each pre-           C - managed
              amplifier (input signal)                       via the
                                                             functionality
                                                             of the NE OPC
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         7.   Optical monitoring port on each                C - managed
              booster-amplifier (output signal)              via the
                                                             functionality
                                                             of the NE OPC
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
6.5           INVENTORY DATA
------------------------------------------------------------------------------------------------------------------------
         1.   Electronic Label Read Access via Management    Nortel's INM
              Interfaces                                     Network
                                                             Management system
                                                             offers the option
                                                             of centralised
                                                             inventory
                                                             management, which
                                                             is accessed via the
                                                             GNB and allows the
                                                             user to retrieve an
                                                             inventory of the
                                                             remotely located
                                                             NEs. The retrieved
                                                             information can be
                                                             displayed and saved
                                                             to a file suitable
                                                             for further
                                                             processing
------------------------------------------------------------------------------------------------------------------------
         1.   Automatic Electronic Label Upgrade             See response
                                                             to 6.5.1 above
------------------------------------------------------------------------------------------------------------------------
         2.   Compatibility Check of Equipment Hardware      See response
              Releases                                       to 6.5.1 above
------------------------------------------------------------------------------------------------------------------------
         3.   Compatibility Check of Equipment Firmware      See response
              Releases                                       to 6.5.1 above
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         2.   Compatibility Check of Equipment Software      Management by
              Releases                                       release
                                                             automatically
                                                             defines a set of
                                                             compatible software
                                                             loads (called the
                                                             software lineup)
                                                             for all
                                                             downloadable CPs in
                                                             a span of control
                                                             and enforces strict
                                                             software
                                                             configuration
                                                             management among
                                                             these loads.
------------------------------------------------------------------------------------------------------------------------
         4.   Compatibility Check of Equipment Software      See response
              Releases to the Management System              to 6.5.4 above
------------------------------------------------------------------------------------------------------------------------
         5.   Electronic Label contents:                     See response
              o Unit hardware release / version              to 6.5.1
              o Unit hardware serial number                  above
              o Unit firmware release / version
              o Unit software release / version
              o Unit installation date of unit/NE
              o Production date of unit/NE
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
7             ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL
              COMPATIBILITY AND SAFETY
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
7.1           CLIMATIC CONDITIONS
------------------------------------------------------------------------------------------------------------------------
         1.   Compliance with Stationary Use Conditions      C
              acc. to prETS 300 019-2-3 Class T 3.2
------------------------------------------------------------------------------------------------------------------------
         2.   No need for air conditioning via elevated      C
              ground floor
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
7.2           ELECTROMAGNETIC COMPATIBILITY
------------------------------------------------------------------------------------------------------------------------
         1.   Compliance with EN 55022                       C
------------------------------------------------------------------------------------------------------------------------
         1.   Compliance with EN 50082                       C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
7.3           SAFETY
------------------------------------------------------------------------------------------------------------------------
         1.   CE certification available                     C
------------------------------------------------------------------------------------------------------------------------
         2.   Electrical safety according to EN 41003        C
------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
Para                                                         AVAILABLE NOW    AVAILABLE      AVAILABLE    Comment
                                                                               12/1999        12/2000
------------------------------------------------------------------------------------------------------------------------
<S>      <C>  <C>                                            <C>              <C>            <C>          <C>
         3.   General requirements according to EN 60950     C
              A1, A2
------------------------------------------------------------------------------------------------------------------------
         4.   Fire and heat safety according to ETS 300      C
              019-2
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
8             PHYSICAL CONSTRUCTION
------------------------------------------------------------------------------------------------------------------------
         1.   Rack size according to ETSI 300 119, 600 mm x  C
              300 mm
------------------------------------------------------------------------------------------------------------------------
         2.   Rack size according to ETSI 300 119, 600 mm x
              600 mm
------------------------------------------------------------------------------------------------------------------------
         3.   System installation and h/w upgrade via front  C
              access possible
------------------------------------------------------------------------------------------------------------------------
         4.   Number of required Racks in minimum            1                IR            IR
              configuration
------------------------------------------------------------------------------------------------------------------------
         5.   Number of required Racks in maximum            1                IR            IR
              configuration
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
9             POWER SUPPLY
------------------------------------------------------------------------------------------------------------------------
         1.   Nominal input voltage -48V                     C
------------------------------------------------------------------------------------------------------------------------
         1.   Minimum accepted input voltage                 -38V             IR            IR
------------------------------------------------------------------------------------------------------------------------
         2.   Maximum accepted input voltage                 -75V             IR            IR
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
10            AVAILABILITY
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier shall provide MTBF figures for    C - see Annex 1  IR            IR
              each functional unit of the offered equipment
              based on his statistical evaluations
              according to the template as attached in
              Annex 1
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
11            POWER CONSUMPTION
------------------------------------------------------------------------------------------------------------------------
         1.   The supplier shall provide worst case power    C - see Annex 1  IR            IR
              consumption figures for each functional unit
              of the offered equipment according to the
              template as attached in Annex 1
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
12            SYSTEM MANUALS
------------------------------------------------------------------------------------------------------------------------
         3.   System Description in Hypertext Format on CD   C
------------------------------------------------------------------------------------------------------------------------
         4.   System O&M Manuals in Hypertext Format on CD   C
------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------
UNIT NAME/TYPE                         UNIT ID         UNIT FIT FIGURE       MAXIMUM POWER
                                                                             CONSUMPTION
----------------------------------------------------------------------------------------------------
<S>                                    <C>             <C>                   <C>
MANDATORY CONTROL
----------------------------------------------------------------------------------------------------
Shelf Controller                       NTCA41BA                1125                 13W/20W
----------------------------------------------------------------------------------------------------
Half Height Breaker                    NTCA40CA                 256                  5W/8W
----------------------------------------------------------------------------------------------------
Maintenance Interface                  NTCA42AA                1139                 7.5W/10W
----------------------------------------------------------------------------------------------------
Message Transfer                       NTCA48AA                 677                  8W/10W
----------------------------------------------------------------------------------------------------
OPTIONAL CONTROL
----------------------------------------------------------------------------------------------------
Parallel Telemetry Interface           NTCA45AA                 703                  2W/5W
----------------------------------------------------------------------------------------------------
AMPLIFIER/FILTER OPTIONS
----------------------------------------------------------------------------------------------------
MOR+ Red Pre/ Blue Post with OSC       NTCA11PK                4499                 35W/50W
----------------------------------------------------------------------------------------------------
MOR+ Blue Pre/Red Post with OSC        NTCA11NK                4499                 35W/50W
----------------------------------------------------------------------------------------------------
OSC                                    NTCA11CA                1024                 25W/40W
----------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                   with regard to TN-16X
                          SYSTEM FEATURE DESCRIPTION ADM-16/4

                          -----------------------------------------------------

ID                        ST-rfx-0007
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

                          -----------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature description ADM-16-4-10

                          -----------------------------------------------------

DESCRIPTION               This document lists the features of ADM-16/4 Equipment

                          The equipment shall mainly be applied for combining
                          VC-4 add/drop to/from backbone rings.

                          -----------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

-------------------------------------------------------------------------------

<PAGE>
                                   with regard to TN-16X

1        REQUESTED FEATURES
<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------

<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
1                 INTERFACE TYPES
-------------------------------------------------------------------------------------------------------------------------------
1.1               ELECTRICAL TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------

           1.     STM-1 G.703                                                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
1.2               OPTICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
1.2.1             TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           2.     S-1.1                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           3.     L-1.1                                                                   Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           4.     L-1.2                                                                   Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           5.     S-4.1                                                                   Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           6.     L-4.1                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           7.     L-4.2                                                                   Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           8.     V-4.2                                                                   Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           9.     S-16.1                                                                  Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           10.    L-16.1                                                                  Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           11.    L-16.2                                                                  Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           12.    V-16.2                                                                  Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
1.2.2             AGGREGATE INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           13.    S-16.1                                                                  Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           14.    L-16.1                                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           15.    L-16.2                                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           16.    V-16.2                                                                  Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           17.    Coloured Interfaces 100 GHz channel spacing                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           18.    Coloured Interfaces 50 GHz channel spacing                              Nc      Nc       Nc    07.12217
-------------------------------------------------------------------------------------------------------------------------------
1.3               EQUIPPING OF INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
1.3.1             TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           19.    Higher order tributary interface types can be mixed without             C        C       C
                  affecting the tributary capacity
-------------------------------------------------------------------------------------------------------------------------------
           20.    Up to 16 active STM-1 el. or optical interfaces.                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           21.    Up to 4 active optical STM-4 interfaces.                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
2                 CONNECTIVITY
-------------------------------------------------------------------------------------------------------------------------------
2.1               CONNECTION TYPES
-------------------------------------------------------------------------------------------------------------------------------
           22.    Bi-directional Connections                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           23.    Bi-directional Connections of contiguously concatenated  VC-4           C        C       C
                  (VC-4-4c)
-------------------------------------------------------------------------------------------------------------------------------
           24.    Bi-directional Connections of contiguously concatenated  VC-4           Nc      Nc       Nc
                  (VC-4-16c)
-------------------------------------------------------------------------------------------------------------------------------
2.2               QUANTITATIVE REQUIREMENTS
-------------------------------------------------------------------------------------------------------------------------------
           25.    High order add/drop capacity of 16 * VC-4 equivalents from              C        C       C
                  aggregate east
-------------------------------------------------------------------------------------------------------------------------------
           26.    High order add/drop capacity of 16 * VC-4 equivalents from              C        C       C
                  aggregate west
-------------------------------------------------------------------------------------------------------------------------------
           27.    High order add/drop capacity of 16 * VC-4 equivalents from              C        C       C
                  aggregate east and west
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>

           28.    High Order aggregate to aggregate connectivity of 16 STM-1              C        C       C
                  equivalents (east and west)
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
3                 SYNCHRONISATION
-------------------------------------------------------------------------------------------------------------------------------
3.1               INTERNAL EQUIPMENT TIMING
-------------------------------------------------------------------------------------------------------------------------------
3.1.1             TIMING SOURCES
-------------------------------------------------------------------------------------------------------------------------------
           29.    STM-N  timing                                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           30.    2048 kHz timing                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           31.    Internal Oscillator acc. to G.813                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.1.2             TIMING SOURCE QUALITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           32.    STM-N Timing at all SDH i/fs (Timing Marker Support)                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           33.    2048 kHz timing, fixed to G.811 quality                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           34.    2048 kHz timing, configurable timing source quality                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.1.3             TIMING SOURCE PRIORITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           35.    Priority List of (at least 6 entries)                                   Nc      Nc       Nc    07.31335
-------------------------------------------------------------------------------------------------------------------------------
3.1.4             SELECTION ALGORITHMS
-------------------------------------------------------------------------------------------------------------------------------
           36.    Autonomous Timing Source Selection acc. to highest quality and          C        C       C
                  highest priority
-------------------------------------------------------------------------------------------------------------------------------
           37.    Manual Timing Source Selection                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2               EXTERNAL TIMING OUTPUT (T4)
-------------------------------------------------------------------------------------------------------------------------------
3.2.1             TIMING OUTPUT PORT
-------------------------------------------------------------------------------------------------------------------------------
           38.    One 2048 kHz timing output port                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           39.    Configurable timing output squelch function                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.2             TIMING SOURCES
-------------------------------------------------------------------------------------------------------------------------------
           40.    STM-N                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.3             TIMING SOURCE QUALITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           41.    STM-N Timing (Timing Marker Support)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.4             TIMING SOURCE PRIORITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           42.    Priority List (at least 7 entries)                                      Nc      Nc       Nc    07.31335
-------------------------------------------------------------------------------------------------------------------------------
3.2.5             SELECTION ALGORITHMS
-------------------------------------------------------------------------------------------------------------------------------
           43.    Autonomous timing source selection                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           44.    Manual Timing Source selection                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
4                 OVERHEAD ACCESS
-------------------------------------------------------------------------------------------------------------------------------
4.1               OVERHEAD BYTES
-------------------------------------------------------------------------------------------------------------------------------
           45.    Access to F1 as transparent channel                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           46.    Access to E1 as transparent channel                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           47.    Access to F2 as transparent channel                                     Nc      Nc       Nc       07.4147
-------------------------------------------------------------------------------------------------------------------------------
4.2               OVERHEAD ACCESS INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           48.    64 K on V.11 (towards either MSOH or RSOH of aggregate interface)       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           49.    64 K on V.11 (towards POH of tributary interface)                       Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
4.3               OVERHEAD CHANNEL CROSS CONNECTIONS
-------------------------------------------------------------------------------------------------------------------------------
           50.    64 K between synchronous ports and towards external interface           C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
5                 ENGINEERING ORDERWIRE
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>

5.1               INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           51.    1 * 2 wire i/f (towards PSTN)                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           52.    2 * 2 wire  i/f (towards standard handset)                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
5.2               FUNCTIONS
-------------------------------------------------------------------------------------------------------------------------------
           53.    Selective Call                                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           54.    Conference Call (up to four participants)                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
6                 MANAGEMENT COMMUNICATION
-------------------------------------------------------------------------------------------------------------------------------
6.1               COMMUNICATION INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           55.    F- Interface   (RS 232)                                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           56.    Q- interface as gateway to the EMS                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           57.    Qecc via any ECCR  on optical  interfaces                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           58.    Qecc via any ECCM on optical  interfaces                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           59.    Qecc via any ECCR  on electrical  interfaces                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           60.    Qecc via any ECCM on electrical  interfaces                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           1.     Qecc Routing (level 2 IS-IS acc. to ISO 10589-8473)                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           61.    Domain Partitioning Repair function                                     Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           62.    Definition of Manual Adjacencies (NSAP of dedicated NE)                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           63.    Manual definition of reachable addresses (set address prefix)           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           64.    ECC can be inserted / extracted to/from VC-4 POH Byte of SDH            Nc      Nc       Nc
                  tributary interface
                  (Application: for transparent transmission of ECC via other
                  operator's SDH network)
-------------------------------------------------------------------------------------------------------------------------------
6.2               O & M INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           65.    8 x Remote Control Inputs                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           66.    Remote Control Outputs                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           67.    Card LED support                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           68.    Subrack LED support                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           69.    Rack Alarm support                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
7                 PERFORMANCE MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------
           70.    Performance History Data Collection (ES, SES and UAT) ...               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           71.    at any VC-4 TTP                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           72.    at any MST                                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           73.    at any RST                                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           74.    at any AU-4 CTP                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           75.    for any AU-4 Tandem Connection                                          Nc      Nc       Nc       07.775
-------------------------------------------------------------------------------------------------------------------------------
           76.    from remote TTPs based on FEBE evaluation                               Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           77.    Threshold Crossing Notification                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
8                 FAULT AND STATUS MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
8.1               DETECTED ANOMALIES, DEFECTS AND CONSEQUENT ACTIONS
-------------------------------------------------------------------------------------------------------------------------------
8.1.1             ALL SYNCHRONOUS PHYSICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
           78.    Detection of Transmit Fail on any optical STM-N interface               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           79.    Detection of Laser Shutdown on any optical interface                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           80.    Detection of disabled ALS on any optical interface                      Nc      Nc       Nc       07.880
-------------------------------------------------------------------------------------------------------------------------------
           81.    Detection of Optical Source Power High on any optical interface         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           82.    Detection of LOS, LOS status change hysteresis                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           83.    Insertion of AIS upon detection of LOS                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.2             ALL REGENERATOR SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           84.    Detection of OOF                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           85.    Detection of LOF                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           86.    Insertion of AIS upon persisting LOF detection                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           87.    Detection of RS EBER (10E-3) based on  B1 BIP-8 parity calculation      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.3             ALL MULTIPLEX SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           88.    Detection of MS-AIS                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           89.    Insertion of all 1 upon detection of MS-AIS                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           90.    Detection of Signal Degrade                                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           91.    Detection of MS-EBER (10E-3) upon B2 BIP-24 parity                      C        C       C
                  error calculation
-------------------------------------------------------------------------------------------------------------------------------
           92.    Insertion of AIS and FERF upon detection of MS-AIS                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           93.    Detection of FERF                                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           94.    Insertion of MS-FEBE based on detection of B2 parity calculations       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.4             ALL MULTIPLEX SECTION ADAPTATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           95.    Detection  of AU-LOP                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           96.    Detection of AU-AIS                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           97.    Detection of Number of AU-Pointer Justification Events                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           98.    Insertion of AU-AIS upon receive of all 1                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           99.    Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           100.   Detection of HP-Trace Invalid                                           Nc      Nc       Nc      07.81100
-------------------------------------------------------------------------------------------------------------------------------
           101.   Detection of HP-TIM                                                     Nc      Nc       Nc      07.81100
-------------------------------------------------------------------------------------------------------------------------------
           102.   Detection of HP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           103.   Detection of HP-FERF                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           104.   Detection of B3- EBER (10E-3)                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.6             ALL HIGH ORDER PATH TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           105.   Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           106.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           107.   Detection of HP-Trace Invalid                                           Nc      Nc       Nc      07.81100
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>

           108.   Detection of HP-TIM                                                     Nc      Nc       Nc      07.81100
-------------------------------------------------------------------------------------------------------------------------------
           109.   Insertion of AIS and HP-FERF upon detection of HP-TIM                   Nc      Nc       Nc      07.81100
-------------------------------------------------------------------------------------------------------------------------------
           110.   Detection of HP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           111.   Insertion of AIS and HP-FERF upon detection of HP-SLM                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           112.   Detection of HP-FERF                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           113.   Detection of B3- EBER (10E-3)                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.7             ALL PLESIOCHRONOUS PHYSICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           114.   Detection of Trib.-AIS                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           115.   Detection of Trib.-LOS                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           116.   Detection of Trib.-LOF                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           117.   Insertion of AIS upon detection of Trib.-AIS, Trib.-LOS, Trib.-LOF      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.8             SETS AND SETPI
-------------------------------------------------------------------------------------------------------------------------------
           118.   Detection of Sync. Source Fail                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           119.   Detection of SETG - Hold                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           120.   Detection of SETG - Out of Lock                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           121.   Detection of SETG - Fail                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           122.   Detection of Sync. Degrade                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           123.   Detection of Excessive Sync. Degrade                                    C        C       C       07.81123
-------------------------------------------------------------------------------------------------------------------------------
           124.   Detection of Sync. Source Threshold Crossing                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           125.   Detection of Sync. LOS                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.9             MANAGEMENT COMMUNICATION FUNCTION
-------------------------------------------------------------------------------------------------------------------------------
           126.   Detection of Remote Control Input Active                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           127.   Detection of RS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           128.   Detection of MS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.10            SYSTEMS MANAGEMENT FUNCTION
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>

           129.   Detection of Secondary Power Fail                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
???        130.   C                                                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           131.   Detection of Re-Boot Fail                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           132.   Detection of Configuration Data Integrity Check Failure                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           133.   Detection of System Software Integrity Check Failure                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           134.   Detection of Network Element Controller Fail                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           135.   Detection of Card Protection Switch Failure                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           136.   Detection of Card Out                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           137.   Detection of Card Fail (upon detection of internal parity
                  mismatch etc.)                                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           138.   Detection of Wrong Card                                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           139.   Network Protection Switch Failure                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
8.2               STATUS EVENTS
-------------------------------------------------------------------------------------------------------------------------------
           140.   Configuration Data Integrity Fail                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           141.   System Software Integrity Fail                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           142.   Laser Restart for Test                                                  Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           143.   Synchronous Equipment Timing Generator A/B active                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           144.   Synchronisation Source Quality Change                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           145.   Synchronisation Source Switch Event                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           146.   External Synchronisation Output Squelched                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           147.   Section Layer Protection Switch Active                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           148.   Network Protection Switch Event                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           149.   Card Protection Switch Active                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           150.   Fault / Status Log Capacity Exceeded                                    Nc      Nc       Nc      07.82150
-------------------------------------------------------------------------------------------------------------------------------
           151.   Configuration Data Transaction Log Capacity Exceeded                    Nc      Nc       Nc      07.82150
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>
<PAGE>

                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>

           152.   Performance Monitoring Log Capacity Exceeded                            Nc      Nc       Nc      07.82150
-------------------------------------------------------------------------------------------------------------------------------
           153.   Access Log Capacity Exceeded                                            Nc      Nc       Nc      07.82150
-------------------------------------------------------------------------------------------------------------------------------
           154.   Software Download in Progress                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           155.   Software Download Failure                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           156.   Software Download Failure - Retry in Progress                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           157.   Software Download Complete                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           158.   Card Restoration Complete                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           159.   Re-Boot Restoration Complete                                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
???        160.   Electronic Label Update                                                 NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
8.3               ALARM EVENT HANDLING
-------------------------------------------------------------------------------------------------------------------------------
           161.   Alarm Persistence Filter (filtering of toggling alarms)                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           162.   Alarm Correlation Filter (F3 filter, suppression of consequent          C        C       C
                  alarms)
-------------------------------------------------------------------------------------------------------------------------------
           163.   Alarm Inversion Facility                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           164.   Performance of the alarm throughput GREATER THAN 10 alarms per second   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           165.   It is possible to block/unblock each single traffic relevant
                  alarm per port                                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           166.   It is possible to block/unblock each single traffic relevant
                  alarm group per card                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           167.   It is possible to block/unblock each single traffic relevant
                  alarm group per NE                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
???        168.   Indication of Alarm Event Forwarding Suppression per functional         C        C       C
                  unit (e.g. Regenerator Section ...)
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
9                 CONFIGURATION MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------
9.1               GENERAL
-------------------------------------------------------------------------------------------------------------------------------
           169.   Upload of Configuration Data - on single command                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           170.   Upload of Configuration Data - on bulk command                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           171.   Download of Configuration Data - on bulk command                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
9.2               CONFIGURATION OF FUNCTIONAL BLOCKS
-------------------------------------------------------------------------------------------------------------------------------
9.2.1             ALL SYNCHRONOUS OPTICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
           172.   Enable / Disable Automatic Laser Shutdown                               NA      NA       NA       07.880
-------------------------------------------------------------------------------------------------------------------------------
           173.   Enable / Disable Laser                                                  NA      NA       NA       07.9173
-------------------------------------------------------------------------------------------------------------------------------
           174.   Enable Laser for Test Purposes  (2s  / 90s)                             NA      NA       NA       07.9173
-------------------------------------------------------------------------------------------------------------------------------
9.2.2             ALL MULTIPLEX SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           175.   Set Threshold Signal Degrade                                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           176.   Set Threshold B2-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
9.2.3             ALL REGENERATOR SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           177.   Set Threshold B1-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
9.2.4             ALL HIGH ORDER PATH TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           178.   Set Threshold B3-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           179.   Set Threshold HP-FEBE                                                   Nc      Nc       Nc      07.92179
-------------------------------------------------------------------------------------------------------------------------------
           180.   Enable / Disable consequent actions from detection of
                  HP-TIM (per Path)                                                       Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           181.   Enable / Disable consequent actions from detection of
                  HP-SLM (per Path)                                                       Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           182.   Set expected Signal Label (per Path)                                    Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           183.   Set expected Path Trace (per Path)                                      Nc      Nc       Nc      07.92183
-------------------------------------------------------------------------------------------------------------------------------
9.2.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           184.   Set Threshold B3-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           185.   Set Threshold HP-FEBE                                                   Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           186.   Set expected Signal Label (per Path)                                    Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           187.   Set expected Path Trace (per Path)                                      Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
10                NETWORK PROTECTION
-------------------------------------------------------------------------------------------------------------------------------
10.1              HIGHER ORDER LINEAR VC TRAIL PROTECTION (SINGLE ENDED)
-------------------------------------------------------------------------------------------------------------------------------
           188.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
           189.   Detection Criterion Signal Degrade (B3 Bit Error Rate)                  NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           190.   Switch-Over Completion Time LESS THAN 300ms                             NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           191.   Configurable Hold-Off Time                                              NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           192.   Enable / Disable Automatic Switching                                    NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           193.   Manual Switching via Management Interface                               NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           194.   Configurable Wait Time to Restore                                       NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
10.2              HIGHER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I)
-------------------------------------------------------------------------------------------------------------------------------
           195.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           196.   Switch-Over Completion Time LESS THAN 100ms                             NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           197.   Configurable Hold-Off Time                                              NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           198.   Enable / Disable Automatic Switching                                    NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           199.   Manual Switching via Management Interface                               NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
           200.   Configurable Wait Time to Restore                                       NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
10.3              1+1 LINE PROTECTION
-------------------------------------------------------------------------------------------------------------------------------
           201.   MSP function on all aggregates                                          Nc      Nc       Nc       07.201
-------------------------------------------------------------------------------------------------------------------------------
           202.   MSP function on all optical tributaries                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           203.   MSP function on all electrical STM-1 tributaries                        Nc      Nc       Nc       07.203
-------------------------------------------------------------------------------------------------------------------------------
           204.   Detection Criterion Signal Fail and Signal Degrade according            C       C        C
                  to Section 2.3 of ITU-T rec. G.783
-------------------------------------------------------------------------------------------------------------------------------
           205.   Switch-Over Completion Time LESS THAN 50ms                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           206.   Enable / Disable Automatic Switching                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           207.   Manual Switching via Management Interface                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           208.   Configurable Wait Time to Restore                                       NA      NA       NA
-------------------------------------------------------------------------------------------------------------------------------
10.4              MS SHARED RING PROTECTION (MSBSHR)
-------------------------------------------------------------------------------------------------------------------------------
           209.   Detection Criterion Signal Fail and Signal Degrade according            C       C        C
                  to Section 2.3 of ITU-T rec. G.783
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
           210.   Switch-Over Completion Time LESS THAN 50ms                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           211.   Manual Switching via Management Interface                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           212.   Revertive Switching                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           213.   Configurable Wait Time to Restore                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           214.   Maximum number of network elements in the ring                          C        C       C        07.214
-------------------------------------------------------------------------------------------------------------------------------
           215.   It is possible to configure (unprotected) low priority traffic          C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
11                OPERATION AND MAINTENANCE
-------------------------------------------------------------------------------------------------------------------------------
11.1              GENERAL
-------------------------------------------------------------------------------------------------------------------------------
           216.   Event buffer                                                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           217.   Heart Beat Function                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           218.   Re-boot function                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           219.   Real time clock function                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           220.   NSAP Address modification                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           221.   Local Software Download                                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           222.   Remote Software Download                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           223.   Manager Decision Process for equipment access control                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           224.   Display of VC-4 Path Trace at HPT                                       Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           225.   Display of VC-4 Signal Label at HPT                                     Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           226.   Display of VC-4 Path Trace at HPOM                                      Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           227.   Display of VC-4 Signal Label at HPOM                                    Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
           228.   Display of Optical Transmit Power Level                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
11.2              LOGS
-------------------------------------------------------------------------------------------------------------------------------
           229.   Alarm / Status Log                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           230.   Performance Log                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
           231.   Configuration  Log                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           232.   Access Control  Log                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
11.3              REDUNDANCY
-------------------------------------------------------------------------------------------------------------------------------
           233.   1+1 (electrical) Tributary Card Protection STM-1 G.703                  Nc      Nc       Nc      07.11233
-------------------------------------------------------------------------------------------------------------------------------
           234.   1+1 Protection of all Central Traffic Carrying Cards                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           235.   1+1 Protection of Clock System                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           236.   Duration LESS THAN 5s for card protection automatic switch over         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
11.4              EQUIPMENT TESTING FUNCTIONS
-------------------------------------------------------------------------------------------------------------------------------
           237.   Integrity Check of Configuration Data                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           238.   Integrity Check of System Software                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           239.   Configuration of Loop Back on all PDH Interface Cards                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           240.   Configuration of Loop Back on all electrical SDH Interface Cards        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           241.   Configuration of Loop Back on all optical SDH Interface Cards           Nc      Nc       Nc      07.11241
-------------------------------------------------------------------------------------------------------------------------------
???        242.   Configuration of Loop Back on the HPC functional block                  Nc      Nc       Nc      07.11241
-------------------------------------------------------------------------------------------------------------------------------
           243.   Test Interface on all electrical interfaces                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           244.   Optical Line Testing                                                    Nc      Nc       Nc
-------------------------------------------------------------------------------------------------------------------------------
11.5              INVENTORY DATA
-------------------------------------------------------------------------------------------------------------------------------
???        245.   Electronic Label Read Access via Management Interfaces                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           246.   Automatic Electronic Label Upgrade                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           247.   Compatibility Check of Equipment Hardware Releases                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           248.   Compatibility Check of Equipment Firmware Releases                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           249.   Compatibility Check of Equipment Software Releases                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           250.   Compatibility Check of Equipment Software Releases to the               C        C       C
                  Management System
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
12                ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL
                  COMPATIBILITY AND SAFETY
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
12.1              CLIMATIC CONDITIONS
-------------------------------------------------------------------------------------------------------------------------------
           251.   Stationary Use Conditions acc. to prETS 300 019-2-3 Class T 3.2         Nc      Nc       Nc      07.12251
-------------------------------------------------------------------------------------------------------------------------------
           252.
-------------------------------------------------------------------------------------------------------------------------------
12.2       253.   ELECTROMAGNETIC COMPATIBILITY
-------------------------------------------------------------------------------------------------------------------------------
           254.   Compliance with EN 55022 class B                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           255.   Compliance with EN 50082                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
12.3              SAFETY REQUIREMENTS
-------------------------------------------------------------------------------------------------------------------------------
           256.   Compliance with EN 60950                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           257.   Compliance with IEC 825-1 and IEC 825-2                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
13                PHYSICAL CONSTRUCTION
-------------------------------------------------------------------------------------------------------------------------------
           258.   Rack size according to ETSI 300 119, 600 mm x 300 mm                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           259.   System installation and h/w upgrade via front access possible           C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
14                POWER SUPPLY
-------------------------------------------------------------------------------------------------------------------------------
           260.   Nominal input voltage -48V                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           261.   Minimum accepted input voltage                                          -40 V    -40 V   -40 V
-------------------------------------------------------------------------------------------------------------------------------
           262.   Maximum accepted input voltage                                          -60 V    -60 V   -60 V
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
15                AVAILABILITY
-------------------------------------------------------------------------------------------------------------------------------
           263.   The supplier shall provide MTBF figures for each functional unit of     IR       IR      IR       ANNEX 1
                  the offered equipment based on his statistical evaluations
                  according to the template as attached in Annex 1
-------------------------------------------------------------------------------------------------------------------------------
           264.
-------------------------------------------------------------------------------------------------------------------------------
16                POWER CONSUMPTION
-------------------------------------------------------------------------------------------------------------------------------
           265.   The supplier shall provide worst case power consumption figures for     IR       IR      IR       ANNEX 1
                  each functional unit of the offered equipment according to the
                  template as attached in Annex 1
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
17                SYSTEM MANUALS
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
           266.   System Description in Hypertext Format on CD                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           267.   System O&M Manuals in Hypertext Format on CD                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                                   with regard to TN-16X

2        REFERENCES

2.1      REFERENCES TO STANDARDS

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS    DATE    TITLE
----------------------------------------------------------------------------------------------------------------------
<S>                  <C>       <C>     <C>
CECC 86 275-80                 09/95   Detail Specification: Connector sets for optical fibres and cables Type
                                       LSH-HRL
----------------------------------------------------------------------------------------------------------------------
ITU-T G.703                    04/91   Physical/Electrical characteristics of Hierarchical Digital Interfaces
----------------------------------------------------------------------------------------------------------------------
ITU-T G.707                    1991    Synchronous digital hierarchy bit rates
----------------------------------------------------------------------------------------------------------------------
ITU-T G.782                    1994    Types and general characteristics of synchronous digital hierarchy (SDH)
                                       equipment
----------------------------------------------------------------------------------------------------------------------
ITU-T G.783                    1994    Characteristics of synchronous digital hierarchy /SDH) equipment functional
                                       blocks
----------------------------------------------------------------------------------------------------------------------
ITU-T G.813                    1996    Timing Characteristics of SDH equipment slave clocks.
----------------------------------------------------------------------------------------------------------------------
ITU-T G.825                    1993    The control of Jitter and Wander within Digital Networks which are based on
                                       synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------
ITU-T G.826                    11/93   Error performance parameters and objectives for International constant
                                       Bit Rate Digital Paths at or above the Primary Rate
----------------------------------------------------------------------------------------------------------------------
ITU-T G.841                    1995    Types and Characteristics of SDH Network Protection Architectures
----------------------------------------------------------------------------------------------------------------------
ITU-T G.957                    1993    Optical Interfaces and Systems relating to the synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
ETS 300 019          pr        02/92   Environmental conditions and Environmental Tests for Telecommunications
                                       Equipment
                                       Part A:  Introduction and Terminology
                                       Part B:  classification of Environmental conditions
----------------------------------------------------------------------------------------------------------------------
ETS 300 119                            European Telecommunication Standard for Equipment Practice
                               03/93   Part 2:  Engineering Requirements for Racks
                               09/93   Part 3:  Engineering Requirements for Miscellaneous Racks and cabinets
                               09/93   Part 4:  Engineering Requirements for Subracks
----------------------------------------------------------------------------------------------------------------------
ETS 300 253                    01/95   Earthing and  bonding of telecommunication equipment in telecommunication
                                       centres
----------------------------------------------------------------------------------------------------------------------
EN 41003                       1991    Particular safety requirements for equipment to be connected to
                                       telecommunication network
----------------------------------------------------------------------------------------------------------------------
EN 55022                       05/95   Grenzwerte  und  Me(beta)verfahren fur Funkstorungen von Einrichtungen   der
                                       Informationstechnik
----------------------------------------------------------------------------------------------------------------------
EN 50082                               Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                               12/94   Part 1:  Elektromagnetische  Vertraglichkeit - Fachgrundnorm  Storfestigkeit -
                                       Teil 1: Wohnbereich, Geschafts- und Gewerbebereiche sowie Kleinbetriebe

                               02/96   Part 2:  Elektromagnetische  Vertraglichkeit - Fachgrundnorm  Storfestigkeit -
                                       Teil 2: Industriebereich
----------------------------------------------------------------------------------------------------------------------
DIN 47295                              HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
----------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
                                   with regard to TN-16X

ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------
UNIT NAME/TYPE     UNIT ID                                 UNIT FIT      MAXIMUM POWER
                                                            FIGURE       CONSUMPTION / W
--------------------------------------------------------------------------------------------------
<S>                <C>                                      <C>          <C>
NT7E19AA           External synchronisation                  1823        11.2 (Note: Dissipation
                   interface carrier                                     figure is for 2 ESI units
                                                                         plus the carrier)
--------------------------------------------------------------------------------------------------
NTFW27AA           External Synchronisation                  2220
                   Interface (2 MHz)
--------------------------------------------------------------------------------------------------
NTFW27AA           External Synchronisation                  2220
                   Interface (2 MHz)
--------------------------------------------------------------------------------------------------
NT7E20GC           SH PROCESSOR FOR SDH (DCC                 6397                               25
                   HUBBING)
--------------------------------------------------------------------------------------------------
NT7E23AA           Maintenance Interface Unit                4028                               15
--------------------------------------------------------------------------------------------------
NT7E24BC           OPC with tape drive                      59964                               70
--------------------------------------------------------------------------------------------------
NT8E02DD           OC-48/STM16 LR SAW Rx Interface          11458                               30
                   (SC)
--------------------------------------------------------------------------------------------------
NT8E02DD           OC-48/STM16 LR SAW Rx Interface          11458                               30
                   (SC)
--------------------------------------------------------------------------------------------------
NT8E06AB           OC-48/STM-16 Ring Demux                   5395                               54
--------------------------------------------------------------------------------------------------
NT8E06AB           OC-48/STM-16 Ring Demux                   5395                               54
--------------------------------------------------------------------------------------------------
NTFW01AD           STM16 LR 1557 Ring Tx (SC)                7907                               45
--------------------------------------------------------------------------------------------------
NTFW01AD           STM16 LR 1557 Ring Tx (SC)                7907                               45
--------------------------------------------------------------------------------------------------
NTFW08CA           STM1e/140 Mbit/s tributary                4653                               16
                   mapper
--------------------------------------------------------------------------------------------------
NTFW08CA           STM1e/140 Mbit/s tributary                4653                               16
                   mapper
--------------------------------------------------------------------------------------------------
NTFW11CD           STM1o IR 1310 Tributary I/F (SC)          4568                              6.5
--------------------------------------------------------------------------------------------------
NTFW14AA           STM1e/140 Mbits/s I/O i/f                  614                                4
--------------------------------------------------------------------------------------------------
NTFW14BA           34 Mbit/s I/O i/f                          153                                0
--------------------------------------------------------------------------------------------------
NTFW19BA           STM1 Optical Carrier Assembly             1823                                8
--------------------------------------------------------------------------------------------------
NTFW21AB           34 M Mapper (Slot 16 compatable           4520                               20
--------------------------------------------------------------------------------------------------
NTFW21AB           34 M Mapper (Slot 16 compatable           4520                               20
--------------------------------------------------------------------------------------------------
NTFW50EA           STM16 LTE/ADM/RING SHELF                  5337                                0
--------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

<TABLE>
<CAPTION>
================================================================================
UNIT      UNIT ID             UNIT FIT FIGURE          MAXIMUM POWER
NAME/                                                  CONSUMPTION
TYPE
--------------------------------------------------------------------------------
<S>       <C>                 <C>                      <C>

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

================================================================================
</TABLE>

end of document

<PAGE>

ANNEX 2: ANSWERS ON TN-64 X QUESTIONS FOR CCG HANNOVER

1.   CIRCUIT PACK POWER DISSIPATION

                                                       System Specifications 1-7
--------------------------------------------------------------------------------

TABLE 1-9
CIRCUIT PACK POWER DISSIPATION

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
CIRCUIT PACK                            TYPICAL POWER       MAXIMUM POWER
                                        DISSIPATION         DISSIPATION
--------------------------------------------------------------------------------
<S>                                     <C>                 <C>
STM-64 transmit interface               80 W                105 W
--------------------------------------------------------------------------------
STM-64 DWDM transmit interface          80 W                105 W
--------------------------------------------------------------------------------
STM-64 regen transmit interface         60 W                70 W
--------------------------------------------------------------------------------
STM-64 DWDM regen transmit interface    60 W                70 W
--------------------------------------------------------------------------------
STM-64 long reach receive interface     34 W                72 W
--------------------------------------------------------------------------------
STM-64 short reach receive interface    35 W                70 W
--------------------------------------------------------------------------------
STM-64 demultiplexer                    53 W                67 W
--------------------------------------------------------------------------------
STM-64 data overhead switch             145 W               206 W
--------------------------------------------------------------------------------
STM-16 transmit/receive interface       65 W                80 W
--------------------------------------------------------------------------------
STM-4 transmit/receive interface        14 W                20 W
--------------------------------------------------------------------------------
OPC storage                             12.5 W              17 W
--------------------------------------------------------------------------------
OPC controller                          11 W                15 W
--------------------------------------------------------------------------------
OPC interface                           2.5 W               6 W
--------------------------------------------------------------------------------
OPC removable media                     0.5 W               2 W
--------------------------------------------------------------------------------
Shelf controller                        13 W                20 W
--------------------------------------------------------------------------------
Maintenance interface                   7.5 W               10 W
--------------------------------------------------------------------------------
Message exchange                        8 W                 10 W
--------------------------------------------------------------------------------
Parallel telemetry                      2 W                 5 W
--------------------------------------------------------------------------------
External synchronization interface      10 W                14 W
--------------------------------------------------------------------------------
Breaker/filter module                   5 W                 8 W
--------------------------------------------------------------------------------
Fan module                              22 W                27 W
--------------------------------------------------------------------------------
Multiwavelength optical repeater        35 W                50 W
--------------------------------------------------------------------------------
</TABLE>

--------------------------------------------------------------------------------
                                          Nortel TN-64X Technical Specifications

<PAGE>

2. FITS (MTBF) TN-64X

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
FITS TN-64X
DESCRIPTION                                            FITS      MTBF
                                                                 YEARS
<S>                                                    <C>       <C>
TN-64X (RELEASE 1)
STM-64 Tx (DWDM)                                       13790      8.28
STM-64 Rx                                              14596      7.82
STM-64 Demux                                            7891     14.47
STM-64 Regen Tx (DWDM)                                 12333      9.26
4FR Switcher (DOS)                                     11426      9.99
STM-16 1310nm/1557nm Tx/Rx Tributary Card              13255      8.61
MOR without OSC                                        18417      6.20
MOR with 1510nm OSC                                    23844      4.79
OSC (1620nm)                                            5427     21.03
DWDM Coupler/mux - 8 wavelengths                        5734     19.91
DWDM Coupler/mux - 16 wavelength upgrade                5098     22.39
DWDM - PBA Mux/Demux                                    4515     25.28
DWDM - PBA Dual Red/Blue Splitter                       2650     43.08
1550/1625 WDM Coupler                                   5427     21.03
DWDM OADM Coupler - 2 wavelengths                       3604     31.67
TN-64X (RELEASE 1 OVERLAY)
MOR Plus with 1510nm OSC                               23844      4.79
TN-64X (FUTURE RELEASE)
MOR Plus without OSC                                   18417      6.20
Orderwire                                               4171     27.37
--------------------------------------------------------------------------------
</TABLE>
<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier:                                    Reference No.: No. of Tribcards per
Nortel Dasa                                  interface type
Network Systems GmbH & Co. KG
Hahnstrasse 37 - 39                          Document No.: ST-rfx-0007
60528 Frankfurt / Main
                                             Chapter:

                                             Item No.:
--------------------------------------------------------------------------------

                              With Regard to TN-64X

--------------------------------------------------------------------------------
1. Item
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
2. Description
--------------------------------------------------------------------------------

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
Release           Trib Type    No per Card     No available      No available
                                               protected         unprotected
--------------------------------------------------------------------------------
<S>               <C>          <C>             <C>               <C>
R2  current       STM16o       1               4W, 4P            4W
                  STM 4o       4               16W, 16P          16W

--------------------------------------------------------------------------------
R3 e/o Q2 2000    STM16o       1               4W, 4P            8W
                  STM 4o       4               16W. 16P          32W

--------------------------------------------------------------------------------
R4 e/o 2000       As           Release         3                 +
                  STM 1o       4 (16?)         16W, 16P          32W
                  STM1e        4               16W, 16P          32W

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier:                                              Reference No.: 6.1
Nortel Dasa
Network Systems GmbH & Co. KG                          Document No.: ST-rfx-0007
Hahnstrasse 37 - 39
60528 Frankfurt / Main                                 Chapter: 6

                                                       Item No.: 1
--------------------------------------------------------------------------------

                              With Regard to TN-64X

--------------------------------------------------------------------------------
1. Item
--------------------------------------------------------------------------------

Q ecc routing

--------------------------------------------------------------------------------
2. Description
--------------------------------------------------------------------------------

In the current Release (R2) it is set to 0000.

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

================================================================================
Supplier:                                    Reference No.: 7.1
Nortel Dasa
Network Systems GmbH & Co. KG                otel.o Document No.: ST-rfx-0007
Hahnstrasse 37 - 39
60528 Frankfurt / Main                       Chapter: 1

                                             Item No.: 1
================================================================================

                              With Regard to TN-64X

--------------------------------------------------------------------------------
1. Item
--------------------------------------------------------------------------------

Electrical Tributary Interface STM-1 G.703

--------------------------------------------------------------------------------
2. Description
--------------------------------------------------------------------------------

Proposed availability date is 2(nd) quarter 2000.

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

================================================================================
Supplier:                                    Reference No.: 7.1
Nortel Dasa
Network Systems GmbH & Co. KG                otel.o Document No.: ST-rfx-0007
Hahnstrasse 37 - 39
60528 Frankfurt / Main                       Chapter: 6

                                             Item No.: 59
================================================================================

                              With Regard to TN-64X

--------------------------------------------------------------------------------
1. Item
--------------------------------------------------------------------------------

F-Interface

--------------------------------------------------------------------------------
2. Description
--------------------------------------------------------------------------------

Local maintenance is possible with a VT100 Terminal.

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

================================================================================
Supplier:                                    Reference No.: 7.1
Nortel Dasa
Network Systems GmbH & Co. KG                otel.o Document No.: ST-rfx-0007
Hahnstrasse 37 - 39
60528 Frankfurt / Main                       Chapter: 7

                                             Item No.: 78
================================================================================

                              With Regard to TN-64X

--------------------------------------------------------------------------------
1. Item
--------------------------------------------------------------------------------

Performance Management at any AU-4 CTP

--------------------------------------------------------------------------------
2. Description
--------------------------------------------------------------------------------

Performance monitoring on transiting AU4s can be done by using Intermediate Path
Performance Monitoring (IPPM), which is implemented on current releases.
<PAGE>

<TABLE>
<S>                       <C>
                       SYSTEM FEATURE DESCRIPTION ADM-16/1

                          ------------------------------------------------------------------------------------

ID                        ST-RFX-00011
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

                          ------------------------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description ADM-16-1-10

                          -------------------------------------------------------------------------------------

DESCRIPTION               This document lists the features of the ADM-16/1 Equipment.

                          The equipment shall mainly be applied for cost efficient combination of VC-4 add/drop
                          to/from backbone rings with low order trail termination..

                          ------------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

--------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

1         REQUESTED FEATURES

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
1                 INTERFACE TYPES
-----------------------------------------------------------------------------------------------------------------------------
1.1               TRIBUTARY INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           1.     2 Mbit/s G.703                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           2.     2 Mbit/s G.704 frame monitoring option on incoming traffic              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           3.     2 Mbit/s, retiming 250 us buffer
-----------------------------------------------------------------------------------------------------------------------------
           4.     34 Mbit/s G.703                                                         NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           5.     45 Mbit/s G.703                                                         NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           6.     STM-1 G.703                                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           7.     S-1.1                                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           8.     S-4.1                                                                   NC      NC       C
-----------------------------------------------------------------------------------------------------------------------------
           9.     S-16.11                                                                 NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
1.2               AGGREGATE INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           10.    S-1.1                                                                   NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           11.    S-4.1                                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           12.    S-16.1(1)                                                                  NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           13.    L-16.1                                                                  NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           14.    L-16.2                                                                  NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           15.    V-16.2                                                                  NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           16.    Coloured Interfaces 100 GHz channel spacing                             NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           17.    Coloured Interfaces 50 GHz channel spacing                              NC      NC       NC      11.1216
-----------------------------------------------------------------------------------------------------------------------------
1.3               EQUIPPING OF INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
1.3.1             TRIBUTARY INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           18.    Up to (t.b.d.) electrical 2 Mbit/s ports can be equipped               252      252     252
-----------------------------------------------------------------------------------------------------------------------------
           19.    Up to (t.b.d.) electrical 34 Mbit/s ports can be equipped               24      24       24
-----------------------------------------------------------------------------------------------------------------------------
           20.    Up to (t.b.d.) electrical 45 Mbit/s ports can be equipped               24      24       24
-----------------------------------------------------------------------------------------------------------------------------
           21.    Up to (t.b.d.) el. 155 Mbit/s ports can be equipped                     8        8       8
-----------------------------------------------------------------------------------------------------------------------------
1.3.2             AGGREGATE INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           22.    up to (t.b.d.) aggregates of type  STM-1 el.                            NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           23.    up to (t.b.d.) aggregates of type STM-4                                 2        2       2
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
2                 CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
2.1               CONNECTION TYPES
-----------------------------------------------------------------------------------------------------------------------------
           24.    Bi-directional Connections on VC-12 level                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           25.    Bi-directional Connections on VC-3 level                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           26.    Bi-directional Connections on VC-4 level                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           27.    Bi-directional Connections of contiguously concatenated  VC-4           NC       C       C
                  (VC-4-4c)
-----------------------------------------------------------------------------------------------------------------------------
           28.    Bi-directional Connections of contiguously concatenated  VC-4           NC       C       C
                  (VC-4-16c)
-----------------------------------------------------------------------------------------------------------------------------
2.2               QUANTITATIVE REQUIREMENTS
-----------------------------------------------------------------------------------------------------------------------------
2.2.1             HIGHER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

--------------------------------------
(1) interface shall be applied for contiguous concatenation AU-4-16c

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           29.    HO add/drop of 16 * VC-4 equivalents from aggregate east                NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           30.    HO add/drop of 16 * VC-4 equivalents from aggregate west                NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           31.    HO add/drop of 32 * VC-4 equivalents from aggregate east and west       NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           32.    HO aggregate to aggregate connectivity of 16 STM-1 equivalents          NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
2.2.2             LOWER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
           33.    VC-12 and VC-3 cross connect function for up to 16 VC-equivalents       NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           34.    VC-12 and VC-3 cross connect function for up to 32 VC-4 equivalents     NC       C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
3                 SYNCHRONISATION
-----------------------------------------------------------------------------------------------------------------------------
3.1               INTERNAL EQUIPMENT TIMING
-----------------------------------------------------------------------------------------------------------------------------
3.1.1             TIMING SOURCES
-----------------------------------------------------------------------------------------------------------------------------
           35.    STM-N timing                                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           36.    2048 kHz timing                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           37.    Internal Oscillator acc. to G.813                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.1.2             TIMING SOURCE QUALITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
           38.    STM-N Timing at all SDH i/fs (Timing Marker Support)                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           39.    2048 kHz timing, fixed to G.811 quality                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           40.    2048 kHz timing, configurable timing source quality                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.1.3             TIMING SOURCE PRIORITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
           41.    Priority List of (at least 6 entries)                                   NC      NC       NC      11.341
-----------------------------------------------------------------------------------------------------------------------------
3.1.4             SELECTION ALGORITHMS
-----------------------------------------------------------------------------------------------------------------------------
           42.    Autonomous Timing Source Selection                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           43.    Manual Timing Source Selection                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
3.2               EXTERNAL  TIMING OUTPUT (T4)
-----------------------------------------------------------------------------------------------------------------------------
3.2.1             TIMING  OUTPUT PORT
-----------------------------------------------------------------------------------------------------------------------------
           44.    One 2048 kHz timing output port                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           45.    Configurable timing output squelch function                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.2.2             TIMING SOURCES
-----------------------------------------------------------------------------------------------------------------------------
           46.    STM-N  timing                                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.2.3             TIMING SOURCE QUALITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
           47.    STM-N Timing (Timing Marker Support)c                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.2.4             TIMING SOURCE PRIORITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
           48.    Priority List (at least 7 entries)                                      NC      NC       NC      11.341
-----------------------------------------------------------------------------------------------------------------------------
3.2.5             SELECTION ALGORITHMS
-----------------------------------------------------------------------------------------------------------------------------
           49.    Autonomous timing source selection                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           50.    Manual Timing Source selection                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
4                 OVERHEAD ACCESS
-----------------------------------------------------------------------------------------------------------------------------
4.1               OVERHEAD BYTES
-----------------------------------------------------------------------------------------------------------------------------
           51.    Access to F1 as transparent channel                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           52.    Access to E1 as transparent channel                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           53.    Access to F2 as transparent channel                                     NC      NC       NC      11.453
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
4.2               OVERHEAD ACCESS INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           54.    64 K on V.11 (towards either MSOH or RSOH of aggregate interface)       NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           55.    64 K on V.11 (towards POH of tributary interface)                       NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
4.3               OVERHEAD CHANNEL CROSS CONNECTIONS
-----------------------------------------------------------------------------------------------------------------------------
           56.    64 K between synchronous ports and towards external interface           NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
5                 ENGINEERING ORDERWIRE
-----------------------------------------------------------------------------------------------------------------------------
5.1               INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           57.    1 * 2 wire i/f (towards PSTN)                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           58.    2 * 2 wire  i/f (towards standard handset)                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
5.2               FUNCTIONS
-----------------------------------------------------------------------------------------------------------------------------
           59.    Selective Call                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           60.    Conference Call (up to four participants)                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           61.
-----------------------------------------------------------------------------------------------------------------------------
6                 MANAGEMENT COMMUNICATION
-----------------------------------------------------------------------------------------------------------------------------
6.1               COMMUNICATION INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           62.    F- Interface   (RS 232)                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           63.    Q I/F (Ethernet)                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           64.    Q- interface as gateway to the EMS                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           65.    Qecc via any ECC(R) on optical interfaces                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           66.    Qecc via any ECC(M) on optical interfaces                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           67.    Qecc via any ECC(R) on electrical interfaces                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           68.    Qecc via any ECC(M) on electrical interfaces                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           69.    Qecc Routing (level 2 IS-IS acc. to ISO 10589-8473)                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           70.    Domain Partitioning Repair function
-----------------------------------------------------------------------------------------------------------------------------
           71.    Definition of Manual Adjacencies (NSAP of dedicated NE)                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           72.    Manual definition of reachable addresses (set address prefix)           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           73.    ECC can be inserted / extracted to/from VC-4 POH Byte                   C        C       C
                  (Application: for transparent transmission of ECC via other
                  operator's SDH network)
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
6.2               O & M INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           74.    8 x Remote Control Inputs                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           75.    Remote Control Outputs                                                  NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           76.    Card LED support                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           77.    Subrack LED support                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           78.    Rack Alarm support                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
7                 PERFORMANCE MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
           79.    Performance History Data Collection (ES, SES and UAT) ...               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           80.    at any MST                                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           81.    at any RST                                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           82.    at any VC-4 TTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           83.    at any VC-3 TTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           84.    at any VC-12 TTP                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           85.    at any AU-4 CTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           86.    at any VC-3 CTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           87.    at any VC-12 CTP                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           88.    for any AU-4 Tandem Connection                                          NC      NC       NC      11.788
-----------------------------------------------------------------------------------------------------------------------------
           89.    for any TU-3 Tandem Connection                                          NC      NC       NC      11.788
-----------------------------------------------------------------------------------------------------------------------------
           90.    for any TU-12 Tandem Connection                                         NC      NC       NC      11.788
-----------------------------------------------------------------------------------------------------------------------------
           91.    from remote TTPs based on FEBE evaluation                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           92.    Threshold Crossing Notification                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
8                 FAULT AND STATUS MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
8.1               DETECTED ANOMALIES, DEFECTS AND CONSEQUENT ACTIONS
-----------------------------------------------------------------------------------------------------------------------------
8.1.1             ALL SYNCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           93.    Detection of Transmit Fail on any optical STM-N interface               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           94.    Detection of Laser Shutdown on any optical interface                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           95.    Detection of disabled ALS on any optical interface                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           96.    Detection of Optical Source Power High on any optical interface         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           97.    Detection of LOS, LOS status change hysteresis                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           98.    Insertion of AIS upon detection of LOS                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.2             ALL REGENERATOR SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           99.    Detection of OOF                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           100.   Detection of LOF                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           101.   Insertion of AIS upon persisting LOF detection                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           102.   Detection of RS EBER (10E-3) based on  B1 BIP-8 parity calculation      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.3             ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           103.   Detection of MS-AIS                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           104.   Insertion of all 1 upon detection of MS-AIS                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           105.   Detection of Signal Degrade                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           106.   Detection of MS-EBER (10E-3) upon B2 BIP-24 parity error
                  calculation                                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           107.   Insertion of AIS and FERF upon detection of MS-AIS                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           108.   Detection of FERF                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           109.   Insertion of MS-FEBE based on detection of B2 parity calculations       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.4             ALL MULTIPLEX SECTION ADAPTATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           110.   Detection  of AU-LOP                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           111.   Detection of AU-AIS                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           112.   Detection of Number of AU-Pointer Justification Events                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           113.   Insertion of AU-AIS upon receive of all 1                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
8.1.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           114.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           115.   Detection of HP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           116.   Detection of HP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           117.   Detection of HP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           118.   Detection of HP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           119.   Detection of B3- EBER (10E-3)                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.6             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-----------------------------------------------------------------------------------------------------------------------------
           120.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           121.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           122.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           123.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           124.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           125.   Detection of EBER                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.7             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-12)
-----------------------------------------------------------------------------------------------------------------------------
           126.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           127.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           128.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           129.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           130.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           131.   Detection of EBER                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.8             ALL HIGH ORDER PATH TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           132.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           133.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           134.   Detection of HP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           135.   Detection of HP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           136.   Insertion of AIS and HP-FERF upon detection of HP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           137.   Detection of HP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           138.   Insertion of AIS and HP-FERF upon detection of HP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           139.   Detection of HP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           140.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.9             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-----------------------------------------------------------------------------------------------------------------------------
           141.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           142.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           143.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           144.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           145.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           146.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           147.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           148.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           149.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.10            ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-----------------------------------------------------------------------------------------------------------------------------
           150.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           151.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           152.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           153.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           154.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           155.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           156.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           157.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           158.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.11            ALL PLESIOCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           159.   Detection of Trib.-AIS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           160.   Detection of Trib.-LOS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           161.   Detection of Trib.-LOF                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           162.   Insertion of AIS upon detection of Trib.-AIS, Trib.-LOS, Trib.-LOF      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.12            SETS AND SETPI
-----------------------------------------------------------------------------------------------------------------------------
           163.   Detection of Sync. Source Fail                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           164.   Detection of SETG - Hold                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           165.   Detection of SETG - Out of Lock                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           166.   Detection of SETG - Fail                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           167.   Detection of Sync. Degrade                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           168.   Detection of Excessive Sync. Degrade                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           169.   Detection of Sync. Source Threshold Crossing                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           170.   Detection of Sync. LOS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.13            MANAGEMENT COMMUNICATION FUNCTION
-----------------------------------------------------------------------------------------------------------------------------
           171.   Detection of Remote Control Input Active                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           172.   Detection of RS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           173.   Detection of MS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.14            SYSTEMS MANAGEMENT FUNCTION
-----------------------------------------------------------------------------------------------------------------------------
           174.   Detection of Secondary Power Fail                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           175.   Detection of Primary Power Fail                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           176.   Detection of Re-Boot Fail                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           177.   Detection of Configuration Data Integrity Check Failure                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           178.   Detection of System Software Integrity Check Failure                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           179.   Detection of Network Element Controller Fail                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           180.   Detection of Card Protection Switch Failure                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           181.   Detection of Card Out                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           182.   Detection of Card Fail (upon detection of internal parity
                  mismatch etc.)                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           183.   Detection of Wrong Card                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           184.   Network Protection Switch Failure                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.2               STATUS EVENTS
-----------------------------------------------------------------------------------------------------------------------------
           185.   Configuration Data Integrity Fail                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           186.   System Software Integrity Fail                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           187.   Laser Restart for Test                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           188.   Synchronous Equipment Timing Generator A/B active                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           189.   Synchronisation Source Quality Change                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           190.   Synchronisation Source Switch Event                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           191.   External Synchronisation Output Squelched                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           192.   Section Layer Protection Switch Active                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           193.   Network Protection Switch Event                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           194.   Card Protection Switch Active                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           195.   Fault / Status Log Capacity Exceeded                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           196.   Configuration Data Transaction Log Capacity Exceeded                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           197.   Performance Monitoring Log Capacity Exceeded                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           198.   Access  Log Capacity Exceeded                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           199.   Software Download in Progress                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           200.   Software Download Failure                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           201.   Software Download Failure - Retry in Progress                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           202.   Software Download Complete                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           203.   Card Restoration Complete                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           204.   Re-Boot Restoration Complete                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           205.   Electronic Label Update                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.3               ALARM EVENT HANDLING
-----------------------------------------------------------------------------------------------------------------------------
           206.   Alarm Persistence Filter (filtering of toggling alarms)                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           207.   Alarm Correlation Filter (F3 filter, suppression of consequent          C        C       C
                  alarms)
-----------------------------------------------------------------------------------------------------------------------------
           208.   Alarm Inversion Facility                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           209.   Performance of the alarm throughput > 10 alarms per second              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           210.   It is possible to block/unblock each single traffic relevant
                  alarm C C C per port
-----------------------------------------------------------------------------------------------------------------------------
           211.   It is possible to block/unblock each single traffic relevant
                  alarm C C C group per card
-----------------------------------------------------------------------------------------------------------------------------
           212.   It is possible to block/unblock each single traffic relevant
                  alarm C C C group per NE
-----------------------------------------------------------------------------------------------------------------------------
           213.   Indication of Alarm Event Forwarding Suppression per functional         C        C       C
                  unit (e.g. Regenerator Section ...)
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
9                 CONFIGURATION MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
9.1               GENERAL
-----------------------------------------------------------------------------------------------------------------------------
           214.   Upload of Configuration Data - on single command                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           215.   Upload of Configuration Data - on bulk command                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           216.   Download of Configuration Data - on bulk command                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2               CONFIGURATION OF FUNCTIONAL BLOCKS
-----------------------------------------------------------------------------------------------------------------------------
9.2.1             ALL SYNCHRONOUS OPTICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           217.   Enable / Disable Automatic Laser Shutdown                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           218.   Enable / Disable Laser                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           219.   Enable Laser for Test Purposes  (2s  / 90s)                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.2             ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           220.   Set Threshold Signal Degrade                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           221.   Set Threshold B2-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.3             ALL REGENERATOR SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           222.   Set Threshold B1-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.4             ALL HIGH ORDER PATH TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           223.   Set Threshold B3-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           224.   Set Threshold HP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           225.   Enable / Disable consequent actions from detection of HP-TIM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           226.   Enable / Disable consequent actions from detection of HP-SLM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           227.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           228.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.5             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-----------------------------------------------------------------------------------------------------------------------------
           229.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           230.   Set Threshold LP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           231.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           232.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           233.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           234.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.6             ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-----------------------------------------------------------------------------------------------------------------------------
           235.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           236.   Set Threshold LP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           237.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           238.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           239.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           240.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.7             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           241.   Set Threshold B3-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           242.   Set Threshold HP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           243.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           244.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.8             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-----------------------------------------------------------------------------------------------------------------------------
           245.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           246.   Set Threshold FEBE                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           247.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           248.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.9             ALL HIGH ORDER CONNECTION SUPERVISION POINTS (TU-12)
-----------------------------------------------------------------------------------------------------------------------------
           249.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           250.   Set Threshold FEBE                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           251.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           252.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
10                NETWORK PROTECTION
-----------------------------------------------------------------------------------------------------------------------------
10.1              HIGHER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I)
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           253.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           254.   Switch-Over Completion Time less than 100ms                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           255.   Configurable Hold-Off Time                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           256.   Enable / Disable Automatic Switching                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           257.   Manual Switching via Management Interface                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           258.   Configurable Wait Time to Restore                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
10.2              LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-3)
-----------------------------------------------------------------------------------------------------------------------------
           259.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           260.   Switch-Over Completion Time less than 300ms                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           261.   Configurable Hold-Off Time                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           262.   Enable / Disable Automatic Switching                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           263.   Manual Switching via Management Interface                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           264.   Configurable Wait Time to Restore                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
10.3              LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-12)
-----------------------------------------------------------------------------------------------------------------------------
           265.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           266.   Switch-Over Completion Time less than 300ms                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           267.   Configurable Hold-Off Time                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           268.   Enable / Disable Automatic Switching                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           269.   Manual Switching via Management Interface                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           270.   Configurable Wait Time to Restore                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
10.5              1+1 LINE PROTECTION
-----------------------------------------------------------------------------------------------------------------------------
           271.   1+1 Line Protection function on all aggregates                          NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           272.   1+1 Line Protection function on all optical tributaries                 NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           273.   1+1 Line Protection function on all electrical STM-1 tributaries        NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           274.   Detection Criterion Signal Fail and Signal Degrade according
                  to Section 2.3 of ITU-T rec. G.783                                      NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           275.   Switch-Over Completion Time less than 50ms                              NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           276.   Enable / Disable Automatic Switching                                    NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           277.   Manual Switching via Management Interface                               NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           278.   Configurable Wait Time to Restore                                       NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
10.6              MS SHARED RING PROTECTION (MSBSHR)
-----------------------------------------------------------------------------------------------------------------------------
           279.   Detection Criterion Signal Fail and Signal Degrade according to         NC      NC       NC
                  Section 2.3 of ITU-T rec. G.783
-----------------------------------------------------------------------------------------------------------------------------
           280.   Switch-Over Completion Time less than 50ms                              NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           281.   Manual Switching via Management Interface                               NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           282.   Revertive Switching                                                     NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           283.   Configurable Wait Time to Restore                                       NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           284.   Maximum number of network elements in the ring                          NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           285.   It is possible to configure (unprotected) low priority traffic          NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
11                OPERATION AND MAINTENANCE
-----------------------------------------------------------------------------------------------------------------------------
11.1              GENERAL
-----------------------------------------------------------------------------------------------------------------------------
           286.   Event buffer                                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           287.   Heart Beat Function                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           288.   Re-boot function                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           289.   Real time clock function                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           290.   NSAP Address modification                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           291.   Local Software Download                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           292.   Remote Software Download                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           293.   Manager Decision Process for equipment access control                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           294.   Display of VC-4 Path Trace at HPT                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           295.   Display of VC-4 Signal Label at HPT                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           296.   Display of VC-4 Path Trace at HPOM                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           297.   Display of VC-4 Signal Label at HPOM                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           298.   Display of VC-3 Path Trace at LPT                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           299.   Display of VC-3 Signal Label at LPT                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           300.   Display of VC-3 Path Trace at LPOM                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           301.   Display of VC-3 Signal Label at LPOM                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           302.   Display of VC-12 Path Trace at LPT                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           303.   Display of VC-12 Signal Label at LPT                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           304.   Display of VC-12 Path Trace at LPOM                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           305.   Display of VC-12 Signal Label at LPOM                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           306.   Display of Optical Transmit Power Level                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
11.2              LOGS
-----------------------------------------------------------------------------------------------------------------------------
           307.   Alarm / Status Log                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           308.   Performance Log                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           309.   Configuration  Log                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           310.   Access Control  Log                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
11.3              REDUNDANCY
-----------------------------------------------------------------------------------------------------------------------------
           311.   1:N Tributary Card Protection 2 Mbit/s                                  NC      NC       C
-----------------------------------------------------------------------------------------------------------------------------
           312.   1:N or 1+1  Tributary Card Protection 34 Mbit/s                         NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           313.   1:N or 1+1 Tributary Card Protection 45 Mbit/s                          NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           314.   1:M or 1+1 (electrical) Tributary Card Protection  STM-1 G.703          NC       C       C
-----------------------------------------------------------------------------------------------------------------------------
           315.   1+1 Protection of all Central Traffic Carrying Cards                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           316.   1+1 Protection of Clock System                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           317.   Duration less than 5s for card protection automatic switch over         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
11.4              EQUIPMENT TESTING FUNCTIONS
-----------------------------------------------------------------------------------------------------------------------------
           318.   Integrity Check of Configuration Data                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           319.   Integrity Check of System Software                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           320.   Configuration of Loop Back on port level on all PDH Interface Cards     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           321.   VC-4 level Configuration of Loop Back on STM-1 el. i/f                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           322.   VC-4 level Configuration of Loop Back on all STM-4 opt. interfaces      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           323.   VC-3 level Configuration of Loop Back on all electrical SDH             C        C       C
                  Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
           324.   VC-3 level Configuration of Loop Back on all optical SDH Interface      C        C       C
                  Cards
-----------------------------------------------------------------------------------------------------------------------------
           325.   VC-12 level Configuration of Loop Back on all electrical SDH            C        C       C
                  Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
           326.   VC-12 level Configuration of Loop Back on all optical SDH Interface     C        C       C
                  Cards
-----------------------------------------------------------------------------------------------------------------------------
           327.   Configuration of Loop Back on the HPC functional block                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           328.   Configuration of Loop Back on the LPC functional block                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           329.   Test Access Interface on all electrical interfaces                      NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           330.   Test Access Interface on all optical interfaces                         NC      NC       NC
-----------------------------------------------------------------------------------------------------------------------------
           331.   Optical Line Testing                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
11.5              INVENTORY DATA
-----------------------------------------------------------------------------------------------------------------------------
           332.   Electronic Label Read Access via Management Interfaces                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           333.   Automatic Electronic Label Upgrade                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           334.   Compatibility Check of Equipment Hardware Releases                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           335.   Compatibility Check of Equipment Firmware Releases                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           336.   Compatibility Check of Equipment Software Releases                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           337.   Compatibility Check of Equipment Software Releases to the               C        C       C
                  Management System
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
12                ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL COMPATIBILITY AND SAFETY
-----------------------------------------------------------------------------------------------------------------------------
12.1              CLIMATIC CONDITIONS
-----------------------------------------------------------------------------------------------------------------------------
           338.   Stationary Use Conditions acc. to prETS 300 019-2-3 Class T 3.2         NC      NC    NC         11.12338
-----------------------------------------------------------------------------------------------------------------------------
12.2              ELECTROMAGNETIC COMPATIBILITY
-----------------------------------------------------------------------------------------------------------------------------
           339.   Compliance with EN 55022 class B                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           340.   Compliance with EN 50082                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
12.3              SAFETY REQUIREMENTS
-----------------------------------------------------------------------------------------------------------------------------
           341.   Compliance with EN 60950                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           342.   Compliance with IEC 825-1 and IEC 825-2                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
13                PHYSICAL CONSTRUCTION
-----------------------------------------------------------------------------------------------------------------------------
           343.   Rack size according to ETSI 300 119, 600 mm x 300 mm                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           344.   Rack size according to ETSI 300 119, 600 mm x 600 mm                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           345.   System installation and h/w upgrade via front access possible           C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
14                POWER SUPPLY
-----------------------------------------------------------------------------------------------------------------------------
           346.   Nominal input voltage -48V                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           347.   Minimum accepted input voltage                                          -38V     -38V    -38V
-----------------------------------------------------------------------------------------------------------------------------
           348.   Maximum accepted input voltage                                          -75V     -75V    -75V
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
15                AVAILABILITY
-----------------------------------------------------------------------------------------------------------------------------
           349.   The supplier shall provide MTBF figures for each functional unit of     IR       IR      IR       ANNEX 1
                  the offered equipment based on his statistical evaluations
                  according to the template as attached in Annex 1
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
16                POWER CONSUMPTION
-----------------------------------------------------------------------------------------------------------------------------
           350.   The supplier shall provide worst case power consumption figures for     IR       IR      IR       ANNEX 1
                  each functional unit of the offered equipment according to the
                  template as attached in Annex 1
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
17                SYSTEM MANUALS
-----------------------------------------------------------------------------------------------------------------------------
           351.   System Description in Hypertext Format on CD                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           352.   System O&M Manuals in Hypertext Format on CD                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                 with regard to TN-4XE/TN-16XE

2        REFERENCES

2.1      REFERENCES TO STANDARDS

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS    DATE    TITLE
----------------------------------------------------------------------------------------------------------------------
<S>                  <C>       <C>     <C>
CECC 86 275-80                 09/95   Detail Specification: Connector sets for optical fibres and cables Type
                                       LSH-HRL
----------------------------------------------------------------------------------------------------------------------
ITU-T G.703                    04/91   Physical/Electrical characteristics of Hierarchical Digital Interfaces
----------------------------------------------------------------------------------------------------------------------
ITU-T G.707                    1991    Synchronous digital hierarchy bit rates
----------------------------------------------------------------------------------------------------------------------
ITU-T G.782                    1994    Types and general characteristics of synchronous digital hierarchy (SDH)
                                       equipment
----------------------------------------------------------------------------------------------------------------------
ITU-T G.783                    1994    Characteristics of synchronous digital hierarchy/SDH) equipment functional
                                       blocks
----------------------------------------------------------------------------------------------------------------------
ITU-T G.813                    1996    Timing Characteristics of SDH equipment slave clocks.
----------------------------------------------------------------------------------------------------------------------
ITU-T G.825                    1993    The control of Jitter and Wander within Digital Networks which are based on
                                       synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------
ITU-T G.826                    11/93   Error performance parameters and objectives for International
                                       constant Bit Rate Digital Paths at or above the Primary Rate
----------------------------------------------------------------------------------------------------------------------
ITU-T G.841                    1995    Types and Characteristics of SDH Network Protection Architectures
----------------------------------------------------------------------------------------------------------------------
ITU-T G.957                    1993    Optical Interfaces and Systems relating to the synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
ETS 300 019          pr        02/92   Environmental conditions and Environmental Tests for Telecommunications
                                       Equipment

                                       Part A:  Introduction and Terminology
                                       Part B:  classification of Environmental conditions
----------------------------------------------------------------------------------------------------------------------
ETS 300 119                            European Telecommunication Standard for Equipment Practice
                               03/93   Part 2:  Engineering Requirements for Racks
                               09/93   Part 3:  Engineering Requirements for Miscellaneous Racks and cabinets
                               09/93   Part 4:  Engineering Requirements for Subracks
----------------------------------------------------------------------------------------------------------------------
ETS 300 253                    01/95   Earthing and bonding of telecommunication equipment in telecommunication
                                       centres
----------------------------------------------------------------------------------------------------------------------
EN 41003                       1991    Particular safety requirements for equipment to be connected to
                                       telecommunication network
----------------------------------------------------------------------------------------------------------------------
EN 55022                       05/95   Grenzwerte und Messverfahren fur Funkstorungen von Einrichtungen der
                                       Informationstechnik
----------------------------------------------------------------------------------------------------------------------
EN 50082                               Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                               12/94   Part 1:  Elektromagnetische Vertraglichkeit - Fachgrundnorm
                                       Storfestigkeit - Teil 1: Wohnbereich, Geschafts- und
                                                Gewerbebereiche sowie Kleinbetriebe
                               02/96   Part 2:  Elektromagnetische Vertraglichkeit - Fachgrundnorm
                                       Storfestigkeit - Teil 2: Industriebereich
----------------------------------------------------------------------------------------------------------------------
DIN 47295                              HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
----------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                 with regard to TN-4XE/TN-16XE

         ANNEX1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

The following tables list details of the power dissipation, weight, FITS and
size for the TN-4XE equipment.

TABLE 8-1
SUBRACK KEY SPECIFICATION DETAILS

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------
     UNIT               POWER               WEIGHT          FITS     EXTERNAL DIMENSIONS (MM)
(SEE CHAPTER 4)      CONSUMPTION
------------------------------------------------------------------------------------------------------
<S>                  <C>                   <C>              <C>     <C>
TN-4XE Mux           Maximum               18 kg (max.)      41     Height:
assembly             (full fit):253 W      (unequipped)             550 mm (Including fibretray)
NTEU70AA                                   20 kg (actual)           459 mm (excluding fibre tray}
                                                                    An additional height of 50 mm if
                     Typical:220 W                                  2 Mbit/s tributary cabling is
                                                                    installed.
                                                                    Width:
                                                                    450 mm (excl. mounting flanges)
                                                                    Depth:
                                                                    280 mm (incl. doors/covers)
------------------------------------------------------------------------------------------------------
Fan Tray             TBD                    TBD              TBD    Height:
NTEUSSAA                                                            75 mm
------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-2
AGGREGATE UNIT KEY SPECIFICATION DETAILS

<TABLE>
------------------------------------------------------------------------------------------------------
            UNIT                        POWER CONSUMPTION     WEIGHT       FITS        WIDTH
      (SEE CHAPTER 5)                                          (KG)                    (MM)
------------------------------------------------------------------------------------------------------
<S>                                    <C>                    <C>          <C>         <C>
STM-4 1310 mm short haul optical       Maximum: 40W           1.875        2609        76.2
aggregate
NTEU20AA                               Typical: 36W
------------------------------------------------------------------------------------------------------
STM-4 1550 mm long haul optical        Maximum: 40W           1.875        2609        76.2
aggregate
NTEU21AA                               Typical: 36W
------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                 with regard to TN-4XE/TN-16XE

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------
            UNIT                          POWER               WEIGHT       FITS        NOMINAL
      (SEE CHAPTER 6)                   CONSUMPTION            (KG)                     WIDTH
                                                                                         (MM)
------------------------------------------------------------------------------------------------------
<S>                                     <C>                   <C>          <C>         <C>
STM-1 optical dual-port tributary       Maximum: 20 W         1.250        2184        25.4
unit (1310 mm, short haul)
NTEU10AA                                Typical: 17.5 W
------------------------------------------------------------------------------------------------------
STM-1a/140 Mibit/s tributary unit       Maximum: 20W          TBD          TBD         25.4
NTEU13AA
                                        Typical: 17.5 W
------------------------------------------------------------------------------------------------------
2 Mbit/s G.703 75 ohm tributary         Maximum: 20 W         TBD          500         25.4
unit
NTEU11AA                                Typical: 17.5 W
------------------------------------------------------------------------------------------------------
2 Mbit/s G.703 75 ohm tributary unit    Maximum: 20 W         TBD          500         25.4
NTEU12AA
                                        Typical: 17.5 W
------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-4
SERVICE INTERFACE MODULE (SIM) KEY DETAILS

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------
            UNIT                           POWER              WEIGHT       FITS        NOMINAL
      (SEE CHAPTER 4)                   CONSUMPTION            (KG)                     WIDTH
                                                                                         (MM)
------------------------------------------------------------------------------------------------------
<S>                                     <C>                   <C>          <C>         <C>
ETHERNET SIM PCB Assembly                   TBD                 TBD         28           25.4
NTEU6006
------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-5
CONNECTOR PANEL KEY DETAILS

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------
            UNIT                           POWER              WEIGHT       FITS        WIDTH
      (SEE CHAPTER 4)                   CONSUMPTION            (KG)                     (MM)
------------------------------------------------------------------------------------------------------
<S>                                     <C>                   <C>          <C>         <C>
End Of Shelf Upper                      Maximum: 5 W          0.468        345         25.4
NTEU4DAA
                                        Typical: 3 W
------------------------------------------------------------------------------------------------------
End Of Shelf Lower                      Maximum: 8 W          0.468        439         25.4
NTEU41AA
                                        Typical: 5 W
------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-6
SPECIAL FUNCTION UNITS SPECIFICATION DETAILS

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
            UNIT                          POWER               WEIGHT       FITS     EXTERNAL DIMENSIONS
      (SEE CHAPTER 7)                   CONSUMPTION                                        (MM)
-------------------------------------------------------------------------------------------------------
<S>                                     <C>                   <C>          <C>      <C>
Engineering Orderwire                   Maximum: 12 W         TBD          TBD       TBD
(EOW) card
NTEU43AA                                Typical: 8 W
------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier:                                      Reference No.: 11.1
Nortel Dasa
Network Systems GmbH & Co. KG                  otel.o Document No.: ST-rfx-00011
Rheinstrasse 37 - 39
60528 Frankfurt / Main                         Chapter: 1

                                               Item No.: 8
--------------------------------------------------------------------------------

                           With Regard to TN-4XE/16XE

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------

STM-4 Tributary

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

Gate 2 is February 2000.

Gate 2a is March 2000.

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems         Reference No.: 11.12.16

                                              otel.o Document No.: ST-rfx-00011

                                              Chapter: 1

                                              Item No.: 16, 17
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Coloured Interfaces 100/50 GHz Channel Spacing

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
The Transmitters and Regenerators provide a high performance tight wavelength
optical signal aligned with the 200 GHz ITU-T grid with a wavelength tolerance
of plus or minus 0.25 nm and provisionable output power.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /   Compliant development planned until     / / T1    / / T2      / / after T2
/ /   Further Development planned but not compliant with o.tel.o requirements
/ /   No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems          Reference No.: 11.12338

                                               otel.o Document No.: ST-rfx-00011

                                               Chapter: 12

                                               Item No.: 338
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Stationary Use Conditions acc. To prETS 300 019-2-3 Class T 3.2

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

OPERATIONAL AMBIENT TEMPERATURE

The TN-4XE can operate in the following operating environments as specified in
ETS 300-019 class 3.1 (Temperature Controlled Locations) subject to the thermal
management limitations specified above.

NON-OPERATIONAL AMBIENT TEMPERATURE

For storage and transportation, the equipment withstands non-operational
temperatures between -40 and +70 degrees C as specified in ETSI Standard ETS
300-019.

RELATIVE HUMIDITY

CONTINUOUS OPERATION

20 to 55% relative humidity or 3.6 kPa water vapor pressure, whichever is less,
over the normal temperature range; no condensation. Temperature: +4.5 degrees to
+38 degrees C.

SHORT-TERM OPERATION

Testing methodology IEC 68-2-56 Cb +30 degrees C, 95% relative humidity.

NOTE: Short-term is defined to be no more than 72 consecutive hours and a total
of not more than 15 days in one year.

EXCHANGE ENVIRONMENT

Normal operating environment 0 to +40 degrees C Exceptional operating
environment -5 to +45 degrees C.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /   Compliant development planned until    / / T1    / / T2       / / after T2
/ /   Further Development planned but not compliant with o.tel.o requirements
/ /   No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems          Reference No.: 11.341

                                               otel.o Document No.: ST-rfx-00011

                                               Chapter: 3

                                               Item No.: 41, 48
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Timing Source Priority Levels

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

Each of the selection circuits has a synchronization source hierarchy list.
These contain up to four synchronization sources listed in order of selection
preference. If the operator wishes to amend the hierarchy list all entries must
be re-entered.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /   Compliant development planned until    / / T1    / / T2       / / after T2
/ /   Further Development planned but not compliant with o.tel.o requirements
/ /   No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
NO

<PAGE>
                                with regard to TN-4XE / TN-16XE

                       SYSTEM FEATURE DESCRIPTION DXC-N/1

<TABLE>
<S>                       <C>
                          ----------------------------------------------------------------------------------------

ID                        ST-rfx-0009
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

                          ----------------------------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description DXC-N-1-10

                          ----------------------------------------------------------------------------------------

DESCRIPTION               This document lists the features of the Lower Order DXC Equipment.

                          The equipment shall mainly be applied for grooming lower order VCs from local access
                          providers or co-located customers towards STM-16 rings.

                          ----------------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

1        REQUESTED FEATURES

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
1                 INTERFACE TYPES
-----------------------------------------------------------------------------------------------------------------------------
1.1               INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           1.     2 Mbit/s G.703                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           2.     2 Mbit/s G.704 frame monitoring option on incoming traffic              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           3.     2 Mbit/s, retiming 250 us buffer
-----------------------------------------------------------------------------------------------------------------------------
           4.     34 Mbit/s G.703                                                         Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           5.     45 Mbit/s G.703                                                         Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           6.     STM-1 G.703                                                             Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           7.     S-1.1                                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           8.     S-4.1                                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           9.     S-16.1                                                                  Nc
-----------------------------------------------------------------------------------------------------------------------------
           10.    L-16.1                                                                  Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           11.    L-16.2                                                                  Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           12.    V-16.2                                                                  Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
1.3               EQUIPPING OF INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           13.    Up to (t.b.d.) electrical 2 Mbit/s ports can be equipped               252      252     252
-----------------------------------------------------------------------------------------------------------------------------
           14.    Up to (t.b.d.) electrical 34 Mbit/s ports can be equipped               24      24       24
-----------------------------------------------------------------------------------------------------------------------------
           15.    Up to (t.b.d.) electrical 45 Mbit/s ports can be equipped               24      24       24
-----------------------------------------------------------------------------------------------------------------------------
           16.    Up to (t.b.d.) el. 155 Mbit/s ports can be equipped                     8        8       8
-----------------------------------------------------------------------------------------------------------------------------
           17.    up to (t.b.d.) ports of type  STM-1 el. can be equipped                 8        8       8
-----------------------------------------------------------------------------------------------------------------------------
           18.    up to (t.b.d.) prots of type STM-4 can be equipped                      2        2       4
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
2                 CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
2.1               CONNECTION TYPES
-----------------------------------------------------------------------------------------------------------------------------
           19.    Bi-directional Connections on VC-12 level                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           20.    Bi-directional Connections on VC-3 level                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           21.    Bi-directional Connections on VC-4 level                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           22.    Bi-directional Connections of contiguously concatenated  VC-4           Nc       C       C
                  (VC-4-4c)
-----------------------------------------------------------------------------------------------------------------------------
           23.    Bi-directional Connections of contiguously concatenated  VC-4           Nc       C       C
                  (VC-4-16c)
-----------------------------------------------------------------------------------------------------------------------------
2.2               QUANTITATIVE REQUIREMENTS
-----------------------------------------------------------------------------------------------------------------------------
2.2.1             HIGHER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
           24.    HO connectivity of 16 * VC-4 equivalents                                Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           25.    HO connectivity of 64 * VC-4 equivalents                                Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           26.    HO connectivity of 128 * VC-4 equivalents                               Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
2.2.2             LOWER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
           27.    LO connectivity of 16 * VC-4 equivalents                                Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           28.    LO connectivity of 64 * VC-4 equivalents                                Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           29.    LO connectivity of 128 * VC-4 equivalents                               Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
3                 SYNCHRONISATION
-----------------------------------------------------------------------------------------------------------------------------
3.1               INTERNAL EQUIPMENT TIMING
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
3.1.1             TIMING SOURCES
-----------------------------------------------------------------------------------------------------------------------------
           30.    STM-N timing                                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           31.    2048 kHz timing                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           32.    Internal Oscillator acc. to G.813                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.1.2             TIMING SOURCE QUALITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
           33.    STM-N Timing at all SDH i/fs (Timing Marker Support)                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           34.    2048 kHz timing, fixed to G.811 quality                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           35.    2048 kHz timing, configurable timing source quality                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.1.3             TIMING SOURCE PRIORITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
           36.    Priority List of (at least 6 entries)                                   Nc      Nc       Nc      09.336
-----------------------------------------------------------------------------------------------------------------------------
3.1.4             SELECTION ALGORITHMS
-----------------------------------------------------------------------------------------------------------------------------
           37.    Autonomous Timing Source Selection                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           38.    Manual Timing Source Selection                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
3.2               EXTERNAL  TIMING OUTPUT (T4)
-----------------------------------------------------------------------------------------------------------------------------
3.2.1             TIMING  OUTPUT PORT
-----------------------------------------------------------------------------------------------------------------------------
           39.    One 2048 kHz timing output port                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           40.    Configurable timing output squelch function                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.2.2             TIMING SOURCES
-----------------------------------------------------------------------------------------------------------------------------
           41.    STM-N  timing                                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.2.3             TIMING SOURCE QUALITY LEVELS
----------------------------------------------------------------------------------------------------------------------------
           42.    STM-N Timing (Timing Marker Support)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
3.2.4             TIMING SOURCE PRIORITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
           43.    Priority List (at least 7 entries)                                      Nc      Nc       Nc      09.336
-----------------------------------------------------------------------------------------------------------------------------
3.2.5             SELECTION ALGORITHMS
-----------------------------------------------------------------------------------------------------------------------------
           44.    Autonomous timing source selection                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           45.    Manual Timing Source selection                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
4                 OVERHEAD ACCESS
-----------------------------------------------------------------------------------------------------------------------------
4.1               OVERHEAD BYTES
-----------------------------------------------------------------------------------------------------------------------------
           46.    Access to F1 as transparent channel                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           47.    Access to E1 as transparent channel                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           48.    Access to F2 as transparent channel                                     Nc      Nc       Nc      09.448
-----------------------------------------------------------------------------------------------------------------------------
4.2               OVERHEAD ACCESS INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           49.    64 K on V.11 (towards either MSOH or RSOH of aggregate interface)       Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           50.    64 K on V.11 (towards POH of tributary interface)                       Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
4.3               OVERHEAD CHANNEL CROSS CONNECTIONS
-----------------------------------------------------------------------------------------------------------------------------
           51.    64 K between syNchronous ports and towards external interface           Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
5                 ENGINEERING ORDERWIRE
-----------------------------------------------------------------------------------------------------------------------------
5.1               INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           52.    1 * 2 wire i/f (towards PSTN)                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           53.    2 * 2 wire  i/f (towards standard handset)                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
5.2               FUNCTIONS
-----------------------------------------------------------------------------------------------------------------------------
           54.    Selective Call                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           55.    Conference Call (up to four participants)                               Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
6                 MANAGEMENT COMMUNICATION
-----------------------------------------------------------------------------------------------------------------------------
6.1               COMMUNICATION INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           56.    F- Interface   (RS 232)                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           57.    Q- interface as gateway to the EMS                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           58.    Q I/F (Ethernet)                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           59.    Qecc via any ECC(R) on optical interfaces                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           60.    Qecc via any ECC(M) on optical interfaces                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           61.    Qecc via any ECC(R) on electrical interfaces                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           62.    Qecc via any ECC(M) on electrical interfaces                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           63.    Qecc Routing (level 2 IS-IS acc. to ISO 10589-8473)                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           64.    Domain Partitioning Repair function
-----------------------------------------------------------------------------------------------------------------------------
           65.    Definition of Manual Adjacencies (NSAP of dedicated NE)                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           66.    Manual definition of reachable addresses (set address prefix)           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           67.    ECC can be inserted / extracted to/from VC-4 POH Byte of SDH            C        C       C
                  interface
                  (Application: for transparent transmission of ECC via other
                  operator's SDH network)
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
6.2               O & M INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           68.    8 x Remote Control Inputs                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           69.    Remote Control Outputs                                                  Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           70.    Card LED support                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           71.    Subrack LED support                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           72.    Rack Alarm support                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
7                 PERFORMANCE MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
           73.    Performance History Data Collection (ES, SES and UAT) ...               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           74.    at any MST                                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           75.    at any RST                                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           76.    at any VC-4 TTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           77.    at any VC-3 TTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           78.    at any VC-12 TTP                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           79.    at any AU-4 CTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           80.    at any VC-3 CTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           81.    at any VC-12 CTP                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           82.    for any AU-4 Tandem Connection                                          Nc      Nc       Nc      09.782
-----------------------------------------------------------------------------------------------------------------------------
           83.    for any TU-3 Tandem Connection                                          Nc      Nc       Nc      09.782
-----------------------------------------------------------------------------------------------------------------------------
           84.    for any TU-12 Tandem Connection                                         Nc      Nc       Nc      09.782
-----------------------------------------------------------------------------------------------------------------------------
           85.    from remote TTPs based on FEBE evaluation                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           86.    Threshold Crossing Notification                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
8                 FAULT AND STATUS MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
8.1               DETECTED ANOMALIES, DEFECTS AND CONSEQUENT ACTIONS
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
8.1.1             ALL SYNCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           87.    Detection of Transmit Fail on any optical STM-N interface               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           88.    Detection of Laser Shutdown on any optical interface                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           89.    Detection of disabled ALS on any optical interface                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           90.    Detection of Optical Source Power High on any optical interface         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           91.    Detection of LOS, LOS status change hysteresis                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           92.    Insertion of AIS upon detection of LOS                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.2             ALL REGENERATOR SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           93.    Detection of OOF                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           94.    Detection of LOF                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           95.    Insertion of AIS upon persisting LOF detection                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           96.    Detection of RS EBER (10E-3) based on  B1 BIP-8 parity calculation      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.3             ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           97.    Detection of MS-AIS                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           98.    Insertion of all 1 upon detection of MS-AIS                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           99.    Detection of Signal Degrade                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           100.   Detection of MS-EBER (10E-3) upon B2 BIP-24 parity error
                  calculation                                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           101.   Insertion of AIS and FERF upon detection of MS-AIS                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           102.   Detection of FERF                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           103.   Insertion of MS-FEBE based on detection of B2 parity calculations       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.4             ALL MULTIPLEX SECTION ADAPTATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           104.   Detection  of AU-LOP                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           105.   Detection of AU-AIS                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           106.   Detection of Number of AU-Pointer Justification Events                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           107.   Insertion of AU-AIS upon receive of all 1                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
8.1.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           108.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           109.   Detection of HP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           110.   Detection of HP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           111.   Detection of HP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           112.   Detection of HP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           113.   Detection of B3- EBER (10E-3)                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.6             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-----------------------------------------------------------------------------------------------------------------------------
           114.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           115.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           116.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           117.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           118.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           119.   Detection of EBER                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.7             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-12)
-----------------------------------------------------------------------------------------------------------------------------
           120.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           121.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           122.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           123.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           124.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           125.   Detection of EBER                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.8             ALL HIGH ORDER PATH TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           126.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           127.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>

<CAPTION>

-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           128.   Detection of HP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           129.   Detection of HP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           130.   Insertion of AIS and HP-FERF upon detection of HP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           131.   Detection of HP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           132.   Insertion of AIS and HP-FERF upon detection of HP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           133.   Detection of HP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           134.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.9             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-----------------------------------------------------------------------------------------------------------------------------
           135.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           136.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           137.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           138.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           139.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           140.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           141.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           142.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           143.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.10            ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-----------------------------------------------------------------------------------------------------------------------------
           144.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           145.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           146.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           147.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           148.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           149.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           150.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           151.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           152.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.11            ALL PLESIOCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           153.   Detection of Trib.-AIS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           154.   Detection of Trib.-LOS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           155.   Detection of Trib.-LOF                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           156.   Insertion of AIS upon detection of Trib.-AIS, Trib.-LOS, Trib.-LOF      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.12            SETS AND SETPI
-----------------------------------------------------------------------------------------------------------------------------
           157.   Detection of Sync. Source Fail                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           158.   Detection of SETG - Hold                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           159.   Detection of SETG - Out of Lock                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           160.   Detection of SETG - Fail                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           161.   Detection of Sync. Degrade                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           162.   Detection of Excessive Sync. Degrade                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           163.   Detection of Sync. Source Threshold Crossing                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           164.   Detection of Sync. LOS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.13            MANAGEMENT COMMUNICATION FUNCTION
-----------------------------------------------------------------------------------------------------------------------------
           165.   Detection of Remote Control Input Active                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           166.   Detection of RS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           167.   Detection of MS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.1.14            SYSTEMS MANAGEMENT FUNCTION
-----------------------------------------------------------------------------------------------------------------------------
           168.   Detection of Secondary Power Fail                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           169.   Detection of Primary Power Fail                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           170.   Detection of Re-Boot Fail                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           171.   Detection of Configuration Data Integrity Check Failure                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           172.   Detection of System Software Integrity Check Failure                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           173.   Detection of Network Element Controller Fail                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           174.   Detection of Card Protection Switch Failure                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           175.   Detection of Card Out                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           176.   Detection of Card Fail (upon detection of internal parity
                  mismatch etc.)                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           177.   Detection of Wrong Card                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           178.   Network Protection Switch Failure                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.2               STATUS EVENTS
-----------------------------------------------------------------------------------------------------------------------------
           179.   Configuration Data Integrity Fail                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           180.   System Software Integrity Fail                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           181.   Laser Restart for Test                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           182.   Synchronous Equipment Timing Generator A/B active                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           183.   Synchronisation Source Quality Change                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           184.   Synchronisation Source Switch Event                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           185.   External Synchronisation Output Squelched                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           186.   Section Layer Protection Switch Active                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           187.   Network Protection Switch Event                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           188.   Card Protection Switch Active                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           189.   Fault / Status Log Capacity Exceeded                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           190.   Configuration Data Transaction Log Capacity Exceeded                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           191.   Performance Monitoring Log Capacity Exceeded                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           192.   Access  Log Capacity Exceeded                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           193.   Software Download in Progress                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           194.   Software Download Failure                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           195.   Software Download Failure - Retry in Progress                           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           196.   Software Download Complete                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           197.   Card Restoration Complete                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           198.   Re-Boot Restoration Complete                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           199.   Electronic Label Update                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
8.3               ALARM EVENT HANDLING
-----------------------------------------------------------------------------------------------------------------------------
           200.   Alarm Persistence Filter (filtering of toggling alarms)                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           201.   Alarm Correlation Filter (F3 filter, suppression of consequent          C        C       C
                  alarms)
-----------------------------------------------------------------------------------------------------------------------------
           202.   Alarm Inversion Facility                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           203.   Performance of the alarm throughput > 10 alarms per second              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           204.   It is possible to block/unblock each single traffic relevant
                  alarm per port                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           205.   It is possible to block/unblock each single traffic relevant
                  alarm group per card                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           206.   It is possible to block/unblock each single traffic relevant
                  alarm group per NE                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           207.   Indication of Alarm Event Forwarding Suppression per functional         C        C       C
                  unit (e.g. Regenerator Section ...)
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
9                 CONFIGURATION MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
9.1               GENERAL
-----------------------------------------------------------------------------------------------------------------------------
           208.   Upload of Configuration Data - on single command                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           209.   Upload of Configuration Data - on bulk command                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           210.   Download of Configuration Data - on bulk command                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2               CONFIGURATION OF FUNCTIONAL BLOCKS
-----------------------------------------------------------------------------------------------------------------------------
9.2.1             ALL SYNCHRONOUS OPTICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
           211.   Enable / Disable Automatic Laser Shutdown                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           212.   Enable / Disable Laser                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           213.   Enable Laser for Test Purposes  (2s  / 90s)                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.2             ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           214.   Set Threshold Signal Degrade                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           215.   Set Threshold B2-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.3             ALL REGENERATOR SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           216.   Set Threshold B1-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.4             ALL HIGH ORDER PATH TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           217.   Set Threshold B3-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           218.   Set Threshold HP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           219.   Enable / Disable consequent actions from detection of HP-TIM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           220.   Enable / Disable consequent actions from detection of HP-SLM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           221.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           222.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.5             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-----------------------------------------------------------------------------------------------------------------------------
           223.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           224.   Set Threshold LP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           225.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           226.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           227.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           228.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.6             ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-----------------------------------------------------------------------------------------------------------------------------
           229.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           230.   Set Threshold LP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           231.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           232.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
-----------------------------------------------------------------------------------------------------------------------------
           233.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           234.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
9.2.7             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-----------------------------------------------------------------------------------------------------------------------------
           235.   Set Threshold B3-EBER                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           236.   Set Threshold HP-FEBE                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           237.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           238.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.8             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-----------------------------------------------------------------------------------------------------------------------------
           239.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           240.   Set Threshold FEBE                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           241.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           242.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
9.2.9             ALL HIGH ORDER CONNECTION SUPERVISION POINTS (TU-12)
-----------------------------------------------------------------------------------------------------------------------------
           243.   Set Threshold EBER                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           244.   Set Threshold FEBE                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           245.   Set expected Signal Label (per Path)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           246.   Set expected Path Trace (per Path)                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
10                NETWORK PROTECTION
-----------------------------------------------------------------------------------------------------------------------------
10.1              HIGHER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I)
-----------------------------------------------------------------------------------------------------------------------------
           247.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           248.   Switch-Over Completion Time less than 100ms                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           249.   Configurable Hold-Off Time                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           250.   Enable / Disable Automatic Switching                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           251.   Manual Switching via Management Interface                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           252.   Configurable Wait Time to Restore                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
10.2              LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-3)
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           253.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           254.   Switch-Over Completion Time less than 300ms                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           255.   Configurable Hold-Off Time                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           256.   Enable / Disable Automatic Switching                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           257.   Manual Switching via Management Interface                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           258.   Configurable Wait Time to Restore                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
10.3              LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-12)
-----------------------------------------------------------------------------------------------------------------------------
           259.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           260.   Switch-Over Completion Time less than 300ms                             C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           261.   Configurable Hold-Off Time                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           262.   Enable / Disable Automatic Switching                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           263.   Manual Switching via Management Interface                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           264.   Configurable Wait Time to Restore                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
10.5              1+1 LINE PROTECTION
-----------------------------------------------------------------------------------------------------------------------------
           265.   1+1 Line Protection function on all optical tributaries                 Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           266.   1+1 Line Protection function on all electrical STM-1 tributaries        Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           267.   Detection Criterion Signal Fail and Signal Degrade according
                  to Section 2.3 of ITU-T rec. G.783                                      Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           268.   Switch-Over Completion Time LESS THAN 50ms                              Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           269.   Enable / Disable Automatic Switching                                    Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           270.   Manual Switching via Management Interface                               Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           271.   Configurable Wait Time to Restore                                       Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
10.6              MS SHARED RING PROTECTION (MSBSHR)
-----------------------------------------------------------------------------------------------------------------------------
           272.   Detection Criterion Signal Fail and Signal Degrade according to         Nc      Nc       Nc
                  Section 2.3 of ITU-T rec. G.783
-----------------------------------------------------------------------------------------------------------------------------
           273.   Switch-Over Completion Time LESS THAN 50ms                              Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           274.   Manual Switching via Management Interface                               Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           275.   Revertive Switching                                                     Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           276.   Configurable Wait Time to Restore                                       Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           277.   Maximum number of network elements in the ring                          Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           278.   It is possible to configure (unprotected) low priority traffic          Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
11                OPERATION AND MAINTENANCE
-----------------------------------------------------------------------------------------------------------------------------
11.1              GENERAL
-----------------------------------------------------------------------------------------------------------------------------
           279.   Event buffer                                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           280.   Heart Beat Function                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           281.   Re-boot function                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           282.   Real time clock function                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           283.   NSAP Address modification                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           284.   Local Software Download                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           285.   Remote Software Download                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           286.   Manager Decision Process for equipment access control                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           287.   Display of VC-4 Path Trace at HPT                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           288.   Display of VC-4 Signal Label at HPT                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           289.   Display of VC-4 Path Trace at HPOM                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           290.   Display of VC-4 Signal Label at HPOM                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           291.   Display of VC-3 Path Trace at LPT                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           292.   Display of VC-3 Signal Label at LPT                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           293.   Display of VC-3 Path Trace at LPOM                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           294.   Display of VC-3 Signal Label at LPOM                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           295.   Display of VC-12 Path Trace at LPT                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           296.   Display of VC-12 Signal Label at LPT                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           297.   Display of VC-12 Path Trace at LPOM                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           298.   Display of VC-12 Signal Label at LPOM                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           299.   Display of Optical Transmit Power Level                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------
11.2              LOGS
-----------------------------------------------------------------------------------------------------------------------------
           300.   Alarm / Status Log                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           301.   Performance Log                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           302.   Configuration  Log                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           303.   Access Control  Log                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
11.3              REDUNDANCY
-----------------------------------------------------------------------------------------------------------------------------
           304.   1:N Tributary Card Protection 2  Mbit/s                                 Nc      Nc       C
-----------------------------------------------------------------------------------------------------------------------------
           305.   1:N or 1+1  Tributary Card Protection 34 Mbit/s                         Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           306.   1:N or 1+1 Tributary Card Protection 45 Mbit/s                          Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           307.   1:N or 1+1 (electrical) Tributary Card Protection STM-1 G.703           Nc       C       C
-----------------------------------------------------------------------------------------------------------------------------
           308.   1+1 Protection of all Central Traffic Carrying Cards                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           309.   1+1 Protection of Clock System                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           310.   Duration LESS THAN 5s for card protection automatic switch over         C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>

-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
-----------------------------------------------------------------------------------------------------------------------------
11.4              EQUIPMENT TESTING FUNCTIONS
-----------------------------------------------------------------------------------------------------------------------------
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           311.   Integrity Check of Configuration Data                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           312.   Integrity Check of System Software                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           313.   Configuration of Loop Back on port level on all PDH Interface Cards     C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           314.   VC-4 level Configuration of Loop Back on STM-1 el. i/f                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           315.   VC-4 level Configuration of Loop Back on all STM-4 opt. interfaces      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           316.   VC-3 level Configuration of Loop Back on all electrical SDH             C        C       C
                  Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
           317.   VC-3 level Configuration of Loop Back on all optical SDH Interface      C        C       C
                  Cards
-----------------------------------------------------------------------------------------------------------------------------
           318.   VC-12 level Configuration of Loop Back on all electrical SDH            C        C       C
                  Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
           319.   VC-12 level Configuration of Loop Back on all optical SDH Interface     C        C       C
                  Cards
-----------------------------------------------------------------------------------------------------------------------------
           320.   Configuration of Loop Back on the HPC functional block                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           321.   Configuration of Loop Back on the LPC functional block                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           322.   Test Access Interface on all electrical interfaces                      Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           323.   Test Access Interface on all optical interfaces                         Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------------
           324.   Optical Line Testing                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
11.5              INVENTORY DATA
-----------------------------------------------------------------------------------------------------------------------------
           325.   Electronic Label Read Access via Management Interfaces                  C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           326.   Automatic Electronic Label Upgrade                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           327.   Compatibility Check of Equipment Hardware Releases                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           328.   Compatibility Check of Equipment Firmware Releases                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           329.   Compatibility Check of Equipment Software Releases                      C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           330.   Compatibility Check of Equipment Software Releases to the               C        C       C
                  Management System
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
12                ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL COMPATIBILITY AND SAFETY
-----------------------------------------------------------------------------------------------------------------------------
12.1              CLIMATIC CONDITIONS
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           331.   Stationary Use Conditions acc. to prETS 300 019-2-3 Class T 3.2         Nc      Nc       Nc      09.331
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
12.2              ELECTROMAGNETIC COMPATIBILITY
-----------------------------------------------------------------------------------------------------------------------------
           332.   Compliance with EN 55022 class B                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           333.   Compliance with EN 50082                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
12.3              SAFETY REQUIREMENTS

-----------------------------------------------------------------------------------------------------------------------------
           334.   Compliance with EN 60950                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           335.   Compliance with IEC 825-1 and IEC 825-2                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
13                PHYSICAL DIMENSIONS
-----------------------------------------------------------------------------------------------------------------------------
           336.   Rack size according to ETSI 300 119, 600 mm x 300 mm                    C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           337.   System installation and h/w upgrade via front access possible           C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           338.   Number of racks in minimum configuration                                1        1       1
-----------------------------------------------------------------------------------------------------------------------------
           339.   Number of racks in maximum configuration                                1        1       1
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
14                POWER SUPPLY
-----------------------------------------------------------------------------------------------------------------------------
           340.   Nominal input voltage -48V                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           341.   Minimum accepted input voltage                                          -38V     -38V    -38V
-----------------------------------------------------------------------------------------------------------------------------
           342.   Maximum accepted input voltage                                          -75V     -75V    -75V
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
15                AVAILABILITY
-----------------------------------------------------------------------------------------------------------------------------
           343.   The supplier shall provide MTBF figures for each functional unit of     IR       IR      IR       ANNEX 1
                  the offered equipment based on his statistical evaluations
                  according to the template as attached in Annex 1
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
16                POWER CONSUMPTION
-----------------------------------------------------------------------------------------------------------------------------
           344.   The supplier shall provide worst case power consumption figures for     IR       IR      IR       ANNEX 1
                  each functional unit of the offered equipment according to the
                  template as attached in Annex 1
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
17                SYSTEM MANUALS
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-----------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>     <C>
-----------------------------------------------------------------------------------------------------------------------------
           345.   System Description in Hypertext Format on CD                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
           346.   System O&M Manuals in Hypertext Format on CD                            C        C       C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

2        REFERENCES

2.1      REFERENCES TO STANDARDS

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS    DATE    TITLE
----------------------------------------------------------------------------------------------------------------------
<S>                  <C>       <C>     <C>
CECC 86 275-80                 09/95   Detail Specification: Connector sets for optical fibres and cables Type
                                       LSH-HRL
----------------------------------------------------------------------------------------------------------------------
ITU-T G.703                    04/91   Physical/Electrical characteristics of Hierarchical Digital Interfaces
----------------------------------------------------------------------------------------------------------------------
ITU-T G.707                    1991    Synchronous digital hierarchy bit rates
----------------------------------------------------------------------------------------------------------------------
ITU-T G.782                    1994    Types and general characteristics of synchronous digital hierarchy (SDH)
                                       equipment
----------------------------------------------------------------------------------------------------------------------
ITU-T G.783                    1994    Characteristics of synchronous digital hierarchy/SDH) equipment functional
                                       blocks
----------------------------------------------------------------------------------------------------------------------
ITU-T G.813                    1996    Timing Characteristics of SDH equipment slave clocks.
----------------------------------------------------------------------------------------------------------------------
ITU-T G.825                    1993    The control of Jitter and Wander within Digital Networks which are based on
                                       synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------
ITU-T                                  G.826 11/93 Error performance parameters and objectives for International
                                       constant Bit Rate Digital Paths at or above the Primary Rate
----------------------------------------------------------------------------------------------------------------------
ITU-T G.841                    1995    Types and Characteristics of SDH Network Protection Architectures
----------------------------------------------------------------------------------------------------------------------
ITU-T G.957                    1993    Optical Interfaces and Systems relating to the synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
ETS 300 019          pr        02/92   Environmental conditions and Environmental Tests for Telecommunications
                                       Equipment
                                       Part A:  Introduction and Terminology
                                       Part B:  classification of Environmental conditions
----------------------------------------------------------------------------------------------------------------------
ETS 300 119                            European Telecommunication Standard for Equipment Practice
                               03/93   Part 2:  Engineering Requirements for Racks
                               09/93   Part 3:  Engineering Requirements for Miscellaneous Racks and cabinets
                               09/93   Part 4:  Engineering Requirements for Subracks
----------------------------------------------------------------------------------------------------------------------
ETS 300 253                    01/95   Earthing and bonding of telecommunication equipment in telecommunication
                                       centres
----------------------------------------------------------------------------------------------------------------------
EN 41003                       1991    Particular safety requirements for equipment to be connected to
                                       telecommunication network
----------------------------------------------------------------------------------------------------------------------
EN 55022                       05/95   Grenzwerte und Mebverfahren fur Funkstorungen von Einrichtungen der
                                       Informationstechnik
----------------------------------------------------------------------------------------------------------------------
EN 50082                               Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                               12/94   Part 1:  Elektromagnetische  Vertraglichkeit - Fachgrundnorm
                                                Storfestigkeit - Teil 1: Wohnbereich, Geschafts - und
                                                Gewerbebereiche sowie Kleinbetriebe
                               02/96   Part 2:  Elektromagnetische Vertraglichkeit - Fachgrundnorm
                                                Starfestigkeit - Teil 2: Industriebereich
----------------------------------------------------------------------------------------------------------------------
DIN 47295                              HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
----------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

     The following tables list details of the power dissipation, weight, FITS
     and size for the TN-4XE equipment.

TABLE 8-1
SUBRACK KEY SPECIFICATION DETAILS

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
        UNIT                 POWER             WEIGHT        FITS      EXTERNAM DIMENSIONS (MM)
   (SEE CHAPTER 4)        CONSUMPTION
-------------------------------------------------------------------------------------------------------
<S>                     <C>                  <C>             <C>     <C>
TN-4XE Mux              Maximum              18 kg (max.)     41     Height:
assembly                (full fit): 253 W    (unequipped)            550 mm (including fibretray)
NTEU70AA                                     20 kg (actual)          450 mm (excluding fibre tray)
                        Typical: 220 W                               An additional height of 50 mm if
                                                                     2 Mbit's tributary cabling is
                                                                     installed.
                                                                     Width:
                                                                     450 mm (excl. mounting flanges)
                                                                     Depth:
                                                                     280 mm (incl. doors/covers)
-------------------------------------------------------------------------------------------------------
Fan Tray                TBD                  TBD              TBD    Height:
NTEU55AA                                                             75 mm
-------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-2
AGGREGATE UNIT KEY SPECIFICATION DETAILS

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
          UNIT                        POWER CONSUMPTION          WEIGHT          FITS          WIDTH
     (SEE CHAPTER 5)                                              (KG)                          (MM)
-------------------------------------------------------------------------------------------------------
<S>                                   <C>                        <C>             <C>           <C>
STM-4 1310 nm short haul optical      Maximum: 40 W              1.875           2609           76.2
aggregate
NTEU20AA                              Typical: 36 W
-------------------------------------------------------------------------------------------------------
STM-4 1550 nm long haul optical       Maximum: 40 W              1.875           2690           76.2
aggregate
NTEU21AA                              Typical: 36 W
-------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>
                                with regard to TN-4XE / TN-16XE

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
          UNIT                                   POWER                   WEIGHT      FITS      NOMINAL
     (SEE CHAPTER 6)                          CONSUMPTION                 (KG)                  WIDTH
                                                                                                 (MM)
-------------------------------------------------------------------------------------------------------
<S>                                        <C>                           <C>         <C>       <C>
STM-1 optical dual-port tributary          Maximum: 20W                  1.250       2184      25.4
unit (1310 nm, short haul)
NTEU10AA                                   Typical: 17.5 W
-------------------------------------------------------------------------------------------------------
STM-10/140 Mbit/s tributary unit           Maximum: 20 W                 TBD         TBD       25.4
NTEU13AA
                                           Typical 17.5 W
-------------------------------------------------------------------------------------------------------
2 Mbit/s G.703 120 ohm tributary           Maximum: 20 W                 TBD         500       25.4
unit
NTEU12AA                                   Typical: 17.5 W
-------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-4
SERVICE INTERFACE MODULE (SIM) KEY DETAILS

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
          UNIT                                   POWER                   WEIGHT      FITS       WIDTH
     (SEE CHAPTER 4)                          CONSUMPTION                 (KG)                  (MM)
-------------------------------------------------------------------------------------------------------
<S>                                           <C>                        <C>         <C>       <C>
ETHERNET SIM PCB ASSEMBLY                        TBD                      TBD         28         25.4
NTEU6066
-------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-5
CONNECTOR PANEL KEY DETAILS

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
          UNIT                                   POWER                   WEIGHT      FITS       WIDTH
     (SEE CHAPTER 4)                          CONSUMPTION                 (KG)                  (MM)
-------------------------------------------------------------------------------------------------------
<S>                                        <C>                           <C>         <C>       <C>
End Of Shelf Upper                         Maximum: 5 W                  0.468       345        25.4
NTEU40AA
                                           Typical: 3 W
-------------------------------------------------------------------------------------------------------
End Of Shelf Lower                         Maximum: 8 W                  0.468       439        25.4
NTEU41AA
                                           Typical: 5 W
-------------------------------------------------------------------------------------------------------
</TABLE>

TABLE 8-6
SPECIAL FUNCTION UNITS SPECIFICATION DETAILS

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
        UNIT                            POWER             WEIGHT      FITS       EXTERNAL DIMENSIONS
   (SEE CHAPTER 7)                   CONSUMPTION                                        (MM)
-------------------------------------------------------------------------------------------------------
<S>                                 <C>                   <C>         <C>        <C>
Engineering Orderwire               Maximum: 12 W           TBD        TBD        TBD
(EOW) card
NTEU43AA                            Typical: 8 W
-------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems      Reference No.: 09.331

                                           otel.o Document No.: ST-rfx-0009

                                           Chapter: 12

                                           Item No.: 331
------------------------------------------------------------------------------

------------------------------------------------------------------------------
1. Item of non compliance
------------------------------------------------------------------------------
Stationary Use Conditions acc. To prETS 300 019-2-3 Class T 3.2

------------------------------------------------------------------------------
2. Description of non compliance
------------------------------------------------------------------------------

OPERATIONAL AMBIENT TEMPERATURE

The TN-4XE can operate in the following operating environments as specified in
ETS 300-019 class 3.1 (Temperature Controlled Locations) subject to the thermal
management limitations specified above.

NON-OPERATIONAL AMBIENT TEMPERATURE

For storage and transportation, the equipment withstands non-operational
temperatures between -40 and +70 DEG. C as specified in ETSI Standard
ETS 300-019.

RELATIVE HUMIDITY

CONTINUOUS OPERATION

20 to 55% relative humidity or 3.6 kPa water vapor pressure, whichever is less,
over the normal temperature range; no condensation. Temperature: +4.5 DEG. to
+38 DEG. C.

SHORT-TERM OPERATION

Testing methodology IEC 68-2-56 Cb +30 DEG. C, 95% relative humidity.

NOTE: Short-term is defined to be no more than 72 consecutive hours and a total
of not more than 15 days in one year.

EXCHANGE ENVIRONMENT

Normal operating environment 0 to +40 DEG. C
Exceptional operating environment -5 to +45 DEG. C

------------------------------------------------------------------------------
3. Proposed further Development:
------------------------------------------------------------------------------

   / / Compliant development planned until   / / T1   / / T2   / / after T2
   / / Further Development planned but not compliant with o.tel.o requirements
   / / No further development

------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
------------------------------------------------------------------------------

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems      Reference No.: 09.336

                                           otel.o Document No.: ST-rfx-0009

                                           Chapter: 3

                                           Item No.: 36, 43
------------------------------------------------------------------------------

------------------------------------------------------------------------------
1. Item of non compliance
------------------------------------------------------------------------------
Timing Source Priority Levels

------------------------------------------------------------------------------
2. Description of non compliance
------------------------------------------------------------------------------

Each of the selection circuits has a synchronization source hierarchy list.
These contain up to four synchronization sources listed in order of selection
preference. If the operator wishes to amend the hierarchy list all entries
must be re-entered.

------------------------------------------------------------------------------
3. Proposed further Development:
------------------------------------------------------------------------------

   / / Compliant development planned until   / / T1   / / T2   / / after T2
   / / Further Development planned but not compliant with o.tel.o requirements
   / / No further development

------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
------------------------------------------------------------------------------
NO

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems      Reference No.: 09.448

                                           otel.o Document No.: ST-rfx-0009

                                           Chapter: 4

                                           Item No.: 48
------------------------------------------------------------------------------

-------------------------------------------------------------------------------
1. Item of non compliance
-------------------------------------------------------------------------------
Access to F2 as transparent channel

-------------------------------------------------------------------------------
2. Description of non compliance
-------------------------------------------------------------------------------

Bytes F2 and F3 in the POH are reserved for use as 64 kbit/s user channels on a
VC-3 or VC-4 path. Nortel Networks' SDH products are in accordance with ITU-T
Recommendation. G.707 which specifies the requirements for the STM-N signals in
terms of bit rates, frame structures and support for the overhead bytes provided
therein. At the physical level, the position of the F2 byte in the STM-1 frames
of Nortel Networks SDH equipment are in accordance with ITU-T Rec. G.707(1) and
ETS 300 147 (Apr 97). Nortel Networks' SDH products do not currently process the
F2 / F3 byte 64 kbit/s `user channel' of the VC-3 / VC-4 Path Overhead and hence
this feature is not used in present applications. The Tx direction of the F2 and
F3 bytes are set to all ones, and the Rx direction is ignored.

The F2 / F3 byte 64 kbit/s `user channel' feature may be introduced at a later
date with a S/W upgrade.

------------------------------------------------------------------------------
3. Proposed further Development:
------------------------------------------------------------------------------

   / / Compliant development planned until   / / T1   / / T2   / / after T2
   / / Further Development planned but not compliant with o.tel.o requirements
   / / No further development

------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
------------------------------------------------------------------------------
NO

--------------------
(1) ITU-T G.707 (03/96) Recommendation is a merged revised version of
Recommendation G.707, G708 and G.709 approved in 03/93.

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems      Reference No.: 09.782

                                           otel.o Document No.: ST-rfx-0009

                                           Chapter: 7

                                           Item No.: 82, 83, 84
------------------------------------------------------------------------------

------------------------------------------------------------------------------
1. Item of non compliance
------------------------------------------------------------------------------
Performance Management for Tandem Connection

------------------------------------------------------------------------------
2. Description of non compliance
------------------------------------------------------------------------------

At the moment Performance Monitoring is executed at the termination points of
the relevant services. Hence it's possible to determine the QoS for the whole
connection.

------------------------------------------------------------------------------
3. Proposed further Development:
------------------------------------------------------------------------------

   / / Compliant development planned until   / / T1   / / T2   / / after T2
   / / Further Development planned but not compliant with o.tel.o requirements
   / / No further development

------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
------------------------------------------------------------------------------

<PAGE>

                                    With regard to TN-4XE

                                    SYSTEM FEATURE DESCRIPTION TM-N/1
                          ------------------------------------------------------

ID                        ST-RFX-0010
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

                          ------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description TM-N-1-10

                          ------------------------------------------------------

DESCRIPTION               This document lists the features of the TM-N/1
                          Equipment, wheras N=1, 4

                          The equipment shall mainly be applied as SDH trail or
                          connection terminating mux at customer premises.

                          ------------------------------------------------------

CHANGE LOG                1.0 / APPROVED / 09/04/99 / J. Gimmler

--------------------------------------------------------------------------------

<PAGE>
<TABLE>
<CAPTION>

                                    With regard to TN-4XE

1        REQUESTED FEATURES
-------------------------------------------------------------------------------------------------------------

           NO.    ITEM                                                                   SOC      SOC     SOC     REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------
1                 INTERFACE TYPES
-------------------------------------------------------------------------------------------------------------
1.1               TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
           1.     2 Mbit/s G.703                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           2.     2 Mbit/s G.704 frame monitoring option on incoming traffic              C        C       C
-----------------------------------------------------------------------------------------------------------------------
           3.     2 Mbit/s, retiming 250 us buffer
           4.     34 Mbit/s G.703                                                         Nc       C       C
-----------------------------------------------------------------------------------------------------------------------
           5.     45 Mbit/s G.703                                                         Nc       C       C
-----------------------------------------------------------------------------------------------------------------------
           6.     STM-1 G.703                                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           7.     S-1.1                                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
1.2               AGGREGATE INTERFACES
           8.     STM-1 G.703                                                             Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------
           9.     S-1.1                                                                   Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------
           10.    L-1.1                                                                   Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------
           11.    S-4.1                                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           12.    L-4.1                                                                   Nc      Nc       Nc    10.112
1.3               EQUIPPING OF INTERFACES
-----------------------------------------------------------------------------------------------------------------------
1.3.1             TRIBUTARY INTERFACES
-----------------------------------------------------------------------------------------------------------------------
           13.     Up to LESS THAN t.b.d. GREATER THAN electrical 2 Mbit/s ports         252      252     252
                   can be equipped
-----------------------------------------------------------------------------------------------------------------------
           14.     Up to LESS THAN t.b.d. GREATER THAN electrical 34 Mbit/s               24      24       24
                   ports can be equipped
-----------------------------------------------------------------------------------------------------------------------
           15.     Up to LESS THAN t.b.d. GREATER THAN electrical 45 Mbit/s               24      24       24
                   ports can be equipped
-----------------------------------------------------------------------------------------------------------------------
           16.     Up to LESS THAN t.b.d. GREATER THAN el. 155 Mbit/s ports can           8        8       8
                   be equipped
-----------------------------------------------------------------------------------------------------------------------

2                 CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------
2.1               CONNECTION TYPES
-----------------------------------------------------------------------------------------------------------------------
           17.    Bi-directional Connections on VC-12 level                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           18.    Bi-directional Connections on VC-3 level                                C        C       C
-----------------------------------------------------------------------------------------------------------------------
           19.    Bi-directional Connections on VC-4 level                                C        C       C
-----------------------------------------------------------------------------------------------------------------------
           20.    Bi-directional Connections of contiguously concatenated  VC-4           Nc       C       C
                  (VC-4-4c)
-----------------------------------------------------------------------------------------------------------------------
2.2               QUANTITATIVE REQUIREMENTS
-----------------------------------------------------------------------------------------------------------------------
2.2.1             HIGHER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------

           21.     HO termination of LESS THAN t.b.d. GREATER THAN * VC-4                 IR      IR       IR       10.2
                   equivalents from aggregate
-----------------------------------------------------------------------------------------------------------------------
           22.     HO add/drop of LESS THAN t.b.d. GREATER THAN * VC-4                    4        4       4        10.2
                   equivalents from aggregate west
\-----------------------------------------------------------------------------------------------------------------------
           23.     HO add/drop of LESS THAN t.b.d. GREATER THAN * VC-4                    4        4       4        10.2
                   equivalents from aggregate west
-----------------------------------------------------------------------------------------------------------------------
2.2.2             LOWER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------
           24.     LO termination of LESS THAN t.b.d. GREATER THAN * VC-4                 IR      IR       IR       10.2
                   equivalents from aggregate
-----------------------------------------------------------------------------------------------------------------------
           25.     LO add/drop of LESS THAN t.b.d. GREATER THAN * VC-4                    4        4       4        10.2
                   equivalents from aggregate west
-----------------------------------------------------------------------------------------------------------------------

<PAGE>

                                    With regard to TN-4XE

<CAPTION>
<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
           26.    LO add/drop of LESS THAN t.b.d. GREATER THAN * VC-4                     4        4       4        10.2
                  equivalents from aggregate west
-----------------------------------------------------------------------------------------------------------------------

3                 SYNCHRONISATION
-----------------------------------------------------------------------------------------------------------------------
3.1               INTERNAL EQUIPMENT TIMING
-----------------------------------------------------------------------------------------------------------------------
3.1.1             TIMING SOURCES
-----------------------------------------------------------------------------------------------------------------------
           27.    STM-N timing                                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------
           28.    2048 kHz timing                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           29.    Internal Oscillator acc. to G.813                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
3.1.2             TIMING SOURCE QUALITY LEVELS
           30.    STM-N Timing at all SDH i/fs (Timing Marker Support)                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           31.    2048 kHz timing, fixed to G.811 quality                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           32.    2048 kHz timing, configurable timing source quality                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
3.1.3             TIMING SOURCE PRIORITY LEVELS
           33.    Priority List of (at least 6 entries)                                   Nc      Nc       Nc    10.333
-----------------------------------------------------------------------------------------------------------------------
3.1.4             SELECTION ALGORITHMS
           34.    Autonomous Timing Source Selection                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------
           35.    Manual Timing Source Selection                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
3.2               EXTERNAL  TIMING OUTPUT (T4)
-----------------------------------------------------------------------------------------------------------------------
3.2.1             TIMING  OUTPUT PORT
-----------------------------------------------------------------------------------------------------------------------
           36.    One 2048 kHz timing output port                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           37.    Configurable timing output squelch function                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
3.2.2             TIMING SOURCES
           38.    STM-N  timing                                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
3.2.3             TIMING SOURCE QUALITY LEVELS
           39.    STM-N Timing (Timing Marker Support)                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
3.2.4             TIMING SOURCE PRIORITY LEVELS
           40.    Priority List (at least 7 entries)                                      Nc      Nc       Nc    10.333
-----------------------------------------------------------------------------------------------------------------------
3.2.5             SELECTION ALGORITHMS
           41.    Autonomous timing source selection                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------
           42.    Manual Timing Source selection                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------

4                 MANAGEMENT COMMUNICATION
-----------------------------------------------------------------------------------------------------------------------
4.1               COMMUNICATION INTERFACES
-----------------------------------------------------------------------------------------------------------------------
           43.    F- Interface   (RS 232)                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           44.    Q I/F (Ethernet)                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
           45.    Q- interface as gateway to the EMS                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------
           46.    Qecc via any ECCR  on optical  interfaces                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           47.    Qecc via any ECCM on optical  interfaces                                C        C       C
-----------------------------------------------------------------------------------------------------------------------
           48.    Qecc via any ECCR  on electrical  interfaces                            C        C       C
-----------------------------------------------------------------------------------------------------------------------
           49.    Qecc via any ECCM on electrical  interfaces                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           50.    Qecc Routing (level 2 IS-IS acc. to ISO 10589-8473)                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           51.    Domain Partitioning Repair function
           52.    Definition of Manual Adjacencies (NSAP of dedicated NE)                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           53.    Manual definition of reachable addresses (set address prefix)           C        C       C
-----------------------------------------------------------------------------------------------------------------------
<PAGE>
<CAPTION>

<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
           54.    ECC can be inserted / extracted to/from VC-4 POH Byte                   C        C       C
                  (Application: for transparent transmission of ECC via other
-----------------------------------------------------------------------------------------------------------------------
                  operator's SDH network)
           55.    F2 Byte can be inserted / extracted via V.11 Interface                  Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------
                  (Application: for transparent transmission of ECC via
                  bridge and other operator's SDH network)
4.2               O & M INTERFACES
-----------------------------------------------------------------------------------------------------------------------
           56.    8 x Remote Control Inputs                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           57.    Remote Control Outputs                                                  Nc      Nc       Nc
-----------------------------------------------------------------------------------------------------------------------
           58.    Card LED support                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
           59.    Subrack LED support                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           60.    Rack Alarm support                                                      C        C       C
-----------------------------------------------------------------------------------------------------------------------
5                 PERFORMANCE MANAGEMENT
           61.    Performance History Data Collection (ES, SES and UAT) ...               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           62.    at any MST                                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------
           63.    at any RST                                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------
           64.    at any VC-4 TTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           65.    at any VC-3 TTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           66.    at any VC-12 TTP                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
           67.    at any AU-4 CTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           68.    at any VC-3 CTP                                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           69.    at any VC-12 CTP                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
           70.    for any AU-4 Tandem Connection                                          Nc      Nc       Nc    10.570
-----------------------------------------------------------------------------------------------------------------------
           71.    for any TU-3 Tandem Connection                                          Nc      Nc       Nc    10.570
-----------------------------------------------------------------------------------------------------------------------
           72.    for any TU-12 Tandem Connection                                         Nc      Nc       Nc    10.570
-----------------------------------------------------------------------------------------------------------------------
           73.    from remote TTPs based on FEBE evaluation                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           74.    Threshold Crossing Notification                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
6                 FAULT AND STATUS MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------
6.1               DETECTED ANOMALIES, DEFECTS AND CONSEQUENT ACTIONS
-----------------------------------------------------------------------------------------------------------------------
6.1.1             ALL SYNCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------
           75.    Detection of Transmit Fail on any optical STM-N interface               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           76.    Detection of Laser Shutdown on any optical interface                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           77.    Detection of disabled ALS on any optical interface                      C        C       C
-----------------------------------------------------------------------------------------------------------------------
           78.    Detection of Optical Source Power High on any optical interface         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           79.    Detection of LOS, LOS status change hysteresis                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           80.    Insertion of AIS upon detection of LOS                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.2             ALL REGENERATOR SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------
           81.    Detection of OOF                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
           82.    Detection of LOF                                                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
           83.    Insertion of AIS upon persisting LOF detection                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           84.    Detection of RS EBER (10E-3) based on  B1 BIP-8 parity calculation      C        C       C
-----------------------------------------------------------------------------------------------------------------------

<PAGE>

                                    With regard to TN-4XE

<CAPTION>
<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
6.1.3             ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------
           85.    Detection of MS-AIS                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           86.    Insertion of all 1 upon detection of MS-AIS                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           87.    Detection of Signal Degrade                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           88.    Detection of MS-EBER (10E-3) upon B2 BIP-24 parity error
                  calculation                                                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           89.    Insertion of AIS and FERF upon detection of MS-AIS                      C        C       C
-----------------------------------------------------------------------------------------------------------------------
           90.    Detection of FERF                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
           91.    Insertion of MS-FEBE based on detection of B2 parity calculations       C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.4             ALL MULTIPLEX SECTION ADAPTATION POINTS
-----------------------------------------------------------------------------------------------------------------------
           92.    Detection  of AU-LOP                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           93.    Detection of AU-AIS                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           94.    Detection of Number of AU-Pointer Justification Events                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
           95.    Insertion of AU-AIS upon receive of all 1                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
<PAGE>

                                    With regard to TN-4XE

<CAPTION>

<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
6.1.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-----------------------------------------------------------------------------------------------------------------------
           96.    Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           97.    Detection of HP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           98.    Detection of HP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           99.    Detection of HP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           100.   Detection of HP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           101.   Detection of B3- EBER (10E-3)                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.6             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-----------------------------------------------------------------------------------------------------------------------
           102.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           103.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           104.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           105.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           106.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           107.   Detection of EBER                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.7             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-12)
-----------------------------------------------------------------------------------------------------------------------
           108.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           109.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           110.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           111.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           112.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           113.   Detection of EBER                                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.8             ALL HIGH ORDER PATH TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------
           114.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           115.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           116.   Detection of HP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           117.   Detection of HP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           118.   Insertion of AIS and HP-FERF upon detection of HP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------

<PAGE>

                                    With regard to TN-4XE

<CAPTION>
<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
           119.   Detection of HP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           120.   Insertion of AIS and HP-FERF upon detection of HP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           121.   Detection of HP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           122.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.9             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-----------------------------------------------------------------------------------------------------------------------
           123.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           124.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           125.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           126.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           127.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           128.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           129.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           130.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           131.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.10            ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-----------------------------------------------------------------------------------------------------------------------
           132.   Detection of Path AIS upon receive of all 1                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           133.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           134.   Detection of LP-Trace Invalid                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           135.   Detection of LP-TIM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           136.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           137.   Detection of LP-SLM                                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           138.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           139.   Detection of LP-FERF                                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           140.   Detection of EBER (10E-3)                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.11            ALL PLESIOCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------

<PAGE>

                                    With regard to TN-4XE

<CAPTION>
<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
           141.   Detection of Trib.-AIS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
           142.   Detection of Trib.-LOS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
           143.   Detection of Trib.-LOF                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
           144.   Insertion of AIS upon detection of Trib.-AIS, Trib.-LOS, Trib.-LOF      C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.12            SETS AND SETPI
           145.   Detection of Sync. Source Fail                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           146.   Detection of SETG - Hold                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------
           147.   Detection of SETG - Out of Lock                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           148.   Detection of SETG - Fail                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------
           149.   Detection of Sync. Degrade                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------
           150.   Detection of Excessive Sync. Degrade                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           151.   T4 Squelch upon detection of Excessive Sync. Degrade
           152.   Detection of Sync. Source Threshold Crossing                            C        C       C
-----------------------------------------------------------------------------------------------------------------------
           153.   Detection of Sync. LOS                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.13            MANAGEMENT COMMUNICATION FUNCTION
           154.   Detection of Remote Control Input Active                                C        C       C
-----------------------------------------------------------------------------------------------------------------------
           155.   Detection of RS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           156.   Detection of MS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.1.14            SYSTEMS MANAGEMENT FUNCTION
           157.   Detection of Secondary Power Fail                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
           158.   Detection of Primary Power Fail                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           159.   Detection of Re-Boot Fail                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           160.   Detection of Configuration Data Integrity Check Failure                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           161.   Detection of System Software Integrity Check Failure                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
<PAGE>

                                    With regard to TN-4XE

<CAPTION>
<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
           162.   Detection of Network Element Controller Fail                            C        C       C
\-----------------------------------------------------------------------------------------------------------------------
           163.   Detection of Card Protection Switch Failure                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
           164.   Detection of Card Out                                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           165.   Detection of Card Fail (upon detection of internal parity
                  mismatch etc.)                                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           166.   Detection of Wrong Card                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           167.   Network Protection Switch Failure                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.2               STATUS EVENTS
-----------------------------------------------------------------------------------------------------------------------
           168.   Configuration Data Integrity Fail                                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
           169.   System Software Integrity Fail                                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           170.   Laser Restart for Test                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
           171.   Synchronous Equipment Timing Generator A/B active                       C        C       C
-----------------------------------------------------------------------------------------------------------------------
           172.   Synchronisation Source Quality Change                                   C        C       C
-----------------------------------------------------------------------------------------------------------------------
           173.   Synchronisation Source Switch Event                                     C        C       C
-----------------------------------------------------------------------------------------------------------------------
           174.   External Synchronisation Output Squelched                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           175.   Section Layer Protection Switch Active                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
           176.   Network Protection Switch Event                                         C        C       C
-----------------------------------------------------------------------------------------------------------------------
           177.   Card Protection Switch Active                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           178.   Fault / Status Log Capacity Exceeded                                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           179.   Configuration Data Transaction Log Capacity Exceeded                    C        C       C
-----------------------------------------------------------------------------------------------------------------------
           180.   Performance Monitoring Log Capacity Exceeded                            C        C       C
-----------------------------------------------------------------------------------------------------------------------
           181.   Access  Log Capacity Exceeded                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           182.   Software Download in Progress                                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           183.   Software Download Failure                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           184.   Software Download Failure - Retry in Progress                           C        C       C
-----------------------------------------------------------------------------------------------------------------------
           185.   Software Download Complete                                              C        C       C
-----------------------------------------------------------------------------------------------------------------------
<PAGE>

                                    With regard to TN-4XE

<CAPTION>
<S>        <C>    <C>                                                                    <C>      <C>    <C>     <C>
           186.   Card Restoration Complete                                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           187.   Re-Boot Restoration Complete                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------
           188.   Electronic Label Update                                                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
6.3               ALARM EVENT HANDLING
-----------------------------------------------------------------------------------------------------------------------
           189.   Alarm Persistence Filter (filtering of toggling alarms)                 C        C       C
-----------------------------------------------------------------------------------------------------------------------
           190.   Alarm Correlation Filter (F3 filter, suppression of consequent          C        C       C
                  alarms)
-----------------------------------------------------------------------------------------------------------------------
           191.   Alarm Inversion Facility                                                C        C       C
-----------------------------------------------------------------------------------------------------------------------
           192.   Performance of the alarm throughput > 10 alarms per second              C        C       C
-----------------------------------------------------------------------------------------------------------------------
           193.   It is possible to block/unblock each single traffic relevant alarm      C        C       C
                  per port
-----------------------------------------------------------------------------------------------------------------------
           194.   It is possible to block/unblock each single traffic relevant alarm      C        C       C
                  group per card
-----------------------------------------------------------------------------------------------------------------------
           195.   It is possible to block/unblock each single traffic relevant alarm      C        C       C
                  group per NE
-----------------------------------------------------------------------------------------------------------------------
           196.   Indication of Alarm Event Forwarding Suppression per functional         C        C       C
                  unit (e.g. Regenerator Section ...)
-----------------------------------------------------------------------------------------------------------------------
7                 CONFIGURATION MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------
7.1               GENERAL
-----------------------------------------------------------------------------------------------------------------------
           197.   Upload of Configuration Data - on single command                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
           198.   Upload of Configuration Data - on bulk command                          C        C       C
-----------------------------------------------------------------------------------------------------------------------
           199.   Download of Configuration Data - on bulk command                        C        C       C
-----------------------------------------------------------------------------------------------------------------------
7.2               CONFIGURATION OF FUNCTIONAL BLOCKS
-----------------------------------------------------------------------------------------------------------------------
7.2.1             ALL SYNCHRONOUS OPTICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------
           200.   Enable / Disable Automatic Laser Shutdown                               C        C       C
-----------------------------------------------------------------------------------------------------------------------
           201.   Enable / Disable Laser                                                  C        C       C
-----------------------------------------------------------------------------------------------------------------------
           202.   Enable Laser for Test Purposes  (2s  / 90s)                             C        C       C
-----------------------------------------------------------------------------------------------------------------------
7.2.2             ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------
           203.   Set Threshold Signal Degrade                                            C        C       C
-----------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

-------------------------------------------------------------------------------
<TABLE>
<CAPTION>
                                       With regard to TN-4XE
--------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SoC      SoC     SoC     Ref. No.
                                                                                         T1        T2     T3
--------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           204.   Set Threshold B2-EBER                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
7.2.3             ALL REGENERATOR SECTION TERMINATION POINTS
--------------------------------------------------------------------------------------------------------------------------
           205.   Set Threshold B1-EBER                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
7.2.4             ALL HIGH ORDER PATH TERMINATION POINTS
--------------------------------------------------------------------------------------------------------------------------
           206.   Set Threshold B3-EBER                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           207.   Set Threshold HP-FEBE                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           208.   Enable / Disable consequent actions from detection of HP-TIM (per       C        C       C
                  Path)
--------------------------------------------------------------------------------------------------------------------------
           209.   Enable / Disable consequent actions from detection of HP-SLM (per       C        C       C
                  Path)
--------------------------------------------------------------------------------------------------------------------------
           210.   Set expected Signal Label (per Path)                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           211.   Set expected Path Trace (per Path)                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
7.2.5             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
--------------------------------------------------------------------------------------------------------------------------
           212.   Set Threshold EBER                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           213.   Set Threshold LP-FEBE                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           214.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
--------------------------------------------------------------------------------------------------------------------------
           215.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
--------------------------------------------------------------------------------------------------------------------------
           216.   Set expected Signal Label (per Path)                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           217.   Set expected Path Trace (per Path)                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
7.2.6             ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
--------------------------------------------------------------------------------------------------------------------------
           218.   Set Threshold EBER                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           219.   Set Threshold LP-FEBE                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           220.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
--------------------------------------------------------------------------------------------------------------------------
           221.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
--------------------------------------------------------------------------------------------------------------------------
           222.   Set expected Signal Label (per Path)                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           223.   Set expected Path Trace (per Path)                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
<PAGE>
--------------------------------------------------------------------------------------------------------------------------
<CAPTION>
                                       With regard to TN-4XE
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
--------------------------------------------------------------------------------------------------------------------------
7.2.7             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
--------------------------------------------------------------------------------------------------------------------------
           224.   Set Threshold B3-EBER                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           225.   Set Threshold HP-FEBE                                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           226.   Set expected Signal Label (per Path)                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           227.   Set expected Path Trace (per Path)                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
7.2.8             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
--------------------------------------------------------------------------------------------------------------------------
           228.   Set Threshold EBER                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           229.   Set Threshold FEBE                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           230.   Set expected Signal Label (per Path)                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           231.   Set expected Path Trace (per Path)                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
7.2.9             ALL HIGH ORDER CONNECTION SUPERVISION POINTS (TU-12)
--------------------------------------------------------------------------------------------------------------------------
           232.   Set Threshold EBER                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           233.   Set Threshold FEBE                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           234.   Set expected Signal Label (per Path)                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           235.   Set expected Path Trace (per Path)                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
8                 NETWORK PROTECTION
--------------------------------------------------------------------------------------------------------------------------
8.1               HIGHER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I)
--------------------------------------------------------------------------------------------------------------------------
           236.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        C        C       C
--------------------------------------------------------------------------------------------------------------------------
           237.   Switch-Over Completion Time  LESS THAN100ms                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
           238.   Configurable Hold-Off Time                                              C        C       C
--------------------------------------------------------------------------------------------------------------------------
           239.   Enable / Disable Automatic Switching                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           240.   Manual Switching via Management Interface                               C        C       C
--------------------------------------------------------------------------------------------------------------------------
           241.   Configurable Wait Time to Restore                                       C        C       C
--------------------------------------------------------------------------------------------------------------------------
8.2               LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-3)
--------------------------------------------------------------------------------------------------------------------------
<PAGE>
<CAPTION>
                                       With regard to TN-4XE
--------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
--------------------------------------------------------------------------------------------------------------------------
           242.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
--------------------------------------------------------------------------------------------------------------------------
           243.   Switch-Over Completion Time  LESS THAN300ms                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
           244.   Configurable Hold-Off Time                                              C        C       C
--------------------------------------------------------------------------------------------------------------------------
           245.   Enable / Disable Automatic Switching                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           246.   Manual Switching via Management Interface                               C        C       C
--------------------------------------------------------------------------------------------------------------------------
           247.   Configurable Wait Time to Restore                                       C        C       C
--------------------------------------------------------------------------------------------------------------------------
8.3               LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-12)
--------------------------------------------------------------------------------------------------------------------------
           248.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
--------------------------------------------------------------------------------------------------------------------------
           249.   Switch-Over Completion Time  LESS THAN300ms                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
           250.   Configurable Hold-Off Time                                              C        C       C
--------------------------------------------------------------------------------------------------------------------------
           251.   Enable / Disable Automatic Switching                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           252.   Manual Switching via Management Interface                               C        C       C
--------------------------------------------------------------------------------------------------------------------------
           253.   Configurable Wait Time to Restore                                       C        C       C
--------------------------------------------------------------------------------------------------------------------------
9                 OPERATION AND MAINTENANCE
--------------------------------------------------------------------------------------------------------------------------
9.1               GENERAL
--------------------------------------------------------------------------------------------------------------------------
           254.   Event buffer                                                            C        C       C
--------------------------------------------------------------------------------------------------------------------------
           255.   Heart Beat Function                                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
           256.   Re-boot function                                                        C        C       C
--------------------------------------------------------------------------------------------------------------------------
           257.   Real time clock function                                                C        C       C
--------------------------------------------------------------------------------------------------------------------------
           258.   NSAP Address modification                                               C        C       C
--------------------------------------------------------------------------------------------------------------------------
           259.   Local Software Download                                                 C        C       C
--------------------------------------------------------------------------------------------------------------------------
           260.   Remote Software Download                                                C        C       C
V--------------------------------------------------------------------------------------------------------------------------
           261.   Manager Decision Process for equipment access control                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           262.   Display of VC-4 Path Trace at HPT                                       C        C       C
--------------------------------------------------------------------------------------------------------------------------
           263.   Display of VC-4 Signal Label at HPT                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
<PAGE>
<CAPTION>
                                       With regard to TN-4XE
--------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
--------------------------------------------------------------------------------------------------------------------------
           264.   Display of VC-4 Path Trace at HPOM                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           265.   Display of VC-4 Signal Label at HPOM                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           266.   Display of VC-3 Path Trace at LPT                                       C        C       C
--------------------------------------------------------------------------------------------------------------------------
           267.   Display of VC-3 Signal Label at LPT                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
           268.   Display of VC-3 Path Trace at LPOM                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           269.   Display of VC-3 Signal Label at LPOM                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           270.   Display of VC-12 Path Trace at LPT                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           271.   Display of VC-12 Signal Label at LPT                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           272.   Display of VC-12 Path Trace at LPOM                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
           273.   Display of VC-12 Signal Label at LPOM                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           274.   Display of Optical Transmit Power Level                                 C        C       C
--------------------------------------------------------------------------------------------------------------------------
9.2               LOGS
--------------------------------------------------------------------------------------------------------------------------
           275.   Alarm / Status Log                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           276.   Performance Log                                                         C        C       C
--------------------------------------------------------------------------------------------------------------------------
           277.   Configuration  Log                                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           278.   Access Control  Log                                                     C        C       C
--------------------------------------------------------------------------------------------------------------------------
9.3               REDUNDANCY
--------------------------------------------------------------------------------------------------------------------------
           279.   1:N Tributary Card Protection 2 Mbit/s                                  NC      NC       C
--------------------------------------------------------------------------------------------------------------------------
           280.   1:N or 1+1  Tributary Card Protection 34 Mbit/s                         NC       C       C
--------------------------------------------------------------------------------------------------------------------------
           281.   1:N or 1+1 Tributary Card Protection 45 Mbit/s                          NC       C       C
--------------------------------------------------------------------------------------------------------------------------
           282.   1:N or 1+1 (electrical) Tributary Card Protection  STM-1 G.703          NC       C       C
--------------------------------------------------------------------------------------------------------------------------
           283.   1+1 Protection of Clock System                                          C        C       C
--------------------------------------------------------------------------------------------------------------------------
           284.   Duration  LESS THAN5s for card protection automatic switch over                 C        C       C
--------------------------------------------------------------------------------------------------------------------------
<PAGE>
<CAPTION>
                                       With regard to TN-4XE

<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
--------------------------------------------------------------------------------------------------------------------------
9.4               EQUIPMENT TESTING FUNCTIONS
--------------------------------------------------------------------------------------------------------------------------
           285.   Integrity Check of Configuration Data                                   C        C       C
--------------------------------------------------------------------------------------------------------------------------
           286.   Integrity Check of System Software                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           287.   Configuration of Loop Back on port level on all PDH Interface Cards     C        C       C
--------------------------------------------------------------------------------------------------------------------------
           288.   VC-4 level Configuration of Loop Back on STM-1 el. i/f                  C        C       C
--------------------------------------------------------------------------------------------------------------------------
           289.   VC-4 level Configuration of Loop Back on all STM-4 opt. Interfaces      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           290.   VC-3 level Configuration of Loop Back on all electrical SDH             C        C       C
                  Interface Cards
--------------------------------------------------------------------------------------------------------------------------
           291.   VC-3 level Configuration of Loop Back on all optical SDH Interface      C        C       C
                  Cards
--------------------------------------------------------------------------------------------------------------------------
           292.   VC-12 level Configuration of Loop Back on all electrical SDH            C        C       C
                  Interface Cards
--------------------------------------------------------------------------------------------------------------------------
           293.   VC-12 level Configuration of Loop Back on all optical SDH Interface     C        C       C
                  Cards
--------------------------------------------------------------------------------------------------------------------------
           294.   Configuration of Loop Back on the HPC functional block                  C        C       C
--------------------------------------------------------------------------------------------------------------------------
           295.   Configuration of Loop Back on the LPC functional block                  C        C       C
--------------------------------------------------------------------------------------------------------------------------
           296.   Test Access Interface on all electrical interfaces                      NC      NC       NC
--------------------------------------------------------------------------------------------------------------------------
           297.   Test Access Interface on all optical interfaces                         NC      NC       NC
--------------------------------------------------------------------------------------------------------------------------
           298.   Optical Line Testing                                                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
9.5               INVENTORY DATA
--------------------------------------------------------------------------------------------------------------------------
           299.   Electronic Label Read Access via Management Interfaces                  C        C       C
--------------------------------------------------------------------------------------------------------------------------
           300.   Automatic Electronic Label Upgrade                                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           301.   Compatibility Check of Equipment Hardware Releases                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           302.   Compatibility Check of Equipment Firmware Releases                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           303.   Compatibility Check of Equipment Software Releases                      C        C       C
--------------------------------------------------------------------------------------------------------------------------
           304.   Compatibility Check of Equipment Software Releases to the               C        C       C
                  Management System
--------------------------------------------------------------------------------------------------------------------------
10                ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL COMPATIBILITY AND SAFETY
--------------------------------------------------------------------------------------------------------------------------
10.1              CLIMATIC CONDITIONS
<PAGE>
<CAPTION>
                                       With regard to TN-4XE

<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
--------------------------------------------------------------------------------------------------------------------------
           305.   Stationary Use Conditions acc. to prETS 300 019-2-3 Class T 3.2         NC      NC    NC       10.10305
--------------------------------------------------------------------------------------------------------------------------
10.2              ELECTROMAGNETIC COMPATIBILITY
           306.   Compliance with EN 55022 class B                                        C        C       C
--------------------------------------------------------------------------------------------------------------------------
           307.   Compliance with EN 50082                                                C        C       C
--------------------------------------------------------------------------------------------------------------------------
10.3              SAFETY REQUIREMENTS
--------------------------------------------------------------------------------------------------------------------------
           308.   Compliance with EN 60950                                                C        C       C
--------------------------------------------------------------------------------------------------------------------------
           309.   Compliance with IEC 825-1 and IEC 825-2                                 C        C       C
--------------------------------------------------------------------------------------------------------------------------
11                PHYSICAL CONSTRUCTION
--------------------------------------------------------------------------------------------------------------------------
           310.   Rack size according to ETSI 300 119, 600 mm x 300 mm                    C        C       C
--------------------------------------------------------------------------------------------------------------------------
           311.   Wall mountable version                                                  NC      NC       NC
--------------------------------------------------------------------------------------------------------------------------
           312.   System upgrade or modification can be done without rear access          C        C       C
--------------------------------------------------------------------------------------------------------------------------
12                POWER SUPPLY
           313.   Nominal input voltage -48V                                              C        C       C
--------------------------------------------------------------------------------------------------------------------------
           314.   Minimum accepted input voltage                                       -38V     -38V    -38V
--------------------------------------------------------------------------------------------------------------------------
           315.   Maximum accepted input voltage                                       -75V     -75V    -75V
--------------------------------------------------------------------------------------------------------------------------
13                AVAILABILITY
--------------------------------------------------------------------------------------------------------------------------
           316.   The supplier shall provide MTBF figures for each functional unit of  IR       IR      IR       ANNEX 1
                  the offered equipment based on his statistical evaluations
                  according to the template as attached in Annex 1
--------------------------------------------------------------------------------------------------------------------------
14                POWER CONSUMPTION
--------------------------------------------------------------------------------------------------------------------------
           317.   The supplier shall provide worst case power consumption figures for  IR       IR      IR       ANNEX 1
                  each functional unit of the offered equipment according to the
                  template as attached in Annex 1
--------------------------------------------------------------------------------------------------------------------------
15                SYSTEM MANUALS

           318.   System Description in Hypertext Format on CD                            C        C       C
--------------------------------------------------------------------------------------------------------------------------
           319.   System O&M Manuals in Hypertext Format on CD                            C        C       C
--------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>
-------------------------------------------------------------------------------
                             With regard to TN-4XE

2        REFERENCES

2.1      REFERENCES TO STANDARDS
<TABLE>
<CAPTION>

<S>                  <C>       <C>     <C>
--------------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS    DATE    TITLE
--------------------------------------------------------------------------------------------------------------------------
CECC 86 275-80                 09/95   Detail  Specification:  Connector  sets for  optical  fibres and  cables  Type
                                       LSH-HRL
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.703                    04/91   Physical/Electrical characteristics of Hierarchical Digital Interfaces
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.707                    1991    Synchronous digital hierarchy bit rates
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.782                    1994    Types and general  characteristics  of  synchronous  digital  hierarchy  (SDH)
                                       equipment
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.783                    1994    Characteristics  of synchronous  digital hierarchy /SDH) equipment  functional
                                       blocks
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.813                    1996    Timing Characteristics of SDH equipment slave clocks.
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.825                    1993    The control of Jitter and Wander within  Digital  Networks  which are based on
                                       synchronous digital hierarchy
--------------------------------------------------------------------------------------------------------------------------
ITU-T                                  G.826 11/93 Error performance parameters
                                       and objectives for International constant
                                       Bit Rate Digital Paths at or above the
                                       Primary Rate
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.841                    1995    Types and Characteristics of SDH Network Protection Architectures
--------------------------------------------------------------------------------------------------------------------------
ITU-T G.957                    1993    Optical Interfaces and Systems relating to the synchronous digital hierarchy
--------------------------------------------------------------------------------------------------------------------------
ETS 300 019          pr        02/92   Environmental   conditions  and  Environmental  Tests  for  Telecommunications
                                       Equipment
                                       Part A:  Introduction and Terminology
                                       Part B:  classification of Environmental conditions
--------------------------------------------------------------------------------------------------------------------------
ETS 300 119                            European Telecommunication Standard for Equipment Practice
                               03/93   Part 2:  Engineering Requirements for Racks
                               09/93   Part 3:  Engineering Requirements for Miscellaneous Racks and cabinets
                               09/93   Part 4:  Engineering Requirements for Subracks
--------------------------------------------------------------------------------------------------------------------------
ETS 300 253                    01/95   Earthing  and  bonding of  telecommunication  equipment  in  telecommunication
                                       centres
--------------------------------------------------------------------------------------------------------------------------
EN 41003                       1991    Particular safety requirements for equipment to be connected to
                                       telecommunication network
--------------------------------------------------------------------------------------------------------------------------
EN 55022                       05/95   Grenzwerte  und  Me(beta)verfahren  fur   Funkstorungen   von   Einrichtungen   der
                                       Informationstechnik
--------------------------------------------------------------------------------------------------------------------------
EN 50082                               Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                               12/94   Part 1:  Elektromagnetische  Vertraglichkeit - Fachgrundnorm  Storfestigkeit -
                                       Teil 1: Wohnbereich, Geschafts- und
                                                Gewerbebereiche owie Kleinbetriebe
                               02/96   Part 2:  Elektromagnetische  Vertraglichkeit - Fachgrundnorm  Storfestigkeit -
                                       Teil 2: Industriebereich
--------------------------------------------------------------------------------------------------------------------------
DIN 47295                              HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
--------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>
                             With regard to TN-4XE
3        ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION
<TABLE>
<CAPTION>
<S>                         <C>        <C>                 <C>
-------------------------------------------------------------------------------
UNIT NAME/TYPE              UNIT ID    UNIT FIT            MAXIMUM
                                       FIGURE              POWER
                                                           CONSUMPTION
-------------------------------------------------------------------------
TN-4XE Muxassembly          NTEU70AA           41                253 W
-------------------------------------------------------------------------
STM-4 1310nm short haul     NTEU20AA        1.875                 40 W
optical aggregate
-------------------------------------------------------------------------
STM-4 1550 nm long haul     NTEU21AA        1.875                 40 W
optical aggregate
-------------------------------------------------------------------------
STM-1 optical dual-port     NTEU10AA        1.250                 20 W
tributary unit (1310 nm,
short haul)
-------------------------------------------------------------------------
STM-1e/140 Mbit/s           NTEU13AA          TBD                 20 W
tributary unit
-------------------------------------------------------------------------
2 Mbit/s G.703 120 ohm      NTEU12AA          500                 20 W
tributary unit
-------------------------------------------------------------------------
2 Mbit/s G.703 75 ohm       NTEU11AA          500                 20 W
tributary unit
-------------------------------------------------------------------------
ETHERNET SIM PCB Assembly   NTEU6006           28
-------------------------------------------------------------------------
End Of Shelf Upper          NTEU40AA          345                  5 W
-------------------------------------------------------------------------
End Of Shelf Lower          NTEU41AA          439                  8 W
-------------------------------------------------------------------------
Engineering Orderwire       NTEU43AA          TBD                 12 W
(EOW) card
-------------------------------------------------------------------------
-------------------------------------------------------------------------
-------------------------------------------------------------------------
-------------------------------------------------------------------------
-------------------------------------------------------------------------
-------------------------------------------------------------------------
-------------------------------------------------------------------------
-------------------------------------------------------------------------
-------------------------------------------------------------------------
end of document
</TABLE>
<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

<TABLE>
<S>                                                        <C>
---------------------------------------------------------- ---------------------------------------
Supplier:                                                  Reference No.: 10.2
Nortel Dasa                                                otel.o Document No.: ST-frx-0010
Network Systems GmbH & Co. KG
Hahnstrasse 37 - 39                                        Chapter: 2
60528 Frankfurt / Main
                                                           Item No.: 21,23, 25,26
---------------------------------------------------------- ---------------------------------------

                              With Regard to TN-4XE

--------------------------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------------------------

 Add/ drop capacity of n-VC4 equivalents

--------------------------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------------------------

4 * VC4 East,
4 * VC4 West,
8 * VC4 South can be connected in any combination.

</TABLE>

<PAGE>
                             With Regard to TN-1X
                        SYSTEM FEATURE DESCRIPTION TM-N/1

<TABLE>

<CAPTION>

----------------------------------------------------------------------------------------------------

<S>                       <C>
ID                        ST-rfx-0010
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

----------------------------------------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description TM-N-1-10

----------------------------------------------------------------------------------------------------

DESCRIPTION               This document lists the features of the TM-N/1 Equipment, wheras N=1, 4

                          The equipment shall mainly be applied as SDH trail or
                          connection terminating mux at customer premises.

----------------------------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

----------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                             With Regard to TN-1X

1    REQUESTED FEATURES

<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
1                 INTERFACE TYPES
-------------------------------------------------------------------------------------------------------------------------------
1.1               TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           1.     2 Mbit/s G.703                                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           2.     2 Mbit/s G.704 frame monitoring option on incoming traffic              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           3.     2 Mbit/s, retiming 250 us buffer                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           4.     34 Mbit/s G.703                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           5.     45 Mbit/s G.703                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           6.     STM-1 G.703                                                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           7.     S-1.1                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
1.2               AGGREGATE INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           8.     STM-1 G.703                                                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           9.     S-1.1                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           10.    L-1.1                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           11.    S-4.1                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           12.    L-4.1                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
1.3               EQUIPPING OF INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
1.3.1             TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
           13.    Up to (t.b.d.) electrical 2 Mbit/s ports can be equipped                IR                     10.113
-------------------------------------------------------------------------------------------------------------------------------
           14.    Up to (t.b.d.) electrical 34 Mbit/s ports can be equipped               IR                     10.113
-------------------------------------------------------------------------------------------------------------------------------
           15.    Up to (t.b.d.) electrical 45 Mbit/s ports can be equipped               IR                     10.113
-------------------------------------------------------------------------------------------------------------------------------
           16.    Up to (t.b.d.) el. 155 Mbit/s ports can be equipped                     IR                     10.113
-------------------------------------------------------------------------------------------------------------------------------
2                 CONNECTIVITY
-------------------------------------------------------------------------------------------------------------------------------
2.1               CONNECTION TYPES
-------------------------------------------------------------------------------------------------------------------------------
           17.    Bi-directional Connections on VC-12 level                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           18.    Bi-directional Connections on VC-3 level                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           19.    Bi-directional Connections on VC-4 level                                NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           20.    Bi-directional Connections of contiguously concatenated  VC-4           NC      NC       NC
                  (VC-4-4c)
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
2.2               QUANTITATIVE REQUIREMENTS
-------------------------------------------------------------------------------------------------------------------------------
2.2.1             HIGHER ORDER CONNECTIVITY
-------------------------------------------------------------------------------------------------------------------------------
           21.    HO termination of (t.b.d.) * VC-4 equivalents from aggregate            IR      IR       IR
-------------------------------------------------------------------------------------------------------------------------------
           22.    HO add/drop of (t.b.d.) * VC-4 equivalents from aggregate west          IR      IR       IR       10.222
-------------------------------------------------------------------------------------------------------------------------------
           23.    HO add/drop of (t.b.d.) * VC-4 equivalents from aggregate west          IR      IR       IR       10.222
-------------------------------------------------------------------------------------------------------------------------------
2.2.2             LOWER ORDER CONNECTIVITY
-------------------------------------------------------------------------------------------------------------------------------
           24.    LO termination of (t.b.d.) * VC-4 equivalents from aggregate            IR      IR       IR
-------------------------------------------------------------------------------------------------------------------------------
           25.    LO add/drop of (t.b.d.) * VC-4 equivalents from aggregate west          IR      IR       IR       10.225
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>

           26.    LO add/drop of (t.b.d.) * VC-4 equivalents from aggregate west          IR      IR       IR       10.225
-------------------------------------------------------------------------------------------------------------------------------
3                 SYNCHRONISATION
-------------------------------------------------------------------------------------------------------------------------------
3.1               INTERNAL EQUIPMENT TIMING
-------------------------------------------------------------------------------------------------------------------------------
3.1.1             TIMING SOURCES
-------------------------------------------------------------------------------------------------------------------------------
           27.    STM-N timing                                                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           28.    2048 kHz timing                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           29.    Internal Oscillator acc. to G.813                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.1.2             TIMING SOURCE QUALITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           30.    STM-N Timing at all SDH i/fs (Timing Marker Support)                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           31.    2048 kHz timing, fixed to G.811 quality                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           32.    2048 kHz timing, configurable timing source quality                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.1.3             TIMING SOURCE PRIORITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           33.    Priority List of (at least 6 entries)                                   NC      NC       NC       10.333
-------------------------------------------------------------------------------------------------------------------------------
3.1.4             SELECTION ALGORITHMS
-------------------------------------------------------------------------------------------------------------------------------
           34.    Autonomous Timing Source Selection                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           35.    Manual Timing Source Selection                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
3.2               EXTERNAL  TIMING OUTPUT (T4)
-------------------------------------------------------------------------------------------------------------------------------
3.2.1             TIMING  OUTPUT PORT
-------------------------------------------------------------------------------------------------------------------------------
           36.    One 2048 kHz timing output port                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           37.    Configurable timing output squelch function                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.2             TIMING SOURCES
-------------------------------------------------------------------------------------------------------------------------------
           38.    STM-N  timing                                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.3             TIMING SOURCE QUALITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           39.    STM-N Timing (Timing Marker Support)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.4             TIMING SOURCE PRIORITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           40.    Priority List (at least 7 entries)                                      NC      NC       NC       10.333
-------------------------------------------------------------------------------------------------------------------------------
3.2.5             SELECTION ALGORITHMS
-------------------------------------------------------------------------------------------------------------------------------
           41.    Autonomous timing source selection                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           42.    Manual Timing Source selection                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
4                 MANAGEMENT COMMUNICATION
-------------------------------------------------------------------------------------------------------------------------------
4.1               COMMUNICATION INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           43.    F- Interface   (RS 232)                                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           44.    Q I/F (Ethernet)                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           45.    Q- interface as gateway to the EMS                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           46.    Qecc via any ECCR  on optical  interfaces                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           47.    Qecc via any ECCM on optical  interfaces                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           48.    Qecc via any ECCR  on electrical  interfaces                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           49.    Qecc via any ECCM on electrical  interfaces                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           50.    Qecc Routing (level 2 IS-IS acc. to ISO 10589-8473)                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           51.    Domain Partitioning Repair function
-------------------------------------------------------------------------------------------------------------------------------
           52.    Definition of Manual Adjacencies (NSAP of dedicated NE)                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           53.    Manual definition of reachable addresses (set address prefix)           C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           54.    ECC can be inserted / extracted to/from VC-4 POH Byte                   C        C       C
                  (Application: for transparent transmission of ECC via other
                  operator's SDH network)
-------------------------------------------------------------------------------------------------------------------------------
           55.    F2 Byte can be inserted / extracted via V.11 Interface                  NC       NC      NC
                  (Application: for transparent transmission of ECC via
                  bridge and other operator's SDH network)
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
4.2               O & M INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           56.    8 x Remote Control Inputs                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           57.    Remote Control Outputs                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           58.    Card LED support                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           59.    Subrack LED support                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           60.    Rack Alarm support                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
5                 PERFORMANCE MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------
           61.    Performance History Data Collection (ES, SES and UAT) ...               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           62.    at any MST                                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           63.    at any RST                                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           64.    at any VC-4 TTP                                                         NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           65.    at any VC-3 TTP                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           66.    at any VC-12 TTP                                                        C        C       C
------------------------------------------------------------------------------------------------------------------------------
           67.    at any AU-4 CTP                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           68.    at any VC-3 CTP                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           69.    at any VC-12 CTP                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           70.    for any AU-4 Tandem Connection                                          NC      NC       NC       10.570
-------------------------------------------------------------------------------------------------------------------------------
           71.    for any TU-3 Tandem Connection                                          NC      NC       NC       10.570
-------------------------------------------------------------------------------------------------------------------------------
           72.    for any TU-12 Tandem Connection                                         NC      NC       NC       10.570
-------------------------------------------------------------------------------------------------------------------------------
           73.    from remote TTPs based on FEBE evaluation                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           74.    Threshold Crossing Notification                                         C        C       C
------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6                 FAULT AND STATUS MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------
6.1               DETECTED ANOMALIES, DEFECTS AND CONSEQUENT ACTIONS
-------------------------------------------------------------------------------------------------------------------------------
6.1.1             ALL SYNCHRONOUS PHYSICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           75.    Detection of Transmit Fail on any optical STM-N interface               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           76.    Detection of Laser Shutdown on any optical interface                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           77.    Detection of disabled ALS on any optical interface                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           78.    Detection of Optical Source Power High on any optical interface         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           79.    Detection of LOS, LOS status change hysteresis                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           80.    Insertion of AIS upon detection of LOS                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
6.1.2             ALL REGENERATOR SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           81.    Detection of OOF                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           82.    Detection of LOF                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           83.    Insertion of AIS upon persisting LOF detection                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           84.    Detection of RS EBER (10E-3) based on  B1 BIP-8 parity calculation      C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
6.1.3             ALL MULTIPLEX SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           85.    Detection of MS-AIS                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           86.    Insertion of all 1 upon detection of MS-AIS                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           87.    Detection of Signal Degrade                                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           88.    Detection of MS-EBER (10E-3) upon B2 BIP-24 parity error
                  calculation                                                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           89.    Insertion of AIS and FERF upon detection of MS-AIS                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           90.    Detection of FERF                                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           91.    Insertion of MS-FEBE based on detection of B2 parity calculations       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
6.1.4             ALL MULTIPLEX SECTION ADAPTATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           92.    Detection  of AU-LOP                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           93.    Detection of AU-AIS                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           94.    Detection of Number of AU-Pointer Justification Events                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           95.    Insertion of AU-AIS upon receive of all 1                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
6.1.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           96.    Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           97.    Detection of HP-Trace Invalid                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           98.    Detection of HP-TIM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           99.    Detection of HP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           100.   Detection of HP-FERF                                                    C        C       C

-------------------------------------------------------------------------------------------------------------------------------
           101.   Detection of B3- EBER (10E-3)                                           C        C       C

-------------------------------------------------------------------------------------------------------------------------------
6.1.6             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-------------------------------------------------------------------------------------------------------------------------------
           102.   Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           103.   Detection of LP-Trace Invalid                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           104.   Detection of LP-TIM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           105.   Detection of LP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           106.   Detection of LP-FERF                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           107.   Detection of EBER                                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.1.7             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-12)
-------------------------------------------------------------------------------------------------------------------------------
           108.   Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           109.   Detection of LP-Trace Invalid                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           110.   Detection of LP-TIM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           111.   Detection of LP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           112.   Detection of LP-FERF                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           113.   Detection of EBER                                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.1.8             ALL HIGH ORDER PATH TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           114.   Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           115.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           116.   Detection of HP-Trace Invalid                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           117.   Detection of HP-TIM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           118.   Insertion of AIS and HP-FERF upon detection of HP-TIM                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           119.   Detection of HP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           120.   Insertion of AIS and HP-FERF upon detection of HP-SLM                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           121.   Detection of HP-FERF                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           122.   Detection of EBER (10E-3)                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.1.9             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-------------------------------------------------------------------------------------------------------------------------------
           123.   Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           124.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           125.   Detection of LP-Trace Invalid                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           126.   Detection of LP-TIM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           127.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           128.   Detection of LP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           129.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           130.   Detection of LP-FERF                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           131.   Detection of EBER (10E-3)                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.1.10            ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-------------------------------------------------------------------------------------------------------------------------------
           132.   Detection of Path AIS upon receive of all 1                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           133.   Insertion of AIS and HP-FERF upon detection of Path AIS                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           134.   Detection of LP-Trace Invalid                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           135.   Detection of LP-TIM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           136.   Insertion of AIS and LP-FERF upon detection of LP-TIM                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           137.   Detection of LP-SLM                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           138.   Insertion of AIS and LP-FERF upon detection of LP-SLM                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           139.   Detection of LP-FERF                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           140.   Detection of EBER (10E-3)                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
6.1.11            ALL PLESIOCHRONOUS PHYSICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           141.   Detection of Trib.-AIS                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           142.   Detection of Trib.-LOS                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           143.   Detection of Trib.-LOF                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           144.   Insertion of AIS upon detection of Trib.-AIS, Trib.-LOS, Trib.-LOF      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.1.12            SETS AND SETPI
-------------------------------------------------------------------------------------------------------------------------------
           145.   Detection of Sync. Source Fail                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           146.   Detection of SETG - Hold                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           147.   Detection of SETG - Out of Lock                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           148.   Detection of SETG - Fail                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           149.   Detection of Sync. Degrade                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           150.   Detection of Excessive Sync. Degrade                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           151.   T4 Squelch  upon detection of Excessive Sync. Degrade                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           152.   Detection of Sync. Source Threshold Crossing                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           153.   Detection of Sync. LOS                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.1.13            MANAGEMENT COMMUNICATION FUNCTION
-------------------------------------------------------------------------------------------------------------------------------
           154.   Detection of Remote Control Input Active                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           155.   Detection of RS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           156.   Detection of MS - Qecc Comms Fail (LAPD Alarm)                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.1.14            SYSTEMS MANAGEMENT FUNCTION
-------------------------------------------------------------------------------------------------------------------------------
           157.   Detection of Secondary Power Fail                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           158.   Detection of Primary Power Fail                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           159.   Detection of Re-Boot Fail                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           160.   Detection of Configuration Data Integrity Check Failure                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           161.   Detection of System Software Integrity Check Failure                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           162.   Detection of Network Element Controller Fail                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           163.   Detection of Card Protection Switch Failure                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           164.   Detection of Card Out                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           165.   Detection of Card Fail (upon detection of internal parity
                  mismatch etc.)                                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           166.   Detection of Wrong Card                                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           167.   Network Protection Switch Failure                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.2               STATUS EVENTS
-------------------------------------------------------------------------------------------------------------------------------
           168.   Configuration Data Integrity Fail                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           169.   System Software Integrity Fail                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           170.   Laser Restart for Test                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           171.   Synchronous Equipment Timing Generator A/B active                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           172.   Synchronisation Source Quality Change                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           173.   Synchronisation Source Switch Event                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           174.   External Synchronisation Output Squelched                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           175.   Section Layer Protection Switch Active                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           176.   Network Protection Switch Event                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           177.   Card Protection Switch Active                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           178.   Fault / Status Log Capacity Exceeded                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           179.   Configuration Data Transaction Log Capacity Exceeded                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           180.   Performance Monitoring Log Capacity Exceeded                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           181.   Access  Log Capacity Exceeded                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           182.   Software Download in Progress                                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           183.   Software Download Failure                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           184.   Software Download Failure - Retry in Progress                           C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           185.   Software Download Complete                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           186.   Card Restoration Complete                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           187.   Re-Boot Restoration Complete                                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           188.   Electronic Label Update                                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
6.3               ALARM EVENT HANDLING
-------------------------------------------------------------------------------------------------------------------------------
           189.   Alarm Persistence Filter (filtering of toggling alarms)                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           190.   Alarm Correlation Filter (F3 filter, suppression of consequent          C        C       C
                  alarms)
-------------------------------------------------------------------------------------------------------------------------------
           191.   Alarm Inversion Facility                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           192.   Performance of the alarm throughput > 10 alarms per second              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           193.   It is possible to block/unblock each single traffic relevant alarm      C        C       C
                  per port
-------------------------------------------------------------------------------------------------------------------------------
           194.   It is possible to block/unblock each single traffic relevant alarm      C        C       C
                  group per card
-------------------------------------------------------------------------------------------------------------------------------
           195.   It is possible to block/unblock each single traffic relevant alarm      C        C       C
                  group per NE
-------------------------------------------------------------------------------------------------------------------------------
           196.   Indication of Alarm Event Forwarding Suppression per functional         C        C       C
                  unit (e.g. Regenerator Section ...)
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7                 CONFIGURATION MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------
7.1               GENERAL
-------------------------------------------------------------------------------------------------------------------------------
           197.   Upload of Configuration Data - on single command                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           198.   Upload of Configuration Data - on bulk command                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           199.   Download of Configuration Data - on bulk command                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7.2               CONFIGURATION OF FUNCTIONAL BLOCKS
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7.2.1             ALL SYNCHRONOUS OPTICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           200.   Enable / Disable Automatic Laser Shutdown                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           201.   Enable / Disable Laser                                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           202.   Enable Laser for Test Purposes  (2s  / 90s)                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7.2.2             ALL MULTIPLEX SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           203.   Set Threshold Signal Degrade                                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           204.   Set Threshold B2-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
7.2.3             ALL REGENERATOR SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           205.   Set Threshold B1-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
7.2.4             ALL HIGH ORDER PATH TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           206.   Set Threshold B3-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           207.   Set Threshold HP-FEBE                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           208.   Enable / Disable consequent actions from detection of HP-TIM (per       C        C       C
                  Path)
-------------------------------------------------------------------------------------------------------------------------------
           209.   Enable / Disable consequent actions from detection of HP-SLM (per       C        C       C
                  Path)
-------------------------------------------------------------------------------------------------------------------------------
           210.   Set expected Signal Label (per Path)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           211.   Set expected Path Trace (per Path)                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7.2.5             ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-------------------------------------------------------------------------------------------------------------------------------
           212.   Set Threshold EBER                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           213.   Set Threshold LP-FEBE                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           214.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
-------------------------------------------------------------------------------------------------------------------------------
           215.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
-------------------------------------------------------------------------------------------------------------------------------
           216.   Set expected Signal Label (per Path)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           217.   Set expected Path Trace (per Path)                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7.2.6             ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-------------------------------------------------------------------------------------------------------------------------------
           218.   Set Threshold EBER                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           219.   Set Threshold LP-FEBE                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           220.   Enable / Disable consequent actions from detection of LP-TIM (per       C        C       C
                  Path)
-------------------------------------------------------------------------------------------------------------------------------
           221.   Enable / Disable consequent actions from detection of LP-SLM (per       C        C       C
                  Path)
-------------------------------------------------------------------------------------------------------------------------------
           222.   Set expected Signal Label (per Path)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           223.   Set expected Path Trace (per Path)                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
7.2.7             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           224.   Set Threshold B3-EBER                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           225.   Set Threshold HP-FEBE                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           226.   Set expected Signal Label (per Path)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           227.   Set expected Path Trace (per Path)                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7.2.8             ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-------------------------------------------------------------------------------------------------------------------------------
           228.   Set Threshold EBER                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           229.   Set Threshold FEBE                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           230.   Set expected Signal Label (per Path)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           231.   Set expected Path Trace (per Path)                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
7.2.9             ALL HIGH ORDER CONNECTION SUPERVISION POINTS (TU-12)
-------------------------------------------------------------------------------------------------------------------------------
           232.   Set Threshold EBER                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           233.   Set Threshold FEBE                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           234.   Set expected Signal Label (per Path)                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           235.   Set expected Path Trace (per Path)                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
8                 NETWORK PROTECTION
-------------------------------------------------------------------------------------------------------------------------------
8.1               HIGHER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I)
-------------------------------------------------------------------------------------------------------------------------------
           236.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           237.   Switch-Over Completion Time less than 100ms                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           238.   Configurable Hold-Off Time                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           239.   Enable / Disable Automatic Switching                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           240.   Manual Switching via Management Interface                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           241.   Configurable Wait Time to Restore                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
8.2               LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-3)
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           242.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           243.   Switch-Over Completion Time less than 300ms                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           244.   Configurable Hold-Off Time                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           245.   Enable / Disable Automatic Switching                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           246.   Manual Switching via Management Interface                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           247.   Configurable Wait Time to Restore                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
8.3               LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-12)
-------------------------------------------------------------------------------------------------------------------------------
           248.   Detection Criterion Signal Fail (TU-AIS, TU-LOP)                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           249.   Switch-Over Completion Time less than 300ms                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           250.   Configurable Hold-Off Time                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           251.   Enable / Disable Automatic Switching                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           252.   Manual Switching via Management Interface                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           253.   Configurable Wait Time to Restore                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
                                                                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
9                 OPERATION AND MAINTENANCE
-------------------------------------------------------------------------------------------------------------------------------
9.1               GENERAL
-------------------------------------------------------------------------------------------------------------------------------
           254.   Event buffer                                                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           255.   Heart Beat Function                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           256.   Re-boot function                                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           257.   Real time clock function                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           258.   NSAP Address modification                                               C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           259.   Local Software Download                                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           260.   Remote Software Download                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           261.   Manager Decision Process for equipment access control                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           262.   Display of VC-4 Path Trace at HPT                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           263.   Display of VC-4 Signal Label at HPT                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           264.   Display of VC-4 Path Trace at HPOM                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           265.   Display of VC-4 Signal Label at HPOM                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           266.   Display of VC-3 Path Trace at LPT                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           267.   Display of VC-3 Signal Label at LPT                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           268.   Display of VC-3 Path Trace at LPOM                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           269.   Display of VC-3 Signal Label at LPOM                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           270.   Display of VC-12 Path Trace at LPT                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           271.   Display of VC-12 Signal Label at LPT                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           272.   Display of VC-12 Path Trace at LPOM                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           273.   Display of VC-12 Signal Label at LPOM                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           274.   Display of Optical Transmit Power Level                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
9.2               LOGS
-------------------------------------------------------------------------------------------------------------------------------
           275.   Alarm / Status Log                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           276.   Performance Log                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           277.   Configuration  Log                                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           278.   Access Control  Log                                                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
9.3               REDUNDANCY
-------------------------------------------------------------------------------------------------------------------------------
           279.   1:N Tributary Card Protection 2 Mbit/s                                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           280.   1:N or 1+1  Tributary Card Protection 34 Mbit/s                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           281.   1:N or 1+1 Tributary Card Protection 45 Mbit/s                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           282.   1:N or 1+1 (electrical) Tributary Card Protection  STM-1 G.703          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           283.   1+1 Protection of Clock System                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           284.   Duration less than 5s for card protection automatic switch over         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
9.4               EQUIPMENT TESTING FUNCTIONS
-------------------------------------------------------------------------------------------------------------------------------
           285.   Integrity Check of Configuration Data                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           286.   Integrity Check of System Software                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           287.   Configuration of Loop Back on port level on all PDH Interface Cards     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           288.   VC-4 level Configuration of Loop Back on STM-1 el. i/f                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           289.   VC-4 level Configuration of Loop Back on all STM-4 opt. interfaces      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           290.   VC-3 level Configuration of Loop Back on all electrical SDH             C        C       C
                  Interface Cards
-------------------------------------------------------------------------------------------------------------------------------
           291.   VC-3 level Configuration of Loop Back on all optical SDH Interface      C        C       C
                  Cards
-------------------------------------------------------------------------------------------------------------------------------
           292.   VC-12 level Configuration of Loop Back on all electrical SDH            C        C       C
                  Interface Cards
-------------------------------------------------------------------------------------------------------------------------------
           293.   VC-12 level Configuration of Loop Back on all optical SDH Interface     C        C       C
                  Cards
-------------------------------------------------------------------------------------------------------------------------------
           294.   Configuration of Loop Back on the HPC functional block                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           295.   Configuration of Loop Back on the LPC functional block                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           296.   Test Access Interface on all electrical interfaces                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           297.   Test Access Interface on all optical interfaces                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           298.   Optical Line Testing                                                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
9.5               INVENTORY DATA
-------------------------------------------------------------------------------------------------------------------------------
           299.   Electronic Label Read Access via Management Interfaces                  C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           300.   Automatic Electronic Label Upgrade                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           301.   Compatibility Check of Equipment Hardware Releases                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           302.   Compatibility Check of Equipment Firmware Releases                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           303.   Compatibility Check of Equipment Software Releases                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           304.   Compatibility Check of Equipment Software Releases to the               C        C       C
                  Management System
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
10                ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL COMPATIBILITY AND SAFETY
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
10.1              CLIMATIC CONDITIONS
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

                             With Regard to TN-1X
<TABLE>

<CAPTION>

-------------------------------------------------------------------------------------------------------------------------------
<S>       <C>     <C>                                                                    <C>      <C>     <C>     <C>
           305.   Stationary Use Conditions acc. to prETS 300 019-2-3 Class T 3.2         NC      NC       NC      10.10305
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
10.2              ELECTROMAGNETIC COMPATIBILITY
-------------------------------------------------------------------------------------------------------------------------------
           306.   Compliance with EN 55022 class B                                        C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           307.   Compliance with EN 50082                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
10.3              SAFETY REQUIREMENTS
-------------------------------------------------------------------------------------------------------------------------------
           308.   Compliance with EN 60950                                                C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           309.   Compliance with IEC 825-1 and IEC 825-2                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
11                PHYSICAL CONSTRUCTION
-------------------------------------------------------------------------------------------------------------------------------
           310.   Rack size according to ETSI 300 119, 600 mm x 300 mm                    C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           311.   wall mountable version                                                  NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           312.   system upgrade or modification can be done without rear access          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
12                POWER SUPPLY
-------------------------------------------------------------------------------------------------------------------------------
           313.   Nominal input voltage -48V                                              C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           314.   Minimum accepted input voltage                                       -40V     -40V    -40V
-------------------------------------------------------------------------------------------------------------------------------
           315.   Maximum accepted input voltage                                       -72V     -72V    -72V
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
13                AVAILABILITY
-------------------------------------------------------------------------------------------------------------------------------
           316.   The supplier shall provide MTBF figures for each functional unit of  IR       IR      IR       Annex 1
                  the offered equipment based on his statistical evaluations
                  according to the template as attached in Annex 1
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
14                POWER CONSUMPTION
-------------------------------------------------------------------------------------------------------------------------------
           317.   The supplier shall provide worst case power consumption figures for  IR       IR      IR       Annex 1
                  each functional unit of the offered equipment according to the
                  template as attached in Annex 1
-------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------
15                SYSTEM MANUALS
-------------------------------------------------------------------------------------------------------------------------------
           318.   System Description in Hypertext Format on CD                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           319.   System O&M Manuals in Hypertext Format on CD                            C        C       C
-------------------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

<TABLE>
<CAPTION>

----------------------------------------------------------------------------------------------------------------------
                                                  With Regard to TN-1X

2   REFERENCES

2.1   REFERENCES TO STANDARDS

----------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS    DATE    TITLE
<S>                  <C>       <C>     <C>
----------------------------------------------------------------------------------------------------------------------
CECC 86 275-80                 09/95   Detail Specification: Connector sets for optical fibres and cables
                                       Type LSH-HRL
----------------------------------------------------------------------------------------------------------------------
ITU-T G.703                   04/91    Physical/Electrical characteristics of Hierarchical Digital Interfaces
----------------------------------------------------------------------------------------------------------------------
ITU-T G.707                    1991    Synchronous digital hierarchy bit rates
----------------------------------------------------------------------------------------------------------------------
ITU-T G.782                    1994    Types and general characteristics of synchronous digital hierarchy (SDH)
                                       equipment
----------------------------------------------------------------------------------------------------------------------
ITU-T G.783                    1994    Characteristics of synchronous digital hierarchy (SDH) equipment  functional
                                       blocks
----------------------------------------------------------------------------------------------------------------------
ITU-T G.813                    1996    Timing Characteristics of SDH equipment slave clocks.
----------------------------------------------------------------------------------------------------------------------
ITU-T G.825                    1993    The control of Jitter and Wander within  Digital  Networks  which are based on
                                       synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------
ITU-T G.826                   11/93    Error performance parameters and objectives for International constant
                                       Bit Rate Digital Paths at or above the Primary Rate
----------------------------------------------------------------------------------------------------------------------
ITU-T G.841                    1995    Types and Characteristics of SDH Network Protection Architectures
----------------------------------------------------------------------------------------------------------------------
ITU-T G.957                    1993    Optical Interfaces and Systems relating to the synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
ETS 300 019          pr        02/92   Environmental conditions and Environmental Tests for Telecommunications
                                       Equipment
                                       Part A:  Introduction and Terminology
                                       Part B:  classification of Environmental conditions

----------------------------------------------------------------------------------------------------------------------
ETS 300 119                            European Telecommunication Standard for Equipment Practice
                               03/93   Part 2:  Engineering Requirements for Racks
                               09/93   Part 3:  Engineering Requirements for Miscellaneous Racks and cabinets
                               09/93   Part 4:  Engineering Requirements for Subracks
----------------------------------------------------------------------------------------------------------------------
ETS 300 253                    01/95   Earthing and bonding of telecommunication equipment in telecommunication
                                       centres
----------------------------------------------------------------------------------------------------------------------
EN 41003                       1991    Particular safety requirements for equipment to be connected to
                                       telecommunication network
----------------------------------------------------------------------------------------------------------------------
EN 55022                       05/95   Grenzwerte und Me(beta)verfahren fur Funkstorungen von Einrichtungen der
                                       Informationstechnik
----------------------------------------------------------------------------------------------------------------------
EN 50082                               Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                               12/94   Part 1: Elektromagnetische  Vertraglichkeit - Fachgrundnorm  Storfestigkeit -
                                       Teil 1: Wohnbereich, Geschafts- und Gewerbebereiche sowie
                                       Kleinbetriebe

                               02/96   Part 2: Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit -
                                       Teil 2: Industriebereich
----------------------------------------------------------------------------------------------------------------------
DIN 47295                              HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
----------------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------
                                        With Regard to TN-1X

3 ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

-------------------------------------------------------------------------------------------------------
UNIT NAME/TYPE                UNIT ID                        UNIT FIT FIGURE    MAXIMUM POWER CONSUMPTION
<S>                           <C>                                 <C>                 <C>
-------------------------------------------------------------------------------------------------------
SYNC MUX REL2.5 SHELF         25GMU00750GWV                       3174                 11 W
-------------------------------------------------------------------------------------------------------
PBA TRFC ACCESS               25UJJ00750GVZ                        228                  0 W
MOD.75R BT43
-------------------------------------------------------------------------------------------------------
FLEXIBLE ACCESS MODULE        25UJJ00750GWX                         60
-------------------------------------------------------------------------------------------------------
HIGH SPEED TRFC               25UJJ00750GWY                        114                  1 W
ACCESS 120R
-------------------------------------------------------------------------------------------------------
STAR CARD 75R BT43            25UJJ00750GWZ                        115                  0 W
-------------------------------------------------------------------------------------------------------
STATION SERVICE CARD          25UJJ00750GXC                        140                  0 W
-------------------------------------------------------------------------------------------------------
HI-SPD TRFC MOD               25UJJ00750HTD                        139                  1 W
-------------------------------------------------------------------------------------------------------
34MBIT MULT VC12 I/F          25UJU00750HJZ                       1842                8,05 W
-------------------------------------------------------------------------------------------------------
2M TRIB 75R ASSY Q2M          25UJU00750HVT                          0                  8,2 W
-------------------------------------------------------------------------------------------------------
SUBRACK CONTROLLER PBA        25UMN00750GXD                       3620                 11 W
-------------------------------------------------------------------------------------------------------
SYNC REL 2.5 POWER            25UPW00750HAY                       1879                  0 W
SUPPLY
-------------------------------------------------------------------------------------------------------
PAYLOAD MANAGER               NTKD10AA                               0                 10,1 W
(MIXED PAYLOADS)
-------------------------------------------------------------------------------------------------------
STM-1 1 INCH OPTICAL TRIB     NTKD11AA                               0                    7
(MIXED PAYLOADS)
-------------------------------------------------------------------------------------------------------
STM-1 1 INCH                  NTKD12AA                               0                    7
ELECTRICAL TRIB
(MIXED PAYLOADS)
-------------------------------------------------------------------------------------------------------
34/45M VC3 TRIBUTARY          NTKD16AA                               0                    0
-------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>
-------------------------------------------------------------------------------
                             With Regard to TN-1X

end of document

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

<TABLE>
<S>                                                        <C>
---------------------------------------------------------- --------------------------------------
Supplier:                                                  Reference No.: 10.113
Nortel Dasa
Network Systems GmbH & Co. KG                              otel.o Document No.: ST-rfx-0010
Hahnstrasse 37 - 39
60528 Frankfurt / Main                                     Chapter: 1

                                                           Item No.: 13/14/15/16
---------------------------------------------------------- --------------------------------------

                              With Regard to TN-1X

-------------------------------------------------------------------------------------------------
1. Item
-------------------------------------------------------------------------------------------------

Tributary Interface

-------------------------------------------------------------------------------------------------
2. Description
-------------------------------------------------------------------------------------------------

The TN-1X provides the following tributaries:

- 2048 kbit/s electrical ports
--  up to sixty-three 2048 kbit/s electrical ports

- 34368 kbit/s or 45736 kbit/s electrical ports
--  up to four 34368 kbit/s or 45736 kbit/s ports. Only three of these can
carry traffic at any time.

- 34368 kbit/s electrical ports (16x2)
--  up to four 34368 kbit/s electrical ports, each port providing access to
sixteen 2048 kbit/s signals

- STM-1 tributary ports
--  up to four STM-1 optical or electrical tributary ports)

</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

<TABLE>
<S>                                                        <C>
---------------------------------------------------------- -------------------------------------
Supplier:                                                  Reference No.: 10.222
Nortel Dasa
Network Systems GmbH & Co. KG                              otel.o Document No.: ST-frx-0010
Hahnstrasse 37 - 39
60528 Frankfurt / Main                                     Chapter: 2

                                                           Item No.: 22/23
---------------------------------------------------------- -------------------------------------

                              With Regard to TN-1X

------------------------------------------------------------------------------------------------
1. Item
------------------------------------------------------------------------------------------------

HO add/drop of (t.b.d.) VC-4 equivalents from aggregate east / west

------------------------------------------------------------------------------------------------
2. Description
------------------------------------------------------------------------------------------------

The connection functionality of the TN-1X relates to the management of
bidirectional VC-12 and VC-3 through and drop connections on the NE. The total
traffic capacity for the multiplexer is four AU-4 payload. The containers within
this payload (VC-3, VC-12) can be dropped from the aggregates to any suitable
tributary unit, or can be through connected. It is possible that the number of
available tributary ports will exceed the number of aggregate ports, but the
total bandwidth for the Network Element (63 x VC-12,3 x VC-3 or a combination of
these) cannot be exceeded.

</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

<TABLE>
<S>                                                        <C>
---------------------------------------------------------- --------------------------------------
Supplier:                                                  Reference No.: 10.225
Nortel Dasa
Network Systems GmbH & Co. KG                              otel.o Document No.: ST-frx-0010
Hahnstrasse 37 - 39
60528 Frankfurt / Main                                     Chapter: 2

                                                           Item No.: 25/26
---------------------------------------------------------- --------------------------------------

                              With Regard to TN-1X

-------------------------------------------------------------------------------------------------
1. Item
-------------------------------------------------------------------------------------------------

LO add/drop of (t.b.d.) VC-4 equivalents from aggregate east / west

-------------------------------------------------------------------------------------------------
2. Description
-------------------------------------------------------------------------------------------------

The connection functionality of the TN-1X relates to the management of
bidirectional VC-12 and VC-3 through and drop connections on the NE. The total
traffic capacity for the multiplexer is four AU-4 payload. The containers within
this payload (VC-3, VC-12) can be dropped from the aggregates to any suitable
tributary unit, or can be through connected. It is possible that the number of
available tributary ports will exceed the number of aggregate ports, but the
total bandwidth for the NE (63 x VC-12,3 x VC-3 or a combination of these)
cannot be exceeded.

</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

<TABLE>
<S>                                                        <C>
---------------------------------------------------------- -------------------------------------
Supplier:                                                  Reference No.: 10.333
Nortel Dasa
Network Systems GmbH & Co. KG                              otel.o Document No.: ST-frx-0010
Hahnstrasse 37 - 39
60528 Frankfurt / Main                                     Chapter: 3

                                                           Item No.: 33/40
---------------------------------------------------------- -------------------------------------

                              With Regard to TN-1X

------------------------------------------------------------------------------------------------
1. Item of non compliance
------------------------------------------------------------------------------------------------

Timing Source Quality Levels

------------------------------------------------------------------------------------------------
2. Description of non compliance
------------------------------------------------------------------------------------------------

The priority list has at least 4 entries.

</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

<TABLE>
<S>                                                        <C>
---------------------------------------------------------- -------------------------------------
Supplier: Nortel Dasa Network Systems                      Reference No.: 10.570

                                                           otel.o Document No.: ST-rfx-00011
                                                           Chapter: 5

                                                           Item No.: 70, 71, 72
---------------------------------------------------------- -------------------------------------

                              With Regard to TN-1X

-------------------------------------------------------------------------------------------------
1. Item of non compliance
-------------------------------------------------------------------------------------------------

Performance Management for Tandem Connection

-------------------------------------------------------------------------------------------------
2. Description of non compliance
-------------------------------------------------------------------------------------------------

At the moment Performance Monitoring is executed at the termination points of
the relevant services. Hence it's possible to determine the QoS for the whole
connection.

</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

<TABLE>
<S>                                                        <C>
---------------------------------------------------------- ---------------------------------------
Supplier:                                                  Reference No.: 10.10305
Nortel Dasa
Network Systems GmbH & Co. KG                              otel.o Document No.: ST-rfx-00010
Rheinstrasse 37 - 39
60528 Frankfurt / Main                                     Chapter: 10

                                                           Item No.: 305
---------------------------------------------------------- ---------------------------------------

                              With Regard to TN-1X

--------------------------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------------------------

Stationary Use Conditions acc. To prETS 300 019-2-3 Class T 3.2

--------------------------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------------------------

External dimensions conform to draft ETSI standard pr ETS 300-119 part 4.

The subrack is designed to meet the requirements of ETSI standard ETS 300-019 as
follows:

Storage: Class 1.2
Transport: Class 2.3
Operation: Class 3.1E.

</TABLE>

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems          Reference No.: 11.453

                                               otel.o Document No.: ST-rfx-00011

                                               Chapter: 4

                                               Item No.: 53
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Access to F2 as transparent channel

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

Bytes F2 and F3 in the POH are reserved for use as 64 kbit/s user channels on a
VC-3 or VC-4 path. Nortel Networks' SDH products are in accordance with ITU-T
Recommendation. G.707 which specifies the requirements for the STM-N signals in
terms of bit rates, frame structures and support for the overhead bytes provided
therein. At the physical level, the position of the F2 byte in the STM-1 frames
of Nortel Networks SDH equipment are in accordance with ITU-T Rec. G.707(1) and
ETS 300 147 (Apr 97). Nortel Networks' SDH products do not currently process the
F2 / F3 byte 64 kbit/s `user channel' of the VC-3 / VC-4 Path Overhead and hence
this feature is not used in present applications. The Tx direction of the F2 and
F3 bytes are set to all ones, and the Rx direction is ignored.

The F2 / F3 byte 64 kbit/s `user channel' feature may be introduced at a later
date with a S/W upgrade.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /   Compliant development planned until    / / T1   / / T2        / / after T2
/ /   Further Development planned but not compliant with o.tel.o requirements
/ /   No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
NO

---------------------------------
(1) ITU-T G.707 (03/96) Recommendation is a merged revised version of
Recommendation G.707, G708 and G.709 approved in 03/93.

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)
--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems          Reference No.: 11.788

                                               otel.o Document No.: ST-rfx-00011

                                               Chapter: 7

                                               Item No.: 88, 89, 90
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Performance Management for Tandem Connection

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

At the moment Performance Monitoring is executed at the termination points of
the relevant services. Hence it's possible to determine the QoS for the whole
connection.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /   Compliant development planned until    / / T1   / / T2        / / after T2
/ /   Further Development planned but not compliant with o.tel.o requirements
/ /   No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------

<PAGE>

                       SYSTEM FEATURE DESCRIPTION ADM-64/4

<TABLE>
<S>                       <C>
                          ----------------------------------------------------------------------------------------

ID                        ST-rfx-0007
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

                          ----------------------------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature description ADM-16-4-10

                          ----------------------------------------------------------------------------------------

DESCRIPTION               This document lists the features of ADM-16/4 Equipment

                          The equipment shall mainly be applied for combining VC-4 add/drop to/from backbone
                          rings.

                          ----------------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

REQUESTED FEATURES

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
1                 INTERFACE TYPES
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
1.1               ELECTRICAL TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           1.     STM-1 G.703                                                             NC      NC       C         07.1
-------------------------------------------------------------------------------------------------------------------------------
1.2               OPTICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
1.2.1             TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           2.     S-1.1                                                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           3.     L-1.1                                                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           4.     L-1.2                                                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           5.     S-4.1                                                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           6.     L-4.1                                                                   C
-------------------------------------------------------------------------------------------------------------------------------
           7.     L-4.2                                                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           8.     V-4.2                                                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           9.     S-16.1                                                                  NC
-------------------------------------------------------------------------------------------------------------------------------
           10.    L-16.1                                                                  C
-------------------------------------------------------------------------------------------------------------------------------
           11.    L-16.2                                                                  C
-------------------------------------------------------------------------------------------------------------------------------
           12.    V-16.2                                                                  NC
-------------------------------------------------------------------------------------------------------------------------------
1.2.2             AGGREGATE INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           13.    S-16.1                                                                  NC
-------------------------------------------------------------------------------------------------------------------------------
           14.    L-16.1                                                                  NC
-------------------------------------------------------------------------------------------------------------------------------
           15.    L-16.2                                                                  NC
-------------------------------------------------------------------------------------------------------------------------------
           16.    V-16.2                                                                  NC
-------------------------------------------------------------------------------------------------------------------------------
           17.    STM-64 S-64.2 (Amplifier required)                                      C
-------------------------------------------------------------------------------------------------------------------------------
           18.    STM-64 L-64.2 (Amplifier required)                                      C
-------------------------------------------------------------------------------------------------------------------------------
           19.    STM-64 L-64.3 (Amplifier required)                                      C
-------------------------------------------------------------------------------------------------------------------------------
           20.    STM-64 V-64.2 (Amplifier required)                                      C
-------------------------------------------------------------------------------------------------------------------------------
           21.    STM-64 V-64.3 (Amplifier required)                                      C
-------------------------------------------------------------------------------------------------------------------------------
           22.    Coloured Interfaces 100 GHz channel spacing                             C
-------------------------------------------------------------------------------------------------------------------------------
           23.    Coloured Interfaces 50 GHz channel spacing                              NC      NC        C
-------------------------------------------------------------------------------------------------------------------------------
1.3               EQUIPPING OF INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
1.3.1             TRIBUTARY INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           24.    STM-4 S-4.1                                                             C
-------------------------------------------------------------------------------------------------------------------------------
           25.    STM-16 S-16.1                                                           C
-------------------------------------------------------------------------------------------------------------------------------
           26.    STM-16 S-16.2                                                           C
-------------------------------------------------------------------------------------------------------------------------------
                  STM-16 L-16.1                                                           C
-------------------------------------------------------------------------------------------------------------------------------
                  STM-16 S-16.2                                                           C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
2                 CONNECTIVITY
-------------------------------------------------------------------------------------------------------------------------------
2.1               CONNECTION TYPES
-------------------------------------------------------------------------------------------------------------------------------
           26.    Bi-directional Connections                                              C
-------------------------------------------------------------------------------------------------------------------------------
           27.    Bi-directional Connections of contiguously concatenated  VC-4           C
                  (VC-4-4c)
-------------------------------------------------------------------------------------------------------------------------------
           28.    Bi-directional Connections of contiguously concatenated  VC-4           C
                  (VC-4-16c)
-------------------------------------------------------------------------------------------------------------------------------
2.2               QUANTITATIVE REQUIREMENTS
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           29.    High order add/drop capacity of 64 * VC-4 equivalents from              C
                  aggregate east
-------------------------------------------------------------------------------------------------------------------------------
           30.    High order add/drop capacity of 64 * VC-4 equivalents from              C
                  aggregate west
-------------------------------------------------------------------------------------------------------------------------------
           31.    High order add/drop capacity of 64 * VC-4 equivalents from              C
                  aggregate east and west
-------------------------------------------------------------------------------------------------------------------------------
           32.    High Order aggregate to aggregate connectivity of 64 STM-1              C
                  equivalents (east and west)
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
3                 SYNCHRONISATION
-------------------------------------------------------------------------------------------------------------------------------
3.1               INTERNAL EQUIPMENT TIMING
-------------------------------------------------------------------------------------------------------------------------------
3.1.1             TIMING SOURCES
-------------------------------------------------------------------------------------------------------------------------------
           33.    STM-N timing                                                            C        C       C        STM-64
-------------------------------------------------------------------------------------------------------------------------------
           34.    2048 kHz timing                                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           35.    Internal Oscillator acc. to G.813                                       C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.1.2             TIMING SOURCE QUALITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           36.    STM-N Timing at all SDH i/fs (Timing Marker Support)                    Nc       C       C        Rel. 3
-------------------------------------------------------------------------------------------------------------------------------
           37.    2048 kHz timing, fixed to G.811 quality                                 C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           38.    2048 kHz timing, configurable timing source quality                     C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.1.3             TIMING SOURCE PRIORITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           39.    Priority List of (at least 6 entries)                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.1.4             SELECTION ALGORITHMS
-------------------------------------------------------------------------------------------------------------------------------
           40.    Autonomous Timing Source Selection acc. to highest quality and          C        C       C
                  highest priority
-------------------------------------------------------------------------------------------------------------------------------
           41.    Manual Timing Source Selection                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2               EXTERNAL  TIMING OUTPUT (T4)
-------------------------------------------------------------------------------------------------------------------------------
3.2.1             TIMING  OUTPUT PORT
-------------------------------------------------------------------------------------------------------------------------------
           42.    One 2048 kHz timing output port                                         C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           43.    Configurable timing output squelch function                             C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.2             TIMING SOURCES
-------------------------------------------------------------------------------------------------------------------------------
           44.    STM-N                                                                   C        C       C
-------------------------------------------------------------------------------------------------------------------------------
3.2.3             TIMING SOURCE QUALITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           45.    STM-N Timing (Timing Marker Support)                                    Nc       C       C        Rel. 3
-------------------------------------------------------------------------------------------------------------------------------
3.2.4             TIMING SOURCE PRIORITY LEVELS
-------------------------------------------------------------------------------------------------------------------------------
           46.    Priority List (at least 7 entries)                                      Nc      Nc       Nc      6 entries
-------------------------------------------------------------------------------------------------------------------------------
3.2.5             SELECTION ALGORITHMS
-------------------------------------------------------------------------------------------------------------------------------
           47.    Autonomous timing source selection                                      C        C       C
-------------------------------------------------------------------------------------------------------------------------------
           48.    Manual Timing Source selection                                          C        C       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
4                 OVERHEAD ACCESS
-------------------------------------------------------------------------------------------------------------------------------
4.1               OVERHEAD BYTES
-------------------------------------------------------------------------------------------------------------------------------
           49.    Access to F1 as transparent channel                                     NC
-------------------------------------------------------------------------------------------------------------------------------
           50.    Access to E1 as transparent channel                                     NC
-------------------------------------------------------------------------------------------------------------------------------
           51.    Access to F2 as transparent channel                                     NC
-------------------------------------------------------------------------------------------------------------------------------
4.2               OVERHEAD ACCESS INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           52.    64 K on V.11 (towards either MSOH or RSOH of aggregate interface)       NC
-------------------------------------------------------------------------------------------------------------------------------
           53.    64 K on V.11 (towards POH of tributary interface)                       NC
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
4.3               OVERHEAD CHANNEL CROSS CONNECTIONS
-------------------------------------------------------------------------------------------------------------------------------
           54.    64 K between synchronous ports and towards external interface           NC
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
5                 ENGINEERING ORDERWIRE                                                   C

                  TWO MODES ARE SUPPORTED:

                  a)       VIA OSC. (THIS REQUIRES MOR TO BE PRESENT
                  b)       NETWORK EOW BASED ON PACKETISED VOICE OVER OSI COMMS
                           CARRIED BY EMBEDDED SDH DCC
-------------------------------------------------------------------------------------------------------------------------------
5.1               INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           55.    1 * 2 wire i/f (towards PSTN)                                                    C
-------------------------------------------------------------------------------------------------------------------------------
           56.    2 * 2 wire  i/f (towards standard handset)                                       C
-------------------------------------------------------------------------------------------------------------------------------
5.2               FUNCTIONS
-------------------------------------------------------------------------------------------------------------------------------
           57.    Selective Call                                                                   C
-------------------------------------------------------------------------------------------------------------------------------
           58.    Conference Call (up to four participants)                                        C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
6                 MANAGEMENT COMMUNICATION
-------------------------------------------------------------------------------------------------------------------------------
6.1               COMMUNICATION INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           59.    F- Interface   (RS 232)                                                 C                          07.59
-------------------------------------------------------------------------------------------------------------------------------
           60.    Q- interface as gateway to the EMS                                      C
-------------------------------------------------------------------------------------------------------------------------------
           61.    Qecc via any ECC(R)  on optical  interfaces                             C
-------------------------------------------------------------------------------------------------------------------------------
           62.    Qecc via any ECC(M) on optical  interfaces                              C
-------------------------------------------------------------------------------------------------------------------------------
           63.    Qecc via any ECC(R)  on electrical  interfaces                          NC
-------------------------------------------------------------------------------------------------------------------------------
           64.    Qecc via any ECC(M) on electrical  interfaces                           NC
-------------------------------------------------------------------------------------------------------------------------------
           1.     Qecc Routing (level 2 IS-IS acc. to ISO 10589-8473)                     NC      NC       C         07.6
-------------------------------------------------------------------------------------------------------------------------------
           65.    Domain Partitioning Repair function                                     NC
-------------------------------------------------------------------------------------------------------------------------------
           66.    Definition of Manual Adjacencies (NSAP of dedicated NE)                 C
-------------------------------------------------------------------------------------------------------------------------------
           67.    Manual definition of reachable addresses (set address prefix) C
-------------------------------------------------------------------------------------------------------------------------------
           68.    ECC can be inserted / extracted to/from VC-4 POH Byte of SDH
                  NC tributary interface (Application: for transparent
                  transmission of ECC via other operator's SDH network)
-------------------------------------------------------------------------------------------------------------------------------
6.2               O & M INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           69.    8 x Remote Control Inputs                                               C
-------------------------------------------------------------------------------------------------------------------------------
           70.    Remote Control Outputs                                                  C
-------------------------------------------------------------------------------------------------------------------------------
           71.    Card LED support                                                        C
-------------------------------------------------------------------------------------------------------------------------------
           72.    Subrack LED support                                                     C
-------------------------------------------------------------------------------------------------------------------------------
           73.    Rack Alarm support                                                      C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
7                 PERFORMANCE MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------
           74.    Performance History Data Collection (ES, SES and UAT) ...               C
-------------------------------------------------------------------------------------------------------------------------------
           75.    at any VC-4 TTP                                                         NC
-------------------------------------------------------------------------------------------------------------------------------
           76.    at any MST                                                              C
-------------------------------------------------------------------------------------------------------------------------------
           77.    at any RST                                                              C
-------------------------------------------------------------------------------------------------------------------------------
           78.    at any AU-4 CTP                                                         C                          7.79
-------------------------------------------------------------------------------------------------------------------------------
           79.    for any AU-4 Tandem Connection                                         IPPM
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           80.    from remote TTPs based on FEBE evaluation                               NC
-------------------------------------------------------------------------------------------------------------------------------
           81.    Threshold Crossing Notification                                         C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
8                 FAULT AND STATUS MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
8.1               DETECTED ANOMALIES, DEFECTS AND CONSEQUENT ACTIONS
-------------------------------------------------------------------------------------------------------------------------------
8.1.1             ALL SYNCHRONOUS PHYSICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           82.    Detection of Transmit Fail on any optical STM-N interface               NC
-------------------------------------------------------------------------------------------------------------------------------
           83.    Detection of Laser Shutdown on any optical interface                    NC
-------------------------------------------------------------------------------------------------------------------------------
           84.    Detection of disabled ALS on any optical interface                      NC
-------------------------------------------------------------------------------------------------------------------------------
           85.    Detection of Optical Source Power High on any optical
                  interface C (STM-64 ONLY)
-------------------------------------------------------------------------------------------------------------------------------
           86.    Detection of LOS, LOS status change hysteresis                          C
-------------------------------------------------------------------------------------------------------------------------------
           87.    Insertion of AIS upon detection of LOS                                  C
-------------------------------------------------------------------------------------------------------------------------------
8.1.2             ALL REGENERATOR SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           88.    Detection of OOF                                                        C
-------------------------------------------------------------------------------------------------------------------------------
           89.    Detection of LOF                                                        C
-------------------------------------------------------------------------------------------------------------------------------
           90.    Insertion of AIS upon persisting LOF detection                          C
-------------------------------------------------------------------------------------------------------------------------------
           91.    Detection of RS EBER (10E-3) based on B1 BIP-8 parity calculation       C
-------------------------------------------------------------------------------------------------------------------------------
8.1.3             ALL MULTIPLEX SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           92.    Detection of MS-AIS                                                     C
-------------------------------------------------------------------------------------------------------------------------------
           93.    Insertion of all 1 upon detection of MS-AIS                             C
-------------------------------------------------------------------------------------------------------------------------------
           94.    Detection of Signal Degrade                                             C
-------------------------------------------------------------------------------------------------------------------------------
           95.    Detection of MS-EBER (10E-3) upon B2 BIP-24 parity error
                  calculation C
-------------------------------------------------------------------------------------------------------------------------------
           96.    Insertion of AIS and FERF upon detection of MS-AIS                      C
-------------------------------------------------------------------------------------------------------------------------------
           97.    Detection of FERF                                                       C
-------------------------------------------------------------------------------------------------------------------------------
           98. Insertion of MS-FEBE based on detection of B2 parity calculations          NC
-------------------------------------------------------------------------------------------------------------------------------
8.1.4             ALL MULTIPLEX SECTION ADAPTATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           99.    Detection  of AU-LOP                                                    C
-------------------------------------------------------------------------------------------------------------------------------
           100.   Detection of AU-AIS                                                     C
-------------------------------------------------------------------------------------------------------------------------------
           101.   Detection of Number of AU-Pointer Justification Events                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           102.   Insertion of AU-AIS upon receive of all 1                               C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
8.1.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           103.   Detection of Path AIS upon receive of all 1                             C
-------------------------------------------------------------------------------------------------------------------------------
           104.   Detection of HP-Trace Invalid                                                            NC
-------------------------------------------------------------------------------------------------------------------------------
           105.   Detection of HP-TIM                                                                      NC
-------------------------------------------------------------------------------------------------------------------------------
           106.   Detection of HP-SLM                                                     NC
-------------------------------------------------------------------------------------------------------------------------------
           107.   Detection of HP-FERF                                                    C
-------------------------------------------------------------------------------------------------------------------------------
           108.   Detection of B3- EBER (10E-3)                                           NC
-------------------------------------------------------------------------------------------------------------------------------
8.1.6             ALL HIGH ORDER PATH TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           109.   Detection of Path AIS upon receive of all 1                                             N/A
-------------------------------------------------------------------------------------------------------------------------------
           110.   Insertion of AIS and HP-FERF upon detection of Path AIS N/A
-------------------------------------------------------------------------------------------------------------------------------
           111.   Detection of HP-Trace Invalid                                                           N/A
-------------------------------------------------------------------------------------------------------------------------------
           112.   Detection of HP-TIM                                                                     N/A
-------------------------------------------------------------------------------------------------------------------------------
           113.   Insertion of AIS and HP-FERF upon detection of HP-TIM                                   N/A
-------------------------------------------------------------------------------------------------------------------------------
           114.   Detection of HP-SLM                                                                     N/A
-------------------------------------------------------------------------------------------------------------------------------
           115.   Insertion of AIS and HP-FERF upon detection of HP-SLM                                   N/A
-------------------------------------------------------------------------------------------------------------------------------
           116.   Detection of HP-FERF                                                                    N/A
-------------------------------------------------------------------------------------------------------------------------------
           117.   Detection of B3- EBER (10E-3)                                                           N/A
-------------------------------------------------------------------------------------------------------------------------------
8.1.7             ALL PLESIOCHRONOUS PHYSICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           118.   Detection of Trib.-AIS                                                                  N/A
-------------------------------------------------------------------------------------------------------------------------------
           119.   Detection of Trib.-LOS                                                                  N/A
-------------------------------------------------------------------------------------------------------------------------------
           120.   Detection of Trib.-LOF                                                                  N/A
-------------------------------------------------------------------------------------------------------------------------------
           121.   Insertion of AIS upon detection of Trib.-AIS, Trib.-LOS,
                  Trib.-LOF N/A
-------------------------------------------------------------------------------------------------------------------------------
8.1.8             SETS AND SETPI
-------------------------------------------------------------------------------------------------------------------------------
           122.   Detection of Sync. Source Fail                                          C
-------------------------------------------------------------------------------------------------------------------------------
           123.   Detection of SETG - Hold                                                C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           124.   Detection of SETG - Out of Lock                                         C
-------------------------------------------------------------------------------------------------------------------------------
           125.   Detection of SETG - Fail                                                C
-------------------------------------------------------------------------------------------------------------------------------
           126.   Detection of Sync. Degrade                                              C
-------------------------------------------------------------------------------------------------------------------------------
           127.   Detection of Excessive Sync. Degrade                                    C
-------------------------------------------------------------------------------------------------------------------------------
           128.   Detection of Sync. Source Threshold Crossing                            NC
-------------------------------------------------------------------------------------------------------------------------------
           129.   Detection of Sync. LOS                                                  C
-------------------------------------------------------------------------------------------------------------------------------
8.1.9             MANAGEMENT COMMUNICATION FUNCTION
-------------------------------------------------------------------------------------------------------------------------------
           130.   Detection of Remote Control Input Active                                C
-------------------------------------------------------------------------------------------------------------------------------
           131.   Detection of RS - Qecc Comms Fail (LAPD Alarm)                          C
-------------------------------------------------------------------------------------------------------------------------------
           132.   Detection of MS - Qecc Comms Fail (LAPD Alarm)                          C
-------------------------------------------------------------------------------------------------------------------------------
8.1.10            SYSTEMS MANAGEMENT FUNCTION
-------------------------------------------------------------------------------------------------------------------------------
           133.   Detection of Secondary Power Fail                                       C
-------------------------------------------------------------------------------------------------------------------------------
           134.   Detection of Primary Power Fail                                         C
-------------------------------------------------------------------------------------------------------------------------------
           135.   Detection of Re-Boot Fail                                               C
-------------------------------------------------------------------------------------------------------------------------------
           136.   Detection of Configuration Data Integrity Check Failure                 C
-------------------------------------------------------------------------------------------------------------------------------
           137.   Detection of System Software Integrity Check Failure                    C
-------------------------------------------------------------------------------------------------------------------------------
           138.   Detection of Network Element Controller Fail                            C
-------------------------------------------------------------------------------------------------------------------------------
           139.   Detection of Card Protection Switch Failure                             C
-------------------------------------------------------------------------------------------------------------------------------
           140.   Detection of Card Out                                                   C
-------------------------------------------------------------------------------------------------------------------------------
           141.   Detection of Card Fail (upon detection of internal parity
                  mismatch C etc.)
-------------------------------------------------------------------------------------------------------------------------------
           142.   Detection of Wrong Card                                                 C
-------------------------------------------------------------------------------------------------------------------------------
           143.   Network Protection Switch Failure                                       C
-------------------------------------------------------------------------------------------------------------------------------
8.2               STATUS EVENTS
-------------------------------------------------------------------------------------------------------------------------------
           144.   Configuration Data Integrity Fail                                       C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           145.   System Software Integrity Fail (NES REBOOT IN THE EVENT OF
                  FAILURE)                                                                NA
-------------------------------------------------------------------------------------------------------------------------------
           146.   Laser Restart for Test                                                  NC
-------------------------------------------------------------------------------------------------------------------------------
           147.   Synchronous Equipment Timing Generator A/B active                       NC
-------------------------------------------------------------------------------------------------------------------------------
           148.   Synchronisation Source Quality Change                                   C
-------------------------------------------------------------------------------------------------------------------------------
           149.   Synchronisation Source Switch Event                                     C
-------------------------------------------------------------------------------------------------------------------------------
           150.   External Synchronisation Output Squelched                               C
-------------------------------------------------------------------------------------------------------------------------------
           151.   Section Layer Protection Switch Active                                  C
-------------------------------------------------------------------------------------------------------------------------------
           152.   Network Protection Switch Event                                         C
-------------------------------------------------------------------------------------------------------------------------------
           153.   Card Protection Switch Active                                           C
-------------------------------------------------------------------------------------------------------------------------------
           154.   Fault / Status Log Capacity Exceeded (CAPACITY IS NEVER
                  EXCEEDED)                                                               NA
-------------------------------------------------------------------------------------------------------------------------------
           155.   Configuration Data Transaction Log Capacity Exceeded                    NA
-------------------------------------------------------------------------------------------------------------------------------
           156.   Performance Monitoring Log Capacity Exceeded                            NA
-------------------------------------------------------------------------------------------------------------------------------
           157.   Access  Log Capacity Exceeded                                           NA
-------------------------------------------------------------------------------------------------------------------------------
           158.   Software Download in Progress                                           C
-------------------------------------------------------------------------------------------------------------------------------
           159.   Software Download Failure                                               C
-------------------------------------------------------------------------------------------------------------------------------
           160.   Software Download Failure - Retry in Progress                           C
-------------------------------------------------------------------------------------------------------------------------------
           161.   Software Download Complete                                              C
-------------------------------------------------------------------------------------------------------------------------------
           162.   Card Restoration Complete                                               C
-------------------------------------------------------------------------------------------------------------------------------
           163.   Re-Boot Restoration Complete                                            C
-------------------------------------------------------------------------------------------------------------------------------
           164.   Electronic Label Update                                                 C
-------------------------------------------------------------------------------------------------------------------------------
8.3               ALARM EVENT HANDLING
-------------------------------------------------------------------------------------------------------------------------------
           165.   Alarm Persistence Filter (filtering of toggling alarms)                 C
-------------------------------------------------------------------------------------------------------------------------------
           166.   Alarm Correlation Filter (F3 filter, suppression of consequent
                  NC alarms)
-------------------------------------------------------------------------------------------------------------------------------
           167.   Alarm Inversion Facility                                                NC
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           168.   Performance of the alarm throughput > 10 alarms per second              NC
-------------------------------------------------------------------------------------------------------------------------------
           169.   It is possible to block/unblock each single traffic relevant
                  alarm C per port                                                        C
-------------------------------------------------------------------------------------------------------------------------------
           170.   It is possible to block/unblock each single traffic relevant
                  alarm C group per card                                                  C
-------------------------------------------------------------------------------------------------------------------------------
           171.   It is possible to block/unblock each single traffic relevant
                  alarm C group per NE                                                    C
-------------------------------------------------------------------------------------------------------------------------------
           172.   Indication of Alarm Event Forwarding Suppression per
                  functional C unit (e.g. Regenerator Section ...)                        C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
9                 CONFIGURATION MANAGEMENT
-------------------------------------------------------------------------------------------------------------------------------
9.1               GENERAL
-------------------------------------------------------------------------------------------------------------------------------
           173.   Upload of Configuration Data - on single command                                         NC
-------------------------------------------------------------------------------------------------------------------------------
           174.   Upload of Configuration Data - on bulk command                                           NC
-------------------------------------------------------------------------------------------------------------------------------
           175.   Download of Configuration Data - on bulk command                                         NC
-------------------------------------------------------------------------------------------------------------------------------
9.2               CONFIGURATION OF FUNCTIONAL BLOCKS
-------------------------------------------------------------------------------------------------------------------------------
9.2.1             ALL SYNCHRONOUS OPTICAL INTERFACES
-------------------------------------------------------------------------------------------------------------------------------
           176.   Enable / Disable Automatic Laser Shutdown                                                NC
-------------------------------------------------------------------------------------------------------------------------------
           177.   Enable / Disable Laser                                                                   NC
-------------------------------------------------------------------------------------------------------------------------------
           178.   Enable Laser for Test Purposes (2s / 90s) NC
-------------------------------------------------------------------------------------------------------------------------------
9.2.2             ALL MULTIPLEX SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           179.   Set Threshold Signal Degrade                                            C
-------------------------------------------------------------------------------------------------------------------------------
           180.   Set Threshold B2-EBER                                                   C
-------------------------------------------------------------------------------------------------------------------------------
9.2.3             ALL REGENERATOR SECTION TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           181.   Set Threshold B1-EBER                                                   C
-------------------------------------------------------------------------------------------------------------------------------
9.2.4             ALL HIGH ORDER PATH TERMINATION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           182.   Set Threshold B3-EBER                                                  N/A      N/A
-------------------------------------------------------------------------------------------------------------------------------
           183.   Set Threshold HP-FEBE                                                  N/A      N/A
-------------------------------------------------------------------------------------------------------------------------------
           184.   Enable / Disable consequent actions from detection of HP-TIM
                  (per N/A N/A Path)                                                     N/A      N/A
-------------------------------------------------------------------------------------------------------------------------------
           185.   Enable / Disable consequent actions from detection of HP-SLM
                  (per N/A N/A Path)                                                     N/A      N/A
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           186.   Set expected Signal Label (per Path)                                   N/A      N/A
-------------------------------------------------------------------------------------------------------------------------------
           187.   Set expected Path Trace (per Path)                                     N/A      N/A
-------------------------------------------------------------------------------------------------------------------------------
9.2.5             ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-------------------------------------------------------------------------------------------------------------------------------
           188.   Set Threshold B3-EBER                                                   C
-------------------------------------------------------------------------------------------------------------------------------
           189.   Set Threshold HP-FEBE                                                   C
-------------------------------------------------------------------------------------------------------------------------------
           190.   Set expected Signal Label (per Path)                                    C
-------------------------------------------------------------------------------------------------------------------------------
           191.   Set expected Path Trace (per Path)                                      C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
10                NETWORK PROTECTION
-------------------------------------------------------------------------------------------------------------------------------
10.1              HIGHER ORDER LINEAR VC TRAIL PROTECTION (SINGLE ENDED)
-------------------------------------------------------------------------------------------------------------------------------
           192.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           193.   Detection Criterion Signal Degrade (B3 Bit Error Rate)                  NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           194.   Switch-Over Completion Time less than 300ms                             NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           195.   Configurable Hold-Off Time                                              NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           196.   Enable / Disable Automatic Switching                                    NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           197.   Manual Switching via Management Interface                               NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           198.   Configurable Wait Time to Restore                                       NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
10.2              HIGHER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I)
-------------------------------------------------------------------------------------------------------------------------------
           199.   Detection Criterion Signal Fail (AU-AIS, AU-LOP)                        NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           200.   Switch-Over Completion Time less than 100ms                             NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           201.   Configurable Hold-Off Time                                              NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           202.   Enable / Disable Automatic Switching                                    NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           203.   Manual Switching via Management Interface                               NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
           204.   Configurable Wait Time to Restore                                       NC      NC       NC
-------------------------------------------------------------------------------------------------------------------------------
10.3              1+1 LINE PROTECTION
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           205.   MSP function on all aggregates                                          C
-------------------------------------------------------------------------------------------------------------------------------
           206.   MSP function on all optical tributaries                                 C
-------------------------------------------------------------------------------------------------------------------------------
           207.   MSP function on all electrical STM-1 tributaries                        N/A      N/A      C
-------------------------------------------------------------------------------------------------------------------------------
           208.   Detection Criterion Signal Fail and Signal Degrade according
                  to C Section 2.3 of ITU-T rec. G.783                                    C
-------------------------------------------------------------------------------------------------------------------------------
           209.   Switch-Over Completion Time less than 50ms                              C
-------------------------------------------------------------------------------------------------------------------------------
           210.   Enable / Disable Automatic Switching                                    C
-------------------------------------------------------------------------------------------------------------------------------
           211.   Manual Switching via Management Interface                               C
-------------------------------------------------------------------------------------------------------------------------------
           212.   Configurable Wait Time to Restore                                       C
-------------------------------------------------------------------------------------------------------------------------------
10.4              MS SHARED RING PROTECTION (MSBSHR)-
                  FOLLOWING ANSWERS GIVEN FOR MS-SPRING
-------------------------------------------------------------------------------------------------------------------------------
           213.   Detection Criterion Signal Fail and Signal Degrade according
                  to C Section 2.3 of ITU-T rec. G.783                                    C
-------------------------------------------------------------------------------------------------------------------------------
           214.   Switch-Over Completion Time less than 50ms                              C
-------------------------------------------------------------------------------------------------------------------------------
           215.   Manual Switching via Management Interface                               C
-------------------------------------------------------------------------------------------------------------------------------
           216.   Revertive Switching                                                     C
-------------------------------------------------------------------------------------------------------------------------------
           217.   Configurable Wait Time to Restore                                       C
-------------------------------------------------------------------------------------------------------------------------------
           218.   Maximum number of network elements in the ring                          16      32
-------------------------------------------------------------------------------------------------------------------------------
           219.   It is possible to configure (unprotected) low priority traffic          NC      NC       C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
11                OPERATION AND MAINTENANCE
-------------------------------------------------------------------------------------------------------------------------------
11.1              GENERAL
-------------------------------------------------------------------------------------------------------------------------------
           220.   Event buffer                                                            C
-------------------------------------------------------------------------------------------------------------------------------
           221.   Heart Beat Function                                                     C
-------------------------------------------------------------------------------------------------------------------------------
           222.   Re-boot function                                                        C
-------------------------------------------------------------------------------------------------------------------------------
           223.   Real time clock function                                                C
-------------------------------------------------------------------------------------------------------------------------------
           224.   NSAP Address modification                                               C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
           225.   Local Software Download                                                 C                        Supported,
                                                                                                                     but NUM
                                                                                                                   recommended
-------------------------------------------------------------------------------------------------------------------------------
           226.   Remote Software Download                                                C
-------------------------------------------------------------------------------------------------------------------------------
           227.   Manager Decision Process for equipment access control                   C
-------------------------------------------------------------------------------------------------------------------------------
           228.   Display of VC-4 Path Trace at HPT                                      N/A
-------------------------------------------------------------------------------------------------------------------------------
           229.   Display of VC-4 Signal Label at HPT                                    N/A
-------------------------------------------------------------------------------------------------------------------------------
           230.   Display of VC-4 Path Trace at HPOM                                      C
-------------------------------------------------------------------------------------------------------------------------------
           231.   Display of VC-4 Signal Label at HPOM                                    C
-------------------------------------------------------------------------------------------------------------------------------
           232.   Display of Optical Transmit Power Level                                 C
-------------------------------------------------------------------------------------------------------------------------------
11.2              LOGS
-------------------------------------------------------------------------------------------------------------------------------
           233.   Alarm / Status Log                                                      C
-------------------------------------------------------------------------------------------------------------------------------
           234.   Performance Log                                                         C
-------------------------------------------------------------------------------------------------------------------------------
           235.   Configuration  Log                                                      C
-------------------------------------------------------------------------------------------------------------------------------
           236.   Access Control  Log                                                     C
-------------------------------------------------------------------------------------------------------------------------------
11.3              REDUNDANCY
-------------------------------------------------------------------------------------------------------------------------------
           237.   1+1 (electrical) Tributary Card Protection STM-1 G.703                 N/A      N/A     Tbc
-------------------------------------------------------------------------------------------------------------------------------
           238.   1+1 Protection of all Central Traffic Carrying Cards                    C
-------------------------------------------------------------------------------------------------------------------------------
           239.   1+1 Protection of Clock System                                          C
-------------------------------------------------------------------------------------------------------------------------------
           240. Duration less than 5s for card protection automatic switch over           C
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
11.4              EQUIPMENT TESTING FUNCTIONS
-------------------------------------------------------------------------------------------------------------------------------
           241.   Integrity Check of Configuration Data                                   C
-------------------------------------------------------------------------------------------------------------------------------
           242.   Integrity Check of System Software                                     N/A
-------------------------------------------------------------------------------------------------------------------------------
           243.   Configuration of Loop Back on all PDH Interface Cards                                   N/A
-------------------------------------------------------------------------------------------------------------------------------
           244.   Configuration of Loop Back on all electrical SDH Interface Cards        NC      NC      TBC
-------------------------------------------------------------------------------------------------------------------------------
           245.   Configuration of Loop Back on all optical SDH Interface Cards           NC      NC
-------------------------------------------------------------------------------------------------------------------------------
           246.   Configuration of Loop Back on the HPC functional block                  C
-------------------------------------------------------------------------------------------------------------------------------
           247.   Test Interface on all electrical interfaces                             NC
-------------------------------------------------------------------------------------------------------------------------------
           248.   Optical Line Testing                                                    C
-------------------------------------------------------------------------------------------------------------------------------
11.5              INVENTORY DATA
-------------------------------------------------------------------------------------------------------------------------------
           249.   Electronic Label Read Access via Management Interfaces                  C
-------------------------------------------------------------------------------------------------------------------------------
           250.   Automatic Electronic Label Upgrade                                      C
-------------------------------------------------------------------------------------------------------------------------------
           251.   Compatibility Check of Equipment Hardware Releases                      C
-------------------------------------------------------------------------------------------------------------------------------
           252.   Compatibility Check of Equipment Firmware Releases                      C
-------------------------------------------------------------------------------------------------------------------------------
           253.   Compatibility Check of Equipment Software Releases                      C
-------------------------------------------------------------------------------------------------------------------------------
           254.   Compatibility Check of Equipment Software Releases to the               C
                  Management System
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
12                ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL COMPATIBILITY AND SAFETY
-------------------------------------------------------------------------------------------------------------------------------
12.1              CLIMATIC CONDITIONS
-------------------------------------------------------------------------------------------------------------------------------
           255.   Stationary Use Conditions acc. to prETS 300 019-2-3 Class T 3.2         C                        PrETS 300
                                                                                                                     019-3
-------------------------------------------------------------------------------------------------------------------------------
           256.
-------------------------------------------------------------------------------------------------------------------------------
12.2       257.   ELECTROMAGNETIC COMPATIBILITY
-------------------------------------------------------------------------------------------------------------------------------
           258.   Compliance with EN 55022 class B                                        C
-------------------------------------------------------------------------------------------------------------------------------
           259.   Compliance with EN 50082                                                C                        EN 50082-1
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------------------
           NO.    ITEM                                                                   SOC      SOC     SOC      REF. NO.
                                                                                          T1      T2       T3
-------------------------------------------------------------------------------------------------------------------------------
<S>        <C>    <C>                                                                    <C>      <C>     <C>      <C>
-------------------------------------------------------------------------------------------------------------------------------
12.3              SAFETY REQUIREMENTS
-------------------------------------------------------------------------------------------------------------------------------
           260.   Compliance with EN 60950                                                C
-------------------------------------------------------------------------------------------------------------------------------
           261.   Compliance with IEC 825-1 and IEC 825-2                                 C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
13                PHYSICAL CONSTRUCTION
-------------------------------------------------------------------------------------------------------------------------------
           262.   Rack size according to ETSI 300 119, 600 mm x 300 mm                    C
-------------------------------------------------------------------------------------------------------------------------------
           263.   System installation and h/w upgrade via front access possible           C
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
14                POWER SUPPLY
-------------------------------------------------------------------------------------------------------------------------------
           264.   Nominal input voltage -48V                                              C
-------------------------------------------------------------------------------------------------------------------------------
           265.   Minimum accepted input voltage                                          -39 V
-------------------------------------------------------------------------------------------------------------------------------
           266.   Maximum accepted input voltage                                          -75 V
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
15                AVAILABILITY
-------------------------------------------------------------------------------------------------------------------------------
           267.   The supplier shall provide MTBF figures for each functional             IR       IR      IR        Attached
                  unit of the offered equipment based on his statistical evaluations
                  according to the template as attached in Annex 1
-------------------------------------------------------------------------------------------------------------------------------
           268.
-------------------------------------------------------------------------------------------------------------------------------
16                POWER CONSUMPTION
-------------------------------------------------------------------------------------------------------------------------------
           269.   The supplier shall provide worst case power consumption                 IR       IR      IR        Attached
                  figures for each functional unit of the offered equipment according
                  to the template as attached in Annex 1
-------------------------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------------------------
17                SYSTEM MANUALS
-------------------------------------------------------------------------------------------------------------------------------
           270.   System Description in Hypertext Format on CD                                                      ftp format
-------------------------------------------------------------------------------------------------------------------------------
           271.   System O&M Manuals in Hypertext Format on CD                                                      ftp format
-------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

REFERENCES

1.1  REFERENCES TO STANDARDS

<TABLE>
<CAPTION>
====================================================================================================================================
STANDARD            STATUS    DATE      TITLE
------------------------------------------------------------------------------------------------------------------------------------
<S>                 <C>       <C>       <C>
CECC 86 275-80                09/95     Detail Specification: Connector sets for optical fibres and cables Type LSH-HRL
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.703                   04/91     Physical/Electrical characteristics of Hierarchical Digital Interfaces
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.707                   1991      Synchronous digital hierarchy bit rates
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.782                   1994      Types and general characteristics of synchronous digital hierarchy (SDH) equipment
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.783                   1994      Characteristics of synchronous digital hierarchy /SDH) equipment functional blocks
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.813                   1996      Timing Characteristics of SDH equipment slave clocks.
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.825                   1993      The control of Jitter and Wander within Digital Networks which are based on synchronous
                                        digital hierarchy
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.826                   11/93     Error performance parameters and objectives for International constant
                                        Bit Rate Digital Paths at or above the Primary Rate
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.841                   1995      Types and Characteristics of SDH Network Protection Architectures
------------------------------------------------------------------------------------------------------------------------------------
ITU-T G.957                   1993      Optical Interfaces and Systems relating to the synchronous digital hierarchy
------------------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------------------
ETS 300 019         pr        02/92     Environmental conditions and Environmental Tests for Telecommunications Equipment
                                        Part A: Introduction and Terminology
                                        Part B: classification of Environmental conditions
------------------------------------------------------------------------------------------------------------------------------------
ETS 300 119                             European Telecommunication Standard for Equipment Practice
                              03/93     Part 2: Engineering Requirements for Racks
                              09/93     Part 3: Engineering Requirements for Miscellaneous Racks and cabinets
                              09/93     Part 4: Engineering Requirements for Subracks
------------------------------------------------------------------------------------------------------------------------------------
ETS 300 253                   01/95     Earthing and bonding of telecommunication equipment in telecommunication centres
------------------------------------------------------------------------------------------------------------------------------------
EN 41003                      1991      Particular safety requirements for equipment to be connected to telecommunication network
------------------------------------------------------------------------------------------------------------------------------------
EN 55022                      05/95     Grenzwerte und Messverfahren fur Funkstorungen von Einrichtungen der Informationstechnik
------------------------------------------------------------------------------------------------------------------------------------
EN 50082                                Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                              12/94     Part 1: Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit -
                                                Teil 1: Wohnbereich, Geschafts- und Gewerbebereiche sowie Kleinbetriebe
                              02/96     Part 2: Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit -
                                                Teil 2: Industriebereich
------------------------------------------------------------------------------------------------------------------------------------
DIN 47295                               HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
====================================================================================================================================
</TABLE>

<PAGE>

                               EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems         Reference No.: 07.8100

                                              otel.o Document No.: ST-rfx-0007

                                              Chapter: 8

                                              Item No.: 100, 101, 107, 108, 109
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Detection of HP-Trace Invalid

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

This functionality is available for 34Mbit/s signal only.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /      Compliant development planned until      / /T1   / /T2      / /after T2

/ /      Further Development planned but not compliant with o.tel.o requirements

/ /      No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------

<PAGE>

                               EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems         Reference No.: 07.81123

                                              otel.o Document No.: ST-rfx-0007

                                              Chapter: 8

                                              Item No.: 123
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Detection of Excessive Sync. Degrade

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

There isn't any separation between the sync. Degrade and the Excessive Sync.
Degrade. The next stage after the Sync. Degrade is detected, it will become the
holdover status and the holdover alarm will be raised.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /      Compliant development planned until      / /T1   / /T2      / /after T2

/ /      Further Development planned but not compliant with o.tel.o requirements

/ /      No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------

<PAGE>

                               EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems       Reference No.: 07.12217

                                            otel.o Document No.: ST-rfx-0007

                                            Chapter: 1

                                            Item No.: 17, 18
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Coloured Interfaces 100/50 GHz Channel Spacing

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
The next generation TN-16X DWDM Transmitter and Regenerator provide a high
performance tight wavelength optical signal aligned with the 200 GHz ITU-T grid
with a wavelength tolerance of +/- 0.25 nm and provisionable output power. Thus,
TN-16X terminal equipment may be used in a variety of configurations, providing
a flexible system that may be integrated and expanded as customers require.
Together with appropriate DWDM optical couplers, the TN-16X DWDM hardware
provides a complete Nortel DWDM system with information capacity of up to 20
Gb/s based on an eight wavelength plan.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /      Compliant development planned until      / /T1   / /T2      / /after T2

/ /      Further Development planned but not compliant with o.tel.o requirements

/ /      No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems         Reference No.: 07.82150

                                              otel.o Document No.: ST-rfx-0007

                                              Chapter: 8

                                              Item No.: 150, 151,152, 153
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Status Events Log Capacity Exceeded

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

Log reports are generated when an event occurs within the TN-16X system and
are generated by both the Network element (NE) and the Operations controller
(OPC). Each report generated is stored for later viewing and/or printing.
Although many logs are informational only, some indicate trouble conditions.
In these cases, trouble-clearing procedures are provided.

The OPC contains a fixed amount of archive storage (5 megabytes) for the
storage of both OPC and network element logs. When this storage is full, new
logs overwrite existing logs. The logs collected by the OPC can be viewed
using the OPC Event Browser tool. When there is a lot of NE log activity the
log is periodically transferred to the OPC (when the size threshold is
crossed) to eliminate the possibility of lost data.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /      Compliant development planned until      / /T1   / /T2      / /after T2

/ /      Further Development planned but not compliant with o.tel.o requirements

/ /      No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: Nortel Dasa Network Systems          Reference No.: 07.92179

                                               otel.o Document No.: ST-rfx-0007

                                               Chapter: 9

                                               Item No.: 179
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Set Threshold HP-FEBE

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------

The threshold value is fixed.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ /      Compliant development planned until      / /T1   / /T2      / /after T2

/ /      Further Development planned but not compliant with o.tel.o requirements

/ /      No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
<PAGE>

                        SYSTEM FEATURE DESCRIPTION TN-1C

-------------------------------------------------------------------------------

ID                        ST-RFX-0010
REVISION                  1.0 / APPROVED
DATE                      09 Apr 1999
CONFIDENCE                CCG CONFIDENTIAL

-------------------------------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  System Feature Description TM-N-1-10

-------------------------------------------------------------------------------

DESCRIPTION               This document lists the features of the TM-N/1
                          Equipment, wheras N=1, 4

                          The equipment shall mainly be applied as SDH trail
                          or connection terminating mux at customer premises.

-------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  /  09/04/99  /  J. Gimmler

-------------------------------------------------------------------------------

<PAGE>

1        REQUESTED FEATURES

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
1                    INTERFACE TYPES
-----------------------------------------------------------------------------------------------------------------------------
1.1                  TRIBUTARY INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                1.   2 Mbit/s G.703                                                         C
-----------------------------------------------------------------------------------------------------------------------------
                2.   2 Mbit/s G.704 frame monitoring option on incoming traffic (with       C
                     Rel. 3 HW)
-----------------------------------------------------------------------------------------------------------------------------
                3.   2 Mbit/s, retiming 250 us buffer                                       C
-----------------------------------------------------------------------------------------------------------------------------
                4.   34 Mbit/s G.703                                                        C
-----------------------------------------------------------------------------------------------------------------------------
                5.   45 Mbit/s G.703                                                        C
-----------------------------------------------------------------------------------------------------------------------------
                6.   STM-1 G.703                                                            NC
-----------------------------------------------------------------------------------------------------------------------------
                7.   S-1.1                                                                  NC
-----------------------------------------------------------------------------------------------------------------------------
1.2                  AGGREGATE INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                8.   STM-1 G.703                                                            NC
-----------------------------------------------------------------------------------------------------------------------------
                9.   S-1.1                                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                10.  L-1.1                                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                11.  S-4.1                                                                  NC
-----------------------------------------------------------------------------------------------------------------------------
                12.  L-4.1                                                                  NC
-----------------------------------------------------------------------------------------------------------------------------
1.3                  EQUIPPING OF INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
1.3.1                TRIBUTARY INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                13.  Up to (t.b.d.) electrical 2 Mbit/s ports can be equipped               IR
                     16 X 2 MBIT/S PORTS CAN BE EQUIPPED WITH 8 X 2 MBIT/S PORTS
                     ON THE MAIN BOARD AND 8 X 2 MBIT/S PORTS ON THE TRIBUTARY
                     EXTENSION CARD TN-1C REL. 5 - UP TO 32 X 2 MBIT/S PORTS CAN
                     BE EQUIPPED WITH 8 X 2 MBIT/S PORTS ON THE MAIN BOARD AND
                     24 X 2 MBIT/S PORTS ON THE TRIBUTARY EXTENSION CARD
-----------------------------------------------------------------------------------------------------------------------------
                14.  Up to (t.b.d.) electrical 34 Mbit/s ports can be equipped              IR
                     2 X 34/45 MBIT/S PORTS CAN BE EQUIPPED ON THE TRIBUTARY
                     EXTENSION CARD (IN ADDITION TO THE 8 X 2 MBIT/S PORTS ON
                     THE MAIN BOARD)
-----------------------------------------------------------------------------------------------------------------------------
                15.  Up to (t.b.d.) electrical 45 Mbit/s ports can be equipped              IR
                     SEE RESPONSE TO 1.3.1 (14) ABOVE
-----------------------------------------------------------------------------------------------------------------------------
                16.  Up to (t.b.d.) el. 155 Mbit/s ports can be equipped                    IR
                     NOT APPLICABLE
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
2                    CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
2.1                  CONNECTION TYPES
-----------------------------------------------------------------------------------------------------------------------------
                17.  Bi-directional Connections on VC-12 level                              C
-----------------------------------------------------------------------------------------------------------------------------
                18.  Bi-directional Connections on VC-3 level                               C
-----------------------------------------------------------------------------------------------------------------------------
                19.  Bi-directional Connections on VC-4 level                               C
-----------------------------------------------------------------------------------------------------------------------------
                20.  Bi-directional Connections of contiguously concatenated  VC-4          NA
                     (VC-4-4c)
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
2.2                  QUANTITATIVE REQUIREMENTS
-----------------------------------------------------------------------------------------------------------------------------
2.2.1                HIGHER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                21.  HO termination of (t.b.d.) * VC-4 equivalents from aggregate           IR     IR      IR

                     THE FOLLOWING BI-DIRECTIONAL CONNECTIONS ARE SUPPORTED:

                     o NO CONNECTION
                     IF THERE IS NO CONNECTION, THE CHANNEL IS NOT IN USE.
                     THEREFORE NO LOW ORDER PATH (LP) ALARMS AND BNO TU ALARMS
                     (TU-LOP AND TU-AIS) ARE REPORTED FOR THIS CHANNEL.

                     o ADD/DROP CONNECTION
                     A TRIBUTARY SIGNAL IS CONNECTED TO A SPECIFIC CHANNEL (TU)
                     IN THE STM-1 SIGNAL. THE 34/45 MBIT/S TRIBUTARIES ARE
                     ASSOCIATED WITH A TU-3, WHILE THE 2 MBIT/S TRIBUTARIES ARE
                     ASSOCIATED WITH TU-12S. FOR UNPROTECTED CONNECTIONS, THE
                     TRIBUTARY IS CONNECTED TO ONE OF THE AGGREGATE PORTS. FOR
                     PROTECTED CONNECTIONS AN ALTERNATIVE PAYLOAD INSTANCE IN
                     THE OTHER AGGREGATE PORTS FOR PATH PROTECTION IS SPECIFIED.

                     o THROUGH CONNECTION
                     A THROUGH CONNECTION CONNECTS MATCHING CHANNELS BETWEEN AGGREGATES
                     A AND B

                     o VC-4 PASSTHROUGH CONNECTION
                     THIS CONNECTS THE VC-4 CONTAINED IN THE STM-1 SIGNAL
                     BETWEEN AGGREGATES A AND B AND WHEN PROVISIONED ALL OTHER
                     PASS CONNECTIONS MUST BE FREE. WHEN A VC-4 PASSTHROUGH
                     CONNECTION IS PROVISIONED, ONLY THE RS, MS AND AU-AIS
                     ALARMS ARE ENABLED.
-----------------------------------------------------------------------------------------------------------------------------
                22.  HO add/drop of (t.b.d.) * VC-4 equivalents from aggregate
                     west                                                                   IR     IR      IR
                     SEE RESPONSE TO 2.2.1 (21) ABOVE
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
                23.  HO add/drop of (t.b.d.) * VC-4 equivalents from aggregate
                     west                                                                   IR     IR      IR
                     SEE RESPONSE TO 2.2.1 (21) ABOVE
-----------------------------------------------------------------------------------------------------------------------------
2.2.2                LOWER ORDER CONNECTIVITY
-----------------------------------------------------------------------------------------------------------------------------
                24.  LO termination of (t.b.d.) * VC-4 equivalents from aggregate           IR     IR      IR
                     SEE RESPONSE TO 2.2.1 (21) ABOVE
-----------------------------------------------------------------------------------------------------------------------------
                25.  LO add/drop of (t.b.d.) * VC-4 equivalents from aggregate
                     west                                                                   IR     IR      IR
                     SEE RESPONSE TO 2.2.1 (21) ABOVE
-----------------------------------------------------------------------------------------------------------------------------
                26.  LO add/drop of (t.b.d.) * VC-4 equivalents from aggregate
                     west                                                                   IR     IR      IR
                     SEE RESPONSE TO 2.2.1 (21) ABOVE
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
3                    SYNCHRONISATION
-----------------------------------------------------------------------------------------------------------------------------
3.1                  INTERNAL EQUIPMENT TIMING
-----------------------------------------------------------------------------------------------------------------------------
3.1.1                TIMING SOURCES
-----------------------------------------------------------------------------------------------------------------------------
                27.  STM-N timing                                                           C
-----------------------------------------------------------------------------------------------------------------------------
                28.  2048 kHz timing                                                        NC
-----------------------------------------------------------------------------------------------------------------------------
                29.  Internal Oscillator acc. to G.813                                      C
-----------------------------------------------------------------------------------------------------------------------------
3.1.2                TIMING SOURCE QUALITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
                30.  STM-N Timing at all SDH i/fs (Timing Marker Support)                   NC
-----------------------------------------------------------------------------------------------------------------------------
                31.  2048 kHz timing, fixed to G.811 quality                                NC
-----------------------------------------------------------------------------------------------------------------------------
                32.  2048 kHz timing, configurable timing source quality                    NC
-----------------------------------------------------------------------------------------------------------------------------
3.1.3                TIMING SOURCE PRIORITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
                33.  Priority List of (at least 6 entries)                                  NC
-----------------------------------------------------------------------------------------------------------------------------
3.1.4                SELECTION ALGORITHMS
-----------------------------------------------------------------------------------------------------------------------------
                34.  Autonomous Timing Source Selection                                     C
-----------------------------------------------------------------------------------------------------------------------------
                35.  Manual Timing Source Selection                                         C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
3.2                  EXTERNAL  TIMING OUTPUT (T4)
-----------------------------------------------------------------------------------------------------------------------------
3.2.1                TIMING  OUTPUT PORT
-----------------------------------------------------------------------------------------------------------------------------
                36.  One 2048 kHz timing output port                                        NC
-----------------------------------------------------------------------------------------------------------------------------
                37.  Configurable timing output squelch function                            NC
-----------------------------------------------------------------------------------------------------------------------------
3.2.2                TIMING SOURCES
-----------------------------------------------------------------------------------------------------------------------------
                38.  STM-N  timing                                                          C
-----------------------------------------------------------------------------------------------------------------------------
3.2.3                TIMING SOURCE QUALITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
                39.  STM-N Timing (Timing Marker Support)                                   NC
-----------------------------------------------------------------------------------------------------------------------------
3.2.4                TIMING SOURCE PRIORITY LEVELS
-----------------------------------------------------------------------------------------------------------------------------
                40.  Priority List (at least 7 entries)                                     NC
-----------------------------------------------------------------------------------------------------------------------------
3.2.5                SELECTION ALGORITHMS
-----------------------------------------------------------------------------------------------------------------------------
                41.  Autonomous timing source selection                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                42.  Manual Timing Source selection                                         NC
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
4                    MANAGEMENT COMMUNICATION
-----------------------------------------------------------------------------------------------------------------------------
4.1                  COMMUNICATION INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                43.  F- Interface   (RS 232)                                                C
-----------------------------------------------------------------------------------------------------------------------------
                44.  Q I/F (Ethernet)                                                       C
-----------------------------------------------------------------------------------------------------------------------------
                45.  Q- interface as gateway to the EMS                                     C
-----------------------------------------------------------------------------------------------------------------------------
                46.  Qecc via any ECCR  on optical  interfaces                              C
-----------------------------------------------------------------------------------------------------------------------------
                47.  Qecc via any ECCM on optical  interfaces (with Rel 5 - C)              NC
-----------------------------------------------------------------------------------------------------------------------------
                48.  Qecc via any ECCR  on electrical  interfaces                           NC
-----------------------------------------------------------------------------------------------------------------------------
                49.  Qecc via any ECCM on electrical  interfaces                            NC
-----------------------------------------------------------------------------------------------------------------------------
                50.  Qecc Routing (level 2 IS-IS acc. to ISO 10589-8473)                    C
-----------------------------------------------------------------------------------------------------------------------------
                51.  Domain Partitioning Repair function                                    C
-----------------------------------------------------------------------------------------------------------------------------
                52.  Definition of Manual Adjacencies (NSAP of dedicated NE)                C
-----------------------------------------------------------------------------------------------------------------------------
                53.  Manual definition of reachable addresses (set address
                     prefix)                                                                C
-----------------------------------------------------------------------------------------------------------------------------
                54.  ECC can be inserted / extracted to/from VC-4 POH Byte                  NC
                     (Application: for transparent transmission of ECC via other
                     operator's SDH network)
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                55.  F2 Byte can be inserted / extracted via V.11 Interface NC
                     (Application: for transparent transmission of ECC via
                     bridge and other operator's SDH network)
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
4.2                  O & M INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                56.  8 x Remote Control Inputs                                              C
-----------------------------------------------------------------------------------------------------------------------------
                57.  Remote Control Outputs                                                 C
-----------------------------------------------------------------------------------------------------------------------------
                58.  Card LED support                                                       C
-----------------------------------------------------------------------------------------------------------------------------
                59.  Subrack LED support (with RAA - C)                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                60.  Rack Alarm support                                                     C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
5                    PERFORMANCE MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
                61.  Performance History Data Collection (ES, SES and UAT) ...              C
-----------------------------------------------------------------------------------------------------------------------------
                62.  at any MST - ?                                                         NC
-----------------------------------------------------------------------------------------------------------------------------
                63.  at any RST - ?                                                         NC
-----------------------------------------------------------------------------------------------------------------------------
                64.  at any VC-4 TTP                                                        C
-----------------------------------------------------------------------------------------------------------------------------
                65.  at any VC-3 TTP                                                        C
-----------------------------------------------------------------------------------------------------------------------------
                66.  at any VC-12 TTP                                                       C
-----------------------------------------------------------------------------------------------------------------------------
                67.  at any AU-4 CTP - ?                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                68.  at any VC-3 CTP - ?                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                69.  at any VC-12 CTP - ?                                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                70.  for any AU-4 Tandem Connection - ?                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                71.  for any TU-3 Tandem Connection - ?                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                72.  for any TU-12 Tandem Connection - ?                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                73.  from remote TTPs based on FEBE evaluation - ?                          NC
-----------------------------------------------------------------------------------------------------------------------------
                74.  Threshold Crossing Notification                                        C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
6                    FAULT AND STATUS MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
6.1                  DETECTED ANOMALIES, DEFECTS AND CONSEQUENT ACTIONS
-----------------------------------------------------------------------------------------------------------------------------
6.1.1                ALL SYNCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                75.  Detection of Transmit Fail on any optical STM-N interface              NC
-----------------------------------------------------------------------------------------------------------------------------
                76.  Detection of Laser Shutdown on any optical interface                   C
-----------------------------------------------------------------------------------------------------------------------------
                77.  Detection of disabled ALS on any optical interface                     C
-----------------------------------------------------------------------------------------------------------------------------
                78.  Detection of Optical Source Power High on any optical
                     interface                                                              C
-----------------------------------------------------------------------------------------------------------------------------
                79.  Detection of LOS, LOS status change hysteresis                         C
-----------------------------------------------------------------------------------------------------------------------------
                80.  Insertion of AIS upon detection of LOS                                 C
-----------------------------------------------------------------------------------------------------------------------------
6.1.2                ALL REGENERATOR SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                81.  Detection of OOF                                                       C
-----------------------------------------------------------------------------------------------------------------------------
                82.  Detection of LOF                                                       C
-----------------------------------------------------------------------------------------------------------------------------
                83.  Insertion of AIS upon persisting LOF detection                         C
-----------------------------------------------------------------------------------------------------------------------------
                84.  Detection of RS EBER (10E-3) based on B1 BIP-8 parity
                     calculation                                                            C
-----------------------------------------------------------------------------------------------------------------------------
6.1.3                ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                85.  Detection of MS-AIS                                                    C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                86.  Insertion of all 1 upon detection of MS-AIS                            C
-----------------------------------------------------------------------------------------------------------------------------
                87.  Detection of Signal Degrade                                            C
-----------------------------------------------------------------------------------------------------------------------------
                88.  Detection of MS-EBER (10E-3) upon B2 BIP-24 parity error
                     calculation                                                            C
-----------------------------------------------------------------------------------------------------------------------------
                89.  Insertion of AIS and FERF upon detection of MS-AIS                     C
-----------------------------------------------------------------------------------------------------------------------------
                90.  Detection of FERF                                                      C
-----------------------------------------------------------------------------------------------------------------------------
                91.  Insertion of MS-FEBE based on detection of B2 parity
                     calculations                                                           NC
-----------------------------------------------------------------------------------------------------------------------------
6.1.4                ALL MULTIPLEX SECTION ADAPTATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                92.  Detection  of AU-LOP                                                   C
-----------------------------------------------------------------------------------------------------------------------------
                93.  Detection of AU-AIS                                                    C
-----------------------------------------------------------------------------------------------------------------------------
                94.  Detection of Number of AU-Pointer Justification Events                 NC
-----------------------------------------------------------------------------------------------------------------------------
                95.  Insertion of AU-AIS upon receive of all 1                              C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
6.1.5                ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                96.  Detection of Path AIS upon receive of all 1                            C
-----------------------------------------------------------------------------------------------------------------------------
                97.  Detection of HP-Trace Invalid                                          C
-----------------------------------------------------------------------------------------------------------------------------
                98.  Detection of HP-TIM                                                    C
-----------------------------------------------------------------------------------------------------------------------------
                99.  Detection of HP-SLM                                                    C
-----------------------------------------------------------------------------------------------------------------------------
                100. Detection of HP-FERF                                                   C
-----------------------------------------------------------------------------------------------------------------------------
                101. Detection of B3- EBER (10E-3)                                          C
-----------------------------------------------------------------------------------------------------------------------------
6.1.6                ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-----------------------------------------------------------------------------------------------------------------------------
                102. Detection of Path AIS upon receive of all 1                            C
-----------------------------------------------------------------------------------------------------------------------------
                103. Detection of LP-Trace Invalid                                          NC
-----------------------------------------------------------------------------------------------------------------------------
                104. Detection of LP-TIM                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                105. Detection of LP-SLM                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                106. Detection of LP-FERF                                                   C
-----------------------------------------------------------------------------------------------------------------------------
                107. Detection of EBER                                                      C
-----------------------------------------------------------------------------------------------------------------------------
6.1.7                ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-12)
-----------------------------------------------------------------------------------------------------------------------------
                108. Detection of Path AIS upon receive of all 1                            C
-----------------------------------------------------------------------------------------------------------------------------
                109. Detection of LP-Trace Invalid                                          NC
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                110. Detection of LP-TIM                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                111. Detection of LP-SLM                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                112. Detection of LP-FERF                                                   C
-----------------------------------------------------------------------------------------------------------------------------
                113. Detection of EBER                                                      C
-----------------------------------------------------------------------------------------------------------------------------
6.1.8                ALL HIGH ORDER PATH TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                114. Detection of Path AIS upon receive of all 1                            C
-----------------------------------------------------------------------------------------------------------------------------
                115. Insertion of AIS and HP-FERF upon detection of Path AIS C
-----------------------------------------------------------------------------------------------------------------------------
                116. Detection of HP-Trace Invalid                                          C
-----------------------------------------------------------------------------------------------------------------------------
                117. Detection of HP-TIM                                                    C
-----------------------------------------------------------------------------------------------------------------------------
                118. Insertion of AIS and HP-FERF upon detection of HP-TIM                  C
-----------------------------------------------------------------------------------------------------------------------------
                119. Detection of HP-SLM                                                    C
-----------------------------------------------------------------------------------------------------------------------------
                120. Insertion of AIS and HP-FERF upon detection of HP-SLM                  C
-----------------------------------------------------------------------------------------------------------------------------
                121. Detection of HP-FERF                                                   C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                122. Detection of EBER (10E-3)                                              C
-----------------------------------------------------------------------------------------------------------------------------
6.1.9                ALL LOW ORDER PATH TERMINATION POINTS (VC-3)
-----------------------------------------------------------------------------------------------------------------------------
                123. Detection of Path AIS upon receive of all 1                            C
-----------------------------------------------------------------------------------------------------------------------------
                124. Insertion of AIS and HP-FERF upon detection of Path AIS C
-----------------------------------------------------------------------------------------------------------------------------
                125. Detection of LP-Trace Invalid                                          NC
-----------------------------------------------------------------------------------------------------------------------------
                126. Detection of LP-TIM                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                127. Insertion of AIS and LP-FERF upon detection of LP-TIM                  NA
-----------------------------------------------------------------------------------------------------------------------------
                128. Detection of LP-SLM                                                    C
-----------------------------------------------------------------------------------------------------------------------------
                129. Insertion of AIS and LP-FERF upon detection of LP-SLM                  C
-----------------------------------------------------------------------------------------------------------------------------
                130. Detection of LP-FERF                                                   C
-----------------------------------------------------------------------------------------------------------------------------
                131. Detection of EBER (10E-3)                                              C
-----------------------------------------------------------------------------------------------------------------------------
6.1.10               ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-----------------------------------------------------------------------------------------------------------------------------
                132. Detection of Path AIS upon receive of all 1                            C
-----------------------------------------------------------------------------------------------------------------------------
                133. Insertion of AIS and HP-FERF upon detection of Path AIS C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                134. Detection of LP-Trace Invalid                                          NC
-----------------------------------------------------------------------------------------------------------------------------
                135. Detection of LP-TIM                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                136. Insertion of AIS and LP-FERF upon detection of LP-TIM                  NA
-----------------------------------------------------------------------------------------------------------------------------
                137. Detection of LP-SLM                                                    C
-----------------------------------------------------------------------------------------------------------------------------
                138. Insertion of AIS and LP-FERF upon detection of LP-SLM                  C
-----------------------------------------------------------------------------------------------------------------------------
                139. Detection of LP-FERF                                                   C
-----------------------------------------------------------------------------------------------------------------------------
                140. Detection of EBER (10E-3)                                              C
-----------------------------------------------------------------------------------------------------------------------------
6.1.11               ALL PLESIOCHRONOUS PHYSICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                141. Detection of Trib.-AIS                                                 C
-----------------------------------------------------------------------------------------------------------------------------
                142. Detection of Trib.-LOS                                                 C
-----------------------------------------------------------------------------------------------------------------------------
                143. Detection of Trib.-LOF                                                 C
-----------------------------------------------------------------------------------------------------------------------------
                144. Insertion of AIS upon detection of Trib.-AIS, Trib.-LOS,               PC
                     Trib.-LOF ( With out Trib-LOF )
-----------------------------------------------------------------------------------------------------------------------------
6.1.12               SETS AND SETPI                                                         C
-----------------------------------------------------------------------------------------------------------------------------
                145. Detection of Sync. Source Fail                                         C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                146. Detection of SETG - Hold                                               C
-----------------------------------------------------------------------------------------------------------------------------
                147. Detection of SETG - Out of Lock                                        C
-----------------------------------------------------------------------------------------------------------------------------
                148. Detection of SETG - Fail                                               NC
-----------------------------------------------------------------------------------------------------------------------------
                149. Detection of Sync. Degrade                                             NC
-----------------------------------------------------------------------------------------------------------------------------
                150. Detection of Excessive Sync. Degrade                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                151. T4 Squelch upon detection of Excessive Sync. Degrade NC
-----------------------------------------------------------------------------------------------------------------------------
                152. Detection of Sync. Source Threshold Crossing                           C
-----------------------------------------------------------------------------------------------------------------------------
                153. Detection of Sync. LOS                                                 C
-----------------------------------------------------------------------------------------------------------------------------
6.1.13               MANAGEMENT COMMUNICATION FUNCTION
-----------------------------------------------------------------------------------------------------------------------------
                154. Detection of Remote Control Input Active                               NC
-----------------------------------------------------------------------------------------------------------------------------
                155. Detection of RS - Qecc Comms Fail (LAPD Alarm)                         C
-----------------------------------------------------------------------------------------------------------------------------
                156. Detection of MS - Qecc Comms Fail (LAPD Alarm)                         C
-----------------------------------------------------------------------------------------------------------------------------
6.1.14               SYSTEMS MANAGEMENT FUNCTION
-----------------------------------------------------------------------------------------------------------------------------
                157. Detection of Secondary Power Fail                                      NA
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                158. Detection of Primary Power Fail                                        NA
-----------------------------------------------------------------------------------------------------------------------------
                159. Detection of Re-Boot Fail                                              C
-----------------------------------------------------------------------------------------------------------------------------
                160. Detection of Configuration Data Integrity Check Failure                C
-----------------------------------------------------------------------------------------------------------------------------
                161. Detection of System Software Integrity Check Failure                   C
-----------------------------------------------------------------------------------------------------------------------------
                162. Detection of Network Element Controller Fail                           NC
-----------------------------------------------------------------------------------------------------------------------------
                163. Detection of Card Protection Switch Failure                            NA
-----------------------------------------------------------------------------------------------------------------------------
                164. Detection of Card Out                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                165. Detection of Card Fail (upon detection of internal parity
                     mismatch C etc.)
-----------------------------------------------------------------------------------------------------------------------------
                166. Detection of Wrong Card                                                C
-----------------------------------------------------------------------------------------------------------------------------
                167. Network Protection Switch Failure                                      NA
-----------------------------------------------------------------------------------------------------------------------------
6.2                  STATUS EVENTS
-----------------------------------------------------------------------------------------------------------------------------
                168. Configuration Data Integrity Fail                                      C
-----------------------------------------------------------------------------------------------------------------------------
                169. System Software Integrity Fail                                         C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                170. Laser Restart for Test                                                 C
-----------------------------------------------------------------------------------------------------------------------------
                171. Synchronous Equipment Timing Generator A/B active                      NC
-----------------------------------------------------------------------------------------------------------------------------
                172. Synchronisation Source Quality Change                                  NC
-----------------------------------------------------------------------------------------------------------------------------
                173. Synchronisation Source Switch Event                                    C
-----------------------------------------------------------------------------------------------------------------------------
                174. External Synchronisation Output Squelched                              NC
-----------------------------------------------------------------------------------------------------------------------------
                175. Section Layer Protection Switch Active                                 NC
-----------------------------------------------------------------------------------------------------------------------------
                176. Network Protection Switch Event                                        NC
-----------------------------------------------------------------------------------------------------------------------------
                177. Card Protection Switch Active                                          NA
-----------------------------------------------------------------------------------------------------------------------------
                178. Fault / Status Log Capacity Exceeded                                   NA
-----------------------------------------------------------------------------------------------------------------------------
                179. Configuration Data Transaction Log Capacity Exceeded                   NA
-----------------------------------------------------------------------------------------------------------------------------
                180. Performance Monitoring Log Capacity Exceeded                           NA
-----------------------------------------------------------------------------------------------------------------------------
                181. Access  Log Capacity Exceeded                                          NA
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                182. Software Download in Progress                                          C
-----------------------------------------------------------------------------------------------------------------------------
                183. Software Download Failure                                              C
-----------------------------------------------------------------------------------------------------------------------------
                184. Software Download Failure - Retry in Progress                          NC
-----------------------------------------------------------------------------------------------------------------------------
                185. Software Download Complete                                             C
-----------------------------------------------------------------------------------------------------------------------------
                186. Card Restoration Complete                                              C
-----------------------------------------------------------------------------------------------------------------------------
                187. Re-Boot Restoration Complete                                           C
-----------------------------------------------------------------------------------------------------------------------------
                188. Electronic Label Update  ?                                             C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
6.3                  ALARM EVENT HANDLING
-----------------------------------------------------------------------------------------------------------------------------
                189. Alarm Persistence Filter (filtering of toggling alarms)                NC
                     (with Rel. 5 - C)
-----------------------------------------------------------------------------------------------------------------------------
                190. Alarm Correlation Filter (F3 filter, suppression of                    C
                     consequent alarms)
-----------------------------------------------------------------------------------------------------------------------------
                191. Alarm Inversion Facility                                               C
-----------------------------------------------------------------------------------------------------------------------------
                192. Performance of the alarm throughput greater than 10 alarms per second  C
-----------------------------------------------------------------------------------------------------------------------------
                193. It is possible to block/unblock each single traffic                    PC
                     relevant alarm per port (Part of alarms)
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                194. It is possible to block/unblock each single traffic                    NC
                     relevant alarm group per card
-----------------------------------------------------------------------------------------------------------------------------
                195. It is possible to block/unblock each single traffic                    PC
                     relevant alarm group per NE (Part of alarms)
-----------------------------------------------------------------------------------------------------------------------------
                196. Indication of Alarm Event Forwarding Suppression per                   NC
                     functional unit (e.g. Regenerator Section ...)
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
7                    CONFIGURATION MANAGEMENT
-----------------------------------------------------------------------------------------------------------------------------
7.1                  GENERAL
-----------------------------------------------------------------------------------------------------------------------------
                197. Upload of Configuration Data - on single command                       C
-----------------------------------------------------------------------------------------------------------------------------
                198. Upload of Configuration Data - on bulk command                         NA
-----------------------------------------------------------------------------------------------------------------------------
                199. Download of Configuration Data - on bulk command                       NA
-----------------------------------------------------------------------------------------------------------------------------
7.2                  CONFIGURATION OF FUNCTIONAL BLOCKS
-----------------------------------------------------------------------------------------------------------------------------
7.2.1                ALL SYNCHRONOUS OPTICAL INTERFACES
-----------------------------------------------------------------------------------------------------------------------------
                200. Enable / Disable Automatic Laser Shutdown                              C
-----------------------------------------------------------------------------------------------------------------------------
                201. Enable / Disable Laser                                                 C
-----------------------------------------------------------------------------------------------------------------------------
                202. Enable Laser for Test Purposes (2s / 90s)                              C
-----------------------------------------------------------------------------------------------------------------------------
7.2.2                ALL MULTIPLEX SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                203. Set Threshold Signal Degrade                                           C
-----------------------------------------------------------------------------------------------------------------------------
                204. Set Threshold B2-EBER                                                  NC
-----------------------------------------------------------------------------------------------------------------------------
7.2.3                ALL REGENERATOR SECTION TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                205. Set Threshold B1-EBER                                                  NC
-----------------------------------------------------------------------------------------------------------------------------
7.2.4                ALL HIGH ORDER PATH TERMINATION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                206. Set Threshold B3-EBER                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                207. Set Threshold HP-FEBE                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                208. Enable / Disable consequent actions from detection of
                     HP-TIM (per C Path)
-----------------------------------------------------------------------------------------------------------------------------
                209. Enable / Disable consequent actions from detection of
                     HP-SLM (per C Path)
-----------------------------------------------------------------------------------------------------------------------------
                210. Set expected Signal Label (per Path)                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                211. Set expected Path Trace (per Path)                                     C
-----------------------------------------------------------------------------------------------------------------------------
7.2.5                ALL LOW ORDER PATH TERMINATION POINTS (VC-3)                           C
-----------------------------------------------------------------------------------------------------------------------------
                212. Set Threshold EBER                                                     C
-----------------------------------------------------------------------------------------------------------------------------
                213. Set Threshold LP-FEBE                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                214. Enable / Disable consequent actions from detection of                  NC
                     LP-TIM (per Path)
-----------------------------------------------------------------------------------------------------------------------------
                215. Enable / Disable consequent actions from detection of                  NC
                     LP-SLM (per Path)
-----------------------------------------------------------------------------------------------------------------------------
                216. Set expected Signal Label (per Path)                                   NC
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                217. Set expected Path Trace (per Path)                                     NC
-----------------------------------------------------------------------------------------------------------------------------
7.2.6                ALL LOW ORDER PATH TERMINATION POINTS (VC-12)
-----------------------------------------------------------------------------------------------------------------------------
                218. Set Threshold EBER                                                     C
-----------------------------------------------------------------------------------------------------------------------------
                219. Set Threshold LP-FEBE                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                220. Enable / Disable consequent actions from detection of                  NC
                     LP-TIM (per Path)
-----------------------------------------------------------------------------------------------------------------------------
                221. Enable / Disable consequent actions from detection of                  NC
                     LP-SLM (per Path)
-----------------------------------------------------------------------------------------------------------------------------
                222. Set expected Signal Label (per Path)                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                223. Set expected Path Trace (per Path)                                     NC
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
7.2.7                ALL HIGH ORDER CONNECTION SUPERVISION POINTS
-----------------------------------------------------------------------------------------------------------------------------
                224. Set Threshold B3-EBER                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                225. Set Threshold HP-FEBE                                                  C
-----------------------------------------------------------------------------------------------------------------------------
                226. Set expected Signal Label (per Path)                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                227. Set expected Path Trace (per Path)                                     C
-----------------------------------------------------------------------------------------------------------------------------
7.2.8                ALL LOW ORDER CONNECTION SUPERVISION POINTS (TU-3)
-----------------------------------------------------------------------------------------------------------------------------
                228. Set Threshold EBER                                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                229. Set Threshold FEBE                                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                230. Set expected Signal Label (per Path)                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                231. Set expected Path Trace (per Path)                                     NC
-----------------------------------------------------------------------------------------------------------------------------
7.2.9                ALL HIGH ORDER CONNECTION SUPERVISION POINTS (TU-12)
-----------------------------------------------------------------------------------------------------------------------------
                232. Set Threshold EBER                                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                233. Set Threshold FEBE                                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                234. Set expected Signal Label (per Path)                                   NC
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                235. Set expected Path Trace (per Path)                                     NC
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
8                    NETWORK PROTECTION - ?
                     WHAT IT IS? IF NETWORK PROTECTION MEANS PATH PROTECTION SO
                     ALL CHAPTER 8 SHOULD BE - C.
-----------------------------------------------------------------------------------------------------------------------------
8.1                  HIGHER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I)
-----------------------------------------------------------------------------------------------------------------------------
                236. Detection Criterion Signal Fail (AU-AIS, AU-LOP)                       NA
-----------------------------------------------------------------------------------------------------------------------------
                237. Switch-Over Completion Time less than 100ms                            NA
-----------------------------------------------------------------------------------------------------------------------------
                238. Configurable Hold-Off Time                                             NA
-----------------------------------------------------------------------------------------------------------------------------
                239. Enable / Disable Automatic Switching                                   NA
-----------------------------------------------------------------------------------------------------------------------------
                240. Manual Switching via Management Interface                              NA
-----------------------------------------------------------------------------------------------------------------------------
                241. Configurable Wait Time to Restore                                      NA
-----------------------------------------------------------------------------------------------------------------------------
8.2                  LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-3)
-----------------------------------------------------------------------------------------------------------------------------
                242. Detection Criterion Signal Fail (TU-AIS, TU-LOP)                       NA
-----------------------------------------------------------------------------------------------------------------------------
                243. Switch-Over Completion Time less than 300ms                            NA
-----------------------------------------------------------------------------------------------------------------------------
                244. Configurable Hold-Off Time                                             NA
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                245. Enable / Disable Automatic Switching                                   NA
-----------------------------------------------------------------------------------------------------------------------------
                246. Manual Switching via Management Interface                              NA
-----------------------------------------------------------------------------------------------------------------------------
                247. Configurable Wait Time to Restore                                      NA
-----------------------------------------------------------------------------------------------------------------------------
8.3                  LOWER ORDER SUB-NETWORK CONNECTION PROTECTION (SNC/I, TU-12)
-----------------------------------------------------------------------------------------------------------------------------
                248. Detection Criterion Signal Fail (TU-AIS, TU-LOP)                       NA
-----------------------------------------------------------------------------------------------------------------------------
                249. Switch-Over Completion Time less than 300ms                             NA
-----------------------------------------------------------------------------------------------------------------------------
                250. Configurable Hold-Off Time                                             NA
-----------------------------------------------------------------------------------------------------------------------------
                251. Enable / Disable Automatic Switching                                   NA
-----------------------------------------------------------------------------------------------------------------------------
                252. Manual Switching via Management Interface                              NA
-----------------------------------------------------------------------------------------------------------------------------
                253. Configurable Wait Time to Restore                                      NA
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
9                    OPERATION AND MAINTENANCE
-----------------------------------------------------------------------------------------------------------------------------
9.1                  GENERAL
-----------------------------------------------------------------------------------------------------------------------------
                254. Event buffer                                                           C
-----------------------------------------------------------------------------------------------------------------------------
                255. Heart Beat Function                                                    NC
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                256. Re-boot function                                                       C
-----------------------------------------------------------------------------------------------------------------------------
                257. Real time clock function                                               C
-----------------------------------------------------------------------------------------------------------------------------
                258. NSAP Address modification                                              NC
-----------------------------------------------------------------------------------------------------------------------------
                259. Local Software Download                                                C
-----------------------------------------------------------------------------------------------------------------------------
                260. Remote Software Download                                               C
-----------------------------------------------------------------------------------------------------------------------------
                261. Manager Decision Process for equipment access control                  C
-----------------------------------------------------------------------------------------------------------------------------
                262. Display of VC-4 Path Trace at HPT                                      C
-----------------------------------------------------------------------------------------------------------------------------
                263. Display of VC-4 Signal Label at HPT                                    C
-----------------------------------------------------------------------------------------------------------------------------
                264. Display of VC-4 Path Trace at HPOM                                     C
-----------------------------------------------------------------------------------------------------------------------------
                265. Display of VC-4 Signal Label at HPOM                                   C
-----------------------------------------------------------------------------------------------------------------------------
                266. Display of VC-3 Path Trace at LPT                                      NC
-----------------------------------------------------------------------------------------------------------------------------
                267. Display of VC-3 Signal Label at LPT                                    C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                268. Display of VC-3 Path Trace at LPOM                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                269. Display of VC-3 Signal Label at LPOM                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                270. Display of VC-12 Path Trace at LPT                                     NC
-----------------------------------------------------------------------------------------------------------------------------
                271. Display of VC-12 Signal Label at LPT                                   C
-----------------------------------------------------------------------------------------------------------------------------
                272. Display of VC-12 Path Trace at LPOM                                    NC
-----------------------------------------------------------------------------------------------------------------------------
                273. Display of VC-12 Signal Label at LPOM                                  NC
-----------------------------------------------------------------------------------------------------------------------------
                274. Display of Optical Transmit Power Level                                NC
-----------------------------------------------------------------------------------------------------------------------------
9.2                  LOGS
-----------------------------------------------------------------------------------------------------------------------------
                275. Alarm / Status Log                                                     C
-----------------------------------------------------------------------------------------------------------------------------
                276. Performance Log                                                        C
-----------------------------------------------------------------------------------------------------------------------------
                277. Configuration  Log                                                     C
-----------------------------------------------------------------------------------------------------------------------------
                278. Access Control  Log                                                    C
-----------------------------------------------------------------------------------------------------------------------------
9.3                  REDUNDANCY
-----------------------------------------------------------------------------------------------------------------------------
                279. 1:N Tributary Card Protection 2 Mbit/s                                 NC
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                280. 1:N or 1+1  Tributary Card Protection 34 Mbit/s                        NC
-----------------------------------------------------------------------------------------------------------------------------
                281. 1:N or 1+1 Tributary Card Protection 45 Mbit/s                         NC
-----------------------------------------------------------------------------------------------------------------------------
                282. 1:N or 1+1 (electrical) Tributary Card Protection STM-1                NC
                     G.703                                                                  NC
-----------------------------------------------------------------------------------------------------------------------------
                283. 1+1 Protection of Clock System                                         NC
-----------------------------------------------------------------------------------------------------------------------------
                284. Duration less than 5s for card protection automatic switch over        NA
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
9.4                  EQUIPMENT TESTING FUNCTIONS
-----------------------------------------------------------------------------------------------------------------------------
                285. Integrity Check of Configuration Data                                  C
-----------------------------------------------------------------------------------------------------------------------------
                286. Integrity Check of System Software                                     C
-----------------------------------------------------------------------------------------------------------------------------
                287. Configuration of Loop Back on port level on all PDH
                     Interface Cards                                                        C
-----------------------------------------------------------------------------------------------------------------------------
                288. VC-4 level Configuration of Loop Back on STM-1 el. i/f C
-----------------------------------------------------------------------------------------------------------------------------
                289. VC-4 level Configuration of Loop Back on all STM-4 opt.
                     Interfaces                                                             NA
-----------------------------------------------------------------------------------------------------------------------------
                290. VC-3 level Configuration of Loop Back on all electrical SDH            NA
                     Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
                291. VC-3 level Configuration of Loop Back on all optical SDH               C
                     Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
                292. VC-12 level Configuration of Loop Back on all electrical               NA
                     SDH Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
                293. VC-12 level Configuration of Loop Back on all optical SDH              C
                     Interface Cards
-----------------------------------------------------------------------------------------------------------------------------
                294. Configuration of Loop Back on the HPC functional block                 NC
-----------------------------------------------------------------------------------------------------------------------------
                295. Configuration of Loop Back on the LPC functional block                 NC
-----------------------------------------------------------------------------------------------------------------------------
                296. Test Access Interface on all electrical interfaces                     C
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
                297. Test Access Interface on all optical interfaces                        NC
-----------------------------------------------------------------------------------------------------------------------------
                298. Optical Line Testing                                                   NC
-----------------------------------------------------------------------------------------------------------------------------
9.5                  INVENTORY DATA
-----------------------------------------------------------------------------------------------------------------------------
                299. Electronic Label Read Access via Management Interfaces                 C
-----------------------------------------------------------------------------------------------------------------------------
                300. Automatic Electronic Label Upgrade ?                                   NC
-----------------------------------------------------------------------------------------------------------------------------
                301. Compatibility Check of Equipment Hardware Releases                     C
-----------------------------------------------------------------------------------------------------------------------------
                302. Compatibility Check of Equipment Firmware Releases                     C
-----------------------------------------------------------------------------------------------------------------------------
                303. Compatibility Check of Equipment Software Releases                     C
-----------------------------------------------------------------------------------------------------------------------------
                304. Compatibility Check of Equipment Software Releases to the              NC
                     Management System
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
10                   ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL COMPATIBILITY AND SAFETY
-----------------------------------------------------------------------------------------------------------------------------
10.1                 CLIMATIC CONDITIONS
-----------------------------------------------------------------------------------------------------------------------------
                305. Stationary Use Conditions acc. to prETS 300 019-2-3 Class T 3.2        C
-----------------------------------------------------------------------------------------------------------------------------
10.2                 ELECTROMAGNETIC COMPATIBILITY
-----------------------------------------------------------------------------------------------------------------------------
                306. Compliance with EN 55022 class B                                       C
-----------------------------------------------------------------------------------------------------------------------------
                307. Compliance with EN 50082                                               C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
10.3                 SAFETY REQUIREMENTS
-----------------------------------------------------------------------------------------------------------------------------
                308. Compliance with EN 60950                                               C
-----------------------------------------------------------------------------------------------------------------------------
                309. Compliance with IEC 825-1 and IEC 825-2                                C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
11                   PHYSICAL CONSTRUCTION
-----------------------------------------------------------------------------------------------------------------------------
                310. Rack size according to ETSI 300 119, 600 mm x 300 mm                   C
-----------------------------------------------------------------------------------------------------------------------------
                311. wall mountable version                                                 C
-----------------------------------------------------------------------------------------------------------------------------
                312. system upgrade or modification can be done without rear access         C
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
12                   POWER SUPPLY
-----------------------------------------------------------------------------------------------------------------------------
                313. Nominal input voltage -48V THE TN-1C MAY ALSO BE OPERATED              C
                     BY AN EXTERNAL MAINS POWER SUPPLY UNIT
-----------------------------------------------------------------------------------------------------------------------------
                314. Minimum accepted input voltage                                         C
                     -20V
-----------------------------------------------------------------------------------------------------------------------------
                315. Maximum accepted input voltage                                         C
                     -72V
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
13                   AVAILABILITY
-----------------------------------------------------------------------------------------------------------------------------
                316. The supplier shall provide MTBF figures for each functional unit of    IR     IR      IR
                     the offered equipment based on his statistical evaluations
                     according to the template as attached in Annex 1
                     SEE ANNEX 1
-----------------------------------------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------------------------------------
14                   POWER CONSUMPTION
-----------------------------------------------------------------------------------------------------------------------------
                317. The supplier shall provide worst case power consumption figures for    IR     IR      IR
                     each functional unit of the offered equipment according to the
                     template as attached in Annex 1
                     SEE ANNEX 1
                -------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
                NO.  ITEM                                                                  SOC    SOC     SOC     REF. NO.
                                                                                            T1     T2      T3
-----------------------------------------------------------------------------------------------------------------------------
<S>             <C>  <C>                                                                   <C>    <C>     <C>    <C>
15                   SYSTEM MANUALS
                -------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
                318. System Description in Hypertext Format on CD
-----------------------------------------------------------------------------------------------------------------------------
                319. System O&M Manuals in Hypertext Format on CD
-----------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

2        REFERENCES
2.1      REFERENCES TO STANDARDS

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS    DATE    TITLE
----------------------------------------------------------------------------------------------------------------------
<S>                  <C>       <C>     <C>
CECC 86 275-80                 09/95   Detail  Specification:  Connector  sets for  optical  fibres and  cables  Type
                                       LSH-HRL
----------------------------------------------------------------------------------------------------------------------
ITU-T G.703                    04/91   Physical/Electrical characteristics of Hierarchical Digital Interfaces
----------------------------------------------------------------------------------------------------------------------
ITU-T G.707                    1991    Synchronous digital hierarchy bit rates
----------------------------------------------------------------------------------------------------------------------
ITU-T G.782                    1994    Types and general characteristics of synchronous digital hierarchy (SDH)
                                       equipment
----------------------------------------------------------------------------------------------------------------------
ITU-T G.783                    1994    Characteristics of synchronous digital hierarchy /SDH) equipment functional
                                       blocks
----------------------------------------------------------------------------------------------------------------------
ITU-T G.813                    1996    Timing Characteristics of SDH equipment slave clocks.
----------------------------------------------------------------------------------------------------------------------
ITU-T G.825                    1993    The control of Jitter and Wander within Digital Networks which are based on
                                       synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------
ITU-T G.826                    11/93   Error performance parameters and objectives for International
                                       constant Bit Rate Digital Paths at or above the Primary Rate
----------------------------------------------------------------------------------------------------------------------
ITU-T G.841                    1995    Types and Characteristics of SDH Network Protection Architectures
----------------------------------------------------------------------------------------------------------------------
ITU-T G.957                    1993    Optical Interfaces and Systems relating to the synchronous digital hierarchy
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
ETS 300 019          pr        02/92   Environmental conditions and Environmental Tests for Telecommunications
                                       Equipment
                                       Part A:  Introduction and Terminology
                                       Part B:  classification of Environmental conditions
----------------------------------------------------------------------------------------------------------------------
ETS 300 119                            European Telecommunication Standard for Equipment Practice
                               03/93   Part 2:  Engineering Requirements for Racks
                               09/93   Part 3:  Engineering Requirements for Miscellaneous Racks and cabinets
                               09/93   Part 4:  Engineering Requirements for Subracks
----------------------------------------------------------------------------------------------------------------------
ETS 300 253                    01/95   Earthing  and  bonding of  telecommunication  equipment  in  telecommunication
                                       centres
----------------------------------------------------------------------------------------------------------------------
EN 41003                       1991    Particular safety requirements for equipment to be connected to
                                       telecommunication network
----------------------------------------------------------------------------------------------------------------------
EN 55022                       05/95   Grenzwerte und  Messverfahren fur Funkstorungen von Einrichtungen der
                                       Informationstechnik
----------------------------------------------------------------------------------------------------------------------
EN 50082                               Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                               12/94   Part 1:  Elektromagnetische  Vertraglichkeit - Fachgrundnorm  Storfestigkeit -
                                       Teil 1: Wohnbereich, Geschafts- und         Gewerbebereiche              sowie
                                       Kleinbetriebe
                               02/96   Part 2:  Elektromagnetische  Vertraglichkeit - Fachgrundnorm  Storfestigkeit -
                                       Teil 2: Industriebereich
----------------------------------------------------------------------------------------------------------------------
DIN 47295                              HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
----------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

3        ANNEX 1 - UNIT MTBF FIGURES AND POWER CONSUMPTION

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------
UNIT NAME/TYPE                                 UNIT ID       UNIT FIT     MAXIMUM POWER
                                                             FIGURE       CONSUMPTION
---------------------------------------------------------------------------------------------------
<S>                                            <C>           <C>          <C>
STM-1 Optical Mux (8x2) PIU 1310nm SH          NTFT02AA         10144               24 W
---------------------------------------------------------------------------------------------------
34/45 Mbit/s (VC-3) Tributary PIU              NTFT31AA          667               3.4 W
---------------------------------------------------------------------------------------------------
8x2 Tributary PIU                              NTFT08AA          2968               5 W
---------------------------------------------------------------------------------------------------
STM-1 Optical Mux (8x2) PIU 1310nm SH          NTFT02BA          7955               20 W
---------------------------------------------------------------------------------------------------
STM-1 Optical Mux (8x2) PIU 1310nm LH          NTFT02BB          7955               20 W
---------------------------------------------------------------------------------------------------
STM-1 Optical Mux (8x2) PIU 1550nm LH          NTFT02BC          7955               20 W
---------------------------------------------------------------------------------------------------
2x 34/45 Mbit/s (VC-3) Tributary PIU           NTFT31AB          2453              4.5 W
---------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

              SYSTEM FEATURE DESCRIPTION ELEMENT MANAGEMENT SYSTEM

                      ----------------------------------------------------------
ID                    ST-RFX-0012
REVISION              1.0 / APPROVED
DATE                  09 Apr 1999
CONFIDENCE            CCG CONFIDENTIAL

                      ----------------------------------------------------------

AUTHOR                Systemtechnik              Jorg Gimmler

APPROVED              Netzbetrieb

NOTICE                Netzlanung

FILENAME              System Feature Description Element Management System-10

                      ----------------------------------------------------------

DESCRIPTION           This document lists the requested features of an
                      Element Manager for SDH systems DWDM systems or both.

                      ----------------------------------------------------------

CHANGE LOG            1.0  / APPROVED / 09/04/99 / J. Gimmler

                      ----------------------------------------------------------

<PAGE>

-------------------------------------------------------------------------------

1        DEFINITIONS AND ABBREVIATIONS

AIS                            Alarm Indication Signal
API                            Applications Programmer Interface
BER                            Bit Error Ratio
BIP                            Bit Interleaved Parity
c                              fully compliant
CM                             Configuration Management
CSES                           Consecutive Severely Errored Seconds
CV                             Code Violation
DCN                            Data Communication Network
DMA                            Deferred Maintenance Alarm
EB                             Errored Block
EBER                           Excessive Bit Error Rate
EFD                            Event Forwarding Discriminator
EMS                            Element Management System
ES                             Errored Second
ESD                            Electro-static Discharge
EMC                            Electro-magnetic Compatibility
FEBE                           Fare End Block Error
FERF                           Far End Receive Failure
FM                             Fault Management
GNE                            Gateway Network Element
GUI                            Graphical User Interface
ISO                            International Organisation for Standardisation
LAN                            Local Area Network
LMT                            Local Maintenance Terminal
MCF                            Message Communications Function
MIB                            Management Information Base
MTBF                           Mean Time Between Failure
NE                             Network Element
NMC                            Network Management Centre
NMS                            Network (Layer) Management System
O&M                            Operation and Maintenance
OSS                            Operation Support System
PCB                            Printed Circuit Board
PM                             Performance Management
PMA                            Prompt Maintenance Alarm
PRBS                           Pseudo Random Bit Sequence
QoS                            Quality of Service
RAI                            Remote Alarm Indication
SDH                            Synchronous Digital Hierarchy
SEMF                           Synchronous Equipment Management Function
SNC                            Subnetwork Connection
SSMB                           Synchronisation Status Message Byte
TMP                            Total (Performance) Measurement Period
TP                             Termination Points
TTP                            Trail Termination Point
UAS                            Unavailable Second
UT                             Unavailable Time
VC                             Virtual Container
WAN                            Wide Area Network

<PAGE>

<TABLE>
<CAPTION>
2        REQUESTED FEATURES
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
1                  MANAGED NE TYPES
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS supports the offered SDH NE functionality and as                     C      C      C
                   stated to be available via compliance statement to the
                   network element requirements specifications.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS supports the offered DWDM NE functionality and as                    C      C      C
                   stated to be available via compliance statement to the
                   network element requirements specifications.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
2                  GENERAL SYSTEM REQUIREMENTS
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS is based on a standard commercially available                        C      C      C
                   operating system.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS hardware is a standard commercially available system                 C      C      C
                   with non modified external interfaces.
------------------------------------------------------------------------------------------------------------------------------
            3.     The parallel usage of additional standard application                        C      C      C
                   software is possible.
------------------------------------------------------------------------------------------------------------------------------
            4.     A failure in the EMS is in no case service affecting.                        C      C      C
-----------------------------------------------------------------------------------------------------------------------------
            5.     The downtime of the EMS is less than four hours per month.                   C      C      C
-----------------------------------------------------------------------------------------------------------------------------
            6.     The EMS is a multi-user system.                                              C      C      C
-----------------------------------------------------------------------------------------------------------------------------
            7.     The EMS can be operated by at least three operators on                       C      C      C
                   different terminals simultaneously.
-----------------------------------------------------------------------------------------------------------------------------
            8.     It is possible to apply EMS hardware redundancy on all                       C      C      C
                   critical components which might have impact on the EMS
                   availability.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
3                   NORTHBOUND INTERFACE
------------------------------------------------------------------------------------------------------------------------------
            1.     It is planned to interface the EMS to other vendor's network                 IR     IR     IR     OSI
                   administration tools. The supplier shall specify the type of
                   available northbound interface.
------------------------------------------------------------------------------------------------------------------------------
            2.     It is possible to retrieve all configuration data by an                      C      C      C
                   external CORBA client.
------------------------------------------------------------------------------------------------------------------------------
            3.     It is possible to retrieve all equipment and transmission                    C      C      C
                   alarm data by an external CORBA client.
------------------ --------------------------------------------------------------------------- ------ ------ ------ ---------
            4.     It is possible to retrieve all Quality of Service Data by an                 C      C      C
                   external CORBA client.
------------------------------------------------------------------------------------------------------------------------------
            5.     It is possible to retrieve all Service Management data by an                 C      C      C
                   external C C C CORBA client.
------------------------------------------------------------------------------------------------------------------------------
            6.     The supplier commits to supply the following information to
                   the northbound interface:
                   o Description of the applied communication protocols per each
                     layer
                   o Description of the message encoding rules
                   o Description of the Info Model

                   o Description of the DB table names
                   o Description of the DB table entries
                   o Description on how the information is coded
                   o Description on the DB triggers
                   o Description on the DB functions
                   o Description on the DB procedures
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
4                  USER INTERFACE
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
4.1                GENERAL
------------------------------------------------------------------------------------------------------------------------------
            1.     The system supports a centralised online alarm viewer                        NC     NC     NC     1
                   allowing to centrally monitor equipment alarms at a single
                   screen, even if more than one element manager is required
                   for managing the network.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to transfer displayed information to a clipboard.             NC     NC     NC       1
------------------------------------------------------------------------------------------------------------------------------
            3.     The GUI is based on high resolution colour graphics, 1280 x 1024.            NC     NC     NC       1
------------------------------------------------------------------------------------------------------------------------------
            4.     It is possible to connect at least three monitors to one EMS                 NC     NC     NC       1
                   user station.
------------------------------------------------------------------------------------------------------------------------------
            5.     The three monitors of the EMS user station can be configured                 NC     NC     NC       1
                   to display as one logical sceen.
------------------------------------------------------------------------------------------------------------------------------
            6.     All EMS functionality stated as compliant in this document is                C      C      C
                   available at the GUI.
------------------------------------------------------------------------------------------------------------------------------
            7.     The EMS provides a facility to tailor the display in order to                C      C      C
                   give maximum flexibility in presenting information to
                   the operator.
------------------------------------------------------------------------------------------------------------------------------
            8.     The GUI is capable of immediately displaying updates in case                 NC     NC     NC       2
                   of MIB changes.
------------------------------------------------------------------------------------------------------------------------------
            9.     In case of display update on operator request, changes in                    NC     NC     NC       2
                   the MIB are indicated to the operator.
-------------------------------------------------------------------------------------------------------------------------------
            10.    It is possible to enter all GUI commands by using the mouse and              NC     NC     NC       1
                   alternatively by using the keyboard.
------------------------------------------------------------------------------------------------------------------------------
            11.    The EMS allows the entering of all characters of the German                  NC     NC     NC       1
                   icharacter set ncluding a,o,u etc.
------------------------------------------------------------------------------------------------------------------------------
            12.    The EMS supports a German keyboard.                                          NC     NC     NC       1
------------------------------------------------------------------------------------------------------------------------------
            13.    Dialogue boxes are used to confirm operator actions which may                C      C      V
                   probably affect network traffic.
------------------------------------------------------------------------------------------------------------------------------
            14.    The EMS provides a facility to select objects and actions                    C      C      C
                   applicable to these objects.
------------------------------------------------------------------------------------------------------------------------------
            15.    The EMS provides a facility to modify applicable object                      C      C      C
                   attributes in parameter windows.
------------------------------------------------------------------------------------------------------------------------------
            16.    The execution of all long term operations is indicated to the                C      C      C
                   operator.
------------------------------------------------------------------------------------------------------------------------------
            17.    End of execution of operations are immediately indicated to                  C      C      C
                   the operator.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
4.2                NE REPRESENTATION ON THE GUI
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides at least three layers of NE object representation:          NC     NC     NC       3
                   (a) Network map layer showing the subordinate NE objects on a
                   geographic map.
                   (b) NE equipment layer showing the equipment of a NE object
                   in its full depth (subrack, module, card, ...)
                   (c) NE transmission layer showing the transmission
                   information of a NE object (TPs, port configuration, cross
                   connection ...)
------------------------------------------------------------------------------------------------------------------------------
            2.     Layer (a), (b), (c) are concurrently available in different                  NC     NC     NC       3
                   windows at the GUI.
------------------------------------------------------------------------------------------------------------------------------
            3.     In the network map layer, the NE objects are depicted as                     NC     NC     NC       3
                   icons on a geographical map.
------------------------------------------------------------------------------------------------------------------------------
            4.     The layout with the NE objects and its connections on the                    NC     NC     NC       3
                   geographic map can be stored by the operator in his operator
                   environment.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS  provides a facility to modify the graphical                         NC     NC     NC       3
                   representation  map with the help of a network editor.
-------------------------------------------------------------------------------------------------------------------------------
            6.     The GUI supports the operator for the configuration of                       C      C      C
                   cross-connections between traffic termination points.
------------------------------------------------------------------------------------------------------------------------------
            7.     The NE equipment layer shows structure and properties of the                 NC     NC     NC       3
                   equipment being part of a NE including at least subracks,
                   modules and cards of the NE.
------------------------------------------------------------------------------------------------------------------------------
            8.     NE  pictures resemble the physical equipment and layout.                     NC     NC     NC       3
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
------------------------------------------------------------------------------------------------------------------------------
            9.     The GUI supports navigation between layers in a comfortable way.             NC     NC     NC       3
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
4.3                OPERATOR INTERFACE MANAGEMENT
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS user administration provides facilities to create,                   C      C      C
                   delete and modify operators and their access rights.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS logs all operator sessions including log in and                      C      C      C
                   log out operation.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS provides a facility to generate a print out of any                   C      C      C
                   information stored within the EMS (e.g. alarm logs,
                   screen prints etc.)
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS provides a facility for a comfortable print management               C      C      C
                   (cancel print jobs, select printer, ...)
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS supports at least 3 user classes, configurable by the                C      C      C
                   administrator
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
4.4                NE STATUS PRESENTATION
------------------------------------------------------------------------------------------------------------------------------
            1.     NE status changes (such as operational state or alarm state)                 C      C      C
                   are displayed by means of clearly visible and audible
                   signals).
------------------------------------------------------------------------------------------------------------------------------
            2.     It is possible to disable audible signals.                                   C      C      C
------------------------------------------------------------------------------------------------------------------------------
            3.     The change of the administrative state of a certain object                   C      C      C
                   leads to according state modifications of subordinate
                   objects in the EMS management information base (MIB) and
                   vice versa, wherever reasonable.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
4.5                TEXTUAL REPRESENTATION
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides a textual representation of all information                 C      C      C
                   in its MIB.
------------------------------------------------------------------------------------------------------------------------------
            2.     The textual representation is a formatted list of MIB                        C      C      C
                   contents (e.g. logs, object attributes).
------------------------------------------------------------------------------------------------------------------------------
            3.     The operator is able to choose between different levels of                   C      C      C
                   detail in the textual representation.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS provides scope and filter mechanisms to customise list               C      C      C
                   representations.
------------------------------------------------------------------------------------------------------------------------------
            5.     The information is presented in a scrollable list.                           C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
4.6                HELP SYSTEM
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides a context sensitive on-line help system for                 C      C      C
                   each window and (sub) menu
------------------------------------------------------------------------------------------------------------------------------
            2.     The help system is extensible by the operator.                               C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
5                  PERFORMANCE REQUIREMENTS
------------------------------------------------------------------------------------------------------------------------------
                   Under normal operating conditions, the worst case                            C      C      C
                   duration for ....
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
            1.     ... Creation of a NE is below 10  minutes                                    C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     ... System Software download to a NE is 10 minutes                           C      C      C
------------------------------------------------------------------------------------------------------------------------------
            3.     ... Configuration data download to a NE is below 10 minutes                  C      C      C
                   (Please state the maximum duration of a traffic restoration
                   process).
------------------------------------------------------------------------------------------------------------------------------
            4.     ... Data consistency check with a NE is 1 minute                             C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
            5.     ... NE Reboot is below 5 minutes                                             C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
            6.     ... Upload of single configuration data is within 1 minute                   C      C      C
 ------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
            7.     ... Configuration of a single cross connection within a NE                   C      C      C
                   is 1 second.
------------------------------------------------------------------------------------------------------------------------------
            8.     ... Acceptance of a command entered at the user interface                    C      C      C
                   is 2 seconds.
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
            9.     ... Notifying a traffic affecting failure upon detection                     C      C      C
                   at the NE is 2.5 seconds
------------------------------------------------------------------------------------------------------------------------------
            10.    Under normal operating conditions, the maximum number of                     C      C      C
                   events forwarded to the EMS is not limited.
------------------------------------------------------------------------------------------------------------------------------
            11.    The supplier shall state the maximum number of manageable                    IR     IR     IR    EC1:128,
                   network elements (per NE type).                                                                  OPC:24
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6                  CORE FEATURES
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.1                CONFIGURATION MANAGEMENT
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.1.1              SUPPORT OF NE FEATURES
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS supports all NE Traffic Interface related configuration              C      C      C
                   commandsas listed in the NE specification and committed to be
                   available.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS supports all NE Connectivity related configuration                   C      C      C
                   commands as listed in the NE specification and committed to
                   be available.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS supports all Network Protection Switching related                    C      C      C
                   configuration commands as listed in the NE specification and
                   committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS supports all NE Synchronisation related configuration                C      C      C
                   commands as listed in the NE specification and committed to
                   be available.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS supports all NE Management Interfaces related                        C      C      C
                   configuration commands as listed in the NE specification
                   and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            6.     The EMS supports all General Configuration commands as listed                C      C      C
                   in the NE specification and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            7.     The EMS supports all Fault Management related configuration                  C      C      C
                   commands as listed in the NE specification and committed to
                   be available.
------------------------------------------------------------------------------------------------------------------------------
            8.     The EMS supports all Performance Management related                          C      C      C
                   configuration commands as listed in the NE specification and
                   committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            9.     The EMS supports all O&M related configuration commands as                   C      C      C
                   listed in the NE specification and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.1.2              EQUIPMENT CREATION
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to add NE objects to the EMS database.                        C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to use default attribute values for new                       C      C      C
                   equipment, unless specified or changed by the operator.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS allows to set equipment attributes before creation is                C      C      C
                   performed: Internal ID, Official ID, name, information
                   to objects (such as address, customer ID or other
                   supplementary information deemed to be helpful for the
                   maintenance process)
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS allows to assign a unique user friendly name to each NE.             C      C      C
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS allows to create NEs, regardless of whether physical                 C      C      C
                   equipment exists.
------------------------------------------------------------------------------------------------------------------------------
            6.     The EMS allows to create a new equipment object by using templates           C      C      C
------------------------------------------------------------------------------------------------------------------------------
            7.     The EMS performs attributes value consistency checks before                  C      C      C
                   creation is performed.
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
            8.     The EMS reports errors to the operator, at least unsuccessful                C      C      C
                   operations and invalid attribute values.
------------------------------------------------------------------------------------------------------------------------------
            9.     The EMS automatically creates all termination point objects                  C      C      C
                   during NE creation.
------------------------------------------------------------------------------------------------------------------------------
            10.    The EMS can create a list of all NEs which are managed by the EMS.           C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.1.3              TRANSMISSION CONFIGURATION
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides a graphical view showing HO connection                      NC     NC     NC       4
                   termination points.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS provides a graphical view showing cross-connections                  NC     NC     NC       4
                   configured within in the NE.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS provides a lists of termination points sorted acc.                   C      C      C
                   identifier order and operational state.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS provides lists of cross-connections sorted acc. and                  C      C      C
                   identifier order and operational state.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS allows to configure the object representation by                     C      C      C
                   means of selection criteria (operational state, identifier
                   order).
------------------------------------------------------------------------------------------------------------------------------
            6.     The EMS allows to configure cross connections in lists.                      C      C      C
------------------------------------------------------------------------------------------------------------------------------
            7.     The EMS allows to configure cross connections in graphical view.             NC     NC     NC       4
------------------------------------------------------------------------------------------------------------------------------
            8.     The EMS allows to download pre-defined MIB for traffic                       NC     NC     NC       5
                   restoration purposes (please state the quantity of restoration
                   configurations that can be predefined and stored in
                   parallel).
------------------------------------------------------------------------------------------------------------------------------
            9.     The EMS allows to download by bulk command all MIB parts                     NC     NC     NC       5
                   which need to be downloaded for restoration purposes.
------------------------------------------------------------------------------------------------------------------------------
            10.    The EMS allows to download by bulk command selected MIB                      NC     NC     NC       5
                   parts (e.g.  cross connections).
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.1.4              ALARM CONFIGURATION
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to set alarm severity PMA, DMA and MEI                        NC     NC     NC       6
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to set alarm severity to active and inactive                  NC     NC     NC       6
                   alarms.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS allows to set the severity of an alarm per ...                       NC     NC     NC       6
                   ... single type of alarm.
                   ... single NE instance (port, card,...).
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS allows to set the criteria for activating the audible                C      C      C
                   alarm indication (e.g. alarm priority).
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS allows to set the alarm on-line printing.                            C      C      C
------------------------------------------------------------------------------------------------------------------------------
            6.     The EMS allows to set alarm masking of any alarm.                            C      C      C
------------------------------------------------------------------------------------------------------------------------------
            7.     The masking of an active alarm does not cause inconsistencies                C      C      C
                   between the list of current alarms and the alarm log.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.1.5              EQUIPMENT MODIFICATION
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to set equipment attributes name, information                 C      C      C
                   to objects (such as address, customer ID or other
                   supplementary information deemed to be helpful for the
                   maintenance process).
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to insert multiple equipment attribute changes                C      C      C
                   before performing these modifications.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS checks attributes values prior to performing the                     C      C      C
                   modification.
------------------------------------------------------------------------------------------------------------------------------
            4.     It is possible but not mandatory that attribute modifications                C      C      C
                   which will have impact on existing service are to be
                   confirmed by the operator prior to performing the
                   modification.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
6.1.6              EQUIPMENT DELETION
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to delete NE objects in the EMS database.                     C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to delete NE objects in the EMS database                      C      C      C
                   without impact on the carried traffic.
------------------------------------------------------------------------------------------------------------------------------
            3.     NE object deletion needs to be confirmed by the operator.                    C      C      C
------------------------------------------------------------------------------------------------------------------------------
            4.     If a resource is physically removed, the corresponding                       C      C      C
                   equipment object shall is not automatically deleted in
                   the EMS database.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2                FAULT AND STATUS MANAGEMENT
------------------------------------------------------------------------------------------------------------------------------
6.2.1              SUPPORT OF NE FEATURES
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS supports all NE Traffic Interface related alarms as                  C      C      C
                   listed in the NE specification and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS supports all Network Protection Switching related                    C      C      C
                   alarms and status information as listed in the NE specification
                   and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS supports all Synchronisation related alarms and                      C      C      C
                   status information as listed in the NE specification
                   and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS supports all Management Communication related alarms                 C      C      C
                   and status information as listed in the NE specification and
                   committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS supports all Fault and Status Management features as                 C      C      C
                   listed in the NE specification and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            6.     The EMS supports all Performance Management related alarms                   C      C      C
                   and status messages as listed in the NE specification and
                   committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            7.     The EMS supports all O&M related alarms and status messages                  C      C      C
                   as listed in the NE specification and committed to be
                   available.
------------------------------------------------------------------------------------------------------------------------------
            8.     The EMS supports all Power Supply related alarms as listed                   C      C      C
                   in the NE specification and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.2              ALARM AND STATUS INFORMATION RECEIVING
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS is capable of retrieving all not yet received alarms                 C      C      C
                   after loss of communication between EMS and NE (especially
                   after system shutdown).
------------------------------------------------------------------------------------------------------------------------------
            2.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.3              ALARM ACKNOWLEDGMENT
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides a facility to acknowledge alarms.                           C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     When alarm acknowledgement is performed, acknowledgement                     C      C      C
                   information shall be stored by the EMS with at least:
                          a)  user ID of acknowledging operator,
                          b)  date and time of acknowledgement,
------------------------------------------------------------------------------------------------------------------------------
            3.     It is possible to clearly identify the alarm status                          C      C      C
                   "acknowledged" in the alarm log
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS shall provide a facility to acknowledge one or more                  C      C      C
                   alarms simultaneously, e.g. multiple selection in alarm
                   lists.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.4              ALARM LOGGING
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides alarm logs.                                                 C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS stores all alarms in alarm logs.                                     C      C      C
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS has access and can show contents of alarm logs                       C      C      C
                   created by the NEs.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS alarm log is capable of storing at least 50 000 entries.             C      C      C
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS alarm log size is configurable.                                      C      C      C
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
            6.     The EMS informs the operator before the log capacity limit is                C      C      C
                   reached.
------------------------------------------------------------------------------------------------------------------------------
            7.     The EMS allows to print out the content of the alarm log.                    C      C      C
------------------------------------------------------------------------------------------------------------------------------
            8.     The EMS alarm log contains the                                               C      C      C
                   o  the correlated alarm counter number
                   o  alarm ID number,
                   o  alarm name,
                   o  correlated object (s),
                   o  date and time of alarm raise time
                   o  date and time of alarm clear time,
                   o  alarm severity,
                   o  date and time of acknowledgment.
                   o   the correlated alarms
                   o  the deletion and filtering state
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.5              ALARM PRESENTATION
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.5.1            Alarm Presentation Format
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS presents active and acknowledged alarms in textual format.           C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS presents active alarms in graphical format.                          NC     NC     NC       7
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS provides an audible alarm indication in case of a                    C      C      C
                   received alarm event.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS displays a counter of the active and acknowledged alarms.            NC     NC     NC       7
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS displays a counter per each severity class.                          NC     NC     NC       7
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.5.2            List of Active and Acknowledged Alarms
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides a facility to show active alarms.                           C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS provides a facility to configure the alarm presentation              C      C      C
                   presentation to be updated on command.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS provides a facility to configure the alarm presentation              C      C      C
                   to be updated automatically.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS displays the                                                         C      C      C
                   o  alarm ID number,
                   o  alarm name,
                   o  correlated object,
                   o  date and time of alarm status change,
                   o  severity, and the
                   o  acknowledgement status.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS allows to print the List of active and acknowledged alarms.          C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.5.3            Detailed Alarm Information
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to detect the cause of an alarm by locating the alarm         NC     NC     NC       8
                   source in the graphical NE presentation (subrack, modules and cards).
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.5.4            Alarm Filtering and Masking
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides a facility which masks the consequent alarms from the       NC     NC     NC       9
                   primary alarm.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS provides a low pass filter allowing to constantly activate a         NC     NC     NC       9
                   toggling alarm status.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
6.2.5.5            List of Logged Alarms
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS creates alarm lists out of the selected alarm logs.                  C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS creates lists of selected attributes out of the several              C      C      C
                   alarm logs.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS creates lists of selected attributes values out of                   NC     NC     NC      10
                   the several alarm logs.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS allows to store and to retrieve all types of alarm                   C      C      C
                   lists on external storage devices.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS allows to print the list of logged alarms.                           C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.2.5.6            Heart Beat Function
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS is capable of monitoring the connection to the subordinate           C      C      C
                   NEs periodically.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS generates an alarm if the communication to the NE fails.             C      C      C
------------------------------------------------------------------------------------------------------------------------------
                   The EMS regularly sends its status to the NMS in order to                    C      C      C
                   detect a communication failure or EMS failure.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.3                PERFORMANCE MANAGEMENT
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.3.1              PERFORMANCE MEASUREMENT
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS supports Performance Management related features as                  C      C      C
                   listed in the NE specification and committed to be available.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to configure performance measurement on command.              C      C      C
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS automatically receives performance history data at                   C      C      C
                   the end of a measurement period.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS allows to store all performance history data in a                    C      C      C
                   performance log.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS allows to store at least 30 x 24 h and 100 x 15h                     C      C      C
                   minutes performance per each single performance
                   monitoring point of the NE.
------------------------------------------------------------------------------------------------------------------------------
            6.     The performance history data are identified by NE id, NE type                C      C      C
                   and NE port and configurable name.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
6.3.2              PERFORMANCE HISTORY PRESENTATION
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to present the current and reloaded performance               C      C      C
                   history logs in table format
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to present the current and reloaded performance               NC     NC     NC      11
                   history logs in a diagram.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS allows to print out the current and reloaded                         C      C      C
                   performance history  logs in table format.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS allows to export the current and reloaded performance                NC     NC     NC      11
                   history logs in ASCII or EXCEL data format.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7                  EMS OPERATION AND MAINTENANCE
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.1              USER ACCESS CONTROL
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to define different operator classes for supporting           C      C      C
                   functional operation and maintenance domain partitioning.
------------------------------------------------------------------------------------------------------------------------------
            2.     The definition of operator domains is restricted to the system               C      C      C
                   administrator.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS provides an application to administer EMS operators,                 C      C      C
                   their access rights and the definition of a NE domain.
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
            4.     A User ID / Password combination shall be available to get                   C      C      C
                   access to the EMS applications.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS locks an operator log in after a configurable number of              C      C      C
                   unsuccessful attempts.
------------------------------------------------------------------------------------------------------------------------------
            6.     The EMS unlocks locked operator accounts either manually by                  C      C      C
                   the system administrator or automatically by the system
                   after a configurable amount of time.
------------------------------------------------------------------------------------------------------------------------------
            7.     The EMS can lock the screen.                                                 C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.2              LMT ACCESS CONTROL
------------------------------------------------------------------------------------------------------------------------------
            1.     Log in to a NE by a LMT is indicated to the EMS by a notification            C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     Log out from a NE by a LMT is indicated to the EMS by a notification.        C      C      C
------------------------------------------------------------------------------------------------------------------------------
            3.     The equipment avoids access conflicts and possible consequent                C      C      C
                   data inconsistencies due to parallel EMS and LMT access to
                   the NE by password protection.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.3              DATA MANAGEMENT
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.3.1            Data Base
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS MIB is completely stored in the data base.                           C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS provides a MIB browser.                                              NC     NC     NC      12
------------------------------------------------------------------------------------------------------------------------------
            3.     A database transaction log is maintained                                     NC     NC     NC      12
------------------------------------------------------------------------------------------------------------------------------
            4.     The data base transaction log contains at least the following                NC     NC     NC      12
                   information:
                   o   Date and time when the operation was performed
                   o   Operator ID
                   o   data base operation
                   o   Object on which operation was performed
                   o   NE ID to which object belongs
                   o   success/fail transaction
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS provides an open interface to ist data base (e.g. SQL)               C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.3.2            Data Backup
------------------------------------------------------------------------------------------------------------------------------
            1.     The operator interface of the archiving utilities is user                    NC     NC     NC    13
                   friendly (e.g. no sequence of operating system commands
                   is required).
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS allows to manually backup and restore the complete                   C      C      C
                   management data of the EMS.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS allows to automatically backup and restore the                       C      C      C
                   complete management data of the EMS (excluding the data
                   dictionary).
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS provides a facility to log backup operations.                        C      C      C
------------------------------------------------------------------------------------------------------------------------------
            5.     The archive media is delectable.                                             C      C      C
------------------------------------------------------------------------------------------------------------------------------
            6.     The backup operation does not influence system operations.                   C      C      C
------------------------------------------------------------------------------------------------------------------------------
            7.     The result of the archiving operations is reported to the EMS                C      C      C
                   operator.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.3.3            System Upgrade
------------------------------------------------------------------------------------------------------------------------------
            1.     In case of an EMS software update including a change of the                  C      C      C
                   configuration data model, it is possible to extract all EMS
                   configuration data, to perform any conversion required for
                   the new software and to repopulate the database.
------------------------------------------------------------------------------------------------------------------------------
            2.     An EMS software update does not affect the interfaces in any case.           C      C      C
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS logs data base errors in any case.                                   C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
7.4.3.4            Data Consistency between EMS and NEs
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS allows to check the EMS configuration data and the                   C      C      C
                   data of all subordinate NEs (audit function).
------------------------------------------------------------------------------------------------------------------------------
            2.     Upon the data consistency audit, the EMS allows both upload /                C      C      C
                   download of configuration data from / to the NE.
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS monitors the data consistency regularly.                             C      C      C
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS alarms in case of detected H/W to data base inconsistency.           C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.4              EMS SYSTEM SOFTWARE MANAGEMENT
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.4.1            EMS System Software Download
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS software applications can be downloaded as single                    C      C      C
                   packages with version number.
------------------------------------------------------------------------------------------------------------------------------
            2.     Each EMS software application has its own version number.                    C      C      C
------------------------------------------------------------------------------------------------------------------------------
            3.     Error-free transfer of system software download is ensured by                C      C      C
                   verification procedures.
------------------------------------------------------------------------------------------------------------------------------
            4.     The EMS software update does not have any influence on the                   C      C      C
                   network traffic.
------------------------------------------------------------------------------------------------------------------------------
            5.     The EMS shall provide a facility to read the current EMS                     C      C      C
                   software version.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.4.2            EMS Restart
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS restart procedure performs data consistency checks                   C      C      C
                   between the EMS and the configuration data of all
                   subordinate NEs.
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS restart does not have any effects on the network traffic.            C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.4.3            EMS Shutdown
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS provides a facility to shut down the system without                  C      C      C
                   restarting it automatically (e.g. not removable database
                   integrity errors, viral infections).
------------------------------------------------------------------------------------------------------------------------------
            2.     The EMS reports the start of an EMS shutdown to the NMS.                     NC     NC     NC      14
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
            3.     The EMS shutdown does not have any effects on the network traffic.           C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
7.4.4.4            EMS Recovery
------------------------------------------------------------------------------------------------------------------------------
            1.     The EMS contains an EMS recovery mechanism to control all                    C      C      C
                   concurrently running processes within the EMS (e.g. restart
                   of an application process).
------------------------------------------------------------------------------------------------------------------------------
            2.     If any persisting problems are discovered by the EMS, the                    C      C      C
                   recovery procedure performs appropriate actions (e.g.
                   inform the operator etc.)
------------------------------------------------------------------------------------------------------------------------------
            3.     The recovery process is not traffic affecting.                               C      C      C
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
8                  ENVIRONMENTAL CONDITIONS
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
8.1                CLIMATIC CONDITIONS
------------------------------------------------------------------------------------------------------------------------------
            1.     The Equipment allows error free operation in accordance with                 C      C      C
                   ETSI Rec. C C C prETS 300 019-2-3, Class T 3.1.
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
8.2                ELECTRO-MAGNETIC COMPATIBILITY (EMC)
------------------------------------------------------------------------------------------------------------------------------
            1.     The Equipment is compliant with the standards EN 55022 and                   C      C      C
                   EN 50082, class B
------------------------------------------------------------------------------------------------------------------------------
                   The Equipment is marked with the CE-compatibility sign.                      C      C      C
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
            NO.    ITEM                                                                        SOC    SOC    SOC   REF. NO.
                                                                                               T1     T2     T3
------------------------------------------------------------------------------------------------------------------------------
<S>         <C>    <C>                                                                         <C>    <C>    <C>   <C>
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
8.3                SAFETY
------------------------------------------------------------------------------------------------------------------------------
            1.     The Equipment meets the electrical safety requirements of EN 41003.          C      C      C
------------------------------------------------------------------------------------------------------------------------------
            2.     The equipment is designed to ensure operation without hazard                 C      C      C
                   to personnel due to electrical commotion
------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>

3        REFERENCES

3.1      REFERENCES TO STANDARDS

----------------------------------------------------------------------------------------------------------------------
STANDARD                STATUS    DATE      TITLE
----------------------------------------------------------------------------------------------------------------------
<S>                     <C>      <C>        <C>
ITU-T G.703                       04/91     Physical/Electrical characteristics of Hierarchical Digital Interfaces
----------------------------------------------------------------------------------------------------------------------
ITU-T G.707                       1991      Synchronous digital hierarchy bit rates
----------------------------------------------------------------------------------------------------------------------
ITU-T G.782                       1994      Types and general characteristics of synchronous digital hierarchy (SDH)
                                            equipment
----------------------------------------------------------------------------------------------------------------------
ITU-T G.783                       1994      Characteristics of synchronous digital hierarchy  /SDH)  equipment
                                            functional blocks
----------------------------------------------------------------------------------------------------------------------
ITU-T G.826                       11/93     Error performance parameters and objectives for International constant
                                            Bit Rate Digital Paths at or above the Primary Rate
----------------------------------------------------------------------------------------------------------------------
ITU-T G.841                       1995      Types and Characteristics of SDH Network Protection Architectures
----------------------------------------------------------------------------------------------------------------------
ITU-T G.957                       1993      Optical Interfaces and Systems relating to the synchronous digital
                                            hierarchy
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
ETS 300 019             pr        02/92     Environmental conditions and Environmental Tests for Telecommunications
                                            Equipment
                                            Part A: Introduction and Terminology
                                            Part B: classification of Environmental conditions
----------------------------------------------------------------------------------------------------------------------
ETS 300 119                                 European Telecommunication Standard for Equipment Practice
                                  03/93     Part 2:  Engineering Requirements for Racks
                                  09/93     Part 3:  Engineering Requirements for Miscellaneous Racks and cabinets
                                  09/93     Part 4:  Engineering Requirements for Subracks
----------------------------------------------------------------------------------------------------------------------
ETS 300 253                       01/95     Earthing and bonding of telecommunication equipment in telecommunication
                                            centres
----------------------------------------------------------------------------------------------------------------------
EN 41003                          1991      Particular safety requirements for equipment to be connected to
                                            telecommunication network
----------------------------------------------------------------------------------------------------------------------
EN 55022                          05/95     Grenzwerte und  Me(beta)verfahren fur Funkstorungen von Einrichtungen der
                                            Informationstechnik
----------------------------------------------------------------------------------------------------------------------
EN 50082                                    Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                                  12/94     Part 1: Elektromagnetische Vertraglichkeit - Fachgrundnorm
                                            Storfestigkeit - Teil 1: Wohnbereich, Geschafts- und Gewerbebereiche
                                  02 /96    sowie Kleinbetriebe
                                            Part 2: Elektromagnetische Vertraglichkeit - Fachgrundnorm
                                            Storfestigkeit - Teil 2: Industriebereich
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 2
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 4.1
                                               Item No.: 8,9
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Graphical User Interface for EMS

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
The EC-1 and the OPC do not save information in MIBs as this means is part of
the SNMP standard. However all configuration information is stored in the
resilient network elements and the databases contained in those Multiplexers as
the only valid database originating from the assumption that only the network is
the real database for configuration information. Uploads and Downloads of
configuration information to INM via the element controllers is feasable.
Uploaded information is stored in a database at the Element Control level which
the INM system is accessing on request to perform the desired changes from the
pathmanagement system itself. The responsible application is the INM
Trailmanager.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development
--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network

--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 3
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 4.2
                                               Item No.: 1,2,3,4,5,7,8,9

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 NE Representation on the GUI

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 4
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.1.3
                                               Item No.: 1,2,7

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Transmission Configuration

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 5
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.1.3
                                               Item No.: 8,9,10

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Transmission Configuration

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 2.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 6
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.1.4
                                               Item No.: 1,2,3

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Alarm Configuration

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
The severity of an alarm is provided as part of the Network Element generated
fault messages and cannot be changed by the means of using the Element
Controller, as the severity assigned is based on the experience Nortel Networks
has gained through customers during the long period of time since SDH
multiplexers have been available.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------

/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network

--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 7
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.1.5.1
                                               Item No.: 2,4,5

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Alarm Presentation Format

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 8
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.1.5.3
                                               Item No.: 1

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Detailed Alarm Information

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 9
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.1.5.4
                                               Item No.: 1,2

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 Alarm Filtering and Masking

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.

<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 14
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 7.4.4.3
                                               Item No.: 2
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
 EMS Shutdown

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
In case of an EMS shutdown the upper layer INM system recognises the loss of
communication and reports this failure. In the case of redundant EMS systems the
spare EMS takes over management operation and ensures continued network
management operation.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.

<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 10
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.2.5.5
                                               Item No.: 3
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
List of logged Alarms

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>

                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 11
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 6.3.2
                                               Item No.: 2,4
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Performance History Presentation

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 12
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 7.4.3.1
                                               Item No.: 2,3,4
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Data Base

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 1.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.
<PAGE>
                  EXPLANATORY SHEET (TECHNICAL SPECIFICATIONS)

--------------------------------------------------------------------------------
Supplier: NORTEL DASA                          Reference No.: 13
                                               otel.o Document No.: ST-rfx-0012
                                               Chapter: 7.4.3.2
                                               Item No.: 1
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
1. Item of non compliance
--------------------------------------------------------------------------------
Data Backup

--------------------------------------------------------------------------------
2. Description of non compliance
--------------------------------------------------------------------------------
Please refer to note 2.

--------------------------------------------------------------------------------
3. Proposed further Development:
--------------------------------------------------------------------------------
/ / Compliant development planned until / / T1 / / T2 / / after T2
/X/ Further Development planned but not compliant with o.tel.o requirements
/ / No further development

--------------------------------------------------------------------------------
4. Affect of further Product Development on the o.tel.o Network
--------------------------------------------------------------------------------
No.

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
1              TRANSMISSION FEATURES
-----------------------------------------------------------------------------------------------------------------------------------
         1     The supplier provides a link/hop planning tool allowing to                                recommend Nortel
               simulate and design the DWDM network (Attenuation,                                        Network Engineering
               Dispersion,..).                                                                           OPTICAL POWER
                                                                                                         BUDGET TOOL
-----------------------------------------------------------------------------------------------------------------------------------
         2     The supplier provides a released document containing system             IR   IR    IR     see Doc. 323-1251-
               planning and engineering rules based on standard single                                   233 SEC. 8 -Optical
               mode fibres.                                                                              Link Engineering
-----------------------------------------------------------------------------------------------------------------------------------
1.1            TRANSMISSION INTERFACES
-----------------------------------------------------------------------------------------------------------------------------------
         1     Connector Type E2000 APC                                                                  see OPTera Product
                                                                                                         Description SEC. 3.2
-----------------------------------------------------------------------------------------------------------------------------------
1.1.1         INTERFACES ACCYING N x LAMBDAS
-----------------------------------------------------------------------------------------------------------------------------------
         1     Maximum output power of the interfaces                                  IR   IR    IR     see OPTera Product
                                                                                                         Description SEC. 1.3 -
                                                                                                         Wavelength Plan and
                                                                                                         SEC.1.4 - Client
                                                                                                         Interfaces
-----------------------------------------------------------------------------------------------------------------------------------
         2     OADM link/hop limits (attenuation, dispersion,..) as function           IR   IR    IR     see Doc. 323-1251-233
               of number and lengths of hops between terminals.                                          SEC. 8 Optical Link
                                                                                                         Engineering
-----------------------------------------------------------------------------------------------------------------------------------
         3     Automatic output power adjustment depending on the number                                 see OPTera Product
               of received channels                                                                      Description SEC 7.2.2 -
                                                                                                         Performance Management
-----------------------------------------------------------------------------------------------------------------------------------
         4     N x lambda interface on tributary side                                                    see OPTera Product
                                                                                                         Description SEC. 1.3 -
                                                                                                         Wavelength Plan and
                                                                                                         SEC.1.4 - Client
                                                                                                         Interfaces
-----------------------------------------------------------------------------------------------------------------------------------
1.1.2         TRANSPONDERS AND TRIBUTARY INTERFACES
-----------------------------------------------------------------------------------------------------------------------------------
         1     Optical interface I-16.1                                                                  see TN-64X Tech. Spec.
                                                                                                         323-1321-180
                                                                                                         SEC. 2 - Optical
                                                                                                         Interface
                                                                                                         Specification
---------------------------------------------------------------------------------------------------------
         2     Optical interface S-16.1
---------------------------------------------------------------------------------------------------------
         3     Optical interface L-16.1
---------------------------------------------------------------------------------------------------------
         4     Optical interface L-16.2
---------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
         5     Bitrate independent interface                                                             see OPTera Product
                                                                                                         Description SEC. 4.2 -
                                                                                                         Optical Channel Card
                                                                                                         and SEC.4.3 - Optical
                                                                                                         Channel Interface
-----------------------------------------------------------------------------------------------------------------------------------
         6    Optical Power Budget without transponders                                 IR   IR    IR    see Nortel Network
                                                                                                         Engineering OPTICAL
                                                                                                         POWER BUDGET TOOL
-----------------------------------------------------------------------------------------------------------------------------------
         7     Active wavelength control (not only via chip temperature)
-----------------------------------------------------------------------------------------------------------------------------------
         8     Transmit transponders optional for tributary channels
               (option to use output signals from coloured transmitters
               without need to implement transponders)
-----------------------------------------------------------------------------------------------------------------------------------
         9     Receive transponders optional for add/drop channels (option
               to apply DEMUX output signal to SDH-receiver)
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
1.2            SYSTEM CONNECTIVITY                                                                       Wavelengths are organised
                                                                                                         into bands each band
                                                                                                         having four wavelength
                                                                                                         based on 200GHz SPACING
-----------------------------------------------------------------------------------------------------------------------------------
         1     In case of optical channel spacing 100 GHz:                                               see OPTera Product
                                                                                                         Description SEC.1.3 -
                                                                                                         Wavelength Plan
-----------------------------------------------------------------------------------------------------------------------------------
         2     Max. number of optical channels aggregate east to agg. west             IR   IR    IR     (see OPTera Product
                                                                                                         Description SEC.1.3 -
                                                                                                         Wavelength Plan
-----------------------------------------------------------------------------------------------------------------------------------
         3     Min. number of optical channels aggregate west to agg. east             IR   IR    IR     (see OPTera Product
                                                                                                         Description SEC.1.3 -
                                                                                                         Wavelength Plan
-----------------------------------------------------------------------------------------------------------------------------------
         4     Max. number of optical channels added/dropped to/from                   IR   IR    IR     see OPTera Product
               direction east                                                                            Description SEC. 2 -
                                                                                                         Network
                                                                                                         Configurations
-----------------------------------------------------------------------------------------------------------------------------------
         5     Min. number of optical channels added/dropped to/from                   IR   IR    IR     see OPTera Product
               direction east                                                                            Description SEC. 2 -
                                                                                                         Network
                                                                                                         Configurations
-----------------------------------------------------------------------------------------------------------------------------------
         6     Max. number of optical channels added/dropped to/from                   IR   IR    IR     see OPTera Product
               direction west                                                                            Description SEC. 2 -
                                                                                                         Network
                                                                                                         Configurations
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
         7     Min. number of optical channels added/dropped to/from                   IR   IR    IR     see OPTera Product
               direction west                                                                            Description SEC. 2 -
                                                                                                         Network
                                                                                                         Configurations
-----------------------------------------------------------------------------------------------------------------------------------
         8
-----------------------------------------------------------------------------------------------------------------------------------
               IN CASE OF OPTICAL CHANNEL SPACING 50 GHz:
-----------------------------------------------------------------------------------------------------------------------------------
         9     Max. number of optical channels aggregate east to agg. west               IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
         10    Min. number of optical channels aggregate west to agg. east               IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
         11    Max. number of optical channels added/dropped to/from direction east      IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
         12    Min. number of optical channels added/dropped to/from direction east      IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
         13    Max. number of optical channels added/dropped to/from direction west      IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
         14    Min. number of optical channels added/dropped to/from direction west      IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
1.3            STM-64 COMPATIBILITY
-----------------------------------------------------------------------------------------------------------------------------------
         1     It is possible to upgrade aggregate - aggregate channels from                             see OPTera Product
               STM-16 to STM-64 without need to change hardware.                                         Description SEC. 4.2 -
                                                                                                         Optical Channel
                                                                                                         Laser and Detector
                                                                                                         Card
-----------------------------------------------------------------------------------------------------------------------------------
         2     It is possible to upgrade specific aggregate - tributary                                  see OPTera Product
               channels from STM-16 to STM-64 is possible without                                        Description SEC. 4.1 -
               affecting other channels.                                                                 Optical Multiplexer
-----------------------------------------------------------------------------------------------------------------------------------
1.4            OTHER TRANSMISSION FEATURES
-----------------------------------------------------------------------------------------------------------------------------------
         1     Dispersion compensation for aggregate - aggregate channels                                see Doc. 323-1251-233
                                                                                                         SEC. 8 Optical
                                                                                                         Link Engineering
--------------------------------------------------------------------------------------------------------
         2     Automatic gain control
--------------------------------------------------------------------------------------------------------
         3     A aggregate - aggregate channel upgrade is not traffic
               affecting to all channels already in service
--------------------------------------------------------------------------------------------------------
         4     A aggregate - tributary channel upgrade is not traffic
               affecting to all channels already in service
--------------------------------------------------------------------------------------------------------
         5     Forward error correction
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
2              ENGINEERING ORDERWIRE                                                                     see Nortel
                                                                                                         SPEAKEASY EOW
                                                                                                         Overview Document
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------
2.1           INTERFACES
--------------------------------------------------------------------------------------------------------
         1     2 wire i/f (towards PSTN)
--------------------------------------------------------------------------------------------------------
         2     2 wire  i/f (towards standard handset)
--------------------------------------------------------------------------------------------------------
2.2            FUNCTIONS
--------------------------------------------------------------------------------------------------------
         1     Selective Call
--------------------------------------------------------------------------------------------------------
         2     Conference Call (up to four participants)
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
3              MANAGEMENT COMMUNICATION
--------------------------------------------------------------------------------------------------------
3.1            COMMUNICATION INTERFACES                                                                  see OPTera Product
                                                                                                         Description SEC. 5.2.3 -
                                                                                                         Standard
                                                                                                         Communications
                                                                                                         Interfaces and SEC.7.3 -
                                                                                                         Management
                                                                                                         Communication
--------------------------------------------------------------------------------------------------------
         1     F- Interface (RS 232)
--------------------------------------------------------------------------------------------------------
         2     Q- interface as gateway to the EMS
--------------------------------------------------------------------------------------------------------
         3     Qecc Routing (2 level IS-IS)
--------------------------------------------------------------------------------------------------------
         4     Q I/F (Ethernet)
--------------------------------------------------------------------------------------------------------
         5     Optical Supervisory Channel
-----------------------------------------------------------------------------------------------------------------------------------
         6     OSC - wavelength                                                        IR   IR    IR     see OPTera Product
                   - bitrate                                                                             Description SEC. 5.2.2
                   - optical span limit                                                                  - Per Wavelength
                   - transmission protocol                                                               Optical Service
                                                                                                         Channel and SEC.7.3 -
                                                                                                         Management
                                                                                                         Communication
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
3.2            O & M INTERFACES
-----------------------------------------------------------------------------------------------------------------------------------
         1     8 x Remote Control Inputs
-----------------------------------------------------------------------------------------------------------------------------------
         2     Remote Control Outputs
-----------------------------------------------------------------------------------------------------------------------------------
         3     Card LED support
-----------------------------------------------------------------------------------------------------------------------------------
         4     Subrack LED support
-----------------------------------------------------------------------------------------------------------------------------------
         5     Rack Alarm support
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
4              PERFORMANCE MANAGEMENT                                                                    see OPTera Product
                                                                                                         Description SEC. 7.2.2
                                                                                                         - Performance
                                                                                                         Management
--------------------------------------------------------------------------------------------------------
         1     B1 Performance Monitoring on Transponder Unit
--------------------------------------------------------------------------------------------------------
         2     15 min Performance History Data Collection from each
               Regenerator Section Monitoring Point (ES, SES and UAT).
--------------------------------------------------------------------------------------------------------
         3     24 h Performance History Data Collection from each
               Regenerator Section Monitoring Point (ES, SES and UAT).
--------------------------------------------------------------------------------------------------------
         4     15 min Performance History Log for more than 100 intervals
--------------------------------------------------------------------------------------------------------
         5     24 h Performance History Log for more than 30 intervals
--------------------------------------------------------------------------------------------------------
         6     Performance Monitoring Threshold Crossing Notification
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
5              FAULT AND STATUS MANAGEMENT                                                               see OPTera Product
                                                                                                         Description SEC. 7.2.3
                                                                                                         - Fault Management
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
 5.1.1         ALL OPTICAL INTERFACES                                                                    see OPTera Product
                                                                                                         Description SEC. 4.2 -
                                                                                                         Optical Channel
                                                                                                         Card; SEC.4.3 -
                                                                                                         Optical Channel
                                                                                                         Interface; SEC.4.4 -
                                                                                                         Optical Channel
                                                                                                         Manager AND SEC.4.5 -
                                                                                                         Shelf Processor
-----------------------------------------------------------------------------------------------------------------------------------
         1     Laser Restart for Test
--------------------------------------------------------------------------------------------------------
         2     Detection of Laser Shutdown
--------------------------------------------------------------------------------------------------------
         3     Detection of disabled ALS on any optical interface
--------------------------------------------------------------------------------------------------------
         4     Detection of Optical Source Power High on any optical interface
--------------------------------------------------------------------------------------------------------
         5     Detection of LOS, LOS status change hysteresis
--------------------------------------------------------------------------------------------------------
         6     Insertion of AIS upon detection of LOS
--------------------------------------------------------------------------------------------------------
         7     Detection of number of received channels
--------------------------------------------------------------------------------------------------------
         8     Monitoring of laser current for pump laser 1
--------------------------------------------------------------------------------------------------------
         9     Monitoring of laser current for pump laser 2
--------------------------------------------------------------------------------------------------------
         10    Monitoring of temperature for pump laser 1
--------------------------------------------------------------------------------------------------------
         11    Monitoring of temperature for pump laser 2
--------------------------------------------------------------------------------------------------------
         12    Monitoring of laser temperature
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
         13    Monitoring of transmitted wavelength
--------------------------------------------------------------------------------------------------------
         14    Monitoring of received input power
--------------------------------------------------------------------------------------------------------
         15    Monitoring of transmitted output power
--------------------------------------------------------------------------------------------------------
         16    Detection of coupler temperature high
--------------------------------------------------------------------------------------------------------
         17    Detection of grating temperature high
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
 5.1.2         ALL REGENERATOR SECTION MONITORING POINTS                                                 see OPTera Product
                                                                                                         Description SEC. 5.5.-
                                                                                                         Maintenance
--------------------------------------------------------------------------------------------------------
         1     Detection of OOF
--------------------------------------------------------------------------------------------------------
         2     Detection of LOF
--------------------------------------------------------------------------------------------------------
         3     Detection of RS EBER (10E-3) based on  B1 BIP-8 parity
               calculation on demux unit
--------------------------------------------------------------------------------------------------------
         4     Detection of RS EBER (10E-3) based on  B1 BIP-8 parity
               calculation on transponder unit
--------------------------------------------------------------------------------------------------------
         5     Detection of Section Trace Mismatch based on J0 Byte
               monitoring on demux unit
--------------------------------------------------------------------------------------------------------
         6     Detection of Section Trace Mismatch based on J0 Byte
               monitoring on transponder unit
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
 5.1.3         MANAGEMENT COMMUNICATION FUNCTION                                                         see OPTera Product
                                                                                                         Description SEC. 7.3.-
                                                                                                         Management
                                                                                                         Communications
--------------------------------------------------------------------------------------------------------
               Detection of Remote Control Input Active
--------------------------------------------------------------------------------------------------------
               Detection of OSC Comms Fail (LAPD Alarm)
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
 5.1.4         SYSTEMS MANAGEMENT FUNCTION                                                               see OPTera Product
                                                                                                         Description SEC. 7.2.-
                                                                                                         System Management
                                                                                                         and SEC.5 - Software
                                                                                                         Description
--------------------------------------------------------------------------------------------------------
         1     Detection of Secondary Power Fail
--------------------------------------------------------------------------------------------------------
         2     Detection of Primary Power Low
--------------------------------------------------------------------------------------------------------
         3     Detection of Primary Power Fail per each single power feed
--------------------------------------------------------------------------------------------------------
         4     Detection of Re-Boot Fail
--------------------------------------------------------------------------------------------------------
         5     Detection of Configuration Data Integrity Check Failure
--------------------------------------------------------------------------------------------------------
         6     Detection of System Software Integrity Check Failure
--------------------------------------------------------------------------------------------------------
         7     Detection of Network Element Controller Fail
--------------------------------------------------------------------------------------------------------
         8     Detection of Card Protection Switch Failure
--------------------------------------------------------------------------------------------------------
         9     Detection of Card Out
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
         10    Detection of Card Fail (upon detection of internal parity mismatch etc.)
--------------------------------------------------------------------------------------------------------
         11    Detection of Wrong Card
--------------------------------------------------------------------------------------------------------
         12    Network Protection Switch Failure
--------------------------------------------------------------------------------------------------------
         13    Optical Layer Protection Switch Active
--------------------------------------------------------------------------------------------------------
         14    Card Protection Switch Active
--------------------------------------------------------------------------------------------------------
         15    Fault / Status Log Capacity Exceeded
--------------------------------------------------------------------------------------------------------
         16    Configuration Data Transaction Log Capacity Exceeded
--------------------------------------------------------------------------------------------------------
         17    Performance Monitoring Log Capacity Exceeded
--------------------------------------------------------------------------------------------------------
         18    Access  Log Capacity Exceeded
--------------------------------------------------------------------------------------------------------
         19    Software Download in Progress
--------------------------------------------------------------------------------------------------------
         20    Software Download Failure
--------------------------------------------------------------------------------------------------------
         21    Software Download Failure - Retry in Progress
--------------------------------------------------------------------------------------------------------
         22    Software Download Complete
--------------------------------------------------------------------------------------------------------
         23    Card Restoration Complete
--------------------------------------------------------------------------------------------------------
         24    Re-Boot Restoration Complete
--------------------------------------------------------------------------------------------------------
         25    Electronic Label Update
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
5.2            ALARM EVENT HANDLING                                                                      see OPTera Product
                                                                                                         Description SEC. 7.2.3
                                                                                                         - Fault Management
--------------------------------------------------------------------------------------------------------
         1     Alarm Persistence Filter (filtering of toggling alarms)
--------------------------------------------------------------------------------------------------------
         2     Alarm Correlation Filter (F3 filter, suppression of consequent
               alarms)
--------------------------------------------------------------------------------------------------------
         3     Alarm Inversion Facility
--------------------------------------------------------------------------------------------------------
         4     Performance of the alarm throughput GREATER THAN 10 alarms per second
--------------------------------------------------------------------------------------------------------
         5     Indication of Alarm Event Forwarding Suppression per
               functional unit (e.g. Regenerator Section ...)
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
6              CONFIGURATION MANAGEMENT                                                                  see OPTera Product
                                                                                                         Description SEC. 7.2.1
                                                                                                         - Configuration
                                                                                                         Management and
                                                                                                         SEC.5.4 -
                                                                                                         Configuration
                                                                                                         Management
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
6.1            GENERAL                                                                                   see OPTera Product
                                                                                                         Description SEC.5 -
                                                                                                         Software Description and
                                                                                                         SEC. 7.2.- System
                                                                                                         Management
--------------------------------------------------------------------------------------------------------
         1     Upload of Configuration Data - on single command
--------------------------------------------------------------------------------------------------------
         2     Upload of Configuration Data - on bulk command
--------------------------------------------------------------------------------------------------------
         3     Download of Configuration Data on bulk command
--------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------
6.2            CONFIGURATION OF FUNCTIONAL BLOCKS
--------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------
 6.2.1         ALL OPTICAL INTERFACES
--------------------------------------------------------------------------------------------------------
         1     Set of transmitted output power
--------------------------------------------------------------------------------------------------------
         2     Set of input power warning thresholds
--------------------------------------------------------------------------------------------------------
         3     Set input power switch off thresholds
--------------------------------------------------------------------------------------------------------
         4     Set output power warning thresholds
--------------------------------------------------------------------------------------------------------
         5     Set output power switch off thresholds
--------------------------------------------------------------------------------------------------------
         6     Set laser current alarm thresholds
--------------------------------------------------------------------------------------------------------
         7     Set of laser temperature alarm thresholds
--------------------------------------------------------------------------------------------------------
         8     Set of transmitted wavelength alarm thresholds
--------------------------------------------------------------------------------------------------------
         9     Enable / Disable Automatic Laser Shutdown according to ITU-T G.958
--------------------------------------------------------------------------------------------------------
         10    Enable / Disable Laser
--------------------------------------------------------------------------------------------------------
         11    Enable Laser for Test Purposes  (2s  / 90s)
--------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------
 6.2.2         ALL REGENERATOR SECTION MONITORING POINTS
--------------------------------------------------------------------------------------------------------
         1     Set Threshold B1-EBER
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
7              NETWORK PROTECTION                                                                        see OPTera Product
                                                                                                         Description SEC. 5.6 -
                                                                                                         Protection Switching
--------------------------------------------------------------------------------------------------------
7.1            OPTICAL MULTIPLEX SECTION PROTECTION (OMSP)
--------------------------------------------------------------------------------------------------------
         1     OMSP function
--------------------------------------------------------------------------------------------------------
         2     Switch-Over Completion Time (LESS THAN) 50ms
--------------------------------------------------------------------------------------------------------
         3     Enable / Disable Automatic Switching
--------------------------------------------------------------------------------------------------------
         4     Manual Switching via Management Interface
--------------------------------------------------------------------------------------------------------
         5     Configurable Wait Time to Restore
--------------------------------------------------------------------------------------------------------
7.2            WAVELENGTH SELECTIVE PROTECTION SWITCHING
--------------------------------------------------------------------------------------------------------
         1     Wavelength selective Subnetwork Connection Protection
--------------------------------------------------------------------------------------------------------
         2     Switch-Over Completion Time (LESS THAN) 50ms
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
         3     Enable / Disable Automatic Switching
--------------------------------------------------------------------------------------------------------
         4     Manual Switching via Management Interface
--------------------------------------------------------------------------------------------------------
         5     Configurable Wait Time to Restore
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
8              OPERATION AND MAINTENANCE
-----------------------------------------------------------------------------------------------------------------------------------
8.1            GENERAL
-----------------------------------------------------------------------------------------------------------------------------------
         1     Event buffer
-----------------------------------------------------------------------------------------------------------------------------------
         2     Heart Beat Function for all processes
-----------------------------------------------------------------------------------------------------------------------------------
         3     Automatic Re-boot after power failure
-----------------------------------------------------------------------------------------------------------------------------------
         4     Real time clock function
-----------------------------------------------------------------------------------------------------------------------------------
         5     Automatic synchronization of NE real time clock on EMS real time clock
-----------------------------------------------------------------------------------------------------------------------------------
         6     It is possible to set the NE time and date via EMS/LCT
-----------------------------------------------------------------------------------------------------------------------------------
         7     NSAP Address modification
-----------------------------------------------------------------------------------------------------------------------------------
         8     Local Software Download
-----------------------------------------------------------------------------------------------------------------------------------
         9     Remote Software Download
-----------------------------------------------------------------------------------------------------------------------------------
         10    Upload of configuration data to EMS/LCT
-----------------------------------------------------------------------------------------------------------------------------------
         11    Download of configuration data from EMS/LCT
-----------------------------------------------------------------------------------------------------------------------------------
         12    Manager Decision Process for equipment access control
-----------------------------------------------------------------------------------------------------------------------------------
         13    Display of Optical Transmit Power Level
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
8.2            LOGS
-----------------------------------------------------------------------------------------------------------------------------------
         1     Alarm / Status Log
-----------------------------------------------------------------------------------------------------------------------------------
         2     Performance Log (storage capacity at least 8 x 15 min
               intervals and 30 x 24 h interval for each monitoring point)
-----------------------------------------------------------------------------------------------------------------------------------
         3     Configuration  Log (storage capacity at least 24 h)
-----------------------------------------------------------------------------------------------------------------------------------
         4     Access Control  Log (storage capacity at least 10 days)
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
8.3            REDUNDANCY
-----------------------------------------------------------------------------------------------------------------------------------
         1     Dual Power Feed
-----------------------------------------------------------------------------------------------------------------------------------
         2     1+1 Protection of Power Supply
-----------------------------------------------------------------------------------------------------------------------------------
         3     Redundancy of pump lasers
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
8.4            EQUIPMENT TESTING FUNCTIONS
-----------------------------------------------------------------------------------------------------------------------------------
         1     Integrity Check of Configuration Data
-----------------------------------------------------------------------------------------------------------------------------------
         2     Integrity Check of System Software
-----------------------------------------------------------------------------------------------------------------------------------
         3     Configuration of Loop Back on all optical Interface Cards
-----------------------------------------------------------------------------------------------------------------------------------
         4     Optical monitoring port on each transmit transponder (output
               signal)
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
         5     Optical monitoring port on each receive transponder (input
               signal)
-----------------------------------------------------------------------------------------------------------------------------------
         6     Optical monitoring port on each pre-amplifier (input signal)
-----------------------------------------------------------------------------------------------------------------------------------
         7     Optical monitoring port on each booster-amplifier (output
               signal)
-----------------------------------------------------------------------------------------------------------------------------------
8.5            INVENTORY DATA
-----------------------------------------------------------------------------------------------------------------------------------
         1     Electronic Label Read Access via Management Interfaces
-----------------------------------------------------------------------------------------------------------------------------------
         2     Automatic Electronic Label Upgrade
-----------------------------------------------------------------------------------------------------------------------------------
         3     Compatibility Check of Equipment Hardware Releases
-----------------------------------------------------------------------------------------------------------------------------------
         4     Compatibility Check of Equipment Firmware Releases
-----------------------------------------------------------------------------------------------------------------------------------
         5     Compatibility Check of Equipment Software Releases
-----------------------------------------------------------------------------------------------------------------------------------
         6     Compatibility Check of Equipment Software Releases to the
               Management System
-----------------------------------------------------------------------------------------------------------------------------------
         7     Electronic Label contents:
               - Unit hardware release / version
               - Unit hardware serial number
               - Unit firmware release / version -
               - Unit software release / version
               - Unit installation date of unit/NE -
               - Production date of unit/NE
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
9              ENVIRONMENTAL CONDITIONS, ENVIRONMENTAL COMPATIBILITY
               AND SAFETY
-----------------------------------------------------------------------------------------------------------------------------------
9.1            CLIMATIC CONDITIONS
-----------------------------------------------------------------------------------------------------------------------------------
         1     Compliance with Stationary Use Conditions acc. to prETS
               300 019-2-3 Class T 3.2
-----------------------------------------------------------------------------------------------------------------------------------
         2     No need for air conditioning via elevated ground floor
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
9.2            ELECTROMAGNETIC COMPATIBILITY
-----------------------------------------------------------------------------------------------------------------------------------
         1     Compliance with EN 55022
-----------------------------------------------------------------------------------------------------------------------------------
         2     Compliance with EN 50082
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
9.3            SAFETY
-----------------------------------------------------------------------------------------------------------------------------------
         1     CE certification available
-----------------------------------------------------------------------------------------------------------------------------------
         2     Electrical safety according to EN 41003
-----------------------------------------------------------------------------------------------------------------------------------
         3     General requirements according to EN 60950 A1, A2
-----------------------------------------------------------------------------------------------------------------------------------
         4     Fire and heat safety according to ETS 300 019-2
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
10             PHYSICAL CONSTRUCTION
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<S>      <C>   <C>                                                                     <C>  <C>   <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
CCG RFQ-ST-rfx-0005-OPTICAL ADM
-----------------------------------------------------------------------------------------------------------------------------------
(NOTE: see o.Tel.o RFI Part 4 for detailed responses to similar questions.
-----------------------------------------------------------------------------------------------------------------------------------
Additional information is available in the documents identified in the Comment colum)
-----------------------------------------------------------------------------------------------------------------------------------
PARA                                                                                   T1   T2    T3           COMMENT
-----------------------------------------------------------------------------------------------------------------------------------
         1     Rack size according to ETSI 300 119, 600 mm x 300 mm
-----------------------------------------------------------------------------------------------------------------------------------
         2     Rack size according to ETSI 300 119, 600 mm x 600 mm
-----------------------------------------------------------------------------------------------------------------------------------
         3     System installation and h/w upgrade via front access possible
-----------------------------------------------------------------------------------------------------------------------------------
         4     Number of required Racks in minimum configuration                       IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
         5     Number of required Racks in maximum configuration                       IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
11             POWER SUPPLY
-----------------------------------------------------------------------------------------------------------------------------------
         1     Nominal input voltage -48V
-----------------------------------------------------------------------------------------------------------------------------------
         2     Minimum accepted input voltage                                          IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
         3     Maximum accepted input voltage                                          IR   IR    IR
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
12             AVAILABILITY
-----------------------------------------------------------------------------------------------------------------------------------
         1     The supplier shall provide MTBF figures for each functional             IR   IR    IR
               unit of the offered equipment based on his statistical
               evaluations according to the template as attached in Annex 1
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
13             POWER CONSUMPTION
-----------------------------------------------------------------------------------------------------------------------------------
         1     The supplier shall provide worst case power consumption                 IR   IR    IR
               figures for each functional unit of the offered equipment
               according to the tem-plate as attached in Annex 1
-----------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------
14             SYSTEM MANUALS
-----------------------------------------------------------------------------------------------------------------------------------
         1     System Description in Hypertext Format on CD
-----------------------------------------------------------------------------------------------------------------------------------
         2     System O&M Manuals in Hypertext Format on CD
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                                           SPECIFICATION OF SERVICES

ID                        ST-rfx-0015
REVISION                  1.3 / APPROVED
DATE                      06 Sep 1999
CONFIDENCE                CCG CONFIDENTIAL

                          ------------------------------------------------------

AUTHOR                    Systemtechnik                  Jorg Gimmler

APPROVED                  Netzbetrieb

NOTICE                    Netzplanung

FILENAME                  Specification of Services-13

                          ------------------------------------------------------

DESCRIPTION               Attachment to the contract with supplier of DWDM and
                          SDH equipment defining all regular and optional
                          services offered by the supplier in conjunction with
                          type acceptance, installation, commissioning and
                          operation of the systems.

                          ------------------------------------------------------

CHANGE LOG                1.0 / APPROVED / 09/04/99 / J. Gimmler
                          1.1 / APPROVED / 12/04/99 / J. Gimmler, comments from
                                           Netzaufbau  inserted
                          1.2 / APPROVED / 27/08/99 / J. Gimmler, Delivery Times
                                           and Field Acceptance wording, project
                                           interfaces adapted
                          1.3 / APPROVED / 06/09/99 / J. Gimmler, Nortel Dasa
                                           Project Interface Chart inserted

                          ------------------------------------------------------

<PAGE>

TABLE OF CONTENTS

1     Scope....................................................................4
2     Definitions and Abbreviations............................................5
   2.1   Definitions...........................................................5
   2.2   Abbreviations.........................................................6
3     Project Management.......................................................7
   3.1   Project Management Manual.............................................7
   3.2   Contract Plan.........................................................7
   3.3   Reporting.............................................................7
      3.3.1   Product Creation Report..........................................7
      3.3.2   Project Implementation Report....................................7
   3.4   Assigned Key Persons..................................................7
   3.5   Project Meetings......................................................9
      3.5.1   Project Review Meetings..........................................9
      3.5.2   Project Implementation Review Meetings...........................9
      3.5.3   Commercial Meeting..............................................10
      3.5.4   Technical Review Meetings.......................................10
4     Type Acceptance.........................................................11
   4.1   General..............................................................11
   4.2   Type Acceptance Procedure............................................11
      4.2.1   Type Acceptance Documentation...................................11
      4.2.2   Acceptance Test in Test Floor...................................14
      4.2.3   Acceptance on First Site........................................14
      4.2.4   Handling of Deficiencies........................................15
   4.3   Type Acceptance Certificate..........................................16
   4.4   Type Acceptance Fail.................................................16
   4.5   Type Modifications...................................................16
5     Regular Services........................................................17
   5.1   Ordering.............................................................17
   5.2   Delivery Times.......................................................17
      5.2.1   Without Forecast................................................17
      5.2.2   With Forecast...................................................17
   5.3   Goods Installation...................................................18
      5.3.1   General.........................................................18
      5.3.2   Site Survey.....................................................18
      5.3.3   Preparation of Site.............................................18
      5.3.4   System Installation.............................................18
      5.3.5   Installation Documentation......................................19
      5.3.6   Commissioning...................................................19
   5.4   Field Acceptance.....................................................19
      5.4.1   General.........................................................19
      5.4.2   Field Acceptance Documentation..................................20
      5.4.3   Field Acceptance Certificate....................................20
      5.4.4   Field Acceptance Fail...........................................20
   5.5   Training.............................................................20
      5.5.1   General.........................................................20
      5.5.2   Network Operation...............................................20
      5.5.3   System Administration and Maintenance...........................21
6     Maintenance Services....................................................22
   6.1   General..............................................................22
      6.1.1   Classification of Problems......................................22
      6.1.2   Problem Reporting...............................................23
   6.2   Help Desk Services...................................................23

<PAGE>

   6.3   Replacement Service..................................................24
      6.3.1   General.........................................................24
      6.3.2   Replacement Procedure...........................................24
      6.3.3   12 hours Replacement Service....................................24
      6.3.4   24 hours Replacement Service....................................24
   6.4   Corrective Maintenance Service.......................................24
      6.4.1   General.........................................................24
      6.4.2   Time to Repair..................................................25
   6.5   Onsite NMC-Support...................................................25
   6.6   De-Installation......................................................25
7     Quality Assurance.......................................................26
   7.1   Project Management System............................................26
   7.2   Quality Plan.........................................................26
   7.3   Quality Audits.......................................................26
   7.4   Fault History System.................................................26
8     Time Schedules..........................................................27
   8.1   Type Acceptance......................................................27
      8.1.1   Type Acceptance Preparation.....................................27
      8.1.2   Type Acceptance Testing.........................................29

--------------------------------------------------------------------------------

1

<PAGE>

SCOPE

This document specifies all regular and optional services offered by the
supplier in connection with the installation, commissioning and operation of SDH
and DWDM systems.

All services described herein are deemed to be regular services unless
explicitly stated otherwise in this document.

This document is an attachment to the main part of the contract between CCG and
its supplier for SDH-systems. The services described herein are relating to all
systems and components ordered by CCG in the frame of this contract unless
explicitly stated otherwise in this document. 2 DEFINITIONS AND ABBREVIATIONS

<PAGE>

3        DEFINITINS AND ABBREVIATIONS

3.1      DEFINITIONS

Acceptance                         Acceptance shall mean a written declaration
                                   that a particular portion of the Seller's
                                   work has been successfully completed.

Date of Contract                   Date of Contract shall mean the date the
                                   Contract is executed.

Installation                       Installation shall mean materials, labour,
                                   testing and anything else necessary to be
                                   provided or undertaken by the Seller under
                                   the Contract to enable the System to be
                                   installed Ready for Acceptance.

Network Element                    A Network Element shall mean any multiplexer,
                                   cross connect or repeater.

Product Creation                   Product Creation shall mean the process of
                                   product specification and development
                                   including the Seller's System test.

Quality Plan                       Quality Plan shall mean the document setting
                                   out specific quality practices, resources and
                                   sequence of activities relevant to the
                                   tendered goods and services in accordance
                                   with ISO 9001.

Type                               Type shall mean a set of Network Elements or
                                   a Network Management System based on the same
                                   set of hardware, firmware, software and
                                   documentation. A Type is described by the
                                   corresponding Type Acceptance handbook.

Type Modification                  Type Modification shall mean any modification
                                   of a Type after Type Acceptance as requested
                                   by the Seller by change request and agreed by
                                   CCG.

1.

2.                                 Ready for Type   Acceptance Ready for Type
                                   Acceptance shall mean the date at which all
                                   tasks have been finalised to start Type
                                   Acceptance Testing in the test floor.

3.

4.                                 Regression Testing   Regression Testing shall
                                   mean testing of the correct functionality of
                                   a selected range of the features of a
                                   previous Type included in the new Type.

5.

6.                                 Site   Site shall mean land, buildings and
                                   environment where the System shall be
                                   installed.

7.

8.                                 Site Ready for Acceptance   Site Ready for
                                   Acceptance shall mean the date on which all
                                   tasks have been finalised by the Seller so
                                   that Field Acceptance Testing can commence.

9.

10.                                Site Ready for Installation   Site Ready for
                                   Installation shall mean that CCG has
                                   finalised all work on Site so that
                                   implementation can commence.
11.

<PAGE>

3.2      ABBREVIATIONS

BAPT              Bundesamt fur Post und Telekommunikation

BZT               Bundesamt fur Zulassung in der Telekommunikation

DC                Deficiencies Cleared

EMS               Element Management System

FA                Field Acceptance

FAC               Field Acceptance Certificate

FAT               Field Acceptance Test

IMS               Integrated Management System

LMT               Local Maintenance Terminal

MTBF              Mean Time Between Failures

MTTR              Mean Time To Repair

NE                Network Element

SFD               System Feature Description

SS                Site Survey

SSA               Site Survey Announcement

SRI               Site Ready for Installation

SRIA              Site Ready for Installation Announcement

SRA               Site Ready for Acceptance

SRAA              Site Ready for Acceptance Announcement

t                 Working Day

TA                Type Acceptance

TAC               Type Acceptance Certificate

TRA               Type Ready for Acceptance

TRFR              Type Ready for Rollout

w                 5 working days

<PAGE>

4        PROJECT MANAGEMENT

4.1      PROJECT MANAGEMENT MANUAL

1.  The Seller shall submit a Project Management Manual containing details on
    the management structure, procedures to be followed for planning, monitoring
    and reporting of any kind of work from the Seller.

4.2      CONTRACT PLAN

1.  The Seller shall provide a contract plan. The Seller and CCG shall agree on
    the contract plan which describes the work breakdown structure identifying
    and relating hierarchically all technical and management work packages
    required to perform the scope of work defined in the contract and detailing
    responsibilities, all time frames and interfaces for all services specified
    in this document.

2. The contract plan shall relate the work packages to a milestone plan.

4.3      REPORTING

4.3.1    PRODUCT CREATION REPORT

2.  The product creation reports shall be prepared on a quarterly basis. The
    product creation reports shall reach CCG the first Monday of the quarter.

4.3.2    PROJECT IMPLEMENTATION REPORT

1.  The Seller shall prepare Project Implementation Reports comprising all
    project progress information. The project implementation report shall

        -  show delivery dates per Site and any anticipated delivery delays,
        -  clearly work out all non performance of the Seller by providing
           statements to each single milestone
        -  provide decision proposals for solving actual and potential future
           problems.

2.  The Seller shall issue the project implementation reports on a bi-weekly
    basis. The project implementation reports shall reach CCG Mondays.

3. The Seller shall provide CCG with invoice and payment summaries in agreed
   format on a monthly basis.

4.4      ASSIGNED KEY PERSONS

1.  The Seller shall nominate a senior management representative who shall have
    the authority to commit any resource necessary to ensure timely performance
    of the work in accordance with the contract, regardless of the part of the
    company's organisation in which the resource is deployed.

2.  The Seller shall nominate one project implementation manager who shall be
    the primary contact person between the Seller and CCG. The project manager
    shall have the responsibility for resolution of all issues arising from the
    contract, including commercial, ordering and manufacture issues, System
    engineering, installation, commissioning, project and product documentation,
    progress reporting, training, maintenance, repair and quality assurance.

3.  The Seller shall nominate a reasonable number of regional engineers
    reporting to the Seller's project implementation manager. The regional
    engineers shall support the project manager for handling all

<PAGE>

    regional affairs of System engineering, installation, commissioning, project
    and product documentation, project reporting, maintenance, repair and
    quality assurance.

4.  The Seller shall appoint a technical manager with overall responsibility for
    all technical features of any offered product.

5.  The Seller shall appoint a commercial manager as contact person for CCG's
    finance/controlling department. The commercial manager shall be responsible
    for handling all main pricing and penalty issues.

<PAGE>

4.5      PROJECT MEETINGS

                              [GRAPHIC]

                         FIGURE 1: PROJECT MEETINGS

4.5.1    PROJECT REVIEW MEETINGS

1.  The meeting shall address commercial, technical and project implementation
    related issues of general interest.

2. The project review meeting shall be held on regular intervals as required by
   CCG.

3.  The project review meeting shall be attended by the authorities responsible
    for technical issues and by project implementation managers of both parties.

4. The project review meeting shall be chaired by the CCG heading project
   manager.

5.  The minutes of the review meeting shall be recorded by the Seller and
    distributed when CCG has agreed on the content within 3 days.

4.5.2    PROJECT IMPLEMENTATION REVIEW MEETINGS

1.  The meeting shall address the progress of the Seller in performing the
    activities identified in the contract plan.

2.  The project implementation review meetings shall be held at reasonable
    regular intervals as required by CCG.

3. The project review meeting shall be attended by the project implementation
   managers of both parties.

4. The meeting shall be chaired by the CCG project implementation manager.

<PAGE>

5.  Not later than one week in advance of the project implementation review
    meeting the Seller shall submit in writing to the CCG project implementation
    manager the project report to identify the work progress.

6.  The minutes of the review meeting shall be recorded by the Seller and
    distributed when CCG has agreed on the content within 3 days

4.5.3    COMMERCIAL MEETING

1. The meeting shall address all main issues concerning pricing, penalties and
   invoicing.

2. The commercial meetings shall be held as required by CCG.

3. The commercial meeting shall be attended by the commercial managers of both
   parties.

4. The meeting shall be chaired by the CCG commercial manager.

5.  The minutes of the commercial meeting shall be recorded by the Seller and
    distributed when CCG has agreed on the content within 3 days.

4.5.4    TECHNICAL REVIEW MEETINGS

4.5.4.1  PRODUCT STATUS MEETING

1.  The product status meeting shall address the progress of all product
    technical issues up to the product Type Acceptance.

2.  The product status meetings shall be held at reasonable regular intervals as
    required by CCG, typically on a monthly basis.

3. The product status meeting shall be attended by the technical managers of
   both parties.

4. The meeting shall be chaired by the CCG technical manager.

5.  The minutes of the meeting shall be recorded by the Seller and distributed
    when CCG has agreed on the content within 3 days.

3.5.4.2  TYPE ACCEPTANCE REVIEW MEETING

1. The meeting shall address all Type Acceptance related technical issues.

2.  Type Acceptance review meetings shall be held at reasonable regular
    intervals as required by CCG during the entire Type Acceptance process.

3.  The Seller shall name one Type Acceptance project leader as key contact
    person for handling all Type Acceptance related issues during all Type
    Acceptance phases. He shall carry out all official correspondence concerning
    the Type Acceptance.

4.  The Seller shall name an appropriate number of experts who shall accompany
    all phases of the Type Acceptance process.

5.  The Type Acceptance review meeting shall be attended by the Seller's Type
    Acceptance project leader, the Seller's experts accompanying the Type
    Acceptance procedure and the relevant CCG staff involved in the Type
    Acceptance.

6. The meeting shall be chaired by the CCG authority responsible for Type
   Acceptance.

7.  The minutes of the Type Acceptance review meeting shall be recorded by the
    Seller and distributed when CCG has agreed on the content within 3 days.

<PAGE>

6        TYPE ACCEPTANCE

Please note that this specification may not apply at full extend for the
initial implementation project. 4.1 GENERAL

1. The Seller shall verify together with CCG the functionality of the offered
   Type
         - prior to first implementation in CCG Network, or
         - if changes in form, fit and function have been made.

2. The Type Acceptance test shall include but not be restricted to the following
   test areas:
         - completeness with respect to the Type documentation,
         - correctness of Network Element upgrade documentation,
         - regression tests,
         - new functionality with respect to the previous Type,
         - interworking with previous Types,
         - compatibility to other accepted Network Element Types,
         - conformance to CCG specifications, standards which the relevant CCG
           specifications refer to, and other general standards deemed to be
           mandatory by CCG.

4. The Seller shall provide best support for the preparation of Type Acceptance.
5. The Seller shall accompany the Acceptance Test and show that the product
    development and production has been conducted according to agreed
    specifications and requirements.

6.2      TYPE ACCEPTANCE PROCEDURE

6.2.1    TYPE ACCEPTANCE DOCUMENTATION

                              [GRAPHIC]

                     FIGURE 2: TYPE DOCUMENTATION OVERVIEW

<PAGE>

6.2.1.1    GENERAL DOCUMENTATION

1.  The Seller shall provide the information listed in this paragraph not later
    than 6 months prior to Ready For Type Acceptance. For the initial type
    acceptance the Seller shall provide the information right after signing the
    Contract.

6.2.1.1.1  FUNCTIONAL DESCRIPTION
1. The Seller shall provide a detailed system description of the type under
   test.

2. The Seller shall provide a complete system operation & maintenance handbook
   for the Type under test.

3. The Seller shall provide a complete network operation handbook of the type
   under test.

6.2.1.1.2  FEATURE LIST
1.  The Seller shall provide a list of all new features of the Type under test
    with respect to a previous Type.

2.  The Seller shall provide a list of all enhancements of the Type under test.
    Reference shall be made if the enhancement corresponds to an item on a
    deficiency list of a previous Type.

6.2.1.1.3  SYSTEM TEST SPECIFICATION
1. The Seller shall send to CCG his released System test specification for the
   Type under test.

6.2.1.1.4         LIST OF COMMITTED MISSING FEATURES
1.  The Seller shall provide a list of missing features which have been
    committed for the Type under test.

6.2.1.1.5         SYSTEM UPGRADE INFORMATION
1.  The Seller shall provide detailed information on the procedure to upgrade
    previous releases to the Type under test.

6.2.1.2  DETAILED DOCUMENTATION

1.  The Seller shall provide his information listed in this paragraph not later
    than 30 days prior to Ready for Type Acceptance.

6.2.1.2.1  TYPE ACCEPTANCE TEST SPECIFICATION
1.  CCG will prepare a list of requirements which shall be performed as part of
    the Type Acceptance test. The Seller agrees that the Type Acceptance tests
    will be performed on the basis of this Type Acceptance test specification.

2.  CCG will finalise the preparation of the Type Acceptance test specification
    for the relevant Type not later than 10 weeks prior to Ready For Type
    Acceptance.

3.  The Seller shall check the Type Acceptance specification and shall agree on
    it prior to preparation of the Type Acceptance Test procedures.

2.1.2.2    SPECIFICATION OF TYPE ACCEPTANCE TEST PROCEDURES
1.  The Seller shall provide a specification of test procedures based on the
    Type Acceptance test specification of CCG. Such procedures shall also list
    the expected test results in detail.

2.  The Seller shall provide a draft Specification of Type Acceptance test
    Procedures not later than four weeks after having received the Type
    Acceptance Test Specification from CCG.

3.  If CCG finds tests to be insufficient the Type Acceptance test specification
    will be amended by CCG. The Seller shall prepare corresponding test
    procedures and shall agree those with CCG prior to the planned commencement
    of Acceptance testing.

<PAGE>

6.2.1.2.3  FIELD ACCEPTANCE TEST SPECIFICATION
1.  CCG will prepare a list of requirements which shall be performed as part of
    the Field Acceptance test. The Seller agrees that the Field Acceptance tests
    will be performed on basis of this Field Acceptance test specification.

2.  CCG will finalise the preparation of the Field Acceptance test specification
    for the relevant Type not later than 10 weeks prior to Ready For Type
    Acceptance.

3.  The Seller shall check the Field Acceptance test specification and shall
    agree on it prior to preparation of the specification of test procedures.

4.2.1.2.4  SPECIFICATION OF FIELD ACCEPTANCE TEST PROCEDURES
1.  The Seller shall provide a specification of Field Acceptance test procedures
    based on the test specification of CCG. Such procedures shall also list the
    expected test results in detail.

2.  The Seller shall provide a draft Specification of Field Acceptance test
    procedures not later than four weeks after having received the Field
    Acceptance test specification from CCG.

3.  If CCG finds tests to be insufficient the Field Acceptance test
    specification will be amended by CCG. The Seller shall prepare corresponding
    test procedures and shall agree those with CCG prior to the planned
    commencement of field Acceptance testing.

6.2.1.2.5  DEFICIENCY LIST
1.       The  Seller shall provide sufficient information about:

         -  missing features to fully comply with the functionality committed
            for the Type under test,

         -  all detected new or still existing bugs and deficiencies,

         -  any additional bugs or inconsistencies found during Type Acceptance
            shall amend the deficiency list,

         -  any features deemed to require modification shall amend the
            deficiency list.

6.2.1.2.6  LIST OF BUILD LEVELS
1.  Prior to the start of Type Acceptance test the Seller shall provide complete
    documentation of the compatible hardware, firmware and software build level
    providing the full set of features of the relevant Type under test.

6.2.1.2.7  LIST OF EXEMPTIONS
1. A list of exemptions shall be agreed between Seller and CCG.

2.  The list of exemptions shall contain those items which cannot be tested at
    the time of Type Acceptance test execution.

3. The exemptions list shall be part of the Type Acceptance handbook.

4. The Type Acceptance does not apply to features listed on the exemptions list.

5.  Type Acceptance test of items on the exemptions list will be executed as
    soon as the test becomes feasible.

6.2.1.3  TYPE ACCEPTANCE HANDBOOK

1. The Seller shall be responsible for compiling the Type Acceptance handbook.

2.  The content shall be approved by signature of the Seller and CCG after
    having passed the Type Acceptance testing.

3. The Type Acceptance handbook shall include but shall not be restricted to:

   -  the signed agreement to the Type Acceptance handbook from the Seller and
      CCG,

<PAGE>

   -  a reference to a corresponding feature list,

   -  a reference to the functional System description,

   -  a reference to the System upgrade information (where applicable),

   -  the list of build levels,

   -  the list of exemptions,

   -  the specification of Type Acceptance test procedures and its summary,

   -  the field Acceptance test specification and its summary,

   -  the specification of field Acceptance test procedures and its summary,

   -  the Acceptance test protocols,

   -  the list of non-blocking deficiencies,

   -  the Network Operation Handbook

   -  the System Description

   -  the System Operation & Maintenance Handbook

6.2.2    ACCEPTANCE TEST IN TEST FLOOR

1.  The Type Acceptance test shall be performed in the Seller's test floor, or
    if required by CCG, in CCG's test floor.

2. The Seller shall provide the system test configuration as specified by CCG.

3.  The Seller shall provide all necessary tools and test equipment for carrying
    out the Type Acceptance Tests.

4.  The test environment, the system test configuration, the tools and test
    equipment shall be consistent with what has been specified by CCG.

5.  The test environment, the system test configuration, the tools and test
    equipment shall be fixed in the specification of test procedures.

6. All results of the Type Acceptance tests shall be recorded in a Type
   Acceptance test protocol.

6.2.3    ACCEPTANCE ON FIRST SITE

1.  The Acceptance on first site shall be handled as part of the Type Acceptance
    procedure. It may be conducted on an implemented subnetwork under controlled
    operational conditions.

2. The Acceptance test on first Site shall be conducted for testing the

         -  interworking with CCG network.
         -  error free System operation during a certain observation period.

3. The Seller shall provide all necessary tools and test equipment.

4.  The test environment and measurement equipment shall be fixed in the
    specification of test procedures.

5.  Unless required otherwise by CCG, the Acceptance test on First Site shall
    not start before the Type Acceptance in test floor has been passed and clear
    criteria for deficiencies detected in the test floor phase of Type
    Acceptance have been defined.

6.  The Acceptance on first site shall include an evaluation phase to define
    clear criteria of deficiencies for certification of Acceptance.

7.  Type Acceptance will only be certified when all clear criteria for
    certification of Field Acceptance on first site have been fulfilled.

8. During Acceptance test on first site an Acceptance test protocol shall be
   prepared.

<PAGE>

6.2.4    HANDLING OF DEFICIENCIES

1.  All deficiencies detected during the type acceptance test will be documented
    by CCG in its own problem report handling tool (PRDB).

2.  CCG will assign classes to each deficiency listed in the PRDB. The assigned
    priorities will be agreed between the Seller and CCG. In case of
    disagreement the assigned priority by CCG shall prevail.

3.  The Seller shall document its statements and activities as to the deficiency
    clearing in the PRDB. For this purpose gets access to the PRDB.

4.  The Seller shall keep CCG informed of all deficiency clearing activities via
    the PRDB until the deficiencies are removed.

6.2.4.1  DEFICIENCY CLASSES

6.2.4.1.1  BLOCKING DEFICIENCIES (CLASS 1)
1.  Class 1 deficiencies shall be those which results in a degradation or loss
    of transmission services.

2.  Class 1 deficiencies shall block the Type Acceptance. Removal of Class 1
    deficiencies shall be prerequisite to start Field Acceptance testing on 1st
    site.

3.  For Class 1 deficiencies written response time shall be 5 days.

4.  For Class 1 deficiencies removal shall happen within 10 days.

6.2.4.1.2         CRITICAL DEFICIENCIES (CLASS 2)
1.  Class 2 deficiencies shall be those which results in a severe degradation or
    loss of the manageability of the Type under test.

2.  Class 2 deficiencies shall block the Type Acceptance upon decision of CCG.
    Removal of blocking Class 2 Deficiencies shall be prerequisite to start
    Field Acceptance testing.

3.  For Class 2 deficiencies written response time shall be 10 days.

4.  For Class 2 deficiencies removal shall happen within 20 days.

6.2.4.1.3  MAJOR DEFICIENCIES (CLASS 3)
1.  Class 3 deficiencies shall be those which are causing additional effort
    concerning operation and maintenance for the Type under test.

2.  Class 3 deficiencies shall not block the Type Acceptance.

3.  For Class 3 deficiencies written response time shall be 20 days.

4.  For Class 3 deficiencies removal shall happen within 60 days.

6.2.4.1.4  MINOR DEFICIENCY (CLASS 4)
1.  Class 4 deficiencies shall be those which will have no impact neither on
    services nor on operation and maintenance.

2. Class 4 deficiencies shall not block the Type Acceptance.

3.       For Class 4 deficiencies written response time shall be 20 days.

4. For Class 4 deficiencies removal shall happen within the next CCG release.

<PAGE>

6.3      TYPE ACCEPTANCE CERTIFICATE

1.  The Type Acceptance tests shall be completed when the system type is
    successfully implemented in the network and all acceptance blocking
    deficiencies have been solved.

2.  As soon as the Type Acceptance tests have been completed CCG will issue a
    certificate of Type Acceptance (FAC) to the Seller.

6.4      TYPE ACCEPTANCE FAIL

1.  If the Type Acceptance fails, the Seller shall forthwith implement free of
    charge alterations or modifications to the work as it is necessary to repeat
    the final acceptance as soon as the deficiencies are removed.

6.5      TYPE MODIFICATIONS

1.  After the initial Type Acceptance the Seller shall send for any modification
    of a system component (i.e. changes in the HW- or SW-status) a type
    modification request to CCG.

2. The type modification request shall include:

         o description of the reason for modification, impacted units and
           components,
         o description of the modification, impacted units and components,
         o a cross reference to CCG's problem reports (if any),
         o implementation instructions.

3.  If the type modification request reveals any risk of changes in form, fit or
    function the Type Acceptance of the respective unit type shall be partly or
    completely repeated on request of CCG.

4.  CCG will officially release the modified unit type for its network not later
    than 6 months after the receipt of the respective type modification request
    provided that the repetition of the Type Acceptance (if requested by CCG)
    has been successful.

5.

7

<PAGE>

8        REGULAR SERVICES

8.1      ORDERING

1.  The Seller shall provide the means to order systems on unit level without
    detailed knowledge of the system design and system configuration rules.

2.  CCG will send to the Seller for each site a binding purchase order including
    purchase order number plus a Requisition Data Sheet containing all necessary
    information for initiating the System delivery and installation process at
    the Seller.

3.  CCG will provide all necessary information to enable the Seller to review
    the capability of the System planned to be ordered. The Seller shall review
    the information immediately. The Seller shall then clarify inconsistencies
    or ask for missing information within two days.

4.  In the Requisition Data Sheet CCG will state the requested date of Ready for
    Acceptance (RfA). CCG may prolong this date up to a time of 6 months. If
    this period elapse the ordered Hardware and Software will be delivered and
    invoiced to CCG. Respective services such as installation will not be
    invoiced.

5.  CCG may want to modify Requisition Data Sheets during the ordering phase.
    The Seller and CCG will handle such modifictions on a case by case basis.
    Each modification has to be confirmed by an official purchase order.

8.2      DELIVERY TIMES

1.  Delivery time is the time from order received by the Seller to the
    successful completion of the respective Field Acceptance test or - in case
    of deliveries only - to the date of completed delivery to CCG's site.

2.  For orders placed after 09/1999, the figures mentioned under para. 5.2 shall
    be considered as target figures, matter of mutual agreement between the
    seller and CCG.

8.2.1    WITHOUT FORECAST

1.  For those parts of orders exceeding the volumes states in the current
    forecast the Seller guarantees delivery times as stated in the table below.

    ----------------------------------------------------------------------------
       ORDER TYPE                                LEAD TIME
                      ----------------------------------------------------------
                      FROM ORDER RECEIPT    FOR FIELD ACCEPTANCE   FOR COMPLETE
                        TO READY FOR              TEST              DELIVERY
                         ACCEPTANCE
    ----------------------------------------------------------------------------
    complete system      8 weeks                1-3 weeks         9-11 weeks
    ----------------------------------------------------------------------------
    plug-in-units        2 weeks                 1 week            3 weeks
    ----------------------------------------------------------------------------
8.2.2    WITH FORECAST

1.  For those parts of the orders that are within the volumes stated in the
    current forecast the Seller guarantees delivery times as stated in the table
    below.

2.  The forecast shall be a non-binding rolling forecast covering the period of
    the following 6 months stating the expected order volumes for each calendar
    month in the considered period. The forecast shall be updated on a monthly
    basis. The volumes for the first 2 months stated in the updated forecast
    shall not be changed against the corresponding volumes stated the previous
    forecast.

    ----------------------------------------------------------------------------
             ORDER TYPE                          LEAD TIME
    ----------------------------------------------------------------------------

<PAGE>

                       FROM ORDER RECEIPT   FOR FIELD ACCEPTANCE   FOR COMPLETE
                          TO READY FOR              TEST             DELIVERY
                           ACCEPTANCE
    ----------------------------------------------------------------------------
    complete system         3 weeks              1-3 weeks          4-7 weeks
    ----------------------------------------------------------------------------
8.3      GOODS INSTALLATION

8.3.1    GENERAL

1.  The Seller shall be responsible for keeping the System up to date until the
    acceptance has been achieved.

2.  CCG shall have the right to be present and shall be free to carry out
    surveillance at all stages of delivery and installation.

3.  The Seller shall supply all tools and test equipment for his use during
    installation and commissioning.

8.3.2    SITE SURVEY

1. The Seller and CCG shall commonly attend the Site Survey.

2.  The announcement for Site Survey shall be sent to the Seller not later than
    one week prior to its execution.

3.  During the site survey the Seller shall be obliged to identify all action
    items to be done by CCG in order to allow CCG to fulfil his obligation for
    reaching Site Ready For Installation. The Seller and CCG will agree on all
    action items directly on Site.

8.3.3    PREPARATION OF SITE

1.  CCG will be responsible for preparing the Site.

2.  The site shall not deemed ,,Ready for Installation" unless the following
    prerequisites are fulfilled by CCG:

         -  power supply available

         -  grounding points available

         -  connection plan plan

         -  DCN-connections available

         -  floorplan available

         -  access to the site for installation, commissioning and acceptance
             test purposes during normal working hours and - if agreed with
             CCG - at other times.

         -  contact person from CCG available for clarification of details as
            to site access and installation.

         -  completion of all civil works impacting installation and operation
            of the systems.

3.

4.  CCG shall declare ,,Site Ready for Installation" (SRI) not later than 2
    weeks before required ,,Ready for Acceptance" (RfA) date. In case the
    announcement ,,Ready for Installation" is delayed by CCG the RFA date will
    be postponed accordingly.

8.3.4    SYSTEM INSTALLATION

1.  The Seller shall be responsible for properly installing all Systems
    delivered by the Seller. This includes neccessary cabling to network
    interfaces and distribution frames, earthing and interfacing to the power
    feeds in the equipment room.

<PAGE>

2.  The Seller shall install the equipment according to the installation
    guidelines as per contract document "Allgemeine Richtlinie zum Aufbau von
    Prasenzlokationen", "Richtlinie zum Aufbau von Signalverteilern" und
    "Richtlinie zu Kabellangen".

3.  The Seller must be aware that work may be carried out on a non CCG Site. In
    this case special conditions and standards may apply.

8.3.5    INSTALLATION DOCUMENTATION

1.  The Seller shall deliver full installation documentation as defined in the
    document ,,Lieferumfang Aufbaudokumentation".

8.3.6    COMMISSIONING

8.3.6.1  GENERAL

1. The System commissioning shall be under full responsibility of the Seller.

2. Commissioning tests shall be carried out on all installed systems supplied
   under the Contract.

3. All units installed for commissioning shall be of the latest relevant build
   level accepted by CCG unless explicitly requested otherwise by CCG.

4. The Seller shall perform the commissioning of the systems on basis of his
   own commissioning procedures. The Seller shall make this procedures
   available for CCG as soon as the Contract is signed. On request of CCG the
   Seller is obliged to amend or change the procedures.

5. Any modifications in the commissioning procedures have to be agreed by CCG.

8.3.6.2  TOOLS AND TEST EQUIPMENT FOR COMMISSIONING

1.  The Seller shall be responsible for supply of tools and test equipment
    necessary for his use during the commissioning phase.

2. The Seller shall list all tools and test equipment in all appropriate
   commissioning specifications.

8.4      FIELD ACCEPTANCE

8.4.1    GENERAL

1.  The Seller shall provide any support for preparation of and shall accompany
    the Field Acceptance test to show that the integration into the CCG network
    has been conducted according to agreed specifications and requirements.

2.  The Type Acceptance shall be prerequisite for the Field Acceptance unless
    otherwise requested by CCG. The initial network implementation phase in 1999
    is regarded as exceptional case.

3.  The Field Acceptance shall be carried out for each single Network Element.
    The initial network implementation phase in 1999 will also focus on network
    testing.

4.  The  Seller shall give notice to CCG 1 (one) week prior to Site Ready For
    Acceptance.

5.  The Field Acceptance test will be carried out within 1 (one) week after
    Ready for Acceptance and if requested by CCG - may be extended by a
    stability test period of up to two weeks duration. Exceptions may apply
    during the initial network implementation phase in 1999.

6.  All deficiencies detected during the Field Acceptance test shall be cleared
    1 (one) week after start of Field Acceptance latest.

<PAGE>

8.4.2    FIELD ACCEPTANCE DOCUMENTATION

8.4.2.1  FIELD ACCEPTANCE HANDBOOK

1. The Seller shall be responsible for compiling a Field Acceptance Handbook.

2. The Field Acceptance Handbook shall include but not be restricted to the

         -  Field Acceptance Certificate,

         -  detailed test procedures,

         -  field Acceptance test protocol.

8.4.3    FIELD ACCEPTANCE CERTIFICATE

1.  The Field Acceptance tests shall be completed when the system is
    successfully implemented in the network and all acceptance blocking
    deficiencies have been solved.

2.  After Field Acceptance is successfully completed, CCG will issue a Field
    Acceptance Certificate to the Seller.

8.4.4    FIELD ACCEPTANCE FAIL

1.  If the Field Acceptance fails the Seller shall forthwith implement free of
    charge alterations or modifications to the work as it is necessary to repeat
    the Field Acceptance test within 5 days of notification of the failure.

8.5      TRAINING

8.5.1    GENERAL

1. The Seller shall provide training courses for all his offered products.

2.  The Seller shall provide training at the Seller's or CCG's premises. The
    location for training will be chosen on a case by case basis by CCG.

3. The Seller shall have sufficient training capacity to fulfill the
   requirements of CCG.

4. The Seller shall offer separate training courses for each offered system
   family.

5. The lead time for booking of training does not exceed 4 weeks.

6. The Seller shall provide training documentation at least 2 weeks before
   start of the training course.

7. The Seller shall agree with CCG the contents of the courses prior to its
   beginning.

8.  If required by CCG the Seller shall train third party personal on the
    maintenance and/or operation of the Seller's systems.

8.5.2    NETWORK OPERATION

1.  The Seller shall provide operator training seminars which shall put the
    trained staff into the position to operate the transmission network based on
    the Seller's products.

2.  The training courses shall consist of a theoretical and a practical part.
    The theoretical part shall provide essential theoretical technical
    information of the System. The practical training shall cover all areas of
    operation (configuration management, fault management, performance
    management, accounting management, security management and system
    administration). CCG staff shall be especially trained on emergency
    procedures for specific fault situations.

3.  The seller shall provide an appropriate test system configuration where the
    practical part of the training can be carried out in a real-time
    environment.

<PAGE>

8.5.3    SYSTEM ADMINISTRATION AND MAINTENANCE

1.  CCG will nominate Network Management System Administrators. These persons
    shall be sufficiently trained for this function by attending appropriate
    System administration training courses.

2.  The System maintenance training provided for CCG staff shall enable CCG to
    control maintenance services by the Seller and also to fulfill tasks that
    are complementary to the maintenance services of the Seller.

9

<PAGE>

10       MAINTENANCE SERVICES

This section specifies the optional maintenance support service parameters
required from the Seller.

10.1     GENERAL

1.  The Seller shall be responsible for maintenance of all hardware and software
    delivered by the Seller. On request of CCG the maintenance services may be
    restricted to a certain part of the delivered hardware and software. The
    part the maintenance services applies to is determined by CCG.

2.  In case the Seller supplied goods of third parties, the Seller's maintenance
    shall include services offered by the third party. In this case, the Seller
    shall provide all necessary information on the installed hardware, firmware
    and software in order to enable the third party to fulfill the maintenance
    task in the same quality as the Seller.

3. The Seller shall be willing to optionally provide maintenance services for
   other vendor's Systems.

4.  The Seller shall be willing that maintenance services for his Systems are
    optionally provided from other vendors.

5.  The Seller shall provide information to his maintenance concept which shall
    include but not be restricted to

         -  the proposed spare stock model taking into consideration equipment
            reliability, equipment population and stock-out risk,
         -  the ratio of spare unit numbers exclusively stored,
         -  the number and experience of staff proposed to exclusively working
            for CCG for maintenance purposes,
         -  the number of distributed maintenance centres,
         -  the procedure for cyclic spare part tests on central and
            distributed spare stocks (benchmark tests),
         -  the type and number of test equipment required for maintenance
            purposes,
         -  the logistic concept,
         -  his reporting system which includes all datas about Sellers network
            elements used in other transmission networks (e.g. real MTBF,
            failures reasons, measures to reduce failures),
         -  reference information about supplier's maintenance projects of
            similar size.

6.  CCG has the option to choose different Maintenance Services as described in
    the sections 6.2, 6.3, 6.4 and 6.5.

10.1.1   CLASSIFICATION OF PROBLEMS

1.  The classification of all problems shall be in accordance with the following
    guide lines. The classification of an actual problem will be agreed between
    the Seller and CCG. In case of disagreement the classification by CCG shall
    prevail.

10.1.1.1 REAL-TIME EMERGENCY (A)

1.  A Priority (A) problem shall be any hardware or software problem

         -  resulting in loss or degradation of service, or

         -  resulting in loss or degradation of the surveillance of the
            network, or

         -  impacting the network security.

2.

<PAGE>

10.1.1.2  REAL-TIME URGENT (B)

1.  A Priority (B) problem shall be any hardware or software problem not
    classified as (A)

          -  resulting in a loss or degradation of  the managebility of the
             network, or

          -  impacting the data integrity, or

          -  requiring real-time technical assistance.

10.1.1.3  REAL-TIME NON-URGENT (C)

1.  A Priority (C) problem shall be any low level hardware, software or
    documentation problem not classified as (A) or (B).

10.1.2    PROBLEM REPORTING

1.  The Seller shall own and maintain problem reporting tools. CCG will get all
    CCG specific information out of these tools.

2. Problems investigated under this service shall include, but not be limited to
   the following:

          -  Defects in the System hardware and software.
          -  Anomalies where the product does not meet the contractually
             specified performance,
          -  Anomalies where the operational reliability of the product has
             fallen below the contractually agreed MTBF,
          -  Anomalies where the supplier has used a component or manufacturing
             process which introduces systematic failure necessitating remedial
             action,
          -  Problems caused by operations, maintenance, training or training
             documentation,

3.  The Seller shall analyse each incoming formal report to check whether the
    contents are sufficient for an investigation to take place.

4.  If the contents are insufficient, the Seller shall specify precisely what is
    required and then refer to the originator within agreed time scales.

5.  The Seller shall report progress on each formally reported operational
    problem within agreed time scales.

6. The problem report shall be provided free of charge as long as the equipment
   is in use by CCG.

10.2    HELP DESK SERVICES

1. The Seller shall provide a telephone support within 30 minutes after having
   received the request for Help Desk Service.

2. The Seller shall provide a support service covering operational problems
    which shall include, but not be limited to:

         -  General advice and guidance,
         -  Advice indicating possible causes of software or hardware problems
            and if determined to be a known problem, whether a proven solution
            exists.
         -  Advice on proven procedural solutions that can be followed to
            alleviate the impact of a problem.
         -  Resolution of local problems that cannot be solved using standard
            procedures.
         -  Enquiries associated with the progress of problems via problem
            reporting tool.

3.  The Help Desk Service includes a remote support service which guarantees
    direct access to the network management system and is activated by CCG to
    support the fault tracing. In this case the Seller is responsible for
    restoring the service.

4.  The Seller's support staff shall fully co-operate with any member of CCG
    involved in an emergency incident.

<PAGE>

5.       The Seller shall provide the Help Desk Service 24h per day for
         365 days a year.

10.3      REPLACEMENT SERVICE

10.3.1    GENERAL

1.  The Replacement Service has to be provided 24 hours a day for 365 days a
    year.

2.  The replacement units must be fully compatible with the components they are
    replacing.

3.  Freight costs of the returning of the defective equipment to Seller shall be
    borne by CCG. All other transportation costs shall be borne by Seller.

4.  The Seller will charge repairs in case of misuse of equipment or
    inappropriate alteration of the equipment on expense.

5.  The Seller shall be responsible for all stock keeping of spare parts
    necessary to obtain the required replacement times.

10.3.2    REPLACEMENT PROCEDURE

1.  CCG will send a request for replacement equipment on an agreed document to
    the Seller's repair centre.

2.  The Seller shall acknowledge a repair service request by CCG as soon as
    possible but not later than eight hours after having received the request by
    fax.

3.  CCG sends the defective module with a fault description to the Seller's
    Repair Center as soon as possible but not later than five days after having
    received the replacement equipment.

4.  When sending the replacement equipment to CCG, the Seller shall provide an
    accompanying document indicating:

         -  the serial number of the equipment being replaced as reported on
            CCG's request for replacement,
         -  the serial number of the replacement equipment,
         -  the associated repair reference number

5.  After receiving the defective module the Seller will provide a repair report
    including sufficient information about the cause of the failure and
    consequent actions in a reasonable time frame.

10.3.3   12 HOURS REPLACEMENT SERVICE

1.  The replacement equipment must be received by CCG within a timeframe of 12
    hours after request by CCG independent of the place of repair work.

2.  CCG indicates on the request sheet whether this delivery shall be made
    during its working hours or in the committed timeframe.

10.3.4    24 HOURS REPLACEMENT SERVICE

1.  The replacement equipment must be received by CCG within a timeframe of 24
    hours after request by CCG independent of the place of repair work.

2.  CCG indicates on the request sheet whether this delivery shall be made
    during its working hours or in the committed timeframe.

10.4     CORRECTIVE MAINTENANCE SERVICE

10.4.1   GENERAL

<PAGE>

1. Corrective Maintenance Service means in case of a fault all tasks to restore
   the service and bring the system into the specified operational conditions.
   The restoration can also be achieved by a temporary workaround until the
   original fault is solved.

2. The Seller shall correct all anomalies, problems or defects resulting in an
   operational problem.

3. The Corrective Maintenance Service has to be realized 24 hours a day for
   365 days a year.

4. The replacement units must be fully compatible with the Machines or
   components they are replacing.

5. Time to repair (TTR) is the elapsed time from the activation of Corrective
   Maintenance Service at the Seller's helpdesk until the repair is
   successfully completed. The activation of the Corrective Maintenance Service
   shall be performed on a mutually agreed form.

6. The Seller shall be responsible for all stock keeping of spare parts
   necessary to obtain the required repair times.

10.4.2    TIME TO REPAIR

1.  Any problem resulting in an corrective maintenance action shall previously
    classified according to Section 6.1.1, Classification of Problems.

2. For any problem class the Seller guarantees the TTR-figures as stated in the
   table below.

3.  For particular problems CCG may request a higher TTR than stated in the
    table below. CCG shall state such requests in written form upon the
    activation of the corrective maintenance.

      ------------------------------------------------------
         Problem Class                   TTR
      ------------------------------------------------------
               A                       4 hours
      ------------------------------------------------------
               B                      12 hours
      ------------------------------------------------------
               C                      48 hours
      ------------------------------------------------------

10.5      ONSITE NMC-SUPPORT

1. The Seller shall provide an onsite support for the Network Management Center
   (NMC) of CCG.

2. The onsite support shall comprise the following subjects:

         o  operation of the network elements from the management system
            installed at the NMC,
         o  assistance and technical support for CCG's own operators,
         o running online training courses on network management aspects, and
         o development of CCG-specific operational emergency processes.

3. The Seller shall provide one person during the normal working hours (8h per
   day, 5 days per week) exclusively for the onsite NMC-Support. This person
   shall be a well-trained expert on the network elements and the network
   management system and shall be capable to fulfill the tasks listed above.
   During absence due to illness or vacation this person shall substituted by
   another one with similar skill.

4. If necessary the onsite support can be carried out by different experts
   provided that the number does not exceed three persons.

5. On request of CCG the Seller shall exchange the person for the onsite
   support.

10.6      DE-INSTALLATION

1.  The de-installation fee does cover the de-installation service, transport,
    revision, and stockkeeping of relevant units for up to 6 months at the
    suppliers premises.

<PAGE>

11        QUALITY ASSURANCE

11.1      PROJECT MANAGEMENT SYSTEM

1.  The tasks of the project management system are planning, staffing
    forecasting and monitoring of a project or a process implementation. The
    goal of the project management system is to identify risks and to initiate
    actions in order to keep the targets of the project. A major part of the
    project management system is to report status and results of the project to
    its initiators.

2. The project management of the supplier shall be implemented according to the
   rules of ISO 9001.

3. The Seller's project management system shall cover:

         o  A project organisation matrix including responsibilities,
            authorities and resources involved in the project.
         o  A project activity plan including overview, project locations,
            responsibilities and milestones on a task by task basis.
         o  progress monitoring and control
         o  problem monitoring and control
         o  Risk management procedures
         o  Recovery plan in case of deviation from project schedule
         o  Reporting procedures (in form of project specific metrics), e.g.
            for system development, manufacturing and committed services.

11.2      QUALITY PLAN

1. The Seller shall provide a quality manual to CCG on request.

2. The Seller shall supply to CCG within 42 calendar days of the Date of
   Contract a Quality Plan in a form agreed with CCG demonstrating how the
   inspection / quality arrangements specified by CCG are to be applied to the
   Contract.

3. Any quality assurance service is provided without cost for CCG.

11.3      QUALITY AUDITS

1. The Seller shall accept quality audits from CCG or a third party reporting to
CCG.

2. The Seller shall give CCG or a third party reporting to CCG access to all
   sites and key personnel for the purposes of quality audits.

3. The quality audits shall include unrestricted questioning of personnel as
   well as demonstration of the system under development.

4. The dates of technical audits shall be determined by CCG and shall not
   require earlier than 3 working days notice to the supplier.

11.4      FAULT HISTORY SYSTEM

1. The Seller shall demonstrate to CCG that procedures exist for the provision
   and ongoing maintenance of an equipment fault history system. The system
   shall be capable of retaining information with regard to equipment that has
   been returned for repair irrespective of whether a fault has been found.

2. The Seller shall have a facility to track equipment from CCG to the repair
   facility and vice versa. Such records must be kept by the Seller for a
   minimum of one year.

3. The Seller shall provide repair statistics broken down by unit type in
   warranty and post warranty repair sufficient to control the Seller's
   performance against his commitments.

12

<PAGE>

13       TIME SCHEDULES

13.1     TYPE ACCEPTANCE

13.1.1   TYPE ACCEPTANCE PREPARATION

[GRAPHIC OMITTED]

13.1.2

<PAGE>

13.1.3 TYPE ACCEPTANCE TESTING

       [GRAPHIC OMITTED]

<PAGE>

                    SCOPE OF DELIVERY LOCATION DOCUMENTATION

--------------------------------------------------------------------------------

ID                        ST-rfx-0016
REVISION                  1.0 / APPROVED
DATE                      26 Aug 1999
CONFIDENTIALITY           CCG CONFIDENTIAL

--------------------------------------------------------------------------------

AUTHOR                    Systems engineering            Jorg Gimmler

APPROVED                  Network operation

APPROVED                  Network planning

FILE NAME                 Scope of Delivery Location Documentation-10

--------------------------------------------------------------------------------

DESCRIPTION               This guideline defines a general standard for the
                          layout documentation of transmission systems in the
                          CCG network.

--------------------------------------------------------------------------------

CHANGE LOG                1.0  /  APPROVED  / 09/04/99 / J. Gimmler

--------------------------------------------------------------------------------

<PAGE>

TABLE OF CONTENTS

--------------------------------------------------------------------------------

<TABLE>

<S>                                                                           <C>
1         SCOPE .....................................................         3
2         FORMAT ....................................................         3
3         CONTENTS OF DOCUMENTATION .................................         3
  3.1       CHANGE OVERVIEW 3
  3.2       TABLE OF CONTENTS .......................................         3
  3.3       LOCATION-RELATED NETWORK OVERVIEWS ......................         3
   3.3.1        INTERCONNECTION OF NETWORK ELEMENTS .................         3
   3.3.2        NETWORK MANAGEMENT ..................................         4
   3.3.3        SYNCHRONIZATION .....................................         4
   3.3.4        DCN .................................................         4
   3.3.5        SERVICE TELEPHONE ...................................         5
  3.4       INSTALLATION DRAWING ....................................         5
  3.5       EQUIPMENT CONFIGURATIONS ................................         5
   3.5.1        SUBRACK CONFIGURATIONS ..............................         5
   3.5.2        RACK FUSE PANEL .....................................         5
  3.6       CONNECTING CABLES .......................................         6
  3.7       POWER SUPPLY ............................................         6
  3.8       DISTRIBUTION FRAME ASSIGNMENTS ..........................         6
   3.8.1        SYMMETRICAL SIGNAL DISTRIBUTOR ......................         6
   3.8.2        OPTICAL AND COAXIAL DISTRIBUTION FRAMES .............         7
  3.9       LIST OF ABBREVIATIONS ...................................         7
  3.10      CONTACT PERSONS  ........................................         7

</TABLE>

<PAGE>

1      SCOPE

1.   The system supplier shall compile and supply layout documentation for each
     location, at which his system engineering equipment is installed. All
     services provided by the supplier in connection with the installation,
     configuration and commissioning of the technical installations supplied by
     him are described in this documentation.

2      FORMAT

1.  The layout documentation is to be submitted to CCG both in paper format as
    well as in electronic form prior to acceptance by CCG (FAC).
2.  The electronic form of the documentation is to be compiled by means of the
    documentation program Infocable-Registered Trademark- of the Institut fur
    Informatik in Entwurf und Fertigung zu Berlin GmbH.
3.  The documentation in paper form is to be compiled in triplicate.
4.  Any retrofits or changes to the system layout implemented by the system
    supplier are to be documented in the form of change sheets and updates of
    the software documentation.
5.  The revision status of the documentation is indicated by the date of
    transfer.

3      CONTENTS OF DOCUMENTATION

1.  Each sheet of the documentation must contain at least the following
    identification features:

    -        Document name
    -        Page number
    -        Compilation date
    -        Version number

3.1    CHANGE OVERVIEW

1.  The documentation shall contain a change overview specifying the change
    status number and the page numbers concerned. The change overview shall be
    dispensed with in the event of replacing the complete documentation. The
    relevant status/date is to be defined.

3.2    TABLE OF CONTENTS

1.  The documentation shall contain a table of contents listing all
    corresponding sections of the documentation. The table of contents is to be
    structured corresponding to this document. The table of contents can also
    serve as a cover sheet.

3.3    LOCATION-RELATED NETWORK OVERVIEWS

3.3.1  INTERCONNECTION OF NETWORK ELEMENTS

1.  The location-related layout documentation shall contain an overview that
    describes the interconnection of the network elements. The corresponding
    network elements as well as their interface cards are to be specified for
    each connection. The overview is to be compiled separately according to
    locations.

<PAGE>

3.3.2  NETWORK MANAGEMENT

1.  The documentation shall contain an overview of the network management system
    containing at least the following points:

    -   Overview of network management architecture with LAN addresses
    -   Equipment view of LAN connections
    -   Tabular overview of NMS systems used with manufacturer's name and serial
        number
    -   Tabular overview of peripheral devices (e.g. printers) with
        manufacturer's name and serial number

3.3.3  SYNCHRONIZATION

1.  The documentation shall contain an overview of clock priorities set at the
    network elements.

3.3.4  DCN

1.  The documentation shall contain a location-related overview of the DCNs
    specifying at least the following points:

    -        DCN overview of the channel routing
    -        Overview of overhead bytes if applicable
    -        Configuration of overhead byte cross connections
    -        Bridge/router configuration
    -        Address (NSAP, IP etc)

<PAGE>

3.3.5  SERVICE TELEPHONE

1.  The documentation shall contain an overview of the configuration of service
    telephone modules specifying the following points:

    -        Station number
    -        Station name
    -        Service telephone number, internal
    -        Service telephone number, external

3.4    INSTALLATION DRAWING

1.  The documentation shall contain a location-related installation drawing
    containing at least the following points:

    -        Position of the racks in the technical installations room
    -        Arrangement of the racks as well as their rack numbers
    -        Designations of the racks
    -        Arrangement of subracks as well as their subrack numbers
    -        Designation of subracks

2.  The racks and subracks are to be numbered and designated in compliance with
    CCG specifications.

3.5    EQUIPMENT CONFIGURATIONS

3.5.1  SUBRACK CONFIGURATIONS

1.  The documentation shall contain an overview of the equipment configurations,
    containing at least the following points:

    -        Schematic representation of subrack
    -        Rack and subrack number
    -        Designation of NE type (e.g. TM-4/1)
    -        Identification number of subrack
    -        Voltage supply and fuse protection used (e.g. 48 V/fuse 10 A)
    -        Power consumption

    -        Plug-in slot number
    -        Designation of plug-in unit
    -        Serial number
    -        Hardware status
    -        Firmware status
    -        Change status

2.  The racks and subracks are to be numbered and designated in compliance with
    CCG specifications.

3.       If a subrack contains additional interface modules, they must be
         documented accordingly by:

    -        Plug-in slot number
    -        Designation of plug-in unit
    -        Serial number
    -        Hardware status
    -        Firmware status (if applicable)
    -        Change status

3.5.2  RACK FUSE PANEL

1.  The documentation shall contain an overview of the installed rack fuse
    panels containing at least the following points:

<PAGE>

    -        Schematic representation of rack fuse panel
    -        Designation of fuse panel
    -        Rack number
    -        Designation of plug-in module
    -        Voltage supply and fuse protection (e.g. 48 V/20 A)
    -        Designation of respective load or of upstream fuse panel

2. The fuse panels are to be designated in accordance with CCG specifications.

3.6    CONNECTING CABLES

1.  The documentation shall contain an overview of all cabling implemented. This
    requirement also comprises layout-specific DCN, synchronisation and power
    cabling. The overview must contain at least the following points:

    -        Port designation A-end
    -        Port designation B-end
    -        Remarks (e.g. shield protected with insulating sleeve)
    -        Type of cable used

3.7    POWER SUPPLY

1.  The documentation shall contain an overview of all installed power supply
    units containing the following:

    -   Schematic representation of subrack
    -   Designation of type of power supply
    -   ID number
    -   Voltage supply and fuse protection (e.g. 230 V/fuse 10 A)
    -   Designation of plug-in slot
    -   Power supply cabling
    -   Serial number
    -   Hardware status
    -   Firmware status
    -   Change status

2.  The racks and subracks are to be numbered and designated in compliance with
    CCG specifications.

3.8    DISTRIBUTION FRAME ASSIGNMENTS

1.  The documentation shall contain an overview of all distribution frame
    assignments implemented as part of the system installation procedure. The
    contents of the distribution frame documentation are dependent on the type
    of distribution frame system used and is to be described in the following
    subsections.

2.  In any case, the documentation must ensure a distinct local description of
    each individual port. The overviews are to be listed in tabular form in
    compliance with CCG specifications.

3.8.1  SYMMETRICAL SIGNAL DISTRIBUTOR

1.  The documentation shall contain at least the following specifications for
    the connection to the network element in the direction of the patch panel,
    for the connection to the patch panel in the direction of the distributor or
    patch panel and for the connection to the strapping panel in the direction
    of the patch panel:

    -        Bay
    -        Strip
    -        Terminal slot

<PAGE>

2.  The documentation shall contain at least the following specifications for
    the connection to the patch panel in the direction of the network element:

    -        Rack
    -        Subrack
    -        Slot
    -        Port

3.8.2  OPTICAL AND COAXIAL DISTRIBUTION FRAMES

1.  The documentation shall contain at least the following specifications for
    the connection to the network element in the direction of the patch panel,
    for the connection to the patch panel in the direction of the distribution
    frame or patch panel and for the connection to the strapping panel in the
    direction of the patch panel:

    -        Bay
    -        Panel
    -        Coupler unit number

2.  The documentation shall contain at least the following specifications for
    the connection to the patch panel in the direction of the network element:

    -        Rack
    -        Subrack
    -        Slot
    -        Port

3.9    LIST OF ABBREVIATIONS

1.   All abbreviations used are to be written out in full and explained in
     German in the list of abbreviations.

3.10   CONTACT PERSONS

1.   The system supplier and CCG shall nominate at least one contact person and
     one further contact person for further coordination of the layout
     documentation.

<PAGE>

LEGENDEN

<TABLE>

<S>                                          <C>
Seite 3
-------------------------------------------------------------------------------------------------------------
Schrank                                      Cabinet
-------------------------------------------------------------------------------------------------------------
Fluchtrichtung                               Escape direction
-------------------------------------------------------------------------------------------------------------

-------------------------------------------------------------------------------------------------------------
Seite 4
-------------------------------------------------------------------------------------------------------------
Verteilerplatte                              Distribution board
-------------------------------------------------------------------------------------------------------------
Steckerpaar                                  Connector pair
-------------------------------------------------------------------------------------------------------------
z.B.                                         e.g.
-------------------------------------------------------------------------------------------------------------
Schrank                                      Cabinet
-------------------------------------------------------------------------------------------------------------
Bucht                                        Bay
-------------------------------------------------------------------------------------------------------------

Seite 5
-------------------------------------------------------------------------------------------------------------
Zeichnung                                    Drawing
-------------------------------------------------------------------------------------------------------------
(Ansicht von oben)                           (Top view)
-------------------------------------------------------------------------------------------------------------
Zusatzlicher Steg                            Additional web
(Schiene A12386)                             (rail A12386)
fur Verteilertyp                             for distributor types
1, 2, 4 und 5                                1, 2, 4 and 5
-------------------------------------------------------------------------------------------------------------
LWL Umlenkbleche                             Optical fibre cable guide plates
fur 8 Patchkabel                             for 8 patch cables
(ausser bei Typ 5)                            (except for type 5)
-------------------------------------------------------------------------------------------------------------
Seite 6
-------------------------------------------------------------------------------------------------------------
Sender der Systemtechnik                     Transmitter of system engineering
-------------------------------------------------------------------------------------------------------------
Steckerpaar                                  Connector pair
-------------------------------------------------------------------------------------------------------------
Empfanger der Systemtechnik                  Receiver of system engineering
-------------------------------------------------------------------------------------------------------------

Seite 7
-------------------------------------------------------------------------------------------------------------
Gerateseite                                  Equipment side
-------------------------------------------------------------------------------------------------------------
Signalleiste                                 Signal strip
-------------------------------------------------------------------------------------------------------------
Sender Port                                  Transmitter port
-------------------------------------------------------------------------------------------------------------
Empfanger Port                               Receiver port
-------------------------------------------------------------------------------------------------------------
Kabelseite                                   Cable side
-------------------------------------------------------------------------------------------------------------

Seite 8
-------------------------------------------------------------------------------------------------------------
Alarmverteiler                               Alarm distribution frame
-------------------------------------------------------------------------------------------------------------
8x 8 DA-Kroneleisten                         8x8 DA Krone strips
-------------------------------------------------------------------------------------------------------------
(Platz fur 64 DA)                            (place for 64 DA)
-------------------------------------------------------------------------------------------------------------

Seite 9
-------------------------------------------------------------------------------------------------------------
Lochstreben zur Kabelbefestigung              Perforated struts for cable fastening
-------------------------------------------------------------------------------------------------------------
Aluquerstrebe                                 Aluminium cross strut
-------------------------------------------------------------------------------------------------------------
(Befestigung hinterste Ebene)                 (mounting of rearmost level)
-------------------------------------------------------------------------------------------------------------
Kabelfuhrungswinkel                           Cable routing bracket
-------------------------------------------------------------------------------------------------------------
(Rangierhaken)                                (routing hooks)
-------------------------------------------------------------------------------------------------------------
Kabelfuhrung und Zugentlastung fur LWL        Cable routing and strain relief for optical fibre cables
-------------------------------------------------------------------------------------------------------------
(Klemmbugel)                                  (strain relief clamp)
-------------------------------------------------------------------------------------------------------------
Befestigung der LSA+ Stangenprofile           Mounting of LSA+ bar sections
-------------------------------------------------------------------------------------------------------------

</TABLE>

<PAGE>

<TABLE>

-------------------------------------------------------------------------------------------------------------
<S>                                           <C>
Spleissbox von Firma Krone                     Krone splice box
je Spleissbox 24 Fasern                        24 fibres per splice box
(max. 144 Fasern)                             (max. 144 fibres)
-------------------------------------------------------------------------------------------------------------
Kabelabfangblech                              Cable clamping plate
-------------------------------------------------------------------------------------------------------------
230V Steckdose                                230 V socket outlet
-------------------------------------------------------------------------------------------------------------
Gesamtlange 100 cm (3x 1.2 cm Befestigung +   Total length 100 cm (3x 1.2 cm mounting + 96 cm free bar
96 cm freies Stangensystem)                   system)
-------------------------------------------------------------------------------------------------------------
Spleissbox                                     splice box
-------------------------------------------------------------------------------------------------------------

Seite 10
-------------------------------------------------------------------------------------------------------------
Lochstreben zur Kabelbefestigung                       Perforated struts for cable fastening
-------------------------------------------------------------------------------------------------------------
Alustrebe (Befestigung hinterste Ebene)                Aluminium cross strut (mounting of rearmost level)
-------------------------------------------------------------------------------------------------------------
Verteilerplatten fur LWL                               Distribution boards for optical fibre cables
24 Platten Gerateseite                                 24 boards equipment side
(24 Platten je 4 Ports = 96 Ports)                     (24 boards at 4 ports each = 96 ports)
24 Platten Kabelseite                                  24 boards cable side
(24 Platten je 4 Ports = 96 Ports)                     (24 boards at 4 ports each = 96 ports)
-------------------------------------------------------------------------------------------------------------
Kabelfuhrung und Zugentlastung fur LWL                 Cable routing and strain relief for optical fibre
(Klemmbugel)                                           cables (strain-relief clamp)
-------------------------------------------------------------------------------------------------------------
Kabelabfangblech                                       Cable clamping plate
-------------------------------------------------------------------------------------------------------------
230 V Steckdose                                        230 V socket outlet
-------------------------------------------------------------------------------------------------------------
Gerateseite                                            Equipment side
-------------------------------------------------------------------------------------------------------------
Kabelseite                                             Cable side
-------------------------------------------------------------------------------------------------------------

</TABLE>

Seite 12
Perforated struts for cable fastening

Aluminium cross strut (mounting of rearmost level)

Cable routing bracket (routing hooks)

Distribution boards for optical fibre cables (12 boards at 4 fibre pairs each =
48 fibre pairs)

Distribution board for coaxial interfaces 34/140 MBit/s, STM-1 electrical (12
boards at 4 ports each = 48 ports)

Cable routing and strain relief for optical fibre cables (strain-relief clamp)

Aluminium cross strut (mounting of rearmost level)

Aluminium cross strut

Mounting of LSA+ bar sections

LSA Plus isolating plug connectors 8x ABS with jumper wire feed left
Dimensions:
16 ports = 4 strips => 12 cm
Possible number of strips:
128 ports = 24 strips => 98 cm

LSA Plus isolating plug connectors 8x ABS with jumper wire feed right
Dimensions:
16 ports = 4 strips => 12 cm

<PAGE>

Possible number of strips:
128 ports = 24 strips => 98 cm

Aluminium cross strut

Mounting of LSA+ bar sections

Aluminium cross strut

Cable clamping plate

230 V socket outlet

Cable side

Equipment side

For LSA+ strips 2x 48 cm 0 LESS THAN 8x 16 ports
Total length 100 cm (mounting 3x 1.2 cm
+ 96 cm LSA+)

Seite 13

Cable clamping plate

Power supply

Aluminium cross strut

Mounting of LSA+ bar sections

LSA+ isolating strips
8x ABS with jumper wire feed, left

LSA+ isolating strips
8x ABS with jumper wire feed, right

Aluminium cross strut

Distribution boards for coaxial interfaces
34/140 MBit/s, STM-electrical
(4 ports per board)

Mounting of LSA+bar sections

Aluminium cross strut

Cable clamping plate

230 V socket outlet

Cable side

Equipment side

For LSA+ strips 60 cm = 5x 16 ports
Total length 82.4 cm (mounting 2x 1.2 cm + 50 cm LSA+)

Seite 14
--------------------------------------------------------------------------------
Gestellreihe                                           Frame row
--------------------------------------------------------------------------------
Schrankplatz                                           Cabinet location
--------------------------------------------------------------------------------
Rahmen (Shelf)                                         Shelf
--------------------------------------------------------------------------------
Steckplatz                                             Plug-in slot
--------------------------------------------------------------------------------
Stecknummer                                            Connector number
--------------------------------------------------------------------------------

<PAGE>

             GUIDELINES FOR THE LAYOUT OF SIGNAL DISTRIBUTION FRAMES

--------------------------------------------------------------------------------

ID                        ST-rfx-0002
REVISION                  1.0 / DRAFT
DATE                      09 Apr 1999
CONFIDENTIALITY           CCG CONFIDENTIAL

--------------------------------------------------------------------------------

AUTHOR                    Systems engineering            J. Gimmler

APPROVED                  Network operation

APPROVED                  Product management

APPROVED                  Network planning

NOTICE                    Location layout

FILE NAME                 Guidelines for the Layout of Signal Distribution
                          Frames-10

--------------------------------------------------------------------------------

DESCRIPTION               This document describes the guidelines which the
                          system manufacturer must adhere to regarding the
                          layout of the distribution frames for CCG.

                          All connections of the devices and equipment used by
                          CCG are to be routed and assigned to terminal boards.

--------------------------------------------------------------------------------

CHANGE LOG                1.0 / APPROVED / 25/01/99 / J. Gimmler Initial
                          revision

--------------------------------------------------------------------------------

<PAGE>

<TABLE>
<CAPTION>

TABLE OF CONTENTS

<S>                                                                          <C>
1. REQUIREMENTS RELATING TO DISTRIBUTION FRAMES...............................3
1.1 FRAME RACK LAYOUT.........................................................4
   1.2 COUPLER UNIT PANELS....................................................4
   1.3 FIBRE SPLICE BOXES.....................................................6
   1.4 DISTRIBUTION STRIPS FOR SYMMETRICAL CABLING............................6

2. TYPES OF DISTRIBUTION FRAME................................................8
   TYPE 1 -SDH REGENERATOR LOCATION...........................................8
   TYPE 2 -POP CABLE TERMINAL CABINET.........................................9
   TYPE 3 - POP -OPTICAL AND COAX INTERFACES.................................10
   TYPE 4 - POP -COAX AND SYM. INTERFACES....................................11
   TYPE 5 -CUSTOMER LOCATIONS................................................13

LABELLING OF DISTRIBUTION FRAMES.............................................14

NUMBERING SYSTEM.............................................................14

ABBREVIATIONS................................................................15

REFERENCES...................................................................15

--------------------------------------------------------------------------------

</TABLE>

<PAGE>

1. REQUIREMENTS RELATING TO DISTRIBUTION FRAMES

1.    Location           To ensure the distribution cabinet has a defined
                         location in the station irrespective of the station
                         configuration, the distribution cabinet is to be
                         installed at the beginning or end of a row of racks.

                         In rooms with cavity floors, the installation layout is
                         to be adapted to the pitch of the floor tiles.

2.    Mounting           If installed individually, the cabinet is to be secured
                         to the wall and/or ceiling.

3.    Grounding          Each distribution and technical installations cabinet
                         is grounded at the nearest located equipotential
                         bonding strip or earth-circuit connector.

4.    Dimensions         The distribution frames correspond to the dimensions
                         specified by the Standard ETS 300 119 and are:

                         W = 600 mm, H = 2200 mm, T = 300 mm

5.    Doors              In the same way as the technical installations racks,
                         the distribution frames are to be equipped with
                         lockable doors.

                         In compliance with fire protection regulations, the
                         door hinge arrangement must be selected such that the
                         doors fall shut in the direction of the escape route.

                         [GRAPHIC]

6.    Door alarm         Opening of the distribution frame doors is monitored by
      contacts           means of alarm contacts that are contacts connected to
                         the external alarm of the system engineering.

7.    Door locks         The cabinets are locked

8.    230 V connection   A (230 V) socket outlet is to be provided in the lower
                         panel of the cabinets.

<PAGE>

1.1 FRAME RACK LAYOUT

                                    [GRAPHIC]

                    Figure: Example of a distribution cabinet

9.     Cable routing     Cable routing brackets are used to facilitate
       brackets          flexible cable routing specific to system brackets
                         requirements.

                         Optimum utilization of the space available in the
                         various types of distribution frame is to be ensured by
                         using the largest possible routing bracket.

10.   Direction of       Cabinet wiring blocks are to be arranged horizontally
      cabinet wiring     (from bay A to bay B)
      blocks

11.   Carrier system     The LSA 95 mm wide sectional bar supplied by Krone is
      for distribution   used as the basis for symmetrical distribution frame
      frames             systems and splice boxes.

                         The mounting bracket Item No. 6577 2 834-00 is used for
                         mounting the sectional bars. The length of the bar
                         sections depends on the relevant type of distribution
                         frame.

1.2 COUPLER UNIT PANELS

<PAGE>

12.    Application        Signal application and routing for all coaxial STM-1,
                          140 Mbit/s, 34 Mbit/s connections

                          Signal application and routing for all optical STM-1,
                          STM-4, STM-16, STM-64 connections

13.    Mounting panels    Distribution boards are used for mounting the coupler
       for coupler units  units.

                          All cabling to the network elements are routed to the
                          distribution fields from the rear.

                          In principle, the distribution boards for coaxial
                          cables are designed the same as the distribution
                          boards for optical fibre cables.

                          [GRAPHIC]

14.    Type of coupler unit, optical         Coupler unit type E2000/diagonal is
                                             to be used as the optocoupler.

15.    Bending radius                        Appropriate fixing of the optical
                                             fibre patch cables is specified in
                                             order to maintain the minimum
                                             bending radius of 3.5 cm for
                                             optical fibre pigtails.

16.    Type of coupler unit, electrical      The coupler unit type IEC 169-13
                                             1.6/5.6 75 Ohm socket is used as
                                             the electrical coaxial coupler
                                             unit.

                                             The coaxial interfaces are routed
                                             and allocated by means of patch
                                             cables with 1.6/5.6 angle
                                             connectors at both ends.

                                             Strapping is provided in crosswise
                                             configuration.

17.    Labelling                             Transmitters and receivers are
                                             marked by arrow symbols.

<PAGE>

18.    Rx / Tx                               Refered to the systems engineering
                                             interface, the transmitter is
                                             located on the left, the receiver
                                             on the right.

       Location

                                    [GRAPHIC]

19.    Patch cables                          The patch cables in a distribution
                                             cabinet have standard lengths of
                                             1.0 m, 1.6 m and 2.2 m.

                                             The shortest cable length should be
                                             used for wiring block strapping.

1.3 FIBRE SPLICE BOXES

20.    Application                           Optical fibre splice box mounts are
                                             required when longer optical
                                             in-house connections are not used
                                             together with standard
                                             prefabricated optical cables.

21.    Type of splice box                    The type supplied by Krone mounted
                                             on LSA+ sectional round bar system
                                             is used as the fibre splice box.

                                             A carrier system can accept a
                                             maximum of two fibre splice boxes.

                                             Each fibre splice box can contain
                                             up to 12 splices.

                                             The fibres are routed to the
                                             optical fibre distribution boards.

1.4 DISTRIBUTION STRIPS FOR SYMMETRICAL CABLING

22.    Application                           Signal routing and patch
                                             distribution for all 2 M signals

                                             -    All external alarm inputs of
                                                  the devices

                                             -    2 MHz (clock) inputs and
                                                  outputs used

23.    Type of strip                         Cables for the technical
                                             installations and connecting cables
                                             are arranged on Krone LSA+ ABS
                                             distribution strips.

<PAGE>

24.    Cable feed and assignments            The cable side is routed from above
                                             onto the distribution strips, the
                                             strapping side from below.

                                             The strips are assigned in the
                                             minimum configuration of 2 strips
                                             each (see drawing).

                                             Rx and Tx directions are each
                                             arranged on separate strips.
                                             Strapping can therefore be "free of
                                             crossing" between the left and
                                             right bay.

                                    [GRAPHIC]

25.    Special requirements for clock        A distribution strip for clock
       cabling                               distribution is provided for each
                                             row of rack frames. The network
                                             element interfaces (T3 in, T3 out)
                                             are cabled, however, only on
                                             special request.

26.    Special requirements for alarm        The alarm inputs of the technical
       contacts contacts                     installations and the alarm of the
                                             station are routed on LSA+
                                             distribution strips.

                                             The alarm contact for the frame
                                             door to the technical installations
                                             is based on a decentralized
                                             configuration on the respective
                                             system engineering frame and
                                             connected to the alarm contact #1
                                             of the network element implemented
                                             in the frame.

                                             The other alarm contacts are
                                             arranged centrally per row of rack
                                             frames on one distributor.

27.    Distribution assignments for alarm    (t.b.d.)
       contacts

<PAGE>

2. TYPES OF DISTRIBUTION FRAME

TYPE 1 - SDH REGENERATOR LOCATION

No separate distribution cabinet is implemented in the regenerator locations.
Only external alarm signals are to be routed to these locations equipped with 8
Krone LSA+ distribution strips for 8 double cores.

<PAGE>

TYPE 2 - PoP CABLE TERMINAL CABINET

This type of distribution frame serves the purpose of housing several connecting
cables with splice boxes in PoPs.

Application example: Arrangement of optical connecting cables between a removed
cable terminating facility and backbone technical installations.

The Krone splice boxes are arranged in the lower area and the optical fibre
distribution frames in the upper area. With a standard cable lead-in from below,
the splice boxes are expanded from top to bottom.

Splice boxes and distribution boards feature following fixed allocations:
o    Top left splice box (-) Bay A distribution boards 1-3
o    Bottom left splice box (-) Bay A distribution boards 4-6
o    Centre splice box, top bay (-) Bay A distribution boards 7-9
o    Centre splice box, bottom bay (-) Bay A distribution boards 10 - 12
o    Top right splice box (-) Bay B distribution boards 1-3
o    Bottom right splice box (-) Bay B distribution boards 4-6
The outer sockets are to be assigned first.

Distribution frame capacity: Cable connection for maximum 144 fibres, optical
fibre conductors

[GRAPHIC]

<PAGE>

[GRAPHIC]

<PAGE>

TYPE 3 - PoP - OPTICAL AND COAX INTERFACES

This type of distribution frame serves the purpose of internal
optical/electrical routing in the PoP. A maximum of 96 connections can be
allocated.

[GRAPHIC]

<PAGE>

TYPE 4 - PoP - COAX AND SYM. INTERFACES

Symmetrical and asymmetrical interfaces are arranged on the distribution frame.
Application example: Routing between company-own technical system equipment and
co-located system engineering of the customer or local network operator.
Distribution capacity:
48 ports coax equipment side (12 distribution boards)
48 ports coax cable side (12 distribution boards)

[GRAPHIC]

<PAGE>

[GRAPHIC]

128 Ports 2 MBit/s symmetrical - equipment side (96 cm round bar system)
128 Ports 2 MBit/s symmetrical - cable side (96 cm round bar system)

Optional (if fewer 2MBit/s ports are installed):
Alarm distribution frame (10x Krone LSA+ distribution strips)

<PAGE>

TYPE 5 - CUSTOMER LOCATIONS

This type of distribution frame serves as a typical cabinet in the customer
location.

The cabinet contains the system technical installations and a secured power
supply. All types of interface can be mounted on the Krone round bar system.

Alarm distributors (2x Krone LSA+ distribution strips) are provided for external
alarm inputs.

[GRAPHIC]

<PAGE>

LABELLING OF DISTRIBUTION FRAMES

NUMBERING SYSTEM

The cabling from the technical installations to the distribution cabinet is
labelled on both sides.

[GRAPHIC]

The labelling describes the connector on the system engineering side. The
numbering of the cabinets in each station is determined during the planning
phase. The maximum distance of the labelling to the connector should be 10 cm.

Example:

A01 S1-107 02 The device is located in frame rack row A cabinet 01 and shelf 1
        The port assembly in plug-in slot 102 the second connector from the top

Also refer to CCG document "Technical Guidelines for the Labelling of Cabling in
the CCG Transmission Network".

<PAGE>

ABBREVIATIONS

         DA              Double core
         HRL             High Return Loss
         LSA-Plus        KRONE connection system free of soldering, screws and
                         insulation stripping
         LWL             Optical fibre cable
         koax.           Coaxial 75 Ohm interface
         PDH             Plesiochronous Digital Hierarchy
         SDH             Synchronous Digital Hierarchy
         STM             Synchronous Transport Module
         STM-1           155,520 Mbit/s SDH
         STM-4           622,080 Mbit/s SDH
         STM-16          2488,320 Mbit/s SDH
         sym.            Symmetrical 120 Ohm interface

REFERENCES

-------------------------------------------------------------------------------
ID                          Title
-------------------------------------------------------------------------------
ST-rfx-0017                 Technical Guidelines for the Labelling in the CCG
                            Transmission Network
-------------------------------------------------------------------------------
<PAGE>

-------------------------------------------------------------------------------

                      TECHNICAL GUIDELINES ON CABLE LENGTHS

                        -------------------------------------------------------

ID                      ST-rfx-0018
REVISION                2.0 / FINAL
DATE                    14 Jan 2000
CONFIDENCE              LNC CONFIDENTIAL

-------------------------------------------------------------------------------

AUTHOR                  System technology              Jorg Gimmler
                                                       Dirk Geisler

APPROVED                NP
                        NIS

NOTICE                  PM

FILENAME                ST-rfx-0018-2.0

-------------------------------------------------------------------------------

DESCRIPTION             This document describes the guidelines for the cabling
                        within the transmission network of LNC. It specifies
                        the types of cables to be used and their maximum cable
                        length.

                        These guidelines are applicable for cabling the system
                        technology to the distributor for patching on the
                        distributor and for the connection cable within a
                        location.

-------------------------------------------------------------------------------

CHANGE LOG              1.0 / APPROVED / 25/01/99 / J. Gimmler Initial revision
                        2.0 / FINAL / 07/10/00 / D. Geisler Supplement
                              RJ-45 Cabling

-------------------------------------------------------------------------------

1

<PAGE>

-------------------------------------------------------------------------------

2     CONTENTS

-------------------------------------------------------------------------------
<TABLE>

<S>                                                                          <C>
1     Contents.................................................................2
2     Introduction.............................................................3
3     Definitions and abbreviations............................................3
   3.1   Definitions...........................................................3
   3.2   Abbreviations.........................................................3
4     Technical guidelines on cable lengths....................................4
   4.1   Electrical interfaces.................................................4
      4.1.1   Interfaces according to G.703....................................4
      4.1.2   Cable values for coaxial station cable...........................4
      4.1.3   Cable values for symmetrical station cable.......................6
      4.1.4   Connection cable to separate customer distributor................6
      4.1.5   RJ-45 cabling....................................................6
      4.1.6   Patching cable on distributor....................................9
         4.1.6.1   Coaxial patching cable......................................9
         4.1.6.2   Symmetrical patching cable..................................9
5     References...............................................................9
   5.1   Standards.............................................................9
</TABLE>

-------------------------------------------------------------------------------

3

<PAGE>

INTRODUCTION

This document describes the guidelines within the LNC transport network. The
types of cables and maximum cable lengths are specified.
The cabling of the system technology to the distributor, patching on the
distributor and connection cable within a location are described. Connection
cables between two locations are not taken into consideration.

5        DEFINITIONS AND ABBREVIATIONS

5.1      DEFINITIONS

5.2      ABBREVIATIONS

        DA       Twisted pair
        LWL      Fiber optic cable

6

<PAGE>

7      TECHNICAL GUIDELINES ON CABLE LENGTHS
7.1    ELECTRICAL INTERFACES

7.1.1  INTERFACES ACCORDING TO G.703

The guidelines for the maximum attenuation are described by the interface
description according to G.703.

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------------------------------------
     Data rate of interface           Characteristic      Maximum path attenuation    Measured at frequency
       according to G.703               resistance
--------------------------------------------------------------------------------------------------------------
     <S>                              <C>                 <C>                         <C>
            2 Mbit/s                      75 Ohm                    6 dBm                   1,024 kHz
--------------------------------------------------------------------------------------------------------------
            2 Mbit/s                     120 Ohm                    6 dBm                   1,024 kHz
--------------------------------------------------------------------------------------------------------------
            8 Mbit/s                      75 Ohm                    6 dBm                   4,224 kHz
--------------------------------------------------------------------------------------------------------------
           34 Mbit/s                      75 Ohm                   12 dBm                  17,184 kHz
--------------------------------------------------------------------------------------------------------------
           140 Mbit/s                     75 Ohm                   12 dBm                    70 MHz
--------------------------------------------------------------------------------------------------------------
           155 Mbit/s                     75 Ohm                  12.7 dBm                   78 MHz
--------------------------------------------------------------------------------------------------------------
</TABLE>

7.1.2  CABLE VALUES FOR COAXIAL STATION CABLE

Types of cables in bold face are preferred. For the cables with lower
attenuation, the space requirement and greater bending radiuses, particular in
the cabinet, must be taken into consideration due to the larger size.

<TABLE>
<CAPTION>

--------------------------------------------------------------------------------------------------------------------
                                         DATA RATE 2 MBIT/S COAXIAL
--------------------------------------------------------------------------------------------------------------------
                             Characteristic        Cross talk            Attenuation     Range with         Comments
       Type of cable           resistance          attenuation            at 1 MHz      20% reserve
                                 (f=5MHz)                                [dB/100m]
--------------------------------------------------------------------------------------------------------------------
     <S>                     <C>                <C>                      <C>             <C>                <C>
     02Y(St)CY 0.45/2.0           75 Ohm        GREATER THAN 160 dB        1.8 dB          260 m
--------------------------------------------------------------------------------------------------------------------
    02Y(St)CY 8X0.45/2.0          75 Ohm        GREATER THAN 160 dB        1.8 dB          260 m
--------------------------------------------------------------------------------------------------------------------
     2YC(mS)CY 0,5/3,0            75 Ohm        GREATER THAN 160 dB        1.5 dB          320 m
--------------------------------------------------------------------------------------------------------------------
       2YCCY 1,0/6,5              75 Ohm        GREATER THAN 160 dB        0.7 dB          680 m
--------------------------------------------------------------------------------------------------------------------

<CAPTION>

--------------------------------------------------------------------------------------------------------------------
                                         DATA RATE 34 MBIT/S COAXIAL
--------------------------------------------------------------------------------------------------------------------
                             Characteristic        Cross talk            Attenuation     Range with         Comments
       Type of cable           resistance          attenuation            at 17MHz      20% reserve
                                 (f=5MHz)                                [dB/100m]
--------------------------------------------------------------------------------------------------------------------
     <S>                     <C>                <C>                      <C>            <C>                 <C>
     02Y(St)CY 0.45/2.0           75 Ohm        GREATER THAN 160 dB         8 dB           120 m
--------------------------------------------------------------------------------------------------------------------
    02Y(St)CY 8X0.45/2.0          75 Ohm        GREATER THAN 160 dB         8 dB           120 m
--------------------------------------------------------------------------------------------------------------------
     2YC(mS)CY 0.5/3,0            75 Ohm        GREATER THAN 160 dB        6.6 dB          145 m
--------------------------------------------------------------------------------------------------------------------
       2YCCY 1.0/6.5              75 Ohm        GREATER THAN 160 dB         3 dB           320 m
--------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

<TABLE>
<CAPTION>

--------------------------------------------------------------------------------------------------------------------
                                      DATA RATE 140/155 MBIT/S COAXIAL
--------------------------------------------------------------------------------------------------------------------
                             Characteristic        Cross talk            Attenuation     Range with         Comments
       Type of cable           resistance          attenuation            at 70MHz      20% reserve
                                 (f=5MHz)                                [dB/100m]
--------------------------------------------------------------------------------------------------------------------
     <S>                     <C>                <C>                      <C>            <C>                 <C>
     02Y(St)CY 0.45/2.0           75 Ohm        GREATER THAN 160 dB        16.5 dB          58 m
--------------------------------------------------------------------------------------------------------------------
    02Y(St)CY 8X0.45/2.0          75 Ohm        GREATER THAN 160 dB        16.5 dB          58 m
--------------------------------------------------------------------------------------------------------------------
     2YC(mS)CY 0.5/3.0            75 Ohm        GREATER THAN 160 dB         14 dB           68 m
--------------------------------------------------------------------------------------------------------------------
       2YCCY 1.0/6.5              75 Ohm        GREATER THAN 160 dB        6.2 dB          150 m
--------------------------------------------------------------------------------------------------------------------
</TABLE>

The specifications on the range do not include attenuation from distributors or
similar connections. These additional attenuation values must be taken in
consideration in the limit range.

7.1.3

<PAGE>

7.1.4. CABLE VALUES FOR SYMMETRICAL STATION CABLE

<TABLE>
<CAPTION>

--------------------------------------------------------------------------------------------------------------------
                                       DATA RATE 2 MBIT/S SYMMETRICAL
--------------------------------------------------------------------------------------------------------------------
                               Characteristic       Cross talk           Attenuation    Range with         Comments
        Type of cable            resistance         attenuation           at 1MHz      20% reserve
                                  (f=5MHz)                               [dB/100m]
--------------------------------------------------------------------------------------------------------------------
     <S>                     <C>                 <C>                     <C>            <C>                <C>
     S-02YS(St)Y 1X2X0.4           114 Ohm       GREATER THAN 100 dB        4.0 dB          120 m
--------------------------------------------------------------------------------------------------------------------
     2Y(St)Y 1x2x0.5/1.5           113 Ohm       GREATER THAN  98 dB        2.2 dB          210 m
--------------------------------------------------------------------------------------------------------------------
     2Y(St)Y 1x2x0.5/2.2           141 Ohm       GREATER THAN 100 dB        1.6 dB          300 m
--------------------------------------------------------------------------------------------------------------------
    2YDD(ms)Y 1x2x0.5/2.2          141 Ohm       GREATER THAN 135 dB        1.6 dB          300 m
--------------------------------------------------------------------------------------------------------------------
    S-09YS(St)Y 1x 2x 0.4          120 Ohm          -                       4.2 dB          110 m        **1   **2
                                 +/- 12 Ohm
--------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------
</TABLE>

The specifications on the range do not include attenuation from distributors or
similar connections. These additional attenuation values must be taken in
consideration in the limit range.

Use symmetrical cable when the twisted pairs are shielded separately, otherwise,
these cables are not used at LNC.

**1    Supplier: Alcatel Cable  FILOTEX, Alcatel Kabel AG & Co.
**2    Designation: "Betefa-Kabel  1x 2x 0.4"
**3    Designation: "Filotex-Kabel 8x 2x 0.4 - ET 298 571"

7.1.5  CONNECTION CABLE TO SEPARATE CUSTOMER DISTRIBUTOR

Only the types of cable listed above may be used as connection cable to separate
customer transfer distributors.

In order to ensure sufficient protection of the cable, multiple conductor cable
with additional outer jacketing is to be used on a preferred basis.

7.1.6  RJ-45 CABLING

As for all other cabling LambdaNet will install a patch field in the rack to be
wired (here for up to 24 RJ-45) and wire this panel. The customer can use the
cable via the panel sockets.

ISDN CABLE S(0) (CATEGORY 3)

J-2Y(ST)Y STIII BD n x 2 x 0.6
J-2Y(ST)H STIII BD n x 2 x 0.6 halogen-free FRNC

e.g.   20 x 2   d=12mm
       10 x 2   d=9mm
        4 x 2   d=7.5mm

For construction of class C cable paths with transmission bandwidths of up to
16MHz.

<PAGE>

Application:
- System side installation cable between telephone system and telephone patch
  panel
- Installation cable between building distribution and floor distribution
  (secondary cabling)

Standards: Based on DIN VDE 0815

Characteristic resistance (+/- 15%)          100 Ohm
Propagation rate (NVP)                       0.66
Capacity coating                             (30-120)nF/km

On spiral quad, cables diametrically opposing conductors are to be wired as a/b
conductors (see illustration below).

O b1
O O a2 b2
O a1

FIG.: VIEW OF END OF CABLE - SPIRAL QUAD ASSIGNMENT

The cable already used by LCN for conventional 2Mbit/s cabling (120 Ohm) is to
be used for S(2M) connections.

CABLE (CAT. 5 FTP)

J-02YS(ST)Y 4 x 2 x 0.5 (AWG 24)
J-02YS(ST)H 4 x 2 x 0.5 (AWG 24) halogen-free FRNC

e.g.   4 x 2     d=6.3mm

Shielded installation cable for structured cabling. For construction of plastic
cabling paths with transmission bandwidths up to 100 MHz and standard
requirements for EMC and transmission security .

Standards: ISO/IEC 11801, EN 50173, EN 50167, EIA/TIA 568

Application:
- Installation cable between patch panel and equipment connection socket as
  floor cabling (tertiary cabling)
- Ethernet: IEEE 802.3, 10BaseT, 10 Mbps
- Fast Ethernet: IEEE 802.3u, 100BaseT, 100 Mbps
- Token Ring: IEEE 802.5, 4 / 16 Mbps
- ISDN

Characteristic resistance (+/- 15%)                  100 Ohm
Propagation rate (NVP)                               0.78
Bending radius when laying                           48 mm
Bending radius in operation (permanently laid)       24 mm

<PAGE>

CABLE (CAT. 5 S-FTP)

J-02YS(ST)CY 4 x 2 x 0.5 (AWG 24)
J-02YS(ST)CH 4 x 2 x 0.5 (AWG 24) halogen-free FRNC

e.g.   4 x 2     d=6.4mm

Double shielded installation cable for structured cabling system. For
construction of plastic cabling paths with transmission bandwidths up to 100 MHz
and standard requirements for transmission security and high requirements for
EMC.

Standards: ISO/IEC 11801, EN 50173, EN 50167, EIA/TIA 568

Application:
- Installation cable between patch panel and equipment socket as floor cabling
  (tertiary cabling)
- Ethernet: IEEE 802.3, 10BaseT, 10 Mbps
- Fast Ethernet: IEEE 802.3u, 100BaseT, 100 Mbps
- Token Ring: IEEE 802,5, 4 / 16 Mbps
- ATM: 155 Mbps, FDDI: TP-PMD 100 Mbps, ISDN

Characteristic resistance (+/- 15%)                  100 Ohm
Propagation rate (NVP)                               0.78
Bending radius when laying                           52 mm
Bending radius in operation (permanently laid)       26 mm

7.1.7

<PAGE>

7.1.8  PATCHING CABLE ON DISTRIBUTOR

7.1.8.1  COAXIAL PATCHING CABLE

Patching on the distributor is to be accomplished only with suitable cable. The
cable must have the required characteristic resistance. The patching cable
should be designed with sufficient flexibility to allow simple cable routing on
the distributor.

7.1.8.2  SYMMETRICAL PATCHING CABLE

Only shielded symmetrical 120 Ohm cable is to be used for patching on the
distributor and the shield is to be connected at both ends of the patch.

8      REFERENCES

8.1    STANDARDS

<TABLE>
<CAPTION>

-------------------------------------------------------------------------------
ID                  Version          Title:
-------------------------------------------------------------------------------
<S>                 <C>              <C>
ITU-T G.703         1991             Physical/Electrical Characteristics of
                                     Hierarchical Digital Interfaces
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
</TABLE>

<PAGE>
================================================================================

                            CONFIDENTIALITY AGREEMENT

PREAMBLE

The parties have concluded a contractual agreement governing the delivery of
transmission systems and the associated services. During the term of the
contractual agreement, the parties will exchange confidential information for
the purpose of implementing the subject matter of the contractual agreement.
With regard to the parties wishing to avoid abuse of this information, the
following shall be defined by contractual agreement:

(1)  The parties shall herewith commit themselves to treat all information they
     obtain either directly or indirectly from the other party within the
     framework of implementing the contractual agreement, strictly
     confidentially. Treating information confidentially means that the
     information received from the other party must not be made accessible to
     third parties and this information must not be used commercially for own
     purposes or for third parties. The parties shall commit themselves to using
     the received information solely for the purpose stipulated in the preamble.
     Any use of the information beyond the stipulated purpose or its transfer to
     third parties shall require the written approval of the information
     provider. The transfer of information to affiliated group companies and/or
     to individual consultants as deemed necessary for the purpose of
     implementing the contractual agreement shall, however, be permitted without
     specific written approval of the information provider under the
     prerequisite that these persons commit themselves in writing to treating
     the information confidentially in compliance with this contractual
     agreement.

     Each party shall protect the information received from the other party with
     the same care and diligence used to protect the own company and business
     secrets and additionally with the care and diligence of a prudent business
     partner.

(2)  The obligation to observe secrecy shall not apply to information

     which is already publicly known at the time of relinquishment or - through
     no fault of the information recipient - is subsequently known publicly;

     which was already known to the information recipient prior to
     relinquishment or subsequently relinquished to him legitimately by a third
     party without him being obliged to observe secrecy by said third party;

     which, in accordance with legal requirements, is to be published by the
     information recipient. Insofar as permissible, the information recipient
     shall notify the informing party of the publication.

     It shall be incumbent on the information recipient to verify the
     exceptional statuses specified in this subparagraph item.

     (3)  On request of the respective other party, each party shall be
          obligated to immediately return written information or information
          recorded in any other manner (including any copies made) to the
          requesting party or to confirm its eradication by destruction in
          writing.

(4)  The confidentiality agreement shall come into force on being signed by both
     parties. The obligation to observe confidentiality shall remain valid for a
     period of five years - also beyond termination of the contractual agreement
     stipulated in the preamble -.

(5)  The parties shall agree that no transfer of titles of ownership or rights
     of use shall be involved in the transfer of information. Conclusion of this
     contractual agreement shall not entitle any of the parties to act on behalf
     of the other party in any way whatsoever. Any commitment of the parties in
     internal and external relations that extend beyond the framework of this
     contractual agreement shall require a further written contractual
     agreement.

<PAGE>
================================================================================

(6)  If one stipulation of this contractual agreement is or becomes ineffective
     either in full or in part, this shall not affect the validity of the
     remaining stipulations. Instead of the ineffective stipulation, the legally
     permissible arrangement that most closely expresses the meaning and purpose
     of the ineffective stipulation shall be considered as agreed upon. The
     above stipulations shall apply accordingly in the case of a gap or loophole
     requiring amendment.

(7)  Amendments and supplements to this contractual agreement shall require the
     written form. This shall also apply to agreements designed to restrict or
     cancel the requirement of the written form.

(8)  The place of jurisdiction for all disputes stemming from this contractual
     agreement shall be Hanover.
<PAGE>

                                    ANLAGE 8

                               LIST OF AFFILIATES

<PAGE>

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
TERRITORY                NORTEL NETWORKS AFFILIATE (INCLUDING ADDRESS)
--------------------------------------------------------------------------------
<S>                      <C>
FRANCE                   Matra Nortel Communications SAS,
                         50, rue du President Sadate-Creac'h Gwenn,
                         29101 Quimper,
                         France.
--------------------------------------------------------------------------------
UNITED KINGDOM           Nortel Networks plc.,
                         Maidenhead Office Park,
                         Westacott Way,
                         Maidenhead,
                         Berkshire,
                         SL6 3QH,
                         UK.
--------------------------------------------------------------------------------
SPAIN                    Nortel Networks Hispania S.A.,
                         Avenidas de los Dos Castillas 33,
                         Edificio Atica - 2,
                         Pozuelo de Alarcon,
                         28224 Madrid,
                         Spain
--------------------------------------------------------------------------------
ITALY                    Nortel Networks SpA,
                         Via Montenavale 2,
                         Ivrea (Torino),
                         Italy.
--------------------------------------------------------------------------------
PORTUGAL                 Nortel Networks (Portugal) S.A.
                         Campo Grande 35 - 9 D
                         1700 Lisbon
                         Portugal.
--------------------------------------------------------------------------------
AUSTRIA
--------------------------------------------------------------------------------
CZECHIA
--------------------------------------------------------------------------------
DENMARK
--------------------------------------------------------------------------------
LUXEMBOURG
--------------------------------------------------------------------------------
</TABLE>
<PAGE>

                                    ANLAGE 9

                         LIST OF AFFILIATES - LAMBDANET

<PAGE>

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
TERRITORY                LAMBDANET AFFILIATE (INCLUDING ADDRESS)
--------------------------------------------------------------------------------
<S>                      <C>
FRANCE                   LambdaNet Communications France
                         1, Boulevard Vivier Merle; 69443 Lyon Cedex 03
                         France
                         Tel.: + 33 (0) 472 91 28 21
                         Fax: + 33 (0) 472 91 28 23

                         LambdaNet Communications France
                         17, Square Edouard VII
                         75009 Paris
                         Tel.: + 33 1 53 43 94 97
                         Fax: + 33 1 53 43 94 90

--------------------------------------------------------------------------------
UNITED KINGDOM
--------------------------------------------------------------------------------
SPAIN
--------------------------------------------------------------------------------
ITALY
--------------------------------------------------------------------------------
PORTUGAL
--------------------------------------------------------------------------------
AUSTRIA
--------------------------------------------------------------------------------
CZECHIA
--------------------------------------------------------------------------------
DENMARK
--------------------------------------------------------------------------------
LUXEMBOURG
--------------------------------------------------------------------------------
</TABLE><PAGE>
                                                                  Exhibit 10.18

                                  PMP CONTRACT*

                                     between

 FIRSTMARK COMMUNICATION DEUTSCHLAND GMBH, Uhlandstrasse 179/180, 10623 Berlin
                     - hereinafter referred to as "FMCD" -

                                       and

        SIEMENS AKTIENGESELLSCHAFT, Hofmannstra(beta)e 51, 81359 Munchen
                    - hereinafter referred to as "Siemens" -

We refer to (a) the framework agreement between FirstMark Communications Europe
SA ("FirstMark") and Siemens dated _____________ (as amended by Amendment No. 1
dated on or about the date hereof) (the "European Agreement"); and (b) the
facility agreement (the "Facility Agreement") to be entered into between, inter
alios, FMCD as guarantor, FirstMark Communications Deutschland Holding GmbH as
borrower and Deutsche Bank Luxembourg SA as agent (the facilities to be provided
under such agreement, the "Financing").

Terms used in this PMP Contract but not defined shall have the meanings ascribed
to them in the European Agreement.

FMCD, as an Affiliate of FirstMark, is permitted under the terms of the European
Agreement to order as a Purchaser pursuant to the European Agreement Systems
and/or Services and/or any other performance as foreseen in the European
Agreement on the terms and subject to the conditions of the European Agreement
and Siemens is obliged to provide such Systems and/or Services pursuant to a
Contract according to the European Agreement and to provide any other
performance as foreseen in the European Agreement to FMCD on such terms and
subject to such conditions.

In addition to the provisions of the European Agreement the following shall
apply:

1.   Each Order by FMCD for Systems and/or Services for the purposes of the
     Network (as defined in the Facility Agreement) shall refer explicitly to
     this PMP Contract. All invoices for such Systems and Services ordered by
     FMCD shall be addressed to FMCD and directed to it.

-------------------
* Portions of this agreement are confidential and have been omitted and filed
  separately with the Securities and Exchange Commission pursuant to a request
  for confidential treatment in accordance with Rule 406 under the Securities
  Act of 1933 as amended. Asterisks, for example "*****," have been inserted to
  indicate that information has been deleted.

<PAGE>
                                                                         Seite 2

2.   The address to which invoices for FMCD must be sent is:

                    FirstMark Communications Deutschland GmbH

                             Gunther-Wagner-Allee 13

                                 30177 Hannover

3.   FMCD agrees that in accordance with clause 5.2 of the European Agreement,
     the Contractor shall retain title to the equipment delivered under the
     Contract which is the subject of the Financing until (1) each and every
     ********************************** is entitled under the respective
     Contract has been duly satisfied and (2) Siemens is fully and finally
     released from *****************************************************
     between, inter alios, Siemens and Deutsche Bank Luxembourg SA to be dated
     on or about the date hereof. Thereafter the Contractor shall transfer title
     to such equipment supplied to FMCD in reference to the PMP Contract to
     Deutsche Bank Luxembourg SA which shall hold such title subject to and in
     accordance with the security documents to be entered into between, inter
     alios, FMCD and Deutsche Bank Luxembourg SA in respect of the Financing.

     The provisions of clause 8 of the European Agreement shall apply to this
     PMP Contract Agreement, mutis mutandis.

Signed by                                Signed by

/s/ Dr. Dieter Finke                     /s/ Rudi Frey Gunther Brauning
------------------------------------     -------------------------------------
Dr. Dieter Finke                         Rudi Frey Gunther Brauning
on behalf of FIRSTMARK COMMUNICATIONS    on behalf of SIEMENS AKTIENGESELLSCHAFT
DEUTSCHLAND GMBH
Date: 30 May 2000                        Date: 30. May 2000

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                                AMENDMENT NO. 1

This amendment agreement is between FirstMark Communications Europe SA
("FirstMark") and Siemens Aktiengesellschaft ("Siemens") and it amends the
framework agreement between FirstMark and Siemens dated [25.5.2000] (the
"European Agreement").

Terms used herein but not defined shall have the meanings ascribed to them in
the European Agreement.

With effect from May 30, 2000, Section 5.2 of Appendix 1 of the European
Agreement shall be replaced with the following:

5.2

a)    Transfer of Title shall be effected as follows:

aa)   In cases in which the Contractor does not in any way financially support
      financing of a Purchaser to purchase Systems and/or Services, the
      Contractor shall transfer title to the relevant equipment to such
      Purchaser or to a third party as specifically agreed ******
      under the respective Contract has been duly satisfied.

bb)   In cases in which the Contractor financially supports in any way financing
      of the Systems and/or Services purchased by a Purchaser, transfer of title
      to the relevant equipment shall be **************.

b)    Until transfer of title is effected by Contractor in accordance with a)
      above, the Purchaser shall use its best endeavors to ensure that any
      purported retention of title arrangements are valid *******
      and in any event the Purchaser shall (i) not remove the
      relevant System outside the *******************, (ii) not
      transfer possession of the relevant System, and (iii) inform the
      Contractor immediately in writing in case of seizure or other acts or
      interventions by third parties and to cooperate in any required
      registration procedure.

      The provisions of clause 8 of the European Agreement shall apply to this
      Amendment No. 1 to the European Agreement, mutatis mutandis.

Berlin, May 30, 2000                        Berlin, May 30, 2000
Signed by                                   Signed by

/s/ Dr. Dieter Finke                        /s/ Rudi Frey /s/ Grunther Brauning
-----------------------------------         -----------------------------------
Dr. Dieter Finke                            Rudi Frey    Grunther Brauning

on behalf of                                on behalf of
FIRSTMARK COMMUNICATIONS EUROPE SA          SIEMENS AKTIENGESELLSCHAFT

<PAGE>

                              EUROPEAN AGREEMENT*

                                    BETWEEN

                      FIRSTMARK COMMUNICATIONS EUROPE SA

                                      AND

                                  SIEMENS AG

                                 Page 1 of 11

-------------------
* Portions of this agreement are confidential and have been omitted and filed
  separately with the Securities and Exchange Commission pursuant to a request
  for confidential treatment in accordance with Rule 406 under the Securities
  Act of 1933 as amended. Asterisks, for example "*****," have been inserted to
  indicate that information has been deleted.

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

THIS EUROPEAN AGREEMENT is made on the 16 day of May 2000

Between

FIRSTMARK COMMUNICATIONS EUROPE SA, a company existing and organised under
the laws of Luxembourg with its registered office located at 3, rue Jean
Piret, L-2350 Luxembourg ("FirstMark") and Siemens AG, a company duly
incorporated in Germany having its registered office at Munich and being
registered with the commercial register of the lower court of Munich under
HRB 6684 ("Siemens").

WHEREAS

A. FirstMark is establishing a European Telecommunications Network (the
   "Network") through its various present and future Affiliates and wishes
   to appoint Siemens to provide systems and services which will support the
   full range of end to end services of FirstMark to the extent set out in
   this European Agreement.

B. The Parties are entering into this European Agreement under which Siemens
   will be responsible for the design, development, manufacture, supply,
   installation, integration and testing of systems and services to enable
   FirstMark to provide a full range of end to end services to end users.

C. FirstMark wishes to establish and Siemens is willing to agree on
   procedures on which FirstMark and its Affiliates shall order certain systems
   and services and related facilities from Siemens and its Affiliates on the
   terms and conditions hereinafter appearing.

NOW IT IS AGREED AS FOLLOWS:

  1  DEFINITIONS AND INTERPRETATION

1.1  The definitions set out in Appendix 5 shall apply to the terms of this
     European Agreement.

1.2  Except where the context otherwise requires, the masculine gender shall
     include the feminine and neuter and the singular shall include the plural
     and vice versa and reference to persons include bodies corporate and
     incorporate. Reference to a Party to this European Agreement shall include
     the permitted successors and assigns of such Party.

1.3  The Section and Appendix headings and table of contents are for
     convenience of reference only and shall not be taken into account in
     construing this European Agreement.

European Agreement 000510                                           Page 2 of 11

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

1.4  References in this European Agreement to Sections and Appendices are to
     Sections and Appendices of this European Agreement and the Appendices
     form part of this European Agreement and shall have the same force and
     effect as if expressly set out in the body of this European Agreement.

  2  SCOPE OF THE EUROPEAN AGREEMENT

2.1  Unless otherwise expressly agreed in writing, all contractual
     arrangements between FirstMark and Siemens for the provision of Systems
     and Services for the purpose of connecting FirstMark's customers with
     various services shall be subject to the terms and conditions contained
     in this European Agreement.

2.2  The terms and conditions of this European Agreement are subject to
     Siemens and/or suitable Lender providing an executed Loan Agreement as
     detailed in Appendix 9.

2.3  Appendix 6 includes a non-exhaustive list of the European territories in
     which FirstMark plans to establish the Network, and the corresponding
     Siemens and FirstMark contracting entities for the purpose of performing
     the Contracts under this European Agreement. FirstMark and Siemens may
     agree from time to time to extend said list in accordance with
     FirstMark's Network requirements. FirstMark or any of its Affiliates may
     at any time during the period of this European Agreement submit a
     written Order to Siemens for the provision of Systems and/or Services to
     be provided hereunder, which Order shall be in the form of and contain
     the details required in Appendix 4.

2.4  Siemens shall respond promptly (and in any event no later than five
     Working Days) in writing to any Order received pursuant to Section 2.3,
     stating if it accepts the Order and warrants to FirstMark that has all
     necessary powers to so procure. The resulting Contract shall be subject
     to the terms and conditions contained in this European Agreement.

2.5  For the avoidance of doubt all Orders placed by FirstMark or any of its
     Affiliates and accepted by Siemens shall be subject to the terms and
     conditions contained in this European Agreement, which will constitute
     the sole and entire contract between the Parties in respect of the
     provision of Systems and Services comprising the Order.

2.6  Notwithstanding Sections 2.10 and 2.11 of this European Agreement, nothing
     in this European Agreement shall prevent FirstMark from seeking the
     supply of services, equipment or software from parties other than
     Siemens.

European Agreement 000510                                         Page 3 of 11

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

2.7  FirstMark may initiate a joint annual review of all prices and
     commercial and technical terms under this European Agreement within two
     months of the first anniversary and subsequent anniversaries of this
     European Agreement. In addition, if at any time between annual reviews
     FirstMark has reasonable indications that Siemens is not offering a
     competitive package in accordance with Section 2.6, FirstMark may
     initiate an interim review. If within a period of one month of the
     initiation of a review it is demonstrated to FirstMark that Siemens is
     unwilling or unable to offer a competitive package in accordance with
     Section 2.6, FirstMark shall be entitled to terminate this European
     Agreement without liability to Siemens. If so requested by Siemens, such
     alternative arrangements shall be made available by FirstMark to an
     independent third party for verification by Siemens. However, this
     European Agreement shall be deemed to survive with respect to Orders
     outstanding at the time of such termination until the respective
     obligations have been fulfilled.

2.8  After the expiration of 12 months from the date of this European
     Agreement, FirstMark may select another supplier to provide services and
     equipment in the Markets referred to in Sections 2.10 and 2.11 below
     PROVIDED THAT prior to placing any such orders, FirstMark shall give
     Siemens, in a timely manner, the opportunity to match or better any
     alternative arrangements on the basis of price and terms. If so
     requested by the Siemens, such alternative arrangements will be made
     available by FirstMark to an independent third party for verification by
     Siemens.

2.9  At times to be agreed, FirstMark shall submit to Siemens a forecast of
     FirstMark's reasonable estimate of its and its Affiliates' requirements
     for Systems an Services during each of the upcoming twelve months (the
     "Forecast").  Purchases by FirstMark and its Affiliates in any given
     month may be either more or less than the amount specified for such
     month in the Forecast.  The Forecast procedure shall be mutually agreed
     and detailed in Appendix 4.

2.10 Subject to Sections 2.7 and 2.8, FirstMark shall place Orders with
     Siemens for at least *** ("Preferred Supplier") of the Markets in
     Germany that FirstMark rolls out within a period of 12 months from the
     date of this European Agreement. Such Order volumes *** shall not
     necessarily include Siemens' ONU/CMX access equipment.

2.11 Subject to Sections 2.7 and 2.8, FirstMark shall place Orders with
     Siemens for at least ***** Markets in Germany that
     FirstMark rolls out within a period of 12 months from the date of this
     European Agreement.  FirstMark and Siemens shall mutually agree which of
     the Markets are to be the top ***.

European Agreement 000510                                          Page 4 of 11

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

2.12  FirstMark shall place Orders referred to in Sections 2.10 and 2.11
      above, subject to Siemens providing ************** and subject to
      Siemens becoming the Preferred Supplier in the respective country:

      i)  radio planning and other technical services (as more particularly
          described in Appendix 4) for those countries in Europe where
          FirstMark chooses to submit applications for wireless local loop
          licences and shall support FirstMark as its "preferred customer" in
          any competitive tender, including making available to FirstMark, in
          preference to Siemens' other clients, necessary technical and
          regulatory resources. Where such work has been performed by other
          vendors for FirstMark and where Siemens receives an Order from
          FirstMark, Siemens agrees to compensate FirstMark for the payments
          made for those services. However, such compensation shall be
          limited to the efforts which Siemens' would have made if it had
          been in charge of the application support process and shall be
          equivalent to the percentage of the Order volume submitted to
          Siemens in relation to the total order volume submitted by
          FirstMark in that country within a two year period, commencing on
          the date of the first Order in that Country.

     ii)  marketing services whereby Siemens will market FirstMark's products
          in Markets where FirstMark places an Order with Siemens, as
          detailed in Appendix 7.

     iii) PBX equipment (for a maximum of three PBX each of an approximate
          value of **********) as more particularly described in Appendix 8
          in each country in Europe where FirstMark obtains licenses and
          where FirstMark has selected Siemens as supplier for radio
          equipment for the first three years of operations. Notwithstanding
          the aforementioned, FirstMark shall be obligated to pay for such
          equipment if FirstMark fails to obtain licenses or does not grant
          Siemens the Preferred Supplier status in such country.

     iv)  permission for FirstMark to utilize Siemens' sites in Germany and
          Siemens shall use all reasonable efforts in order to make available
          Siemens' sites in other countries where FirstMark places an Order
          with Siemens, so that FirstMark may place base stations and other
          relevant equipment at such sites as detailed in Appendix 4,
          provided that the Point to Multipoint base station equipment has
          been provided by Siemens. The right to use all Siemens' location
          and roof-tops for FirstMark base stations shall be *******
          for the first five years, at favourable rates for the following two
          years and thereafter at *******.

     Provided that if FirstMark fails to receive wireless local loop licences
     in an applicable country, FirstMark shall reimburse Siemens its
     reasonable costs incurred in the performance of the aforementioned
     services for that country, such costs to be agreed between FirstMark and
     Siemens.

2.13  The features which are to be developed for version 6.0 shall be
      discussed, mutually

European Agreement 000510                                         Page 5 of 11

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

      understood and agreed with respect to the main features. It shall be
      deemed agreed by FirstMark that no penalties for the excess of the
      mutually agreed time schedule shall become due.

2.14  Should Siemens or any of its Affiliates receive an Order with lead
      times that are shorter than those specified in Appendix 4, it shall
      indicate in writing to FirstMark or its Affiliate whether such shortened
      lead times are acceptable. If Siemens or its Affiliate shall deem a
      shortened lead time unacceptable, the Parties shall endeavor to agree
      upon lead times that are mutually acceptable, but in no case shall such
      lead times be longer than the lead time specified in Appendix 4 (counted
      from the date of the original Order). Any changes to an accepted Order
      must be mutually agreed upon in writing and be contained in a Change
      Order referencing the original Order.

2.15  The European Agreement comprises the following Appendices:

      Appendix 1 - Terms and Conditions of Contract
      Appendix 2 - Pricing Section
      Appendix 3 - System Specification
      Appendix 4 - Technical Services
      Appendix 5 - Definitions
      Appendix 6 - List of Affiliates
      Appendix 7 - Marketing Agreement
      Appendix 8 - PBX Specification
      Appendix 9 - Loan Agreement

2.16  Where there is a discrepancy between this European Agreement and
      Appendix 1 hereto, then the provisions of Appendix 1 shall prevail.
      Where there is a discrepancy between the content of Appendices 2 to 9,
      then the most detailed provisions shall prevail. Where there is a
      discrepancy between the content of Appendices 2 to 9 And Appendix 1,
      then Appendix 1 shall prevail

  3  PERIOD OF EUROPEAN AGREEMENT

3.1  This European Agreement shall come into full force and effect from the
     date hereof for a period of five years ("Initial Period") and will
     continue until the expiry of the Initial Period.

3.2  At the end of the Initial Period, this European Agreement shall
     automatically continue in full force and effect unless and until
     terminated by either Party giving to the other not less than two months'
     written notice of termination to expire at the end of any anniversary of
     this European Agreement.

3.3  FirstMark shall be entitled to terminate this European Agreement with
     written notice if the Field Acceptance Certificate, as defined in
     Appendix 5 of this European Agreement, with respect to the Saarbruecken
     deployment is not issued.

European Agreement 000510                                         Page 6 of 11
<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

  4  PROJECT MANAGEMENT

4.1  Within two calendar months of the date of this European Agreement,
     Siemens shall establish and maintain a project management system,
     according to the guidelines set out in Appendix 4.

4.2  Project management reports shall be prepared and submitted by Siemens to
     FirstMark, or its Affiliates where applicable, or authorised
     representatives of FirstMark as specified in Appendix 4.

  5  PRICES

5.1  The Prices for the System and Services are set out in Appendix 2. All
     Prices in Appendix 2 are exclusive of value added tax or its equivalent.
     In respect of FirstMark's requirements within the countries set out in
     Part 1 of Appendix 6, deliveries to the Site of Installation are made at
     Siemens' cost, all transportation costs being the responsibility of
     Siemens. In respect of FirstMark's requirements within the countries set
     out in Part 2 of Appendix 6, deliveries to the Site of Installation are
     made at FirstMark's or its Affiliates' cost, all transportation costs
     being the responsibility of FirstMark.  All taxes and customs duties
     shall be borne by Siemens in accordance with Incoterms 1990 DDP terms in
     respect of FirstMark's requirements within the European Union.  All
     taxes and customs duties shall be borne by FirstMark or its Affiliates
     in accordance with Incoterms 1990 DDU terms in respect of FirstMark's
     requirements outside of the European Union.

5.2  All Prices shall not be increased for two years from the date hereof,
     except Service charges, which may be increased in accordance with the
     Labor Index.

5.3  The invoices by Siemens to FirstMark with respect to the project
     management as described in Appendix 4 may be invoiced by Siemens on a
     quarterly basis in advance.

5.4  Siemens shall provide FirstMark with the licence for the radio network
     planning tool (net designer; current version) at competitive prices,
     which shall also depend on the requested configuration. If FirstMark
     however acquires a different radio network planning tool at a higher,
     but competitive market price, than that acquired from Siemens, then
     the differential amount shall be gradually discounted from the invoices
     subsequently submitted by Siemens to FirstMark. However, such gradual
     discount shall in each single invoice not exceed *****.

European Agreement 000510                                          Page 7 of 11

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

  6  ELECTRONIC DATA INTERCHANGE

The Parties shall work together to develop and implement a system of
Electronic Data Interchange ("EDI"). The specifications and requirements
of EDI are set out in Appendix 4.

  7  DEVELOPMENT TEAM

7.1  The Parties shall work together to create a joint development team to
     ensure that FirstMark is kept continually up-dated and involved in
     current and intended developments, including the development and the
     specifications for version 6.0 as more particularly described in
     Appendix 3 and a monitoring process which allows FirstMark current
     information on Siemens' implementation schedule, as detailed in Appendix
     4.

7.2  Where FirstMark has actively participated in the specifications and the
     development of such characteristics of the equipment or in new products
     or has made corresponding financial contributions to the development of
     such products and, where such developments are not made compulsory by the
     regulators in the various countries, such products or features of the
     equipment shall be made available to FirstMark on an exclusive basis for
     a period of time and upon such conditions to be mutually agreed prior to
     the beginning of such development.

  8  LAW AND JURISDICTION

8.1  This European Agreement shall be governed by and construed and
     interpreted in accordance with German law and the Parties submit to the
     exclusive jurisdiction of the German courts without the application of
     the United Nations Convention on Contracts for the International Sale of
     Goods dated April 11, 1980. The venue shall be deemed agreed as the
     court of Berlin.

8.2  The Parties acknowledge that Special Conditions may be applicable to the
     provision of System and Services in particular Territories. Such
     Special Conditions as are agreed between the Parties as at the date
     hereof are set out in Appendix 6.  The Parties further acknowledge and
     agree that Orders submitted pursuant to Section 2.3 may be subject to
     further Special Conditions which shall be the subject of further
     negotiation and if agreed will form part of any Order submitted pursuant
     to this European Agreement.

European Agreement 000510                                         Page 8 of 11
<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

  9  MISCELLANEOUS

9.1  This European Agreement may not be modified except by written amendment
     signed by responsible authorised representatives of both Parties save
     that the address for notices and the responsible authorised
     representatives of the Parties may be added to or changed from time to
     time by written notice to the other Party.

9.2  For the purposes of administration of this European Agreement, including
     amendments and the approval of any change, any communication between the
     Parties shall be enforceable and binding upon the Parties only if signed
     by the appropriate responsible authorised representatives.

9.3  The responsible authorised representatives of the Parties may be changed
     from time to time by notice in writing to the other Party. Until
     further notice the responsible and authorised representative of
     FirstMark shall be Tim Samples, Chief Executive Officer and the
     responsible and authorised representatives of Siemens shall be Reinhard
     Siekaczek, ICN TR, Kaufmaennischer Leiter.

9.4  FirstMark agrees that throughout the term of this European Agreement and
     for the period of 12 months after its termination, neither FirstMark nor
     any of its Affiliates shall employ or engage as an independent
     consultant or offer employment or engagement to any of Siemens' or its
     Affiliates' employees who are involved in the performance of Contracts
     hereunder, without Siemens' prior written agreement.

9.5  In the event that any one or more of the provisions of this European
     Agreement shall, for any reason, be held to be illegal, invalid or
     unenforceable, the remaining provisions of this European Agreement shall
     be unimpaired, and the invalid or unenforceable provision shall be
     replaced by a mutually acceptable provision which, being valid and
     enforceable, comes closest to the intention of the Parties underlying
     the illegal, invalid or unenforceable provision.

9.6  Nothing herein shall create or be deemed to create a joint venture or
     partnership between the Parties nor, save as specifically provided in
     this European Agreement, constitute one Party the agent of the other
     Party.

9.7  This European Agreement shall be binding upon the Parties hereto and
     their successors and permitted assigns. Neither Party may assign this
     Agreement, in whole or in part, without the prior written agreement of
     the other Party, which agreement shall not be unreasonably withheld or
     delayed.

9.8  All correspondence, notices, documentation and communications concerning
     this European Agreement shall be in the English language.

European Agreement 000510                                          Page 9 of 11

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

9.9   A waiver of any breach of any provision hereof shall not be binding upon
      either Party unless made in writing. No such waiver shall affect the
      rights of the Party not in breach with respect to any other or future
      breach of this European Agreement. No delay or failure by a Party to
      exercise any of its rights, or time or indulgence given by it before
      exercising any right or remedy under this European Agreement shall
      operate as a waiver of the same nor shall any single or partial exercise
      of a right or remedy preclude any further exercise of the same or the
      exercise of any other right or remedy.

9.10  All costs and expenses incurred by the Parties in connection with the
      negotiation of and entry into this European Agreement shall be borne by
      the Party incurring the same.

9.11  All notices and other correspondence of a legal nature by either Party
      to the other Party shall be sent to the following address:

      For FirstMark:

      Originals:                              Copy:
      Chief Executive Officer                 General Counsel
      FirstMark Communications Europe SA      FirstMark Communications Services
      3 Rue Jean Piret                        Europe Limited
      L-2350 Luxembourg                       4th Floor
      Luxembourg                              1 James Street
                                              London W1M 5HY
                                              England

                                              General Counsel
                                              FirstMark Communications
                                              Deutschland GmbH
                                              Uhlandstrasse 179/180
                                              D-10623 Berlind
                                              Germany

     For Siemens:

      Siemens AG
      Rechtsabteilung
      Hofmannstrasse 51
      D-81359 Munich
      Germany

9.12  Any notice, report, invoice or other correspondence shall be deemed to
      have been received by one Party on the day on which such communication
      has been received by it.

European Agreement 000510                                          Page 10 of 11

<PAGE>

EUROPEAN AGREEMENT BETWEEN FIRSTMARK COMMUNICATIONS EUROPE SA AND SIEMENS AG

9.13  Neither Party shall make any announcements, news releases or other
      public statements regarding this European Agreement or its subject
      matter without the prior written approval of both FirstMark and Siemens,
      such approval not to be unreasonably withheld or delayed.

9.14  Neither Party shall be liable under this European Agreement, or arising
      out of its termination, or under tort or otherwise howsoever arising,
      for any indirect or consequential loss or damages, costs or losses, or
      for any damages arising from or attributable to failure to realise
      expected savings, loss of data and information, loss of interest and in
      cases of business interruption, capital downtime costs, loss of use,
      loss of goodwill or loss of anticipated or actual revenue or profit
      even if either Party has been advised of possibility of any such damages.

SIGNED for and on behalf of the Parties by a duly authorised representative.

On behalf of Siemens:

By:     /s/                                By:     /s/
        -----------------------                    ---------------------------

Title:  Member of the Board ICN            Title:  Senior Vice President
        -----------------------                    ---------------------------

Date:   25.5.00                            Date:   25.5.00
        -----------------------                    ---------------------------

On behalf of FirstMark:

By:     /s/                                By:     /s/
        -----------------------                    ---------------------------

Title:  CEO FirstMark                      Title:  Director International PM
        -----------------------                    ---------------------------

Date:   (illegible)                        Date:   15-05-00
        -----------------------                    ---------------------------

European Agreement 000510                                          Page 11 of 11

<PAGE>

                                   APPENDIX 1

                        TERMS AND CONDITIONS OF CONTRACT

                                  Page 1 of 29

<PAGE>

<TABLE>
<CAPTION>

CONTENT:
<S>                                                            <C>

1     DEFINITIONS AND INTERPRETATION..................................3
-     ------------------------------

2     OBJECT OF THE CONTRACT..........................................3
-     ----------------------

3.    STANDARD SOFTWARE AND THIRD PARTY SOFTWARE......................4

4     DOCUMENTATION...................................................5
-     -------------

5     DELIVERY AND TITLE..............................................6
-     ------------------

6     INSTALLATION....................................................6
-     ------------

7     FIELD ACCEPTANCE................................................7
-     ----------------

8     CONTRACTOR'S PERSONNEL..........................................8
-     ----------------------

9     COMPLETION DATES................................................9
-     ----------------

10    PRICES..........................................................9
--    ------

11    LIQUIDATED DAMAGES.............................................11
--    ------------------

12    QUALITY ASSURANCE..............................................12
--    -----------------

13    TRAINING AND ASSISTANCE........................................13
--    -----------------------

14    FORCE MAJEURE..................................................13
--    -------------

15    WARRANTIES.....................................................14
--    ----------

16    AVAILABILITY OF SPARE PARTS....................................17
--    ---------------------------

17    LIABILITY......................................................19
--    ---------

18    RIGHTS OF THIRD PARTIES........................................20
--    -----------------------

19    CONFIDENTIALITY AND COPYRIGHT..................................21
--    -----------------------------

20    ASSIGNMENT.....................................................23
--    ----------

21    NEW DEVELOPMENTS, CHANGE REQUESTS AND CANCELLATION.............23
--    --------------------------------------------------

22    TERMINATION....................................................24
--    -----------

23    DISPUTES.......................................................26
--    --------

24    LAW AND JURISDICTION...........................................27
--    --------------------

25    MISCELLANEOUS..................................................27
--    -------------
</TABLE>

                                  Page 2 of 29
<PAGE>

1        DEFINITIONS AND INTERPRETATION

1.1      The definitions set out in Appendix 5 shall apply to the terms and
         conditions contained in this Appendix 1.

1.2      Except where the context otherwise requires, the masculine gender shall
         include the feminine and neuter and the singular shall include the
         plural and vice versa and reference to persons include bodies corporate
         and incorporate. Reference to a Party to the Contract shall include the
         permitted successors and assigns of such Party.

1.3      The Section and Appendix headings and table of contents are for
         convenience of reference only and shall not be taken into account in
         construing the Contract.

1.4      References in this Appendix to Sections and Appendices are to Sections
         of this Appendix and Appendices of the European Agreement.

2        OBJECT OF THE CONTRACT

2.1      Subject to the issue and acceptance of an Order, the Contractor shall
         provide Systems and Services according to the description and
         specification in Appendix 3, 4 and 8.

2.2      Any applicable licenses, permits, approvals or consents relating to the
         manufacture, type, acceptance or general use (other than approvals such
         as point to multi-point frequencies and class 3 and 4 licenses in
         accordance with the German Telecommunications Act required to permit
         the Purchaser to operate the System in a specific area) in the
         respective countries shall be the sole responsibility of the
         Contractor, and the Contractor agrees to obtain at its cost all such
         licenses, permits, approvals or consents in a timely manner. At the
         Purchaser's request and prior to the time the first units of the System
         are delivered, the Contractor shall furnish the Purchaser with evidence
         that such licenses or permits, etc. have been obtained and are in full
         force and effect. The Contractor agrees that the System will conform to
         all applicable mandatory legal and regulatory standards and all other
         standards identified in the System Specifications.

2.3      The Contractor acknowledges it has obtained knowledge of the European
         Agreement dated [     ] between Siemens AG and FirstMark Communications
         Europe SA ("the European Agreement") and that the obligations set forth
         therein shall have full effect on it.

                                                                    Page 3 of 29
<PAGE>

3.       STANDARD SOFTWARE AND THIRD PARTY SOFTWARE

3.1      The Contractor hereby grants to the Purchaser, subject to the payment
         of any applicable licence fees as set out in Appendix 2, an irrevocable
         (save for the provisions of Section 22.6), perpetual, worldwide,
         non-exclusive, non-transferable licence (Nutzungsrecht) to use and
         operate Software to operate the System, at no additional royalty
         payment obligation.

3.2      For the sole purpose of facilitating operation of the System, Purchaser
         shall be entitled to grant sub-licences, without right to further
         sub-license, under and on the same terms as those set out in the
         licence granted in Section 3.1 above to:

         3.2.1    a Purchaser Affiliate; and/or

         3.2.2    third parties, subject to the Contractor's prior written
                  agreement, which shall not be unreasonably withheld or
                  delayed.

3.3      Purchaser, Purchaser Affiliates and third parties shall be entitled to
         make back-up copies of the Software as are appropriate to facilitate
         the use of the Software in accordance with the licence set out in
         Sections 3.1 and 3.2 PROVIDED THAT they take reasonable precautions to
         safeguard such copies against unauthorised disclosure and/or use.
         Purchaser, Purchaser Affiliates and third parties shall be prohibited
         from decompiling, reverse-engineering or otherwise dismantling the
         source-code of the delivered software.

3.4      The Contractor shall procure the grant to Purchaser of licences to
         Third Party Software on the same terms as those set out in Sections 3.1
         and 3.2. Such licences shall be granted no later than delivery of the
         Third Party Software.

3.5      The Contractor or third party licensor shall retain ownership of any
         IPRs it may have in Software. The Purchaser and Purchaser Affiliates
         shall not remove alphanumeric identification margins, trademarks and
         copyright notices. In the event that duplication is permitted, the
         Purchaser and Purchaser Affiliate will also duplicate the above,
         marking all copies with a continuous number that also indicates program
         serial numbers and will keep a list of the locations of all copies,
         which Contractor may inspect upon request.

3.6      The Contractor shall co-operate in all ways necessary to ensure that
         Purchaser may obtain, exercise or protect its rights under this Section
         3. The Contractor shall ensure that any and all of its sub-contractors
         or suppliers are obliged to do what is necessary in order to fulfil
         Purchaser's rights granted under this Section 3. The

                                                                    Page 4 of 29
<PAGE>

         Contractor has or will obtain full power and authority to carry out the
         provisions of this Section 3 from all persons and other entities who
         perform any work under the Contract or any sub-contract related
         thereto. If a dispute arises relating to any infringement of any IPR,
         then Section 18 of this Agreement shall apply.

 3.7     The Contractor shall supply to Purchaser for all the Software to be
         delivered under the Contract full Software Documentation, user manuals
         and explanatory texts according to the requirements set out in Appendix
         3. With respect to the rights derived from Software Documentation, user
         manuals and explanatory texts, Section 4 of this Agreement shall apply.
         Furthermore, the Contractor shall disclose to Purchaser all relevant
         standard and non-standard external interfaces of the Contractor's
         network management system and its Systems in such a way as to enable
         third parties engaged by Purchaser to integrate all functions provided
         by such interfaces into its own software programs, PROVIDED THAT such
         third parties first enter into a satisfactory interface licensing
         agreement with the Contractor, which agreement the Contractor shall not
         unreasonably delay or withhold.

3.8      The Contractor acknowledges and agrees that it is its responsibility to
         deliver, install, implement and support the Software in the manner
         provided for in Appendix 4.

3.9      The Contractor shall deliver, install and configure Standard Software
         and Third Party Software (together with the relevant Software
         Documentation) into the System and ensure that such software is fully
         operational by the date specified in the Contract. The Standard
         Software and Third Party Software shall be delivered to Purchaser in
         object code form and on a machine readable media.

3.10     The Contractor shall implement acceptance tests in respect of the
         Software at the stages specified in Appendix 4.

4        DOCUMENTATION

4.1      The Contractor shall provide to Purchaser such drawings, diagrams,
         specifications and other information ("the Documentation") as specified
         in Appendix 3 and Appendix 4. In particular, the Contractor shall
         furnish to Purchaser before Field Acceptance of the System pursuant to
         Section 7, installation, operating and maintenance instructions,
         together with drawings of the System in sufficient detail to enable
         Purchaser to operate and maintain the System and to commission CPE. The
         System shall not be considered complete for the purposes of Field
         Acceptance until Documentation necessary for operation has been
         supplied to Purchaser.

                                                                    Page 5 of 29
<PAGE>

4.2      All Documentation shall be supplied by the Contractor in the English
         language and within the timescales agreed in the Contract.

4.3      The Contractor shall promptly before Field Acceptance of the System
         take all necessary steps to procure for Purchaser the full right and
         entitlement to use the Documentation in perpetuity, with the right to
         make such Documentation available to third parties for the sole purpose
         of facilitating third party operation of the System, without further
         payment or liability for further payment and the Contractor shall
         execute or procure the execution of all such deeds and documents as
         Purchaser may reasonably require to vest effectively such rights in
         Purchaser, PROVIDED THAT such third parties shall become subject to
         adequate confidentiality obligations (Section 19).

5        DELIVERY AND TITLE

5.1      The Contractor shall deliver the System to the Site(s) of Installation
         on the dates set out in the Orders submitted by Purchaser and confirmed
         by the Contractor and as prescribed in Appendix 3.

5.2      If each and every ***************************************************
         *********** under the respective Contract has been duly satisfied,
         Contractor shall transfer title to the Lender for security purposes.

5.3      The System when in transit, in store and on the Site of Installation
         shall be in all respects the responsibility of and at the risk of the
         Contractor until the Field Acceptance Certificate is issued.

6        INSTALLATION

6.1      The Contractor shall be responsible for the proper and timely
         performance of the entire installation process in accordance with
         Appendix 4.

6.2      The Contractor shall, on the Site(s) of Installation and on the dates
         set out in Orders placed by Purchaser and confirmed in writing by the
         Contractor, install the System. In particular, the Contractor shall
         install the Hardware and implement the Software on the processing units
         specified in Appendix 3.

6.3      It shall be the responsibility of the Contractor to obtain complete and
         accurate information concerning the Site of Installation and any
         equipment presently

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 6 of 29

<PAGE>

         installed on such site. It shall be the responsibility of the
         Contractor to visit the Site of Installation prior to carrying out the
         installation work. Such site visits shall be made at such times and
         subject to such reasonable conditions as shall be mutually agreed upon.
         The Contractor shall give to Purchaser, as described in Appendix 4,
         notice of the Contractor's requirement to visit a Site of Installation.

6.4      No delay and no claim by the Contractor for additional payment will be
         allowed on the grounds of misinterpretation of any matter relating to
         the Site of Installation on which the Contractor could reasonably have
         satisfied himself by a visit, by reference to Purchaser or by any other
         appropriate means which are standard practice.

6.5      The Contractor will procure at no additional cost to Purchaser that
         upon completion of installation work at any Site of Installation, the
         site be left in full repair and in a good and clean condition cleared
         of all unused materials, plant and equipment used in the performance of
         the work and temporary structures.

7        FIELD ACCEPTANCE

7.1      Three months after Ready For Service or at such date as CPE is
         connected to establish a Link within a Sector of a base station,
         whichever is sooner, a Field Acceptance Test shall be carried out by
         the Contractor according to the procedures set out in Appendix 4, at
         the Contractor's expense, to ensure compliance in each and every
         respect with the specifications in Appendix 3. In the event that the
         Purchaser does not attend for such duly notified Field Acceptance Test,
         the Contractor shall be entitled and obligated to conduct such Field
         Acceptance Test and to issue a Field Acceptance Certificate on behalf
         of the Purchaser. Each party shall bear the costs, including travelling
         expenses, for its own employees and authorised representatives
         attending Field Acceptance Tests.

7.2      Purchaser shall issue a Field Acceptance Certificate when the Field
         Acceptance Test has demonstrated to Purchaser's satisfaction that:

         7.2.1    the System has been delivered in accordance with the Contract;
                  and

         7.2.2    the performance of the System meets the requirements of
                  Appendix 3.

7.3      In the event that Purchaser fails to issue either a Field Acceptance
         Certificate or a valid notice of rejection within 3 Working Days after
         completion of the Field Acceptance Test, the Contractor shall be
         entitled to issue and sign the Field Acceptance Certificate on behalf
         of Purchaser.

                                                                    Page 7 of 29
<PAGE>

7.4      If the delivery subject to Field Acceptance is not in full compliance
         with the specifications set forth in Appendix 4, but sufficient to
         enable the Purchaser to efficiently operate the System, the Purchaser
         shall be entitled to issue a partial Field Acceptance Certificate and
         to *******************************************************. The
         withheld portion shall become payable upon rectification of such
         defect, which shall occur no later than six calendar months after issue
         of partial Field Acceptance Certificate. If, however, the rectification
         has not occurred within such period, the *****************************
         **********************. If the responsible engineers of either Party
         for the respective Contract do not mutually agree on the classification
         of the deficiency resulting in the partial Field Acceptance Certificate
         within a period of 30 days from issue of the partial Field Acceptance
         Certificate, then the procedure set out in Section 24.2 shall apply.
         However, the withheld amount constitutes the sole liability of the
         Contractor in this respect and no further damages shall apply.

7.5      The issuance of a Field Acceptance Certificate shall be without
         prejudice to any claim by Purchaser under Section 15 in respect of any
         defects, deficiencies or faults, which may subsequently become apparent
         or be discovered. The Contractor shall accordingly remedy such defects,
         deficiencies or faults in accordance with Section 15.

7.6      In the event of Purchaser provisionally putting the System into
         operation without first issuing a Field Acceptance Certificate (in case
         of emergency or with regard to Purchaser's own or its customers needs
         in order to avoid or mitigate any damages or losses) such action shall
         constitute partial Field Acceptance of the System by Purchaser. For the
         avoidance of doubt, the stipulations set forth in Section 7.4 shall
         apply. Such acceptance shall be without prejudice to the Contractor's
         obligations to complete the System in accordance with the Contract
         requirements.

8        CONTRACTOR'S PERSONNEL

8.1      The Contractor agrees that certain suitably qualified key personnel are
         necessary for the successful completion of the work to be performed
         under the Contract. Purchaser may require at any time with valid reason
         that the Contractor remove certain persons from the performance of the
         work under the Contract and replace them with other suitably qualified
         persons. In case of any compelling reason on the Contractor's side to
         exchange personnel, the Contractor shall notify Purchaser of such
         change as soon as possible. Purchaser shall have the right to review
         the qualifications of key personnel and any proposed replacements and,
         if for good and sufficient reasons Purchaser deems such personnel to be
         unsuitable, Purchaser may require the Contractor to offer alternative
         candidates where such are available.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 8 of 29
<PAGE>

8.2      Notwithstanding its role in approving the Contractor's key personnel
         and their replacements, Purchaser shall have no supervisory control
         over their work and nothing in this Section 8 shall relieve the
         Contractor of any of its obligations under the Contract or of its
         responsibility for any acts or omissions of its personnel.

8.3      Subject to the provisions of Section 19, nothing in the Contract shall
         prevent the Contractor from assigning the Contractor's personnel
         involved in the carrying out of the Services to the provision of
         similar services for third parties or in any way to restrict the
         Contractor's use of such personnel, except that the Contractor shall
         advise the Purchaser accordingly in the event that such personnel are
         in direct contact with the customer in connection with the performance
         of Consultancy Services.

9        COMPLETION DATES

9.1      The Contractor will complete the performance of its work under the
         Contract in accordance with the agreed dates as specified in the
         Contract.

9.2      Any change(s) to dates set out in Section 9.1 shall be made only if
         agreed by both Parties and such change(s) are recorded in a written
         instrument signed by authorised representatives of the Contractor and
         Purchaser.

9.3      If the Contractor has reason to believe that any dates are likely to be
         delayed, the Contractor shall promptly notify Purchaser in writing of
         the cause of delay (giving particulars of the expected effects
         thereof), of the expected period of delay and of the steps proposed by
         the Contractor to minimise the delay to ensure that the works proceed
         in as timely a manner as possible.

9.4      Upon receipt of any notice under Section 9.3, in such circumstances as
         Purchaser considers appropriate, Purchaser may, at its sole discretion,
         extend a milestone date or dates by such time as Purchaser estimates to
         be fair and reasonable.

10       PRICES

10.1     The Prices for the System and Services are set out in Appendix 2. All
         Prices in Appendix 2 are exclusive of value added tax or its
         equivalent, which shall be chargeable extra to Purchaser at the
         prevailing rates. Deliveries to the Site of Installation within
         countries set out in Part 1 of Appendix 6 are made at the Contractor's
         cost, all transportation costs being the responsibility of the
         Contractor. In respect of Purchaser's requirements within the countries
         set out in Part 2 of Appendix 6, deliveries to the Site of Installation
         are made at Purchaser's or its

                                                                    Page 9 of 29
<PAGE>

         Affiliates' cost, all transportation costs being the responsibility of
         Purchaser. In respect of Purchaser's requirements within the EU, all
         taxes (excluding value added tax or its equivalent) and customs duties
         shall be borne by the Contractor in accordance with Incoterms 1990 DDP
         terms. In respect of Purchaser's requirements outside of the European
         Union, all taxes and customs duties shall be borne by Purchaser or its
         Affiliates in accordance with Incoterms 1990 DDU terms.

10.2     All Prices shall not be increased for two years from the date hereof.
         Services charges however may be increased in accordance with the Labour
         Index.

10.3     Payment shall be made as follows:

         10.3.1   35% of the Price for the System delivered shall be paid within
                  thirty calendar days from receipt by Purchaser of the
                  respective and correct invoice, such invoice to be issued upon
                  delivery, whereas the remaining 65% of the Price for the
                  System and 100% of the related installation, commissioning and
                  acceptance Services shall become payable 30 days after all
                  Field Acceptance Certificates comprising a confirmed MDO have
                  been issued pursuant to Section 7, or upon acceptance pursuant
                  to Section 7.6, whichever is the earlier.

         10.3.2   The balance of the Price for Services shall be paid within
                  thirty calendar days from receipt of the respective and
                  correct invoice, such invoice to be issued quarterly in
                  arrears in respect of ongoing Services, or upon completion in
                  respect of other Services.

         10.3.3   However, with respect to Contracts for add-ons of new CPEs,
                  payment shall be made in accordance with the payment and
                  acceptance procedures set out in Appendix 4.

10.4     Purchaser will only make payments against presentation of invoices in
         duplicate, in such form as shall be mutually agreed, quoting the
         correct contract number, purchase order number and if supported by:

         10.4.1 in respect of Systems, relevant delivery notes have been
         presented to the Purchaser; or 10.4.2 in respect of Systems, relevant
         Field Acceptance Certificates; 10.4.3 in respect of Services,
         applicable completion certificates as defined in Appendix 4.

10.5     Notwithstanding any other rights and remedies available to the
         Contractor, if any payment in full is not received on the due date, the
         Contractor shall be entitled to levy default interest at a fixed annual
         rate of 2% above prevailing EURIBOR on any unpaid overdue balance until
         payment in full is received. Interest shall

                                                                   Page 10 of 29
<PAGE>

         continue to accrue notwithstanding termination of the Contract for any
         reason whatsoever.

11       LIQUIDATED DAMAGES

11.1     If the Contractor, other than for reasons of force majeure (as
         described in Section 14) or any material acts or omissions of the
         Purchaser, delays in respect of Systems to achieve Field Acceptance by
         the date set forth in the Contract, or in respect of Services to meet
         the Service Levels set out in Appendix 4, then the Contractor shall pay
         to the Purchaser by way of liquidated damages an agreed amount of
         liquidated damages being a genuine pre-estimate of the likely damages
         that the Purchaser will suffer resulting from delay in the period from
         the date for Field Acceptance until actual date of Field Acceptance, or
         from lack of Service Levels' achievement. Such claim shall have no
         effect on the Purchaser's right to claim, and the Contractor's
         obligation to provide, fulfilment according to the Contract.

11.2     In respect of System acceptance delays, the liquidated damages payable
         shall be an amount equal to 0.2% for each Working Day of delay up to a
         maximum of 10% (ten per cent) of the aggregate price of the System,
         which is i) in delay; and ii) which cannot be put into operation, as
         set out in Appendix 3, as a result of the System delay.

11.3     In respect of Service Level delays, the liquidated damages payable
         shall be, an amount equal to 0.2% for each Working Day of delay up to a
         maximum of 10% of the aggregate service level price of the service,
         which is i) in delay; and ii) which cannot be put into operation, as
         set out in Appendix 4, as a result of the Service Levels delays.

11.4     If a System component or Systems components fail to meet the features
         and roll out criteria set out in Appendix 3, the Contractor shall pay
         to the Purchaser by way of liquidated damages an amount equal to 0.2%
         for each Working Day of failure up to a maximum of 10% of the relevant
         portion of the Contract Price applicable to the System component or
         Systems components, which is i) in delay; or (ii) which cannot be put
         into operation as set out in Appendix 3 as a result of the features and
         roll-out criteria delay.

11.5     If the deployed network of relevant base stations does not reach the
         committed MTBF as specified in Appendix 3, Contractor will deploy, at
         no cost to Purchaser, redundant base station radios for all Sectors of
         any base stations affected by a failure during the measurement period.

                                                                   Page 11 of 29
<PAGE>

11.6     Contractor shall at its own cost provide Purchaser with upgrades up to
         version 4.0 as specified in Appendix 3, including turnkey Services and
         all relevant hardware and software. This excludes free of charge
         upgrades of BSRFU redundancy unless Section 11.5 applies. If a
         requested upgrade is not received as specified in Appendix 3, then
         Contractor shall pay to Purchaser 2% of the purchase cost of the item
         requested to be upgraded for each calendar month of delay up to a
         maximum of 10%.

11.7     If CPE installations are not carried out pursuant to Appendix 4, then
         Contractor shall pay to Purchaser 25 Euros for each day of delay,
         however, not to exceed a total of 5% of the price of the respective
         CPE.

11.8     The Contractor shall not be deemed to be in breach of the Contract
         unless and until the above mentioned maximum liquidated damages shall
         have been reached.

11.9     The obligation of the Contractor to comply with the stipulated time
         requirements for delivery shall be conditional upon the timely receipt
         of all documents, necessary permits and approvals, especially of plans
         to be provided by the Purchaser, which shall have been requested in due
         time by the Contractor from the Purchaser as agreed in Section 2.2, as
         well as fulfilment of the terms of payment and other obligations by the
         Purchaser. Unless these conditions are fulfilled, the time for delivery
         shall be extended accordingly, except where the Contractor is
         responsible for such delay by wilful or negligent act.

11.10    The aggregate liability of the Contractor for liquidated damages as per
         Section 11, shall be limited up to a maximum of 10 per cent of the
         Contract Price. Notwithstanding the Purchaser's right to terminate
         according to Section 22, Purchaser's claims for compensation which
         exceed the limits specified in this Section 11 shall be excluded in all
         cases of delay even after expiry of an extension of time may have been
         granted to the Contractor.

12       QUALITY ASSURANCE

12.1     The Contractor shall, within sixty calendar days of the date of the
         Contract, implement and maintain a quality system for development,
         production and project management conforming with the requirements of
         ISO 9001 or an equivalent standard approved in writing by Purchaser.

12.2     Purchaser or its authorised representatives or agents, upon giving
         reasonable notice in writing to the Contractor, shall have the right to
         carry out quality inspections at the Contractor's production facilities
         at any stage in the manufacture of components comprising the System.
         Purchaser or its agents or authorised representatives shall be given
         reasonable access to all manufacturing locations and records, as
         required

                                                                   Page 12 of 29
<PAGE>

         solely for the purpose of conducting an audit of the effective
         operation of the Contractor's quality system. This right of audit shall
         not affect the Contractor's sole responsibility for design,
         development, production, delivery and installation of the System
         according to the requirements of the Contract. The Purchaser's agents
         or authorised representatives shall be made subject by the Purchaser to
         confidentiality obligations equivalent to those set forth in Section 19
         and shall not be a direct or indirect competitor or direct or indirect
         dependent of a competitor of the Contractor.

12.3     Purchaser has the right to reject any components of the System not in
         compliance with the requirements of Appendix 3. Approval of inspected
         components of the System shall not be considered acceptance of
         components comprising the System and shall not affect the Contractor's
         sole responsibility for the design, development, production, delivery
         and installation of the System according to the requirements of the
         Contract.

13       TRAINING AND ASSISTANCE

         The Contractor shall provide on-going training for designated staff of
         Purchaser and any nominee of Purchaser, as required in accordance with
         Appendix 4 and at the Prices in Appendix 2. The Contractor shall, if so
         requested in writing by Purchaser, provide training and assistance to
         Purchaser's staff, agents and authorised representatives who are to
         install, integrate, commission, operate, maintain and relocate the
         System, to ensure their familiarity with and understanding of the
         functionality and operation of System provided that the Purchaser's
         staff, agents and authorised representatives shall become subject to
         confidentiality obligations as per Section 19.

14       FORCE MAJEURE

14.1     The purpose of this Section 14 is to establish the consequences of
         force majeure events preventing either Party from complying with any of
         its obligations under the Contract.

14.2     As used in this Section 14, the term "force majeure" refers to events
         extrinsic to the Contract that are beyond the reasonable control of,
         and not attributable to negligence or other fault of, the Party relying
         on such events to excuse its failure to perform. The term includes any
         actions or restrictions or other interference imposed by any regulatory
         or governmental body, to which there is no right of appeal. The term
         does not include strikes or other events caused by labour disputes at
         the Contractor's own production plants.

                                                                   Page 13 of 29
<PAGE>

14.3     Any Party whose ability to perform is affected by a force majeure event
         shall take all reasonable steps to mitigate the impact of such event.

14.4     If the effect of a force majeure event is temporary, subject to 14.5,
         the Party so affected shall not be responsible for any consequent delay
         and the relevant milestone date or time period shall be extended
         accordingly if, and only if, notice of the event is given to the other
         Party within seven calendar days after the event has occurred. At the
         time of the initial notice of the occurrence of the event, or as soon
         thereafter as possible, the Party affected shall inform the other Party
         of the extent of the delay expected as a result of the event.

14.5     In the case of one or more force majeure events having a temporary
         effect on the ability of either Party to comply with its obligations
         under the Contract, if the effect is, or will be, to delay performance
         hereunder by more than ninety (90) calendar days, or in the case of
         force majeure events permanently preventing either Party from complying
         with his said obligations, either Party may declare the Contract to be
         terminated, in whole or in part. In such event Purchaser's sole
         liability shall be to pay the Contractor for the System accepted and
         for work carried out up to the date of termination.

15       WARRANTIES

15.1     Notwithstanding the System and Services having been inspected and
         accepted by Purchaser, the Contractor warrants that:

         15.1.1   the System and each component comprising the System shall be
                  free of defects in design, material and workmanship and shall
                  perform in accordance with Appendix 3; and

         15.1.2   the Software shall not contain any computer viruses, logic
                  bombs, trojan horses and/or other items of software intended
                  to disrupt the proper operation of the Software; and

         15.1.3   Software Documentation shall be of such standard as to enable
                  a reasonably competent user to understand and operate the
                  Software; and

         15.1.4   Services shall be performed as set forth in Appendix 4; for a
                  period of eighteen months from the date of issue of each Field
                  Acceptance Certificate or acceptance pursuant to Section 7.6,
                  whichever is the earlier (the "Warranty Period").

                                                                   Page 14 of 29
<PAGE>

15.2     The Contractor warrants the Year 2000 conformity is in compliance with
         the definition of Year 2000 conformity as defined by the British
         Standards Institution, which provides in particular that:

         15.2.1   no value for current date will cause any interruption in
                  operation;

         15.2.2   date-based functionality must behave consistently for dates
                  prior to, during and after Year 2000;

         15.2.3   in all interfaces and data storage, the century in any date
                  must be specified either explicitly or by unambiguous
                  algorithms or inferencing rules;

         15.2.4   Year 2000 must be recognised as a leap year;

         the liability for year 2000 conformity applies only under the condition
         that the Purchaser uses the supplied equipment in the contemplated
         manner, especially correct handling and correct data inputs which are
         suitable for the equipment and specification. In addition, the
         liability for year 2000 conformity does not apply if the Purchaser
         makes modifications without the approval of the Contractor to the
         equipment specification thereof. The liability shall be unlimited in
         time, with respect to the obligations of the Contractor this Section 15
         shall apply exclusively.

15.3     The Contractor warrants that the Services and Systems hereunder shall
         perform or as the case may be, be performed in compliance with the
         requirements of Appendix 3 and 4 and all applicable/relevant laws,
         enactments, orders, regulations, standards and other similar
         instruments and the Contractor shall obtain all licences, permits and
         consents required to comply with the same, and further that the
         Services will be performed with the reasonable skill and care of a
         competent telecommunications contractor in accordance with accepted
         industry practices and so as not to cause unreasonable interference
         with the property rights of third parties.

15.4     The following obligations shall apply during the Warranty Period:

         15.4.1   Purchaser shall notify the Contractor without delay of any
                  defects or faults in the System that come to Purchaser's
                  knowledge. All documents and information that could reasonably
                  assist the Contractor in rectifying the defect or fault shall
                  be submitted with Purchaser's notification. Any such
                  notification under this Section 15.4 shall be confirmed in
                  writing by Purchaser and shall, upon receipt of the said
                  notification by the Contractor, be given a fault report log
                  number detailing the time the notification was received and
                  describing the nature of the defect or fault reported. It
                  shall be the responsibility of the Contractor to remedy all
                  defects or faults as soon as is possible and free of charge.
                  Purchaser shall arrange for the Contractor to

                                                                   Page 15 of 29
<PAGE>

                  have such access to the System as may be necessary for the
                  Contractor to inspect and repair or, as the case may be,
                  replace faulty or defective components;

         15.4.2   the Contractor shall, at its discretion, repair or replace
                  without charge any defective component of Hardware or Software
                  or any parts thereof comprising the System as soon as
                  reasonably practicable, but in any case within a period of 50
                  Working Days beginning with the provision of the Contractor's
                  final commentary in accordance with Appendix 4 f - Section 3.1
                  concerning Hardware errors. If the same Hardware error occurs
                  in another System (epidemic failure), the Purchaser shall
                  grant an adequate time to the Contractor to repair or replace
                  the Hardware of the respective System. As to defects or faults
                  with Hardware, Purchaser shall identify the defective or
                  faulty component and, at its discretion, may arrange for its
                  removal and transportation back to the Contractor at the
                  Contractor's expense. As to defects deemed to lie with
                  Software, it shall be the responsibility of the Contractor to
                  identify any defects therein and to repair or replace such
                  Software at the Site of Installation (without cost to
                  Purchaser). As long as the obligation for elimination of
                  Software errors exists, the Contractor may fulfil its
                  obligation by licensing to the Purchaser a thirty Working Days
                  work-around solution. The thirty Working Days time frame
                  starts with the provision of the Contractor's final commentary
                  in accordance with Section 3.1 of the Appendix 4 f. If the
                  same Software error occurs in another System (epidemic
                  failure), the Purchaser shall additionally grant an adequate
                  time to the Contractor to repair or replace the Software of
                  the respective System. Should the Contractor fail, within such
                  period of time, to eliminate defects or faults in Hardware or
                  Software, Purchaser shall be entitled at its option to a
                  reduction in the Price paid for the defective Hardware or
                  Software; or, at Purchaser's option, to return the defective
                  Hardware or Software to the Contractor in return for a full
                  refund of the Price paid (including installation Prices), in
                  which case the Contractor shall indemnify the Purchaser for
                  his additional direct costs of replacing the defective
                  Hardware or Software, up to a maximum of 20% of the refunded
                  Price. The Contractor may reasonably require the Purchaser to
                  verify that the sum payable has been properly incurred by the
                  Purchaser. The Contractor shall be responsible for any
                  delivery costs under this Section 15. The Contractor shall
                  re-warrant any repaired or replaced component for the
                  unexpired portion of the original Warranty Period, but in any
                  case for minimum period of six months.

15.5     In the event of errors, faults or omissions in the performance of the
         Services, the Contractor shall be responsible for re-performing the
         applicable Services in order to correct the errors, faults or
         omissions. In the event that the Contractor fails to correct such
         errors, faults or omissions within 50 Working Days, the Contractor

                                                                   Page 16 of 29
<PAGE>

         shall, if requested by the Purchaser, repay to the Purchaser an
         applicable part of the relevant Price; in addition, the Purchaser may
         correct such errors, faults or omissions and, in the event of the
         direct costs thereof being greater than the above-mentioned repayment,
         claim from the Contractor such excess costs, subject to a maximum of
         twenty per cent of the amount of the above-mentioned repayment.

15.6     If the System ordered by the Purchaser has been planned incorrectly and
         if such error has been caused by the Contractor, the Contractor shall
         hold the Purchaser harmless of the additional costs incurred due to the
         incorrect planning. This shall apply accordingly if the System turns
         out to have been oversized. Such additional costs shall include and be
         limited to the difference between the actual incurred costs and those
         that would have been incurred if the planning had been performed
         correctly.

15.7     Necessary emergency repairs to the System by Purchaser, its agents or
         authorised representatives shall not invalidate the Contractor's
         warranty, PROVIDED THAT proper care is taken during such emergency
         repair. Purchaser shall promptly notify the Contractor prior to
         undertaking any such emergency repair.

15.8     The warranty obligations hereunder shall not apply in cases such as
         non-reproducable faults, abuse, use in unauthorised applications,
         improper storage, unauthorised alterations, lack of compliance with the
         Contractor's instructions or Documentation.

15.9     The Contractor warrants to the Purchaser that the Contractor has good,
         valid and marketable title to the Hardware, free and clear of any liens
         or encumbrances. The Contractor warrants to the Purchaser that each
         item of Hardware shall, upon delivery to the Purchaser and upon Field
         Acceptance by the Purchaser hereunder, be free and clear of all liens,
         charges or encumbrances of any nature whatsoever, and upon passage of
         title to the Purchaser shall provide good, valid and marketable title
         to the Purchaser for such Hardware.

15.10    The Contractor further warrants to the Purchaser that the Contractor
         has the right and power to grant the Software licence rights granted
         hereunder free and clear of any liens and encumbrances, and the
         Purchaser shall have quiet enjoyment and use of licensed Software as
         long as such licence shall remain in effect.

15.11    The warranty provided in this Section 15 constitutes the sole liability
         of the Contractor in respect of those matters to which it refers. All
         other terms, conditions and warranties expressed or implied whether
         statutorily or otherwise are hereby expressly excluded.

                                                                   Page 17 of 29
<PAGE>

16       AVAILABILITY OF SPARE PARTS

16.1     The Contractor shall provide support and all necessary (spare) parts,
         System components and equipment for a period of ten years commencing
         with the market release date of the released product version. The
         Contractor undertakes to replace any component of the System not
         capable of repair during the said time.

16.2     All spare parts shall be fully compatible in form, fit and function
         with the component(s) to be replaced. Purchaser shall be entitled to
         request from the Contractor random samples of spare parts, for testing
         at its own expense and to reject such spare parts if such testing has
         not been completed to Purchaser's satisfaction.

16.3     Section 15 shall apply in each and every respect to each spare part
         installed in the System.

16.4     If the Contractor discontinues the production of spare parts after
         expiry of the time period specified in Section 16.1, the Contractor
         shall furnish to Purchaser, free of charge, at Purchaser's request, the
         blueprints, drawings, patterns, plans, specifications and all other
         information concerning such spare parts. The Contractor shall take such
         steps to procure for Purchaser the full right and entitlement to
         arrange for production, under licensing terms to be agreed, of the said
         spare parts. The Contractor shall execute or procure the execution of
         all such deeds and documents (without cost to Purchaser) as Purchaser
         may reasonably require to vest effectively such right in Purchaser. The
         Contractor shall notify Purchaser one year in advance of any
         discontinuance of the production of spare parts.

16.5     If, during the time period stated in Section 16.1, the Contractor
         either:

         16.5.1   fails to make available to Purchaser necessary spare parts in
                  accordance with this Section 16; or

         16.5.2   becomes insolvent or goes into liquidation or ceases to carry
                  on business;

         then the Contractor shall at Purchaser's written request furnish to
         Purchaser free of charge blueprints, drawings, patterns, plans,
         specifications and all other information concerning the spare parts.
         Purchaser shall be entitled to retain such blueprints, drawings,
         patterns, plans, specifications and other information under licensing
         terms to be agreed. The Contractor, its trustee in bankruptcy or
         liquidator, as the case may be, shall in such circumstances take such
         steps to procure for Purchaser such full right and entitlement to
         arrange for the production of spare parts and shall execute or procure
         the execution of all such deeds and documents (without cost to

                                                                   Page 18 of 29
<PAGE>

         Purchaser) as Purchaser may reasonably require to vest effectively such
         right in Purchaser.

16.6     The Contractor shall provide spare parts for the duration of the
         warranty period **************************************. If required
         by the Purchaser, the Contractor shall deliver all required spare parts
         to a location to be specified by the Purchaser and delivery shall be at
         the Purchaser's cost. The accumulated volume of spare parts shall be
         calculated in accordance with the guaranteed MTBF values provided in
         Appendix 3. For the duration of the warranty period, the Contractor
         shall be obliged ****************************************************.
         ************************************************************This shall
         include replacing the equipment affected by an outage occurred on site
         and establishing that the equipment is fully functional and in
         accordance with the planning specifications.

         The Contractor shall be obliged to equip their First Line Maintenance
         forces with sufficient spare parts in order to meet the mutually agreed
         MTTR SLAs.

17       LIABILITY

17.1     In the event that any act or omission of one Party, its agents or
         authorised representatives causes or results in damage or loss of or
         destruction to any property and/or death or personal injury to any
         person, then that Party shall indemnify the other Party from and
         against all actions, costs, demands, damages and liabilities resulting
         therefrom. Notwithstanding the foregoing, each Party's maximum
         liability under this Section 17.1 shall, except in the case of
         liability for death or personal injury, in respect of any one event or
         series of connected events giving rise to claims under this Section
         17.1 be limited to EURO 3 million. Notwithstanding any other term of
         the Contract, neither Party shall have any liability, including for
         negligence for consequential loss, loss of interest, loss of
         information or data or in cases of business interruption, loss of
         profit or revenues or other indirect loss suffered by the other Party.

17.2     Without prejudice to the provisions of Section 11, 17.1 and the
         Purchaser's obligations to make any applicable payments, the maximum
         liability of either Party for claims arising out of breach of Contract,
         or under any indemnity given under the Contract, other than that given
         under Section 17.1, shall be limited to the Contract Price or EURO 3
         million, whichever is the lesser.

17.3     Notwithstanding the provisions of this Section 17, the Contractor's
         liability in contract, tort (including negligence) or otherwise for
         errors or omissions in any part of the Consultancy Services provided
         under the Contract, which may arise from any

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 19 of 29
<PAGE>

         failure by the Contractor to exercise the reasonable skill and care of
         a competent telecommunications supplier, will be limited to the
         re-performance of the applicable Service in accordance with the
         provisions of Section 15.5.

17.4     The provisions of this Section 17 shall continue without limit in point
         of time notwithstanding the expiry or termination of the Contract.

17.5     Unless otherwise provided for by mandatory applicable law, the rights
         and remedies contained in this Agreement are exclusive and the Parties
         accept these remedies in lieu of any and all other rights and remedies
         available at law or otherwise, in contract or in tort, for any and all
         claims of any nature arising out of or in connection with this
         Agreement.

18       RIGHTS OF THIRD PARTIES

18.1     The Contractor warrants that any product (or part thereof) supplied and
         furnished hereunder to the Purchaser shall be free of any rightful
         claim of any third party for infringement of any IPR or any other right
         limiting the Purchaser's use in accordance with this Agreement;
         PROVIDED THAT the Purchaser:

         18.1.1   notifies Contractor promptly and in writing of the receipt of
                  any claim that such product (or part thereof) infringes an
                  IPR; and

         18.1.2   does not acknowledge or accept of his own accord any such
                  claim; and

         18.1.3   gives the Contractor information, assistance and exclusive
                  authority to settle and defend such claim; and

         18.1.4   co-operates in the defence of such claim as requested by the
                  Contractor; and

         18.1.5   conducts negotiations with said third party only in agreement
                  with Contractor's instructions.

18.2     The Contractor shall, at its own expense and option, either (i) procure
         for the Purchaser the right to continue using such IPR; or (ii) modify
         the product so that it becomes non-infringing; or (iii) replace the
         product with a substantially similar non-infringing version; or (iv)
         the Contractor agrees to resist and defend, at its own expense, any
         such claims and to pay any royalties and other costs associated with
         any settlement of such claims, and any damages and costs awarded as the
         result of such claims. The Contractor undertakes that any such
         modification or replacement as aforesaid will not result in a material
         diminution of functionality of performance of

                                                                   Page 20 of 29
<PAGE>

         the Hardware or Software or any component comprising System and shall
         in no way restrict Purchaser's capability to run and operate the
         System.

18.3     If it is not possible to modify or to replace the Hardware or the
         Software, and if it is not possible to obtain a right of use for the
         benefit of Purchaser, Purchaser shall be entitled to deliver back to
         the Contractor such Hardware or Software in return for full
         reimbursement of the Price paid by Purchaser less an amount
         corresponding to reasonable depreciation. The Contractor shall be
         responsible for any delivery costs under this Section 18.

18.4     Section 18.1 and 18.2 shall not apply (i) to those elements of any
         product (or part thereof) manufactured according to the Purchaser's
         design or instructions unless the Parties mutually agree to such
         specification; or (ii) to the application or use of any product (or
         part thereof) furnished hereunder in conjunction with any other
         apparatus or material in a manner or for a purpose not stated in the
         specifications; or (iii) to any infringement which results from
         modifications to contractual products not made by the Contractor after
         delivery by the Contractor where such modification is not authorised by
         the Contractor; or (iv) to the application or use of any product (or
         part thereof) furnished hereunder not provided by the Contractor where
         the Contractor has not approved such applications or use. As to any
         product, part or use described in the preceding sentence, the
         Contractor assumes no liability whatsoever for infringement of any IPR.

18.5     Except in the cases stated in Section 18.4, the Contractor shall
         indemnify the Purchaser against any claim of infringement of any IPR of
         others arising from Purchaser's purchase, possession or use of the
         System. Further, Contractor shall pay all litigation costs, reasonable
         attorney's fees, settlement payments and any damages awarded in any
         such infringement claim.

18.6     Unless otherwise provided for by mandatory applicable law, this Section
         states the sole and entire warranty and liability of the Contractor
         with respect to any claims of infringement of IPR, and the rights and
         remedies contained herein are in lieu of any and all other rights and
         remedies available at law or otherwise.

19       CONFIDENTIALITY AND COPYRIGHT

19.1     Each Party shall have the following obligations with respect to the
         information contained in or otherwise relating to the Contract,
         including any work, package, reports provided by disclosing Party to
         receiving Party hereunder; all proprietary data and any information
         supplied by disclosing Party to receiving Party in connection with the
         Contract that can reasonably be assumed, by its nature, to be
         confidential or

                                                                   Page 21 of 29
<PAGE>

         otherwise is identified as confidential at the time it is so supplied.
         Such identification shall be made or confirmed in writing:

         19.1.1   the Parties shall take all reasonable measures to protect the
                  confidentiality of such information;

         19.1.2   the Parties agree that they shall use such information solely
                  in connection with the Contract, unless alternative uses are
                  explicitly authorised by the disclosing Party with respect to
                  specifically designated information or if required by judicial
                  or other governmental order, in which case the receiving Party
                  shall inform the disclosing Party prior to complying with such
                  disclosure request;

         19.1.3   The receiving Party shall not disclose such information to
                  third parties, or allow its disclosure, in any manner or form,
                  so long as it remains confidential, without the explicit
                  written authorisation of the disclosing Party, save that the
                  receiving Party is expressly authorised to disclose to third
                  party suppliers and sub-contractors in connection with
                  performing the Contract, PROVIDED THAT such disclosure is made
                  subject to confidentiality undertakings similar to those
                  contained in this Section 19.

19.2     Subject to Section 19.4, this Section 19 shall continue to apply,
         irrespective of any expiration or termination of the Contract, unless
         and until such time as such information comes into the receiving
         Party's lawful possession independent of disclosure in connection with
         the Contract, or otherwise lawfully comes into the public domain.

19.3     The Parties shall abide by the applicable export licence regulations of
         the respective countries and it is the disclosing Party's obligation to
         apply for an export licence grant prior to transmission of confidential
         information and to inform the receiving Party sufficiently of any
         existing limitation.

19.4     The confidentiality obligations in this Section 19 shall survive the
         expiry or termination of the Contract until the fifth anniversary of
         the expiry or termination date.

19.5     Save as provided elsewhere in the Contract, the copyright in all
         documents and data issued by one Party to the other Party in connection
         with the Contract shall remain the property of the issuing Party, but,
         subject to this Section 19, the receiving Party shall for the period of
         the Contract be entitled to make copies thereof for all reasonable
         purposes in connection with the development, supply, installation,
         operation and maintenance of the System. Upon termination of the
         Contract for whatever reason, each Party shall return forthwith to the
         other Party any documents and copies thereof, supplied by the other
         Party pursuant to the Contract.

                                                                   Page 22 of 29
<PAGE>

19.6     Notwithstanding the provisions of this Section 19, the materials, plans
         and reports produced as a result of the performance of Consultancy
         Services shall be proprietary to the Contractor and shall be prepared
         for the sole use by the Purchaser based on information provided by the
         Purchaser. Reliance on such materials, plans and reports by third
         parties is not permitted without the Contractor's prior written
         consent.

20       ASSIGNMENT

20.1     The Contract is personal to the Parties and neither Party shall assign
         any of its obligations hereunder without the prior written consent in
         writing of the other, such consent not to be unreasonably withheld or
         delayed.

20.2     In the event of an assignment under Section 20.1 the assignor shall
         ensure that the assignee is licensed or otherwise permitted by law or
         regulation to perform the obligations contemplated by the Contract.

20.3     Nothing in the Contract shall prevent or prohibit the Contractor or
         Purchaser, upon written notice to the other, appointing subcontractors
         to perform work in connection with the performance of their obligations
         under the Contract PROVIDED THAT the Party subcontracting the work
         shall remain fully responsible for the performance of such work
         notwithstanding any default or failure by any subcontractor.

20.4     The Purchaser and the Contractor shall have the right to assign this
         Agreement or otherwise delegate all or any of its rights and
         obligations hereunder to an Affiliate upon serving notice in writing on
         the Purchaser or the Contractor as the case may be, with the exception
         of the Appendices 2 through 9. Section 20.1 shall apply.

21       NEW DEVELOPMENTS, CHANGE REQUESTS AND CANCELLATION

21.1     In the event that Purchaser requires changes to the Contractor's
         deliverables and services under the Contract then, subject to agreement
         on cost and the specification of the change and agreement on the date
         the service is to be performed or deliverables to be delivered, the
         Contractor shall implement the agreed change which shall be governed by
         the terms contained in this Contract.

21.2     At any time during the period of the Contract the Purchaser may submit
         a written request to the Contractor requesting the Contractor to
         design, develop, manufacture,

                                                                   Page 23 of 29
<PAGE>

         supply, install, integrate and test new Hardware and/or new Software
         for use in conjunction with the System. Such request will be considered
         a Change Request under Section 21 and shall be subject to prior written
         agreement on cost, specification, software licensing, ownership of
         IPRs, acceptance criteria, project reviews and the date on which the
         new service is to be performed or deliverable to be delivered.

21.3     The Parties shall follow the change control procedure set out in
         Appendix 4.

21.4     The Purchaser may cancel, partially or in total, any or all Contracts
         for Turnkey Services on not less than three months' prior notice, such
         notice to expire at the end of the second or fourth quarter of the
         relevant calendar year (i.e. 30 June or 31 December) PROVIDED THAT the
         Purchaser pays to the Contractor the Contractor's costs pro-rata to the
         Turnkey Services provided up to the date of expiry of notice.

22       TERMINATION

22.1     Without prejudice to any other rights or remedies which Purchaser may
         possess, Purchaser shall be entitled to terminate the Contract
         forthwith:

         22.1.1   if the Contractor shall be in material breach of any of its
                  obligations under the Contract; or

         22.1.2   in accordance with Section 14.5; or

         22.1.3   if the Contractor shall become subject to a change of control;
                  or

         22.1.4   if the Contractor is unable to generally pay its debts,
                  insolvent, bankrupt, in liquidation or ceases to carry on
                  business; or

         22.1.5   if the Contractor falls severely behind with the mutually
                  agreed production and development activities prior to or
                  during roll-out, preventing the Purchaser from meeting agreed
                  roll-out schedules;

         22.1.6   if the Loan Agreement is either not executed or cancelled,
                  rescinded or terminated for reasons other than performance of
                  its terms;

         PROVIDED THAT under Section 22.1.1, the Contractor fails to remedy the
         same within a period of thirty calendar days after receipt of written
         notice requiring the Contractor so to do.

                                                                   Page 24 of 29
<PAGE>

22.2     Without prejudice to any other rights or remedies which the Contractor
         may possess, the Contractor shall be entitled to terminate the Contract
         forthwith:

         22.2.1   if the Purchaser shall be in material breach of any of its
                  obligations under the Contract and/or the Loan Agreement
                  between the Lender and Purchaser dated [       ]; or

         22.2.2   in accordance with Section 14.5; or

         22.2.3   if the Purchaser is unable to generally pay its debts,
                  insolvent, bankrupt, in liquidation or ceases to carry on
                  business; or

         22.2.4   if the Purchaser shall become subject to a change of control;

         22.2.5   if the Loan Agreement is either not executed or cancelled,
                  rescinded or terminated for reasons other than performance of
                  its terms;

         PROVIDED THAT under Section 22.2.1, Purchaser fails to remedy the same
         within a period of thirty calendar days after receipt of written notice
         requiring Purchaser so to do.

22.3     For the purposes of Sections 22.1.3 and 22.2.4, there shall be deemed
         to be a change of control of the Party if a person or group of persons
         obtains ownership of more than fifty per cent of the issued share
         capital of the Party (or any other percentage that enables a person or
         group of persons to elect a majority to the members of the board) or of
         any holding company of the Party, or if a person obtains the right to
         direct the affairs directly or indirectly of the Party in circumstances
         where in the reasonable opinion of other Party the exercise of control
         over the Party will be likely to materially prejudice the commercial,
         financial or operational interests of other Party.

22.4     Upon termination of the Contract as provided for in Section 22.1.1 or
         22.1.4 the Purchaser may at its option continue work either by itself
         or by sub-contracting to a third party. The Contractor shall if so
         required by the Purchaser to the extent allowable by such agreements,
         within 14 (fourteen) calendar days of the date of termination assign to
         the Purchaser without additional payment the rights and obligations of
         any agreement for supply of materials or goods and/or execution of any
         work for the purposes of this Contract. In the event that the Purchaser
         had already paid the price thereof to the Contractor, then the
         Contractor shall promptly repay such sum(s) to the Purchaser. In the
         event of the System being completed by the Purchaser or a third party
         and the total cost incurred by the Purchaser in so completing the
         System being greater than that which would have been incurred had the
         Contract not been terminated then the Contractor shall pay to the
         Purchaser such excess up to a maximum of 20 (twenty) per cent of the
         Contract Price. The

                                                                   Page 25 of 29
<PAGE>

         payment of such excess shall be in full and final settlement of the
         Contractor's liability in respect of termination under Section 22.1.1
         and 22.1.4 of this Contract.

22.5     Upon termination of the Contract in accordance with the provisions of
         Section 22.1.2, 22.1.3, 22.1.5 or 22.2, the Purchaser shall pay to the
         Contractor forthwith upon termination the proportion of the Contract
         Price applicable to the portion or portions in respect of which the
         Contract is so terminated which have been delivered or are in progress
         of manufacture plus the price of Services performed prior to such
         termination. In any case, the sum payable shall not exceed the total
         Contract Price and, on request from Purchaser, the Contractor shall
         provide such evidence as Purchaser may reasonably require to verify
         that the sum payable has been properly incurred by the Contractor.

22.6     Notwithstanding the provisions of Section 22.5, in the event of a
         material breach or violation of the Software licensing conditions
         (Section 3) by the Purchaser or sublicencee, the Contractor shall
         inform the Purchaser by notice in writing, stipulating the nature of
         the breach or violation, and should the breach or violation continue
         for more than 14 (fourteen) calendar days after such notice the
         Contractor may terminate the Software licence or sub-licence forthwith.

22.7     Upon termination of the Software licence in accordance with Section
         22.6, the Contractor shall permit the Purchaser the continued use of
         the Software and associated Software Documentation upon such terms as
         the Contractor may direct. In the event that such terms are not
         accepted and immediately complied with by the Purchaser, the Contractor
         may, at its absolute discretion, require the Purchaser to return all
         copies of the Software and associated documentation within 14
         (fourteen) calendar days of the notice to do so.

22.8     The liability for termination provided in this Section 22 constitutes
         the sole liability of the Contractor in respect of those matters to
         which it refers. All other items, conditions and liabilities expressed
         or implied whether statutorily or otherwise are hereby expressly
         excluded except as provided in this Contract and by mandatory law.

23       DISPUTES

23.1     In the event of a dispute arising between the Parties under the
         Contract the Parties shall consult with each other in good faith with a
         view to resolving the dispute as soon as possible. If the dispute is
         not resolved within a period of thirty days the Parties shall escalate
         the dispute to the following persons who shall work together in good
         faith with a view to resolving the dispute:

                                                                   Page 26 of 29
<PAGE>

         Purchaser representative     Tim Samples, Chief Executive Officer
         Contractor representative    Reinhard Siekaczek,
                                      ICN TR, Kaufmaennischer Leiter

23.2     The escalation procedure contained in this Section 23 is without
         prejudice to any other rights and remedies available to the Parties.

24       LAW AND JURISDICTION

24.1     The Contract shall be governed by and construed and interpreted in
         accordance with German law and the Parties submit to the exclusive
         jurisdiction of the German courts without the application of the United
         Nations Convention on Contracts for the International Sale of Goods
         dated April 11, 1980. The venue shall be deemed agreed as the court of
         Berlin.

24.2     The Parties recognise that certain disputes arising in connection with
         the Contract may be related to matters where resolution of the same
         will require any adjudicator to take expert advice. Each of the Parties
         undertakes, in such circumstances where both of them agree that this is
         the case and they are able to agree on the identity of a suitable
         expert or experts, to endeavour to resolve such a dispute by reference
         to such expert or experts, but nothing in this Section 24.2 shall in
         any way affect the remaining provisions of this Section 24.

25       MISCELLANEOUS

25.1     The Contract may not be modified except by written amendment signed by
         responsible authorised representatives of both Parties save that the
         address for notices and the responsible authorised representatives of
         the Parties may be added to or changed from time to time by written
         notice to the other Party.

25.2     For the purposes of administration of the Contract, including
         amendments and the approval of any change for the purposes of Section
         21, any communication between the Parties shall be enforceable and
         binding upon the Parties only if signed by the appropriate responsible
         authorised representatives.

25.3     The responsible authorised representatives of the Parties may be
         changed from time to time by notice in writing to the other Party.
         Until further notice the responsible and authorised representative of
         Purchaser shall be Tim Samples, the Chief Executive Officer and the
         responsible and authorised representative of the Contractor shall be
         Reinhard Siekaczek, ICN TR, Kaufmaennischer Leiter .

                                                                   Page 27 of 29
<PAGE>

25.4     In the event that any one or more of the provisions of the Contract
         shall, for any reason, be held to be illegal, invalid or unenforceable,
         the remaining provisions of the Contract shall be unimpaired, and the
         invalid or unenforceable provision shall be replaced by a mutually
         acceptable provision which, being valid and enforceable, comes closest
         to the intention of the Parties underlying the illegal, invalid or
         unenforceable provision.

25.5     The Contract shall come into effect upon the date of Order acceptance.

25.6     The European Agreement , the Contract and all the Appendices hereto
         contains the entire agreement and understanding between the parties
         relating to the subject matter hereof. All prior understandings,
         representations and warranties by and between the Parties, written or
         oral, which may be related to the subject matter hereof in any way, are
         superseded by the Contract.

25.7     Nothing herein shall create or be deemed to create a joint venture or
         partnership between the Parties nor, save as specifically provided in
         the Contract, constitute one Party the agent of the other Party.

25.8     The Contract shall be binding upon the Parties hereto and their
         successors and permitted assigns.

25.9     All correspondence, notices, documentation and communications
         concerning the Contract shall be in the English language.

25.10    A waiver of any breach of any provision hereof shall not be binding
         upon either Party unless made in writing. No such waiver shall affect
         the rights of the Party not in breach with respect to any other or
         future breach of the Contract. No delay or failure by a Party to
         exercise any of its rights, or time or indulgence given by it before
         exercising any right or remedy under the Contract shall operate as a
         waiver of the same nor shall any single or partial exercise of a right
         or remedy preclude any further exercise of the same or the exercise of
         any other right or remedy.

25.11    All notices, reports, invoices and other correspondence to be provided
         to Purchaser or the Contractor pursuant to the Contract shall be sent
         for the attention of the responsible and authorised representatives of
         Purchaser and the Contractor at the following addresses:

                    Purchaser:      See Appendix 6

                    Contractor:     See Appendix 6

                                                                   Page 28 of 29
<PAGE>

         25.11.1  All notices and other correspondence of a legal nature by the
                  Contractor to Purchaser shall be sent to the General Counsel
                  of Purchaser at the following address:

                             FirstMark Communications Europe, SA
                             3 rue Jean Piret
                             L-2350 Luxembourg

         25.11.2  Any notice, report, invoice or other correspondence shall be
                  deemed to have been received by the receiving Party on the day
                  on which such communication has been received by it.

25.12    Neither Party shall make any announcements, news releases or other
         public statements regarding the Contract or its subject matter without
         the prior written approval of both Purchaser and the Contractor, such
         approval not to be unreasonably withheld or delayed.

                                                                   Page 29 of 29

<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

                        APPENDIX 2 - PRICES AND DISCOUNTS

DOCUMENT

              ------------------------------------------------------------------
              DOCUMENT NAME              Appendix 2 - Prices and Discounts
              ------------------------------------------------------------------
              BACKGROUND                 This Appendix 2 sets forth the
                                         applicable prices and discounts of the
                                         European Agreement between FirstMark
                                         Europe SA and Siemens AG

              ------------------------------------------------------------------

                                  Page 1 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

CONTENT

<TABLE>

<CAPTION>

<S>                                                                                                          <C>
1     INTRODUCTION............................................................................................3
-     ------------
2     DISCOUNT................................................................................................3
-     --------
3     EQUIPMENT AND RELATED I&C...............................................................................5
-     -------------------------
4     LIST PRICES -SERVICES..................................................................................41
-     ---------------------

</TABLE>

                                                                    Page 2 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

1    INTRODUCTION

This Appendix 2 of the European Agreement sets forth the applicable prices and
discounts.

If not otherwise stated all prices are expressed in Euro and exclusive of VAT in
this Appendix 2.

In case the Purchaser can purchase equipment equal to those listed in this
Appendix 2 from a Third Party at lower costs than the customer price according
to this Appendix 2, the Purchaser shall be entitled to purchase the equipment
from aforesaid Third Party and the Contractor will install such equipment
delivered by a Third Party at the related installation, commissioning and
acceptance prices as set forth in this Appendix 2.

2    DISCOUNT

2.1  GENERAL

The discounts as set out in this section 2 of Appendix 2 shall apply PROVIDED
THAT

the Purchaser places Orders for the WALKair equipment with the Contractor for
at least **************** ("Preferred Supplier") of the Markets in Germany
that the Purchaser rolls out within a period of 12 (twelve) months from the
date of this Agreement. Such Order volumes ***** shall not necessarily include
ONU/CMX access equipment and

the Purchaser places Orders for the WALKair equipment with the Contractor for
at least ************************************ in Germany that the Purchaser
rolls out within a period of (12) twelve months from the date of this Agreement.
The Purchaser and the Contractor shall mutually agree which of the Markets are
to be the top ********************* and

within a period of three (3) years upon the date of this Agreement the
Contractor will be entitled to the of first refusal.

2.2  GLOBAL DISCOUNT SCHEMES

The indicated discounts are applicable to the list prices of the WALKair
equipment as set out in this Appendix 2. For the application of discounts the
date of delivery to the site of installation respectively the agreed delivery
address is valid.

The indicated discounts are applicable on the System list price and to the unit
list price in case of unit deliveries of the then current version of the System
for growth purposes.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 3 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

2.2.1 DISCOUNT ON BASE STATION (BS) DELIVERIES

<TABLE>

<CAPTION>

         ----------------------------------------------------------------------------------------------------
           Date of              Discount applicable to the list price of WALKair base station (BS) equipment
                              -------------------------------------------------------------------------------
                              -------------------------------------------------------------------------------
<S>                             <C>                                <C>
           BS deliveries        26 GHz                             3,5 GHz
         ----------------------------------------------------------------------------------------------------
           from year 2000       *****                              *****
         ----------------------------------------------------------------------------------------------------
           from year 2001       *****                              *****
         ----------------------------------------------------------------------------------------------------
           from year 2002       *****                              *****
           onwards
         ----------------------------------------------------------------------------------------------------

</TABLE>

2.2.2    DISCOUNT ON TERMINAL STATION (TS) DELIVERIES

<TABLE>

<CAPTION>

         ----------------------------------------------------------------------------------------------------
           Date of                 Discount applicable to the list price of WALKair terminal station (TS)
                                                                equipment
                             -------------------------------------------------------------------------------
<S>                             <C>                                <C>
           TS deliveries        26 GHz                             3,5 GHz exclusive TS-RFU
         ----------------------------------------------------------------------------------------------------
           year 2000            *****                              *****
         ----------------------------------------------------------------------------------------------------
           year 2001            *****                              *****
         ----------------------------------------------------------------------------------------------------
           year 2002 onwards    *****                              *****
         ----------------------------------------------------------------------------------------------------

</TABLE>

2.2.3    DISCOUNT ON TURNKEY SERVICES

<TABLE>

<CAPTION>

        ---------------------------------------------------------------------------------------------------
           Discounts applicable to the listed prices of Turnkey Services of the base station and terminal
                                                      station
                                      set out in Section 4 of this Appendix 2
                                              (Turnkey Pricing Matrix)
        ---------------------------------------------------------------------------------------------------
<S>                                        <C>
          Planning Services                **
        ---------------------------------------------------------------------------------------------------
          Other Services                   **
        ---------------------------------------------------------------------------------------------------
          Project Management               **
        ---------------------------------------------------------------------------------------------------

</TABLE>

2.3      DISCOUNT ON BASE STATION (BS) CAPACITY EXPANSION

  For the delivery of additional BS-BU components such as but not limited to
  additional BS-BU components for capacity expansion purposes and/or for initial
  installations, a discount of ******************* shall apply to the list price
  of the BS-BU as set out in section 3.1 of this Appendix 2, PROVIDED THAT:

i.   the ****************** of this Agreement has occurred and

ii.  more than ******************** CPEs are in service in the Purchaser's
     network

2.4  DDF

  The Contractor shall supply the DDF at no additional cost to the Purchaser.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 4 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3    EQUIPMENT AND RELATED I&C

3.1  LIST PRICES - BASE STATION (BS)

3.1.1 LIST PRICE BS SYSTEM WALKAIR - 3,5 GHZ

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------
                                                       EURO                LIST PRICES
---------------------------------------------------------------------------------------------------
  Central Station (BS)                     QTY.        UNIT           SUBTOTAL       TOTAL
---------------------------------------------------------------------------------------------------
<S>                                       <C>         <C>            <C>
  IF MUX 8pol., redundant                  4           *****          *****
---------------------------------------------------------------------------------------------------
  BS RFU 3,5 GHz                           4           *****          *****
---------------------------------------------------------------------------------------------------
  ANT-BS 3,5 / 90                          4           *****          *****
---------------------------------------------------------------------------------------------------
  Common Outdoor parts                                                               *****
---------------------------------------------------------------------------------------------------
  BS-BU (3 x E1)                           3           *****          *****
---------------------------------------------------------------------------------------------------
  BS-BU (2 x E1)                           3           *****          *****
---------------------------------------------------------------------------------------------------
  SW V5.1/V5.2                             6           *****          *****
---------------------------------------------------------------------------------------------------
  Capacity related parts                                                             *****
---------------------------------------------------------------------------------------------------
  LIST PRICE PER BS                                                                  *****
---------------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------------
  SDH-MUX (12xE1 (-) E3/STM-1)                                                       *****
---------------------------------------------------------------------------------------------------
</TABLE>

3.1.2    LIST PRICES BS SYSTEM WALKAIR - 26 GHZ

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------
                                                      EURO                    LIST PRICES
  Central Station (BS)                     QTY.       UNIT            SUM            SUBTOTAL
--------------------------------------------------------------------------------------------------
<S>                                       <C>        <C>             <C>
  IF MUX16pol.                             4          *****           *****
--------------------------------------------------------------------------------------------------
  BS RFU 26 GHz                            4          *****           *****
--------------------------------------------------------------------------------------------------
  ANT-BS 26 / 90                           4          *****           *****
--------------------------------------------------------------------------------------------------
  Common outdoor part                                                                *****
--------------------------------------------------------------------------------------------------
  BS-BU (3 x E1)                           4          *****           *****
--------------------------------------------------------------------------------------------------
  BS-BU (2 x E1)                           4          *****           *****
--------------------------------------------------------------------------------------------------
  SW V5.1/V5.2                             8          *****           *****
--------------------------------------------------------------------------------------------------
  capacity related part                                                              *****
--------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------
  LIST PRICE PER BS                                                                  *****
--------------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 5 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3.2  LIST PRICES - TERMINAL STATION (TS)

  For TS-BU (terminal station - basic unit) modules consisting of a TS-BU unit
  and one or more certain interface (if) units, which are included in one of the
  listed service bundles the list price of the TS-BU module as indicated in this
  Section of the related service bundle shall apply.

  For TS-BU modules, which are not included in below listed service bundles the
  list price of the TS-BU module pursuant to Section 3.3.2 shall apply.

3.2.1 LIST PRICES - TERMINALSTATION SERVICES 3,5 GHZ

  LIST PRICE SERVICE BUNDLE 1

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
  ONU 30 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 10 POTS                                          1
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        2
---------------------------------------------------------------------------------------------
  ISDN (-) TCP/IP card (provided by customer)             2                       *****
                                                                                  *****
---------------------------------------------------------------------------------------------
  CITAM - S0 (-) X.25 Adapter                             1        *****          *****
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>

  LIST PRICE SERVICE BUNDLE 2a
---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT TCP/IP Adapter                     1        *****          *****
---------------------------------------------------------------------------------------------
  ONU 120 consisting of                                   1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 10 POTS                                          1
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        3
---------------------------------------------------------------------------------------------
   - i/f V.35 (64 kbps LL)                                1
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 6 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

LIST PRICE SERVICE BUNDLE 2b
ALTERNATIVE OPTION (REL. V5.X WALKAIR REQUIRED)

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisiting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (64kbps)                        1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT TCP/IP Adapter                     1        *****          *****
---------------------------------------------------------------------------------------------
  ONU 30 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 10 POTS                                          1
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        2
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 3a

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f E1 LL (2 Mbps)                                   1
---------------------------------------------------------------------------------------------
  ONU 120 consisting of                                   1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        4
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 3b

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f E1 LL (2 Mbps)                                   1
---------------------------------------------------------------------------------------------
  ONU 30 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f BR-ISDN                                          3
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 7 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

 LIST PRICE SERVICE BUNDLE 4

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (G.703 for native ATM 2 Mbps)                 1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (512kbps)                       1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        *****          *****
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 5

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f PRI ISDN (2 Mbps)                                1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR (64kbps)                                 1
---------------------------------------------------------------------------------------------
   - i/f V.35 LL (64kbps)                                 1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        *****          *****
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 6a
  (NON CONCENTRATING)

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                2        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f PRI ISDN (2 Mbps)                                2
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 LL (2Mbps)                                    1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR (2Mbps)                                  1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        *****          *****
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                    Page 8 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

  LIST PRICE SERVICE BUNDLE 6b
  (CONCENTRATING)

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                2        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f PRI ISDN (2 Mbps)                                2
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 LL (2Mbps)                                    1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        *****          *****
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 7

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                               QTY.     EURO / UNIT    SUM
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  3,5 GHz TS antenna + RFU                                1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
  V.35 (-) Router; 2 x 10BaseT                            1        *****          *****
---------------------------------------------------------------------------------------------
  ONU 20 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        2
---------------------------------------------------------------------------------------------
  CITAM - S0 (-) X.25 Adapter                             1        *****          *****
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

</TABLE>
                                                                    Page 9 of 49

<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3.2.2    LIST PRICES - TERMINALSTATION SERVICES 26 GHZ

  LIST PRICE SERVICE BUNDLE 1

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
  ONU 30 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 10 POTS                                          1
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        2
---------------------------------------------------------------------------------------------
  ISDN (-) TCP/IP card (provided by customer)             2                       ***
                                    ********                                      *****
---------------------------------------------------------------------------------------------
  CITAM - S0 (-) X.25 Adapter                             1        ***            ***
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                               ******
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 2A

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT TCP/IP Adapter                     1        ***            ***
---------------------------------------------------------------------------------------------
  ONU 120 consisting of                                   1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 10 POTS                                          1
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        3
---------------------------------------------------------------------------------------------
   - i/f V.35 (64 kbps LL)                                1
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                ******
---------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 10 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

  LIST PRICE SERVICE BUNDLE 2B
  ALTERNATIVE OPTION (REL. V5.X WALKAIR REQUIRED)

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisiting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (64kbps)                        1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT TCP/IP Adapter                     1        ***            ***
---------------------------------------------------------------------------------------------
  ONU 30 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 10 POTS                                          1
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        2
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                ******
---------------------------------------------------------------------------------------------

</TABLE>

  LIST PRICE SERVICE BUNDLE 3A

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
--------------------------------------------------------------------------------------------
   - i/f E1 LL (2 Mbps)                                   1
---------------------------------------------------------------------------------------------
  ONU 120 consisting of                                   1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        4
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                ******
---------------------------------------------------------------------------------------------

</TABLE>

  LIST PRICE SERVICE BUNDLE 3B

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  35 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f E1 LL (2 Mbps)                                   1
---------------------------------------------------------------------------------------------
  ONU 30 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f BR-ISDN                                          3
---------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 11 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>

<S>                                                                               <C>
  TOTAL LIST PRICE                                                                ******
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 4

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (G.703 for native ATM 2 Mbps)                 1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (512kbps)                       1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        ***            ***
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------

</TABLE>

  LIST PRICE SERVICE BUNDLE 5

<TABLE>

<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f PRI ISDN (2 Mbps)                                1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR (64kbps)                                 1
---------------------------------------------------------------------------------------------
   - i/f V.35 LL (64kbps)                                 1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        ***            ***
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                *****
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 6A

  (NON CONCENTRATING)

<TABLE>

<CAPTION>

---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 2        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f PRI ISDN (2 Mbps)                                2
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 LL (2Mbps)                                    1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR (2Mbps)                                  1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        ***            ***
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                ******
---------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 12 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

  LIST PRICE SERVICE BUNDLE 6B
  (CONCENTRATING)

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 2        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f PRI ISDN (2 Mbps)                                2
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 LL (2Mbps)                                    1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
  RAD V.35 (-) 10BaseT                                    1        ***            ***
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                ******
---------------------------------------------------------------------------------------------
</TABLE>

  LIST PRICE SERVICE BUNDLE 7

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------
  CPE parts                                                QTY.     EURO /         SUM
                                                                    UNIT
---------------------------------------------------------------------------------------------
<S>                                                       <C>      <C>            <C>
  26 GHz TS antenna + RFU                                 1        *****          *****
---------------------------------------------------------------------------------------------
  TS-BU consisting of                                     1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f E1 (V5.1)                                        1
---------------------------------------------------------------------------------------------
   - i/f V.35 FR with DBA (2Mbps)                         1
---------------------------------------------------------------------------------------------
  V.35 (-) Router; 2 x 10BaseT                            1        *****          *****
---------------------------------------------------------------------------------------------
  ONU 20 consisting of                                    1        *****          *****
---------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                                        2
---------------------------------------------------------------------------------------------
  CITAM - S0 (-) X.25 Adapter                             1        ***            ***
---------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                                                ******
---------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 13 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3.3  DETAILED LIST PRICES ON UNIT LEVEL - BILL OF MATERIAL (BOM) BS EQUIPMENT
     AND CPE

  This Section of Appendix 2 indicates the list prices on unit respectively
  board level of the base station (BS) and customer premises (CPE) equipment.

3.3.1 DETAILED LIST PRICES FOR BASE STATION (BS) EQUIPMENT ON UNIT RESPECTIVELY
      BOARD LEVEL

<TABLE>

<CAPTION>

NAME          TYPE        DESCRIPTION                                      MATERIAL CODE                  UNIT LIST PRICE
-------------------------------------------------------------------------------------------------------------------------------
<S>           <C>        <C>                                            <C>                      <C>            <C>
1. RFU
RFU 3.5GHz    Band A      Radio Frequency Unit for 3.5 GHz, RF Band A      FWS:101001               BS            ************
                          Included: Integrated mounting brackets,
                          1 cable to antenna, 2 mounting bands

              Band B      Radio Frequency Unit for 3.5 GHz, RF Band B      FWS:100078               BS            ************
                          Included:  Integrated mounting brackets,
                          1 cable to antenna, 2 mounting bands

              Band C      Radio Frequency Unit for 3.5 GHz, RF Band C      FWS:101021               BS            ************
                          Included:  Integrated mounting brackets,
                          1 cable to antenna, 2 mounting bands

RFU 26GHz     Band F      Radio Frequency Unit  for 26 GHz, RF Band F      FWS:100066               BS            ************
                          Included: Mounting materials

              Band E      Radio Frequency Unit  for 26 GHz, RF Band E      FWS:100065               BS            ************
                          Included: Mounting materials

              Band D      Radio Frequency Unit  for 26 GHz, RF Band D      FWS:100064               BS            ************
                          Included: Mounting materials

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 14 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>

<CAPTION>
<S>            <C>                                                     <C>                      <C>            <C>
Band C         Radio Frequency Unit  for 26 GHz, RF Band C                FWS:100063               BS            ************
               Included: Mounting materials

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 15 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts
<TABLE>
<CAPTION>

NAME                TYPE           DESCRIPTION                                                      MATERIAL CODE
-----------------------------------------------------------------------------------------------------------------------
<S>                 <C>            <C>                                                              <C>
                    Band B         Radio Frequency Unit  for 26 GHz, RF Band B                      FWS:100062

                                   Included: Mounting materials
                    Band A         Radio Frequency Unit for 26 GHz, RF Band A                       FWS:100061
                                   Included: Mounting materials
2. ANTENNA
60DEG./ 3.5GHz      Vertical       60DEG.sectored vertical antenna for 3.5 GHz                      FWS:101003
                                   Included:  Mounting adapter, 2 Mounting brackets, 2 bands
60DEG./ 3.5GHz      Horizontal     60DEG.sectored horizontal antenna for 3.5 GHz                    FWS:100106
                                   Included:  Mounting adapter, 2 Mounting brackets, 2 bands
90DEG./ 3.5GHz      Vertical       90DEG.sectored vertical antenna for 3.5 GHz                      FWS:100113                  I
                                   Included:  Mounting adapter, 2 Mounting brackets, 2 bands
90DEG./ 3.5GHz      Horizontal     90DEG.sectored horizontal antenna for 3.5 GHz                    FWS:100115
                                   Included:  Mounting adapter, 2 Mounting brackets, 2 bands
30DEG./ 26GHz       Vertical       30DEG.sectored vertical antenna for 26 GHz                       FWS:100051
                                   Included:  Mounting adapter
30DEG./ 26GHz       Horizontal     30DEG.sectored horizontal antenna for 26 GHz                     FWS:100108
                                   Included:  Mounting adapter
45DEG./ 26GHz       Vertical       45DEG.sectored vertical antenna for 26 GHz                       FWS:100087
                                   Included:  Mounting adapter
45DEG./ 26GHz       Horizontal     45DEG.sectored horizontal antenna for 26 GHz                     FWS:100109
                                   Included:  Mounting adapter
90DEG./ 26GH        Vertical       90DEG.sectored vertical antenna for 26 GHz                       FWS:100088
                                   Included:  Mounting adapter
90DEG./ 26GH        Horizontal     90DEG.sectored horizontal antenna for 26 GHz                     FWS:100110
                                   Included:  Mounting adapter
</TABLE>

<TABLE>
<CAPTION>

NAME                 UNIT LIST PRICE
----------------    -------------------------------------------------------
<S>                  <C>                  <C>

                     BS                     ************

                     BS                     ************
2. ANTENNA
60DEG./ 3.5GHz       BS                     **********

60DEG./ 3.5GHz       BS                     **********

90DEG./ 3.5GHz       BS                     **********

90DEG./ 3.5GHz       BS                     **********

30DEG./ 26GHz        BS                     **********

30DEG./ 26GHz        BS                     **********

45DEG./ 26GHz        BS                     **********

45DEG./ 26GHz        BS                     **********

90DEG./ 26GH         BS                     **********

90DEG./ 26GH         BS                     **********

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 16 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>

NAME                     TYPE            DESCRIPTION                                                                  MATERIAL CODE
-----------------------------------------------------------------------------------------------------------------------------------
<S>                      <C>            <C>                                                                           <C>
3. IF MUX

WHEN ORDERING IF MUX, AN ADDITIONAL MOUNTING BARS SHOULD BE ORDERED ACCORDING TO
THE RACK TYPE
IF MUX 8                                 IF-Multiplexer 3.5GHz/10.5GHz, up to 8 BU's                                  FWS:101008
                                         Included: 2 mounting brackets
IF MUX 8 R               Redundancy      IF-Multiplexer 3.5GHz/10.5GHz, up to 8 BU's, redundant IF connection         FWS:100039
                                         Included: 2 mounting brackets
IF MUX 16M                               IF-Multiplexer  26GHz, up to 16 BU's                                         FWS:100050
                                         Included: 2 mounting brackets
IF MUX 16MR              Redundancy      IF-Multiplexer  26GHz, up to 16 BU's, redundant IF connection                FWS:100090
                                         Included: 2 mounting brackets
Mounting Bars            ETSI             Pair of mounting bars fitted to ETSI rack                                   FWS:300013
                         19"              Pair of mounting bars  fitted to 19" rack                                   FWS:300014

5. TELECOM INTERFACES (NO INDIVIDUAL ORDERING)
BS/BU unit                               Base Station unit BS-BU                                                      FWS:000000
E1 Interface Card                        Telecom interface card for E1/G.703/ISDN PRI                                 FWS:101009
V.35-FR Interface Card                   Telecom interface card for V.35 Frame Realy DBA applications                 FWS:100080

</TABLE>

<TABLE>
<CAPTION>

NAME                     TYPE                      UNIT LIST PRICE
------------------------------------------------------------------------------
<S>                      <C>                <C>       <C>
3. IF MUX

WHEN ORDERING IF MUX, AN ADDITIONAL MO
THE RACK TYPE
IF MUX 8                                    BS          **********

IF MUX 8 R               Redundancy         BS        ************

IF MUX 16M                                  BS          **********

IF MUX 16MR              Redundancy         BS        ************

Mounting Bars            ETSI               BS           *********
                         19"                             *********

5. TELECOM INTERFACES (NO INDIVIDUAL O
BS/BU unit                                  BS        ************
E1 Interface Card                           BS          **********
V.35-FR Interface Card                      BS          **********

</TABLE>

  NOTE 1):

  For BS-BU (terminal station - basic unit) modules consisting of a BS-BU unit
  and one or more certain interface (if) units, which are included in one of the
  listed configuration the list price of the BS-BU module as indicated in
  Section 3.1 shall apply.

  For BS-BU modules, which are not included in the listed prices pursuant to
  Section 3.1 the cumulative list price of the parts forming the BS-BU module
  pursuant to this Section 3.3.1 shall apply.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                   Page 17 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3.3.2 DETAILED LIST PRICES FOR CUSTOMER PREMISES STATION EQUIPMENT CPE ON UNIT
RESPECTIVELY BOARD LEVEL

<TABLE>

<CAPTION>

NAME                TYPE      DESCRIPTION                                                     MATERIAL CODE         UNIT LIST PRICE
-----------------------------------------------------------------------------------------------------------------------------------
<S>                 <C>       <C>                                                             <C>           <C>     <C>
1. RFU + ANTENNA
RFU 3.5GHz          Band A    RFU + integrated VERTICAL antenna for 3.5 GHz, RF Band A        FWS:101011     TS     ************
                              Included:  Mounting adapter, 2 mounting bands

                    Band A    RFU + integrated HORIZONTAL antenna for 3.5 GHz, RF Band A      FWS:100102     TS     ************
                              Included:  Mounting adapter, 2 mounting bands

                    Band B    RFU + integrated VERTICAL antenna for 3.5 GHz, RF Band B        FWS:100079     TS     ************
                              Included:  Mounting adapter, 2 mounting bands

                    Band B    RFU + integrated HORIZONTAL antenna for 3.5 GHz, RF Band B      FWS:100103     TS     ************
                             Included:  Mounting adapter, 2 mounting bands

                    Band C   RFU + integrated VERTICAL antenna for 3.5 GHz, RF Band C         FWS:100020     TS     ************
                             Included:  Mounting adapter, 2 mounting bands

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 18 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>

<CAPTION>

NAME        TYPE      DESCRIPTION                                                  MATERIAL CODE           UNIT LIST PRICE
--------------------------------------------------------------------------------------------------------------------------
<S>        <C>       <C>                                                          <C>            <C>    <C>
            Band C    RFU + integrated HORIZONTAL antenna for 3.5 GHz, RF Band C   FWS:100104       TS     ************
                      Included:  Mounting adapter, 2 mounting bands

RFU 26GHz   Band F    Radio Frequency Unit  for 26 GHz, RF Band F                  FWS:100058       TS     ************
                      Included: Attached VERTICAL antenna

            Band E    Radio Frequency Unit  for 26 GHz, RF Band E                  FWS:100057       TS     ************
                      Included: Attached VERTICAL antenna

            Band D    Radio Frequency Unit  for 26 GHz, RF Band D                  FWS:100056       TS     ************
                      Included: Attached VERTICAL antenna

            Band C    Radio Frequency Unit  for 26 GHz, RF Band C                  FWS:100055       TS     ************
                      Included: Attached VERTICAL antenna

            Band B    Radio Frequency Unit  for 26 GHz, RF Band B                  FGWS:100054      TS     ************
                      Included: Attached VERTICAL antenna

            Band A    Radio Frequency Unit  for 26 GHz, RF Band A                  FWS:100053       TS     ************
                      Included: Attached VERTICAL antenna

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 19 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>

<CAPTION>

<S>         <C>       <C>                                                          <C>               <C>   <C>
            Band A    Radio Frequency Unit  for 26 GHz, RF Band A                  FWS:100112        TS    ************
                      Included: Attached HORIZONTAL antenna

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 20 of 49

<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

2. TERMINAL BASIC UNIT (TS-BU)

3.5GHZ
<TABLE>

<S>                        <C>          <C>                                          <C>               <C>          <C>
TS 3.5GHz 48V E1             48V          TS/BU, 3.5GHz, 48V, 1xE1                        FWS:100036      TS          ******** ***
TS 3.5GHz 48V 2xE1           48V          TS/BU, 3.5GHz, 48V, 2xE1                        FWS:100076      TS          ******** ***
TS 3.5GHz 220V E1            110/220V     TS/BU, 3.5GHz, 110/220V,  1xE1                  FWS:100032      TS          ******** ***
TS 3.5GHz 220V 2xE1          110/220V     TS/BU, 3.5GHz, 110/220V,  2xE1                  FWS:100117      TS          ******** ***
TS 3.5GHz 220V 3xE1          110/220V     TS/BU, 3.5GHz, 110/220V,  3xE1                  FWS:100118      TS          ******** ***
TS 3.5GHz 220V E1 V35/X21    110/220V     TS/BU, 3.5GHz, 110/220V,  1xE1, 1xV35/X21       FWS:100070      TS          ******** ***
TS 3.5GHz 220V V35/X21       110/220V     TS/BU, 3.5GHz, 110/220V,  1xV35/X21             FWS:100073      TS          ******** ***
TS 3.5GHz 220V E1 FR         110/220V     TS/BU, 3.5GHz, 110/220V,  1xE1, 1xV35/X21-FR    FWS:100081      TS          ******** ***
TS 3.5GHz 220V FR            110/220V     TS/BU, 3.5GHz, 110/220V,  1xV35/X21-FR          FWS:100084      TS          ******** ***

26GHZ

TS 26GHz 48V E1              48V          TS/BU, 26GHz, 48V, 1xE1                         FWS:100069      TS          ******** ***
TS 26GHz 48V 2xE1            48V          TS/BU, 26GHz, 48V, 2xE1                         FWS:100095      TS          ******** ***
TS 26GHz 220V E1             110/220V     TS/BU, 26GHz, 110/220V,   1xE1                  FWS:100049      TS          ******** ***
TS 26GHz 220V 2xE1           110/220V     TS/BU, 26GHz, 110/220V,   2xE1                  FWS:100120      TS          ******** ***
TS 26GHz 220V 3xE1           110/220V     TS/BU, 26GHz, 110/220V,   3xE1                  FWS:100121      TS          ******** ***
TS 26GHz 220V E1 V35/X21     110/220V     TS/BU, 26GHz, 110/220V,   1xE1, 1xV35/X21       FWS:100072      TS          ******** ***
TS 26GHz 220V V35/X21        110/220V     TS/BU, 26GHz, 110/220V,   1xV35/X21             FWS:100075      TS          ******** ***
TS 26GHz 220V E1 FR          110/220V     TS/BU, 26GHz, 110/220V,   1xE1, 1xV35/X21-FR    FWS:100083      TS          ******** ***
TS 26GHz 220V FR             110/220V     TS/BU, 26GHz, 110/220V,   1xV35/X21-FR          FWS:100086      TS          ******** ***
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 21 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

3. TELECOM INTERFACES (NO INDIVIDUAL ORDERING)
<TABLE>

<S>                        <C>                                                                    <C>
TS unit                      Terminal Basic Unit incl. 48 V or 220 V Power Supply                     FWS:000000   TS   ******** ***
E1 Interface Card            Telecom interface card for E1/G.703/ISDN PRI                             FWS:101009   TS   ******** ***
V.35/X.21 Interface Card     Telecom interface card for V.35/X.21                                     FWS:101027   TS   ******** ***
V.35-FR Interface Card       Telecom interface card for V.35-FR                                       FWS:100080   TS   ******** ***
Ethernet Interface Card      LAN interface card for Ethernet applications                             FWS:100091   TS   ******** ***

4. WALKnet EMS

WALKnet HPOV/PC              EMS Software  license for HPOV/PC platform
                             (not including HPOV platform)

                             Basic EMS package License for up to 20 links                             FWS:300001  EMS   ******** ***
                             License for each additional link (TS) above the first 20 TSs             FWS:300003  EMS   ******** ***

5. SOFTWARE PACKAGE

V5.2                         V5.2/V5.1 software license for a single BS-BU (supports up to 16 TSs)    FWS:300004   SW   ******** ***
                             (supports up to 16 TSs) V5 software is operating over a
                             regular E1 interface

6. ACCESSORIES

Antenna Alignment Unit       Antenna Alignment Unit for fine tuning TS Antenna                        FWS:300002  ACC   ******** ***
                             of  3.5GHz band A, 10.5GHz, 26GHz

7. REPLACEMENT PARTS

Bands                        1 x metal band for pole mounting                                         FWS:MC0050  REP   ******** ***
Blank Panel                  10 x Blank panel for empty interface slot                                FWS:300015  REP   ******** ***
Jumper cables                1x jumper cable for connecting the BS/BU to IF-MUX                       FWS:AS0051  REP   ******** ***
Mounting adapter             Mounting Adapter for  3.5GHz and 10.5GHz RFU/TS                          FWS:AS0123  REP   ******** ***
Rack mounting brackets       1 x rack mounting brackets for BU or IF MUX. fit both 19" and ETSI racks FWS:MC0020  REP   ******** ***
RFU/BS cable 3.5GHz/10.5GHz  1 x cable for connecting the RFU to the antenna in  3.5 Ghz/10.5 GHz     FWS:AS0020  REP   ******** ***

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 22 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

3.4      DETAILED LIST PRICING - BILL OF MATERIAL (BOM) ONU EQUIPMENT

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------------------
  CPE PARTS                               QTY.     EURO /         SUM              EURO / UNIT    SUM           DESCRIPTION
                                                  UNIT
----------------------------------------------------------------------------------------------------------------------------------

<S>                                   <C>      <C>            <C>               <C>            <C>            <C>
  ONU 30 consisting of                   1        *****          *****             *****          *****         ONU 30 core
----------------------------------------------------------------------------------------------------------------------------------
   - i/f 10 POTS                         1                                         *****          *****         Linecard 10x POTS
----------------------------------------------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                       2                                         *****          *****         Linecard 4x Uk0
----------------------------------------------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                               *****                            *****
----------------------------------------------------------------------------------------------------------------------------------

<CAPTION>
----------------------------------------------------------------------------------------------------------------------------------
  CPE PARTS                               QTY.     EURO /         SUM              EURO / UNIT    SUM           DESCRIPTION
                                                  UNIT
----------------------------------------------------------------------------------------------------------------------------------
<S>                                   <C>      <C>            <C>               <C>            <C>            <C>
  ONU 120 consisting of                  1        *****          *****             *****          *****
----------------------------------------------------------------------------------------------------------------------------------
   - i/f 10 POTS                         1                                         *****          *****         Linecard 10x POTS
----------------------------------------------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                       3                                         *****          *****         Linecard 4x Uk0
----------------------------------------------------------------------------------------------------------------------------------
   - i/f V.35 (64 kbps LL)               1                                         *****          *****         Linecard 2x nx64k
----------------------------------------------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                               *****                            *****
----------------------------------------------------------------------------------------------------------------------------------
<CAPTION>
----------------------------------------------------------------------------------------------------------------------------------
  CPE PARTS                               QTY.     EURO /         SUM              EURO / UNIT    SUM           DESCRIPTION
                                                  UNIT
----------------------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------------------
<S>                                   <C>      <C>            <C>               <C>            <C>            <C>
  ONU 30 consisting of                   1        *****          *****             *****          *****         ONU 30 core
----------------------------------------------------------------------------------------------------------------------------------
   - i/f 10 POTS                         1                                         *****          *****         Linecard 10x POTS
----------------------------------------------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                       2                                         *****          *****         Linecard 4x Uk0
----------------------------------------------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                               *****                            *****
----------------------------------------------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 23 of 49
<PAGE>
                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------------------
  CPE PARTS                               QTY.     EURO /         SUM              EURO / UNIT    SUM           DESCRIPTION
                                                  UNIT
----------------------------------------------------------------------------------------------------------------------------------
<S>                                   <C>      <C>            <C>               <C>            <C>            <C>
  ONU 120 consisting of                  1        *****          *****             *****          *****         ONU 120 core
----------------------------------------------------------------------------------------------------------------------------------
   - i/f 4 BR-ISDN                       4                                         *****          *****         Linecard 4x Uk0
----------------------------------------------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                               *****                            *****
----------------------------------------------------------------------------------------------------------------------------------
<CAPTION>
----------------------------------------------------------------------------------------------------------------------------------
  CPE PARTS                               QTY.     EURO /         SUM              EURO / UNIT    SUM           DESCRIPTION
                                                  UNIT
----------------------------------------------------------------------------------------------------------------------------------
<S>                                   <C>      <C>            <C>               <C>            <C>            <C>
  ONU 30 consisting of                   1        *****          *****             *****          *****         ONU 30 core
----------------------------------------------------------------------------------------------------------------------------------
   - i/f BR-ISDN                         3                                         *****          *****         Linecard 4x Uk0
----------------------------------------------------------------------------------------------------------------------------------
  TOTAL LIST PRICE                                               *****                            *****
----------------------------------------------------------------------------------------------------------------------------------

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 24 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3.5      CUSTOMER PRICES - CISCO EQUIPMENT AND RELATED I&C

  This Section of Appendix 2 indicates the unit prices for DCN-equipment and
  related installation, commissioning, integration and acceptance (I&C) Service
  prices on unit level, for which it is assumed that the DCN equipment is
  installed at normal working hours. Normal working hours considered as working
  time during Working Days from Monday to Friday between 8:00 and 16:00.
  Indicated I&C prices include a separate site visit.
<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------------------------
MATERIAL CODE                      DESCRIPTION                                      CUSTOMER PRICE        I&C PRICE IN
                                                                                      IN EURO               EURO 1)
--------------------------------------------------------------------------------------------------------------------------------
<S>              <C>                                                                <C>                   <C>
                  CISCO 3600 SERIES PRODUCTS
----------------------------------------------------------------------------------
CISCO3620-DC      Cisco 3600 2-Slot Modular Router-DC with IP Software                ******** ***          ****** ***
----------------------------------------------------------------------------------
CISCO3640-DC      Cisco 3600 4-slot Modular Router-DC with IP Software                ******** ***          ****** ***
----------------------------------------------------------------------------------
CISCO3661-DC      10/100 E Cisco 3660 6-slot Modular Router-DC with IP SW             ******** ***          ****** ***
----------------------------------------------------------------------------------
CISCO3662-DC      Dual 10/100 E Cisco 3660 6-slot Modular Router-DC with IP SW        ******** ***          ****** ***
----------------------------------------------------------------------------------
CISCO3662-DC-CO   Dual 10/100E Cisco3660 6-slot CO Mod Routr 2xDC PS, Telco SW        ******** ***          ****** ***
----------------------------------------------------------------------------------
                  CISCO 2600 SERIES PRODUCTS
----------------------------------------------------------------------------------
CISCO2610         Ethernet Modular Router w/ Cisco IOS IP Software                    ******** ***          ****** ***
----------------------------------------------------------------------------------
CISCO2610-DC      Ethernet Modular Router w/ Cisco IOS IP Software - DC               ******** ***          ****** ***
----------------------------------------------------------------------------------
CISCO2620         10/100 Ethernet Router w/2 WIC Slots & 1 Network Module Slot        ******** ***          ****** ***
----------------------------------------------------------------------------------
CISCO2620-DC      10/100 Ethernet Modular Router with Cisco IOS IP software-DC        ******** ***          ****** ***
----------------------------------------------------------------------------------
                  CISCO 2600/3600 SERIES NETWORK MODULES
----------------------------------------------------------------------------------
NM-1E             1-Port Ethernet Network Module                                      ******** ***          ****** ***
----------------------------------------------------------------------------------
NM-1FE2W          1 10/100 Ethernet 2 WAN Card Slot Network Module                    ******** ***          ****** ***
----------------------------------------------------------------------------------
NM-1E2W           1 Ethernet 2 WAN Card Slot Network Module                           ******** ***          ****** ***
----------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 25 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
MATERIAL CODE                      DESCRIPTION                                      CUSTOMER PRICE        I&C PRICE IN
                                                                                      IN EURO               EURO 1)
------------------------------------------------------------------------------------------------------------------------
<S>              <C>                                                                <C>                   <C>
NM-2E2W          2 Ethernet 2 WAN Card Slot Network Module                            ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-4B-S/T        4-Port ISDN-BRI Network Module                                       ******** ***          ****** ***

---------------------------------------------------------------------------------
NM-8B-S/T        8-Port ISDN-BRI Network Module                                       ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-1CE1B         1-Port Channelized E1/ISDN-PRI Balanced Network Module               ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-2CE1B         2-Port Channelized E1/ISDN-PRI Balanced Network Module               ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-1FE1CE1B      1 Port F Ethernet 1 Port Channelized E1/ISDN-PRI Balanced NM         ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-1FE2CE1B      1 Port F Ethernet 2 Port Channelized E1/ISDN-PRI Balanced NM         ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-4E            4-Port Ethernet Network Module                                       ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-4E1-IMA       4-port E1 ATM Network Module with IMA                                ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-4T            4-Port Serial Network Module                                         ******** ***          ****** ***
---------------------------------------------------------------------------------
NM-8E1-IMA       8-port E1 ATM Network Module with IMA                                ******** ***          ****** ***
---------------------------------------------------------------------------------
                 CISCO 2600/3600 SERIES WAN INTERFACE CARDS
---------------------------------------------------------------------------------
WIC-1T           1-Port Serial WAN Interface Card                                     ******** ***          ****** ***
---------------------------------------------------------------------------------
WIC-1B-S/T       1-Port ISDN WAN Interface Card(dial and leased line)                 ******** ***          ****** ***
---------------------------------------------------------------------------------
                 CABLES FOR NM
---------------------------------------------------------------------------------
CAB-X21MT        X.21 Cable, DTE, Male, 10 Feet                                       ******** ***          ****** ***
---------------------------------------------------------------------------------
CAB-530MT        RS-530 Cable, DTE, Male, 10 Feet                                     ******** ***          ****** ***
---------------------------------------------------------------------------------
CAB-SS-X21MT     X.21 Cable, DTE Male to Smart Serial, 10 Feet                        ******** ***          ****** ***
---------------------------------------------------------------------------------
CAB-SS-X21FC     X.21 Cable, DCE Female to Smart Serial, 10 Feet                      ******** ***          ****** ***
---------------------------------------------------------------------------------
CAB-E1-PRI       E1- ISDN PRI Cable, 10 Feet                                          ******** ***          ****** ***
---------------------------------------------------------------------------------
                 CISCO 3600 SERIES IOS UPGRADES FOR 11.2 AND NEWER
---------------------------------------------------------------------------------
FL36-C-A=        Cisco IOS 3600 Series IP to Enterprise                               ******** ***          ****** ***
---------------------------------------------------------------------------------
                 CISCO 2600 IOS SOFTWARE
---------------------------------------------------------------------------------
S26AP-12.0.XT    Cisco 2600 Series IOS ENTERPRISE PLUS                                ******** ***          ****** ***
---------------------------------------------------------------------------------
                 CISCO 2500 SERIES PRODUCTS
---------------------------------------------------------------------------------
CISCO2501        Cisco 2501 Ethernet/Dual Serial Router                               ******** ***          ****** ***
---------------------------------------------------------------------------------
                 CISCO 2500 SERIES SOFTWARE OPTIONS - MODELS 2501-2525
---------------------------------------------------------------------------------
S25AP-12.0.XT    Cisco 2500 Series IOS ENTERPRISE PLUS                                ******** ***          ****** ***
---------------------------------------------------------------------------------
S25C-12.0.XT     Cisco 2500 Series IOS IP                                             ******** ***          ****** ***
---------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 26 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
MATERIAL CODE                      DESCRIPTION                                      CUSTOMER PRICE        I&C PRICE IN
                                                                                      IN EURO               EURO 1)
------------------------------------------------------------------------------------------------------------------------
<S>              <C>                                                                <C>                   <C>
-----------------------------------------------------------------------------------------------------------------------
                   CISCO 1700 SERIES MODULAR ACCESS ROUTERS
------------------------------------------------------------------------------------
CISCO1750          10/100 Modular Router w/1VIC, 2WIC/VIC slots,Cisco IOS IP SW       ******** ***          ****** ***
------------------------------------------------------------------------------------
CISCO1750-2V       10/100 Modular Router w/2 Voice channels, IOS IP/VOICE + SW        ******** ***          ****** ***
------------------------------------------------------------------------------------
CISCO1750-4V       10/100 Modular Router w/4 Voice channels, IOS IP/VOICE + SW        ******** ***          ****** ***
------------------------------------------------------------------------------------
WIC-1T             1-Port Serial WAN Interface Card                                   ******** ***          ****** ***
------------------------------------------------------------------------------------
CAB-X21MT          X.21 Cable, DTE, Male, 10 Feet                                     ******** ***          ****** ***
------------------------------------------------------------------------------------
CAB-530MT          RS-530 Cable, DTE, Male, 10 Feet                                   ******** ***          ****** ***
------------------------------------------------------------------------------------
MEM1700-4U8MFC     Cisco 1700 4MB to 8MB Mini-Flash Card Factory Upgrade              ******** ***          ****** ***
------------------------------------------------------------------------------------
                   CISCO 1700 SERIES SOFTWARE OPTIONS
------------------------------------------------------------------------------------
S17C-12.0.XT       Cisco 1700 Series IOS IP                                           ******** ***          ****** ***
------------------------------------------------------------------------------------
                   CISCO 1600 SERIES PRODUCTS
------------------------------------------------------------------------------------
                   NEW CISCO 1600 R ROUTERS WITH IP SOFTWARE
------------------------------------------------------------------------------------
CISCO1605-R        Cisco 1605-R Dual Ethernet/WAN Interface Card slot Router          ******** ***          ****** ***
------------------------------------------------------------------------------------
MEM1600R-4U8FC     4MB to 8MB Flash Factory Upgrade for Cisco 1600 R                  ******** ***          ****** ***
------------------------------------------------------------------------------------
CAB-X21MT          X.21 Cable, DTE, Male, 10 Feet                                     ******** ***          ****** ***
------------------------------------------------------------------------------------
CAB-530MT          RS-530 Cable, DTE, Male, 10 Feet                                   ******** ***          ****** ***
------------------------------------------------------------------------------------
                   CISCO 1600 R ROUTERS SOFTWARE OPTIONS - MODELS 1601 R-1605 R
------------------------------------------------------------------------------------
S16RC-12.0.X       Cisco 1600R Series IOS IP                                          ******** ***          ****** ***
------------------------------------------------------------------------------------
                   CISCO 1000 SERIES PRODUCTS
------------------------------------------------------------------------------------
CISCO1005          Cisco 1005 Ethernet/Synchronous Serial Router                      ******** ***          ****** ***
------------------------------------------------------------------------------------
                   CISCO 1000 SERIES SOFTWARE OPTIONS - MODEL 1005
------------------------------------------------------------------------------------
SF105C4-12.0.X     Cisco 1005 Ser IOS IP (4MB Flash card)                             ******** ***          ****** ***
------------------------------------------------------------------------------------
                   FASTHUB 400 SERIES REPEATERS & MODULES
------------------------------------------------------------------------------------
WS-C412            12-port autosensing 10/100 manageable, stackable repeater          ******** ***          ****** ***
------------------------------------------------------------------------------------
WS-C424            24-port autosensing 10/100 manageable, stackable repeater          ******** ***          ****** ***
-----------------------------------------------------------------------------------------------------------------------
WS-C400-CAB-EXP    Stacking cable for FastHub 400 products                            ******** ***          ****** ***
-----------------------------------------------------------------------------------------------------------------------
  Note:
</TABLE>

1) I&C prices include the visit to site either at installation together with
other BS equipment or CPE at initial installation or at separate installation
subsequently to the initial installation

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 27 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

LIST OF MATERIALS / PATCH CABLES FOR DCN PURPOSES

THE INDICATED LIST PRICES ARE ONLY APPLICABLE IN CASE OF A MINIMUM TOTAL
PURCHASE QUANTITY OF ***.
<TABLE>
<CAPTION>
 POS.                       DESCRIPTION                                     UNIT PRICE (EUR)
--------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------

<S>                                                                               <C>
1     Patchkabel Kat5, 2x RJ45 Stecker, mit Knickschutztulle, flexibel, FTP
      (Folienschirm), 1:1, 8adrig, halogenfrei Farbe Kabel / Knickschutztulle :
      blau

1.1   Length / Lange : 0,5 Meter                                                      *****

1.2   Length / Lange : 1 Meter                                                        *****

1.3   Length / Lange : 1,5 Meter                                                      *****

1.4   Length / Lange : 2 Meter                                                        *****

1.5   Length / Lange : 2,5 Meter                                                      *****

1.6   Length / Lange : 3 Meter                                                        *****

1.7   Length / Lange : 10 Meter                                                       *****

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 28 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3.6      RACKS - CUSTOMER PRICES

3.6.1 BASE STATION RACKS

<TABLE>
<CAPTION>

QUANTITY  DESCRIPTION                                             LIST PRICE PER   TOTAL CUSTOMER    RELATED I&C CUSTOMER
                                                                    UNIT IN EUR      PRICE IN EUR      PRICE IN EUR
-------------------------------------------------------------------------------------------------------------------------
<S>                                                                 <C>              <C>               <C>

1         DDF - RACK  (OHNE 2/MBIT VT) BASED ON SPECIFICATION
          DATED 21.02.00                                            **********       **************    *************
          consisting of / bestehend aus:
1         Rack BHT 800x2000x600 MM
0         - ohne Ruckwand, ohne Tur, ohne Dachblech
1         VE Seitenwande HxT 2000x600 MM, am Rack montiert
1         VE T-Nut Profilschienen +

2         Befestigungswinkel metrisch, im Rack vorne montiert
6         Montagechassis
1         Erdungsset
          TOTAL DDF RACK                                                             **************    *************
1         NETWORK - RACK BASED ON SPECIFICATION DATED 21.02.00      **********       **************    *************
0         consisting of / bestehend aus:
1         Rack BHT 800x2000x600 MM
0          - ohne Ruckwand, ohne Tur, ohne Dachblech
1         VE Seitenwande HxT 2000x600 MM, am Rack montiert
1         VE T-Nut Profilschienen +

2         Befestigungswinkel metrisch, im Rack vorne montiert
6         Montagechassis
1         Erdungsset                                                **********       **************
1         Fuse Panel ETA (Aufnahme 12 Si)                           **********       **************
          TOTAL NETWORK - RACK                                      **********       **************    *************

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 29 of 49

<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>

QUANTITY   DESCRIPTION                                              LIST PRICE PER  TOTAL CUSTOMER   RELATED I&C CUSTOMER
                                                                      UNIT IN EUR     PRICE IN EUR     PRICE IN EUR
-------------------------------------------------------------------------------------------------------------------------
<S>                                                                 <C>             <C>               <C>

1          WALKAIR - RACK BASED ON SPECIFICATION DATED 21.02.00     **********       ***********      **********
           bestehend aus:
1          Rack BHT 800x2000x600 MM
0          - ohne Ruckwand, ohne Tur, ohne Dachblech
1          VE Seitenwande HxT 2000x600 MM, am Rack montiert
1          VE T-Nut Profilschienen +
2          Befestigungswinkel metrisch, im Rack vorne montiert
6          Montagechassis

1          Erdungsset                                               **********       ***********
1          Erdungsschiene                                           **********       ***********
1          Tehalit Kabelkanal                                       **********       ***********
0          HxB 65x107  L=lichte Rackhohe
2          Fuse Panel ETA (Aufnahme 18 Si)                          **********       ***********
           In case IF-Mux is vertical installed
           Zusatzliches/optionales Zubehor wird benotigt wenn
           der IF Mux vertikal eingebaut werden soll
4          Montageschienen 23x23 MM 695 mm                          **********       ***********
4          Tehalit Drahthalteklammer                                **********       ***********
           TOTAL WALKAIR - RACK                                                      ***********      **********

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 30 of 49

<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

3.6.2 OUTDOOR SHELTER

<TABLE>
<CAPTION>
                                                                                           PRICE UNIT
      NO.                                  ITEM                                              (EURO)
-----------------------------------------------------------------------------------------------------------------
<S>            <C>                                                                            <C>

      001      OUTDOOR SHELTER, CONSISTING OF:                                                ******
               WxHxD: 2600x1600x750 mm
               material: aluminium Almg 3
               coated, RAL 7035 structur
               double back plane
               CONSISTING OF:
               - 4 pcs. of single boxes WxHxD: 650x1600x750 mm, right hand door,
                 doors are prepared to carry a heat exchanger:
               - CS side boards, 1x left and 1x right
               - CS two-part roof, 75 mm hight, 25 mm protrusion
               - 4 pcs. CS transport socket, 100 mm hight
               - 3-point security lock
               - 19" profile track, whole cabinet hight
               - 1 of 4: battery cabinet incl. 2 pcs. of mounted shelfs to carry batteries
      002      HEAT EXCHANGER, DOOR MOUNTED                                                   ******
               CONSISTING OF:
               - WxHxD: 510x1005x150 mm
               - fan: 48V DC
               - heater: 400 W, 230 V AC, 50/60 Hz
               - specific caloric capacity: 60 W/K
               - temperature range: -33(degree)C to + 65(degree)C
               - aluminium housing, coated
      003      SMOKE DETECTOR                                                                  ******
               CONSISTING OF:
               - cable to connect the sensor
               - set of plugs to connect accessories
               - power supply 24V
      004      48V POWER SUPPLY MODULE                                                         ******
               CONSISTING OF:
               - backup battery, 4h back up time
----------------------------------------------------------------------------------------------------
               TOTAL OUTDOOR SHELTER (EURO)                                                   ******

</TABLE>

  To build up the above mentioned cabinet configuration an adequate ground
construction is necessary.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 31 of 49

<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>

3.6.3 CPE RACK
                                                                                      PRICE PER UNIT /     TOTAL
 QUANTITY                             DESCRIPTION                                        MATERIAL         MATERIAL         I&C
----------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                                                        <C>                  <C>              <C>

     1     RITTAL QUICK BOX RACK BASED ON SPECIFICATION DATED 02.05.00                **********           **********
           WALL MOUNTED, 360 MM HIGH, HOUSING 19"  EQUIPMENT
           glass front door including micro switch
           RS323 as an LCI port

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 32 of 49

<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>

3.7 CUSTOMER PRICES - ATM MULTIPLEXER EQUIPMENT

                                          ATM - MUX
          NO.                               DESCRIPTION                        UNIT PRICE
---------------------------------------------------------------------------------------------

<S>                    <C>                                                      <C>
   BS-361403-22-FM1    36140 Wireless Solution Basic System including
                       1 X 36140 DC BASIC SYS R2.2
                       1 X E3 ELECT CR
                       1 X 36140 BNC75 E1 CLK PM
                       Total:                                                    ************

   BS-361403-22-FM2    36140 Wireless Solution Basic System including
                       1 X 36140 DC BASIC SYS R2.2
                       1 X STM-1 SM IR OPT SC CR
                       1 X 36140 BNC75 OPT E1 CLK PM
                       Total:                                                    ************

   BS-361444-22-FM1    36144 Wireless Solution Basic System including
                       1 X 36144 DC BASIC SYS R2.2
                       1 X E3 ELECT CR
                       1 X 36144 BNC75 E1 CLK PM
                       Total:                                                    ************

   BS-361444-22-FM2    36144 Wireless Solution Basic System including
                       1 X 36144 DC BASIC SYS R2.2
                       1 X STM-1 SM IR OPT SC CR
                       1 X 36144BNC75 OPT E1 CLK PM
                       Total:                                                    ************

      CE-E010300       OCTAL E1 120 OHM CE
      IF-R450220       36140 RJ45 PM

                       Total:                                                    ************

      FR-V350340       OCTAL V.35/X.21 FR/SMDS
      IF-S680470       36140 V.35/X.21/RS422/RS530 PM

                       Total:                                                    ************
                       1 X E3 ELECT CR
                       1 X 36144 BNC75 E1 CLK PM
                       Total:                                                    ************

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 33 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<CAPTION>

<S>                    <C>                                                      <C>
   BS-361444-22-FM2    36144 Wireless Solution Basic System including
                       1 X 36144 DC BASIC SYS R2.2
                       1 X STM-1 SM IR OPT SC CR
                       1 X 36144BNC75 OPT E1 CLK PM
                       Total:                                                    ************

      CE-E010300       OCTAL E1 120 OHM CE
      IF-R450220       36140 RJ45 PM

                       Total:                                                    ************

      FR-V350340       OCTAL V.35/X.21 FR/SMDS
      IF-S680470       36140 V.35/X.21/RS422/RS530 PM

                       Total:                                                    ************

                       Total Price

3.8 SYNCHRONISATION EQUIPMENT

3.8.1 SYMMETRICOM

<S>                                      <C>                                                  <C>
 NO.                                     DESCRIPTION                                          UNIT PRICE
--------------------------------------------------------------------------------------------------------------

 001 STAND-ALONE E1 GPS PRIMARY REFERENCE SOURCE                                                  ************
     WANDEL & GOLDERMANN
     CONSISTING OF:
     Symmetricom Model Time Source 3100 - Single Channel wtith main-
     frame, documentation, redundant power supply, GPS module with
     DCOCXO, alarm contact outputs, RS-232, 10*2,048 MHz outputs,
     antenna (with mounting kit)
     Antenna cabel 300m                                                                           ************
--------------------------------------------------------------------------------------------------------------
     PRICE PER COMPLETE SYSTEM                                                                    ************

Second system necessary for complete redundancy, but outputs not automatically
squelchable.

  Discount on Symmetricom equipment:

                           QUANTITY                    DISCOUNT
                            1 to 20                      *****
                           21 to 49                      *****
                       from 50 onwards                   *****

3.8.1 OSCILLOQUARTZ
                                                                                                     UNIT PRICE
--------------------------------------------------------------------------------------------------------------------

-----------------------
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  pursuant to a request for confidential treatment.

                                 Page 34 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<CAPTION>

                                                                                                     UNIT PRICE
  NO.                                          DESCRIPTION                                              (EUR)
-------------------------------------------------------------------------------------------------------------------

<S>                                                                                                       <C>
  001   SYNCHRONISATION DISTRIBUTION UNIT
        CONSISTING OF:
        Oscilloquartz Model 5533C-SDU -  Single Input (1*2,048 MHz)                                       *********
        with ETSI/6U mainframe, documentation, single power supply unit,
        16*2,048 MHz outputs
        OPTIONS
        Dual input (2*2,048 MHz)                                                                          *********
        Dual power supply unit                                                                            *********
        Holdover unit (OCXO 8741)                                                                         *********
        MAC2-R alarm module, LM - Local Manager Software                                                  *********
        Upgrade possibilities according Product Description
        Specification according attached Datasheet

  002   ACTIVE CLOCK DISTRIBUTOR
        CONSISTING OF:
        VTM-A1 module with 1*2,048 MHz input, 6*2,048 MHz outputs,                                        *********
        Sub-D, 75/120 Ohm, alarm contact outputs, without power supply
        unit, (SIEMENS SSU2001 family)
        or
        VTM-A2 module with 1*2,048 MHz input, 6*2,048 MHz outputs,                                        *********
        koax, 75 Ohm, alarm contact outputs, without power supply unit,
        (SIEMENS SSU2001 family)

        Cascadable and ETSI rack mountable

  003   STAND-ALONE GPS SYNCHRONISATION SYSTEM
        CONSISTING OF:
        Oscilloquartz Model 5581C GPS-SR Receiver - Single Channel                                        *********
        with ETSI/6U mainframe, documentation, single power supply unit,
        GPS module 4510 (with OCXO 8663,  additional 1*2,048 MHz
        external input (priority setting), alarm contact outputs, RS-232 C,
        preset time constant of 4000s leading to a high filter effiecency for
        jitter and wander), antenna (with mounting kit, 60 m cable),
        16*2,048 MHz outputs
        OPTIONS
        Dual GPS 4510 module with antenna set                                                             *********
        Dual power supply                                                                                 *********
        MAC2-R alarm module, LM - Local Manager Software                                                  *********
        Upgradable to complete redundancy
        Specification according attached Datasheet

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

Page 35 of 49

<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<CAPTION>

<S>   <C>                                                                                           <C>
                                                                                                    UNIT PRICE
 NO.                                        DESCRIPTION                                               (EUR)
-------------------------------------------------------------------------------------------------------------------
 004 GPS SYNCHRONISATION MODULE
     CONSISTING OF:
     Oscilloquartz Model 4510 GPS-SM with OCXO 8663-B6SG,                                                 *********
     antenna, mounting kit, 30 m cable, additional 1*2,048 MHz external
     input, alarm contact outputs, RS-232 C, 1*2,048 MHz output, preset
     time constant of 4000s leading to a high filter effiecency for jitter
     and wander, power supply unit
     Specification according attached Datasheet

3.9 RF PLANNING TOOL - NETDESIGNER

NetDesigner-PMP, standard product, licence and maintenance

<S>                          <C>                 <C>                    <C>

NUMBER OF LICENCES          LIST PRICE           MAINTENANCE            LEASING
                            (INCL. 24 MONTHS     (AFTER 24 MONTHS     (12 MONTHS)
                             MAINTENANCE)         ANNUAL)             INCL. MAINTENANCE
---------------------------------------------------------------------------------------

            1-4             *************        *************         *************

            5-14            *************        *************         *************

           15-24            *************        *************         *************

           25-29            *************        *************         *************

      from 30 onwards       *************        *************         *************

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 36 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<CAPTION>

3.10 CMXII AND SISA EQUIPMENT AND RELATED I&C
<S>       <C>                                                                 <C>   <C>       <C>        <C>       <C>
                                                                                LIST
                                                                             PRICE UNIT  TOTAL LIST PRICE   I&C PRICE  TOTAL I&C
   ITEM                               DESCRIPTION                 QUANTITY       (EUR)       UNIT (EU)     UNIT (EUR)  PRICE (EUR)
-----------------------------------------------------------------------------------------------------------------------------------

1          CMXII

1.1        CMXII core unit                                               1         ********    ********      *******        *******
1.2        Port Unit 2Mbit                                               4         ********    ********      *******        *******
1.3        Port Unit SISA                                                1         ********    ********      *******        *******
-------------------------------------------------------------------------------------------------------    ---------    -----------
           TOTAL CMXII                                                                         ********                    ********
           -----------                                                                       ----------                    --------

1.4a       option : expansion with V5 FR card for V5 signalling                    ********                 ********
1.4b       option : V5.2 license fee per configured 64kbps line                    ********

2          SISA - GKE
2.1        SISA - GKE                                                    1         ********    ********      *******        *******

3          OPTIONAL RACK EQUIPMENT FOR CMXII / SISA-GKE
3.1        Terminal Panel for Rack (ETSI) with QD2 distr. modul                    ********                 ********
3.2        Fuse panel (for 6 circuit breaker) for Terminal Panel                   ********                 ********
3.3        Circuit Breaker 4A for Fuse Panel                                       ********                 ********

4          ASA 32
4.1        SISA - ASA 32                                                 1         ********    ********      *******        *******

5          OPTIONAL RACK EQUIPMENT FOR ASA 32
5.1        Infrastructure unit / BW7R housing with                                 ********                 ********
           installation kit

6.         MM-G.703-X.21-DC                                              1         ********   *********
           For the MM-G.703-X.21-DC the following VOLUME DISCOUNT
           applies: purchase quantity > = 10 a discount of ** on
           the list price purchase quantity > = 100 a discount of
           ** on the list price
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 37 of 49

<PAGE>

                                     European Agreement
                                         Appendix 2
                                    Prices and Discounts

                                       38 of 49

<PAGE>

                                      European Agreement
                                          Appendix 2
                                     Prices and Discounts

3.11 NETWORK MANAGEMENT SYSTEM
<TABLE>
<CAPTION>
                                                                                                             BASE         PER TS
ITEM                                                                               PRICE (EURO)    QTY    PRICE * QTY   PRICE * QTY
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                               <C>            <C>   <C>              <C>
ACI MANAGEMENT
BASIC EQUIPMENT (UPTO 5000 SUBSCRIBERS)
PC High-End Server incl. Systemsoftware (1 Server for Operation, 1 for Standby)      *********      2    *************
PC Client incl. Systemsoftware (8 Clients for Operation, 1 for Standby)               ********      9    *************
LCT incl.Systemsoftware (Notebooks)                                                   ********      4    *************

Software License Single/Multi-User Client, English                                      ******      9     ************
Software & License Single/Multi-User Server V5.1 for FL, FMXII, PDH, SRAL, English    ********      2    *************
Interface Alarming (all equipment)                                                    ********      1     ************
Software & License LCT V5.1 for FL, FMXII, PDH, SRAL, English                         ********      4    *************
Documentation V5.1 , English                                                            ******                ********

Sum ACI Management                                                                                      **************

LICENCE PER TS
License Alarming (Assumption: 8 Subscriber per TS)                                        ****      8                     ********
License FASTlink (per subs.)                                                              ****      8                    *********

Sum Licence per TS                                                                                                       *********

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 39 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts
<TABLE>
<CAPTION>
                                                                                                            BASE          PER TS
ITEM                                                                              PRICE (EURO)     QTY    PRICE * QTY   PRICE * QTY
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                               <C>            <C>   <C>              <C>
BASIC EQUIPMENT (UP TO 5000 SUBSCRIBERS)
WALKAIR MANAGEMENT
PC Client incl. Systemsoftware                                                      ********        3    ************
SUN Ultra 10 Modell 333 incl. Solaris                                               ********        1    ************
HP OpenView HPOV 6.x Entry Version (250) Solaris                                    ********        1    ************
HP OpenView HPOV fur Windows 95                                                     ********        3    ************
Total Walkair Management                                                                                *************

LICENCE PER TS
WALKnet application license                                                           ******        1                    **********

UMBRELLA MANAGEMENT - INMS, BASIC EQUIPMENT (UP TO 5000 SUBSCRIBERS)
SUN Ultra 60 Modell 2360 incl. Solaris                                             *********        1   *************
SUN Ultra 10 Modell 333 incl. Solaris                                               ********        4   *************
HP OpenView HPOV 6.x Entry Version (250) Solaris                                    ********        1    ************
INMS-Base-Licence                                                                  *********        1   *************
Service Package incl. planning, INMS-installation, Consulting, Putting into O
peration, common design of acceptance test specification, support of putting
into operation                                                                     *********        1   *************
SUM UMBRELLA MANAGEMENT - INMS                                                                         **************

LICENCE PER TS
INMS Connection Licence per WalkAir TS-BU and ONU                                     ******        1                    **********

NETWORK MANAGEMENT BASE - EQUIPMENT: (EURO)                                                            **************

PRICE PER TERMINAL STATION FOR ALL OFFERED LICENCES : (EURO)                                                             **********

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 40 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

                                 Page 41 of 49
<PAGE>

                                     European Agreement
                                         Appendix 2
                                    Prices and Discounts

4        LIST PRICES - SERVICES

  This Section of Appendix 2 sets forth the pricing of Services.

4.1 PROJECT MANAGEMENT

  A total customer lump sum fee of *********************************************
  for the project management services over four (4) years applies. This lump sum
  fee is already deducted by the *************** as set forth in Section 2.2.3
  of this Appendix 2.

  The yearly project management fee amounts to **************
********************************.

  An additional total amount of ***************************** applies in case
  the Contractor performs 25 (twenty-five) installations at the Contractor's
  regional premises of the Purchaser's core database management system RDMS as
  described in Appendix 4, section Project Management.

4.2 HANDLING FEE ON CIVIL WORKS (BUILD COORDINATION)

  A handling fee for build coordination service of *********
  ********************* shall apply on the civil works of standard BS sites
  which are set out in Appendix 4. For all BS sites exceeding the standard civil
  work layout as set out in Appendix 4 the Purchaser shall reimburse the
  incurred costs for build coordination.

  NOTE: The standard civil work layout is not agreed and subject to negotiation

4.4 TRAINING

  All training prices are exclusive of travel expenses.

  The Purchaser shall reimburse the trainer's documented travel expenses
(economy) in case the training is conducted at the Purchaser's premise.

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------------
  DESCRIPTION                                              CUSTOMER PRICE IN    BASIS
                                                           EUR
---------------------------------------------------------------------------------------------------------------------------
<S>                                                        <C>                <C>
  Training courses at the Contractor's training centres    ******               per day and participant
---------------------------------------------------------------------------------------------------------------------------
  Onsite Training at Purchaser's premises                  ********             per trainer and day (exclusiv travel
                                                                                expenses)
---------------------------------------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 42 of 49
<PAGE>
                               European Agreement
                                   Appendix 2
                              Prices and Discounts

<TABLE>
<CAPTION>

<S>                                                        <C>                <C>
---------------------------------------------------------------------------------------------------------------------------
  Preparation for onsite training at the Purchaser's       ********             per day of trainer's preparation at
  premises if necessary (configuration of Purchaser's                           Purchaser's premises
  equipment)
---------------------------------------------------------------------------------------------------------------------------
</TABLE>

4.5 SURCHARGE NON- WORKING HOURS

  All indicated Service prices assume the Service to be performed during
standard working hours.

  The Contractor's standard working hours are during Working Days (Monday to
Friday) from 8:00 to 16:00 CET.

  In case Services outside these standard working hours are requested a general
  surcharge of **** shall be applicable on the indicated customer price of the
  related Service.

4.6 SITE VISIT

  For installations subsequent to the initial installation for instance in case
of subsequent upgrades the following lump sum shall apply:

<TABLE>
<CAPTION>
                                 DESCRIPTION                                            PRICE

<S>                                                                                    <C>
Equipment zusammenstellen; Anfahrt; Abfahrt; Entsorgung Verpackungsmaterial            **********

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 43 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

4.7 TURNKEY SERVICES

4.7.1    TURNKEY SERVICES BASE STATION - BS

  This section of Appendix 2 indicates the Turnkey Service prices applicable to
the base station System.

<TABLE>
<CAPTION>
            PRICELIST BS TURNKEY SERVICES                       LIST PRICE    LIST PRICE  DISCOUNT  CUSTOMER   CUSTOMER   TOTAL
                                                                SECTOR IN     BS IN EUR             PRICE PER  PRICE PER  CUSTOMER
                                                                EUR                                 SECTOR IN  BS IN EUR  PRICE IN
                                                                                                    EUR                   EUR
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                           <C>           <C>         <C>       <C>        <C>        <C>
            assumed number of sectors per base station                        4                     4

  1.        Planning Wireless Local Loop

            Define customer service requirements and capacity

            - raw data                                          ***
            - demand analysis                                   *****

  1.1.      Radio Planning includes following bullets           *****         *****       ***       *****       *****      *****
            (included Travel Time and based on 70% low
            - 20% medium - 10% low density areas)
            - initial radio planning                            see detailed Annex
            - initial site search                               see detailed Annex
            - confirm site with FMDC                            see detailed Annex
            - detail radio planning                             see detailed Annex
            - path calculations                                 see detailed Annex
            - parameter engineering                             see detailed Annex
            - frequency planning                                see detailed Annex
            - database creation and support                     see detailed Annex
            - LOS 360 out of tool                               included
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 44 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

<TABLE>
<CAPTION>
            PRICELIST BS TURNKEY SERVICES                               LIST      LIST   DISCOUNT   CUSTOMER    CUSTOMER    TOTAL
                                                                        PRICE     PRICE              PRICE PER  PRICE PER  CUSTOMER
                                                                      SECTOR IN    BS               SECTOR IN    BS IN     PRICE IN
                                                                         EUR     IN EUR                EUR        EUR        EUR
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                    <C>      <C>          <C>         <C>    <C>        <C>
  1.2. LOS on site                                                                  *****       ***         n.a    ***       ***
        - 360DEG. LOS
        - travelling included

  1.3. Micro wave links per hop                                                     *****       ***         n.a    *****

  2.   Site Acquisition                                                             *****                   n.a    *****     *****

  3.   Site survey (Site visit with Civil works to define
       requirements)                                                                *****       ***         n.a    *****     *****
        - define telecommunications equipment requirements,
          container or rack                                                incl
        - power supply definintion and requirements, dedicated supply      incl
        - define environmental requirements, container or rack
          space a.c.                                                       incl
        - transmission system e.g MW, LL and associated cable runs,        incl
          presentations
        - mounting structures, poles, frames, cableways                    incl

  4.   Civil works

       please refer to Appendix 4, section 4d, Site Design and Civil Works

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 45 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

<TABLE>
<CAPTION>

            PRICELIST BS TURNKEY SERVICES                       LIST PRICE    LIST PRICE  DISCOUNT  CUSTOMER   CUSTOMER   TOTAL
                                                                SECTOR IN     BS IN EUR             PRICE PER  PRICE PER  CUSTOMER
                                                                EUR                                 SECTOR IN  BS IN EUR  PRICE IN
                                                                                                    EUR                   EUR
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                           <C>           <C>         <C>       <C>        <C>        <C>
  5.        BS Installation

            (assumes all CW is complete; assumesNon Protected per
            Sector 90DEG.a` 4 BS-BU)
            including

  5.1.      Work preparation, clearance                          ***        *****         ***        ***        *****      *****
             - equipment delivery
             - unpack & check inventory
             - site clearance

  5.2.      Hardware Installation                                ***        *****         ***        ***        *****      *****
             - inter-chassis cabling
             - card / module installation
             - power up racks / IDU
             - transmission equipment

  5.3.      IDU-ODU cabling & connectorising
             - coax cable 1/4" as required

             - installation/connectorisation of coax cable

  5.3.1.    up to 50 m; including                                ***        *****         ***        ***        *****      *****
             -  ground connector set
            cable clamps
            connectors
            mixed calculation
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 46 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

<TABLE>
<CAPTION>
            PRICELIST BS TURNKEY SERVICES                       LIST PRICE    LIST PRICE  DISCOUNT  CUSTOMER   CUSTOMER   TOTAL
                                                                SECTOR IN     BS IN EUR             PRICE PER  PRICE PER  CUSTOMER
                                                                EUR                                 SECTOR IN  BS IN EUR  PRICE IN
                                                                                                    EUR                   EUR
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                           <C>           <C>         <C>       <C>        <C>        <C>
  5.3.2.    50 to 100 m                                         *****         *****         ***       *****      *****
             -  ground connector set
            cable clamps

            connectors
            mixed calculation

  5.3.3.    100 to 150 m                                        *****         *****         ***       *****      *****
             ground connector set
            cable clamps

            connectors
            mixed calculation

  5.4.      Installation ODU / Antenna                            ***           ***         ***         ***        ***        ***

  5.5.      Functional testing HW / SW                          *****         *****         ***       *****      *****      *****
            (in station)
             - sector field test

             - completion of all documentation, test results
             - stand alone; ready for service status message
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 47 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

<TABLE>
<CAPTION>
            PRICELIST BS TURNKEY SERVICES                       LIST PRICE    LIST PRICE  DISCOUNT  CUSTOMER   CUSTOMER   TOTAL
                                                                SECTOR IN     BS IN EUR             PRICE PER  PRICE PER  CUSTOMER
                                                                EUR                                 SECTOR IN  BS IN EUR  PRICE IN
                                                                                                    EUR                   EUR
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                           <C>           <C>         <C>       <C>        <C>        <C>
  5.6.      Expansion RFU-Antenna cable                           ***         ***          ***      ***        ***
             - installation
             - 3 m cable

  6.        Commissioning                                                                           n.a.        **           **
            assumes cusomer is ready to take delivery of service
             - delivery of documentation and test results                     ***          ***

  7.        acceptance

            - mutual visit from FMC/Siemens for acceptance                  *****          ***      n.a.     *****        *****

            TOTAL                                                                                                        ******

</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 48 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

<TABLE>
<CAPTION>

  4.7.2 TURNKEY SERVICES - TERMINAL STATION TS
            PRICELIST TS TURNKEY SERVICES                                             LIST PRICE    DISCOUNT  CUSTOMER      TOTAL
                                                                                      PER CPE IN               PRICE      CUSTOMER
                                                                                      EUR                     ER CPE IN    PRICE IN
                                                                                                                EUR           EUR
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                                <C>              <C>       <C>          <C>

  1.        Installation CP (assumes all CW is complete)

            exluding CW and Infrastucture (cable runways;
            power supply;racks/cabinets;...)

  1.1.      CPE planning

             - LOS out of tool                                                           **            ***      **
             - LOS onsite including travel                                               ***           ***      ***
            Sum planning CPE LOS (weighted)                                                            ***                    ***

  1.2.      Work preparation, site clearance                                             ***           ***      ***           ***
             - equipment delivery
             - unpack & check inventory
             - site clearance

  1.3.      Hardware installation IDU or cabinet                                         ***           ***      ***           ***
             - power up equipment

  1.4.      IDU-ODU cabling & connectorising                                             ***           ***      ***           ***
             - including 40 m cable

  1.5.      ODU / Antenna Installation                                                   ***           ***      ***           ***
             - alignment of CP antenna
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 49 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

  4.7.2 TURNKEY SERVICES - TERMINAL STATION TS
            PRICELIST TS TURNKEY SERVICES

<TABLE>
<CAPTION>
            PRICELIST TS TURNKEY SERVICES                                                 LIST PRICE    DISCOUNT CUSTOMER   TOTAL
                                                                                          PER CPE IN              PRICE    CUSTOMER
                                                                                            EUR                  PER CPE   PRICE IN
                                                                                                                  IN EUR        EUR
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                                                       <C>           <C>       <C>       <C>
  1.6.      Functional in-station HW / SW testing                                            **            ***      ***       ***
             - completion of all documentation, test results

  2.        Commissioning (assumes customer is ready to take delivery of service)            **            ***      ***       ***
            customer is ready to take delivery of service
             - OMC based network integration of CPE

  3.        Acceptance                                                                       **            ***      ***       ***
            - flat rate per CPE
            assumes visiting of 2% of installed CPE's with FMC

-----------------------------------------------------------------------------------------------------------------------------------
            TOTAL PER CPE [EURO]                                                                                            *****
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 50 of 49
<PAGE>

                                                  European Agreement
                                                       Appendix 2
                                                  Prices and Discounts

4.8 DETAILED I&C - ONU EQUIPMENT

                     ONU PART / INSTALLATION & COMISSIONING
       TERMINALSTATION SERVICES 3,5 GHZ / TERMINALSTATION SERVICES 26 GHZ
<TABLE>
<CAPTION>
                                                                         I&C PER UNIT IN
                                                             QUANTITY          EURO          TOTAL I&C                 DESCRIPTION
-----------------------------------------------------------------------------------------------------------------------------------
<S>                                                           <C>                   <C>             <C>       <C>
ONU 30 CONSISTING OF                                             1                     ***             ***     ONU 30 core
 - i/f 10 POTS                                                   1                      **              **     Linecard 10x POTS
 - i/f 4 BR-ISDN                                                 2                      **             ***     Linecard 4x Uk0
-----------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                                                                  ***

ONU 120 CONSISTING OF                                            1                   *****           *****     ONU 120 core
 - i/f 10 POTS                                                   1                      **              **     Linecard 10x POTS
 - i/f 4 BR-ISDN                                                 3                      **             ***     Linecard 4x Uk0
 - i/f V.35 (64 kbps LL)                                         1                      **              **     Linecard 2x nx64k
-----------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                                                                *****

ONU 120 CONSISTING OF                                            1                   *****           *****     ONU 120 core
 - i/f 4 BR-ISDN                                                 4                      **             ***     Linecard 4x Uk0
-----------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                                                                *****

ONU 30 CONSISTING OF                                             1                     ***             ***     ONU 30 core
 - i/f BR-ISDN                                                   3                      **             ***     Linecard 4x Uk0
-----------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                                                                  ***

ONU 20 CONSISTING OF                                             1                     ***             ***     ONU 20 core
 - i/f 4 BR-ISDN                                                 2                      **             ***     Linecard 4x Uk0
-----------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                                                                  ***
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 51 of 49
<PAGE>

                               European Agreement
                                   Appendix 2
                              Prices and Discounts

4.9 I&C - UPGRADE BS-BU

  This section of Appendix 2 indicates the list prices installation,
  commissioning, integration and acceptance (I&C) by a BS-BU unit either 3,5GHz
  or 26GHz, which forms part of the base station BS subsequent and separately to
  the initial BS installation.

                                      I&C - BS-BU EXTENSION
<TABLE>
<CAPTION>
                               DESCRIPTION                              I&C

<S>                                                                    <C>
Einbau Basic Unit 26 GHz oder 3, 5 GHz                                       ***** ***
Einbau der Sicherung, SV Kabel und Erdung                                    ***** ***
Cable IF-Mux - BU                                                            ***** ***
Verlegung und Abschlussder 2/ Mbit Leitung bis 10 m                          ***** ***
Beschriftung der Komponenten und am DDF                                      ***** ***
                                                                        ---------------
                                                                            ****** ***
                                                                        ===============

</TABLE>

4.10 DE-INSTALLATION AND DISPOSAL

  In case of de-installation Services *** of the respective installation Service
price shall apply.

  For the disposal of the equipment a maximum of *** of the respective customer
  price of the respective equipment shall apply, which includes transport from
  site to site of recycling.1

--------
1 This price is subject to negotiation and not agreed between the Parties.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                 Page 52 of 49

<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

           SYSTEM FEATURE DESCRIPTION FOR THE CONTRACTOR WLL SOLUTION

------------------------- -----------------------------------------------------
DOCUMENT NAME             3_Appendix 3a_1 - WLL System Feature requirements
                          document 000510
------------------------- -----------------------------------------------------
DESCRIPTION               This document as part of the European Agreement
                          between Purchaser and Contractor lists relevant
                          features of the WALKair system.
------------------------- -----------------------------------------------------

                                                                         1 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------------------------
          NO.    FEATURE                                                                 AVAILABLE AVAILABLE AVAILABLE AVAILABLE
                                                                                           IN V3     IN V4     IN V5     IN V6
--------------------------------------------------------------------------------------------------------------------------------
General
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
1                GENERAL SYSTEM FEATURES
--------------------------------------------------------------------------------------------------------------------------------
1.1              TRAFFIC INTERFACES
--------------------------------------------------------------------------------------------------------------------------------
          1.     V5.1 compatible interface to Purchaser's voice switch
--------------------------------------------------------------------------------------------------------------------------------
          2.     V5.2 compatible interface to Purchaser's voice switch
--------------------------------------------------------------------------------------------------------------------------------
          3.     It is possible to monitor the incoming G.704 frame as an option                                 X
                                                                                                               E1 PM
--------------------------------------------------------------------------------------------------------------------------------
          4.     The E1 traffic needs not be framed acc. to G.704.                        X
                 WALKair provides unframed G.703 as well as framed G.704
--------------------------------------------------------------------------------------------------------------------------------
          5.     The output jitter at the X.21 and G.703 interface does not               X
                 exceed the limits as specified in ITU-T G.823.
--------------------------------------------------------------------------------------------------------------------------------
          6. Internal interface card for four ISDN BRA line within the TS
--------------------------------------------------------------------------------------------------------------------------------
          7.     FR is represented at a X.21/V.35 port at TS and BS-BU                               X
--------------------------------------------------------------------------------------------------------------------------------
          8.     Each X.21/V.35 port at the BS-BU can deliver several FR streams                     X
                 from different TS, containing several DLCIs each (up to 600
                 DLCIs per BS-BU)
--------------------------------------------------------------------------------------------------------------------------------
          9.     Each FR E1 port at the BS-BU can deliver several FR streams                                     X
                 from different TS, containing several DLCIs each (up to 600
                 DLCIs per BS-BU )
--------------------------------------------------------------------------------------------------------------------------------
          10.    The FR port at the terminal supports up to 30 simulateneous DLCIs                    X
--------------------------------------------------------------------------------------------------------------------------------
          11.    X21/V35, E1, physical equipment interface is a female DB-25              X
                 connector.  X21/V35 - female DB-25                                      E1-
                 E1 - RJ45                                                              RJ45
--------------------------------------------------------------------------------------------------------------------------------
          12.    FR is represented at a X.21/V.35 or at E1 port at the BS-BU                          X      X
                                                                                                   V35/X     E1
                                                                                                     21
--------------------------------------------------------------------------------------------------------------------------------
          13.    The TS includes FRAD functionality within the X.21/V.35 port                         X
                 Not Including routing functionality. The interface supplies
                 standard FR UNI interface.
--------------------------------------------------------------------------------------------------------------------------------
          14.    TS to BS-BU IP traffic of up to 2 Mbit/s data rate is FR                             X           X
                 encapsulated acc to RFC 1490. The frame relay packets are sent                      vi a      built-in
                 towards the FR network via FR DLCI , according to the                              extern
                 attributes assigned in the configuration. BS-BU to TS IP                           al tiny
                 traffic encapsulated in FR packets are translated to Ethernet                      router
                 packets using address resolution which translates the
                 destination IP address to router LAN MAC address.
                 Some setting have to be configured such as min/max bandwith
                 etc.

--------------------------------------------------------------------------------------------------------------------------------

          15.    The Walkair system provides an external router to provide IP                         X
                 bandwidth of up to 2 Mbit/s bandwidth using standard IETF
                 encapsulation (RFC 1490).

--------------------------------------------------------------------------------------------------------------------------------
          16.    The Walkair system itself provides an 10baseT port for IP
                 traffic using standard |X| IETF encapsulation (RFC 1490) for FR                                  X
--------------------------------------------------------------------------------------------------------------------------------
          17.    The link transmission delay in case of non shared media for E1,          X
                 fractional E1 and X.21/V.35 traffic and V5.2 concentrated
                 voice without committed bandwidth is
                 - downstream less than 1ms
                 - upstream less than 11ms
                 - round trip less than 12ms
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         2 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
          18.    Link transmission delay in case of shared media at 60% loaded TS/BS-BU               X
                 capacity for X.21/V.35 FR port is
                 -        downstream less than 15ms
                 -        upstream delay less than 25ms
                 -        round trip delay less than 40ms.
                 Note: the above numbers are estimated, since the feature was not
                 released yet.
--------------------------------------------------------------------------------------------------------------------------------
          19.    Each TS IDU has up to 3 interfaces, possible interface combinations
                 as follows:
                 0        1 E1 G.703, 120ohms,                                               X
                 1        2xE1 G.703, 120ohms                                                X
                 2        3xE1, G.703, 120ohms,                                              X
                 3        1xE1 G.703, 120ohms + 1xV.35/X.21,                                 X
                 4        1xV.35/X.21                                                        X
                 5        1xE1 G.703, 120ohms+ 1xV.35/X.21 (FR),                                      X
                 6        1xV.35/X.21 (FR)                                                            X
                 7        1x10BaseT                                                                   X *       X
                 8        1xE1 G.703, 120ohms,+ 1x10BaseT                                             X *       X
                          total maximum transmission capacity per BS-BU=                     X
                          64 x 64 kbit/s = 4096 kbit/s
                 * via external Tiny Router
--------------------------------------------------------------------------------------------------------------------------------
          20.    All connectors can be accessed from the front Except for                             X
                 power & grounding, and external clock
--------------------------------------------------------------------------------------------------------------------------------
          21.    The V.35/X.21 can be configured as DCE and DTE using external               X
                 cable adapter f or DTE mode. Timing signals for DCE mode
                 are generated internally
--------------------------------------------------------------------------------------------------------------------------------
          22.    The selection between X.21 or V.35 can be done by software of               X
                 the management system Walknet
--------------------------------------------------------------------------------------------------------------------------------
          23.    X.21 clear channel at the terminal station can be presented at              X
                 the E1 port of the BS-BU
--------------------------------------------------------------------------------------------------------------------------------
          24.    A combiner allows the delivery of more than 2 x E1s of capacity
                 to a single site through single outdoor unit.
                 The combiner will reduce the link budget by less than 5dB.
                 Note: the above number is estimated, since the feature was not
                 released yet. Delivery will be 6 month after Purchaser's
                 commitment of at least 200 such units.
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
1.2              DYNAMIC BANDWIDTH ALLOCATION
--------------------------------------------------------------------------------------------------------------------------------
          25.    The system provides dynamic bandwidth allocation for voice                  X
                 (individual ISDN and POTS lines) by concentration of voice
                 calls within one BS-BU. The voice channels are presented at the
                 base station via V5.2 interface. The signalling channel is
                 transmitted over the embedded operational channel of WALKair.
                 No additional air channel assignment for signalling information
                 is needed. The information elements of the signalling data are
                 transparently transferred to the relevant port.
--------------------------------------------------------------------------------------------------------------------------------
          26.    Each BS-BU can be configured with one V5.2 interface only, with             X
                 up to 3 E1 links  and the C-channel in slot 16 only.
--------------------------------------------------------------------------------------------------------------------------------
          27.    The V5.2/V5.1 configuration can be configured online and                    X
                 re-configured via the network management
--------------------------------------------------------------------------------------------------------------------------------
          28.    The Walkair system handles WLL specific situation "loss of                  X
                 air-link" with the shut down and re-establishment of the
                 link
--------------------------------------------------------------------------------------------------------------------------------
          29.    A blocked air-interface is handled by the V5.2 protocol with a              X
                 normal trunk blocking procedure
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         3 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
          30.    The system provides dynamic bandwidth allocation for voice by               X
                 concentration of voice calls at each BS-BU from V5.1 ports at
                 those TS which are connected with this BS-BU.
--------------------------------------------------------------------------------------------------------------------------------
          31.    Fractional E1 V5.1 can be configured at the TS, so that the                          X
                 remaining TS capacity can be assigned to other ports
--------------------------------------------------------------------------------------------------------------------------------
          32.    Configurable separate QoS parameters for voice traffic                               X
                 (individual POTS and ISDN ports) and FR per customer TS
                 -        Minimum committed bandwidth
                 -        Maximum usable bandwidth
--------------------------------------------------------------------------------------------------------------------------------
          33.    The system provides dynamic bandwidth allocation for frame                           X
                 relay traffic according the requested bandwidth during the
                 connection.
--------------------------------------------------------------------------------------------------------------------------------
          34.    Bandwidth within a BS-BU that is assigned to a specific TS                           X
                 (even the committed bandwidth) and is not used can be used
                 by other TSs. The committed bandwidth will be released on 5 ms
                 boundary if demand from the relevant TS occurs.
--------------------------------------------------------------------------------------------------------------------------------

          35.    The adaptation of the air-interface capacity is done within                          X
                 less than 100ms
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
2                AIR-INTERFACE
--------------------------------------------------------------------------------------------------------------------------------
2.1              GENERAL
--------------------------------------------------------------------------------------------------------------------------------
          36.    The air interface modulation is on the uplink is 64 QAM with                X
                 convolutional coding rate 2/3
--------------------------------------------------------------------------------------------------------------------------------
          37.    The air interface modulation is on the downlink is 64 QAM with              X
                 convolutional coding rate 2/3
--------------------------------------------------------------------------------------------------------------------------------
          38.    The spectral efficiency is 2.5bit/sec/Hz                                    X
--------------------------------------------------------------------------------------------------------------------------------
          39.    Used bandwidth per carrier in the uplink is 1.75 MHz                        X
--------------------------------------------------------------------------------------------------------------------------------
          40.    Used bandwidth per carrier in the downlink is 1.75 MHz                      X
--------------------------------------------------------------------------------------------------------------------------------
          41.    Used bandwidth per carrier in the uplink is 14 MHz                                                        X
                 New system hardware required
--------------------------------------------------------------------------------------------------------------------------------
          42.    Used bandwidth per carrier in the downlink is 14 MHz                                                     X
                 New system hardware required
--------------------------------------------------------------------------------------------------------------------------------
          43.    Available netto capacity per carrier (1,75MHz) in the uplink is 4 Mbit/s    X
--------------------------------------------------------------------------------------------------------------------------------
          44. Available netto capacity per carrier (1,75 MHz) in the downlink is 4 Mbit/s    X
--------------------------------------------------------------------------------------------------------------------------------
          45.    Available net capacity per carrier (14 MHz) in the uplink is 34 Mbit/s                                   X
                 New system hardware required
--------------------------------------------------------------------------------------------------------------------------------
          46.    Available netto capacity per carrier (14 MHz) in the downlink is 34 Mbit/s                               X
                 New system hardware required
--------------------------------------------------------------------------------------------------------------------------------
          47.    Number of 1,75 MHz carriers per 28(14) MHz frequency band in the uplink     X
                 is 16(8)
--------------------------------------------------------------------------------------------------------------------------------
          48.    Number of 1,75 MHz carriers per 28(14) MHz frequency band in the downlink   X
                 is 16(8)
--------------------------------------------------------------------------------------------------------------------------------
          49.    Number of 14 MHz carriers per 28(14) MHz frequency band in the uplink is                                 X
                 2(1) New system hardware required
--------------------------------------------------------------------------------------------------------------------------------
          50.    Number of 14 MHz carriers per 28(14) MHz frequency band in the downlink                                  X
                 is 2(1) New system hardware required
--------------------------------------------------------------------------------------------------------------------------------
          51.    The air interface uses a TDMA frame of 5 ms providing up to 64 channels     X
                 a 64 kbit/s throughput + signalling and management overhead
--------------------------------------------------------------------------------------------------------------------------------
          52.    C/I optimisation is done by TX power adjustment and antenna                 X
                 tilt in base station, based on pre-defined network planning
                 results and RTPC in TS.
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         4 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
          53.    The system provides RTPC (Receive and transmit power control)               X
                 in the TS based on adaptive equaliser and modem algorithms to              RTPC
                 reduce interference.                                                        TS
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
2.2              26 GHz SYSTEM RADIO PERFORMANCE
--------------------------------------------------------------------------------------------------------------------------------
          54.    The radio performance and capacity does not declines if all                 X
                 carriers of the available spectrum are used in one sector as                                   X
                 follows:
                 up to 6 carriers
                 up to 16 carriers
--------------------------------------------------------------------------------------------------------------------------------
          55.    Minimum receive level for BER 10-3 is -88dBm                                X
--------------------------------------------------------------------------------------------------------------------------------
          56.    Minimum receive level for BER 10-6 is -87 dBm                               X
--------------------------------------------------------------------------------------------------------------------------------
          57.    Minimum receive level for BER 10-9 -85 dBm                                  X
--------------------------------------------------------------------------------------------------------------------------------
          58.    C/I for BER 10-3 is 18 dB                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          59.    C/I for BER 10-6 is 19 dB                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          60.    C/I for BER 10-9 is 21 dB                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          61.    Max transmit power at base station and terminal is 24dBm                    X
--------------------------------------------------------------------------------------------------------------------------------
          62.    Committed range for BER=10-9, Zone H, vertical polarisation,                X
                 availability due to radio propagation effects of 99.99%, 30
                 Mbit/sector with 28 MHz standard antenna at B/S (90 degree) and
                 TS is 4.1 3 km. 3.9 km can be reached using the high gain
                 antenna at TS. For more details see availability statement
                 below.
--------------------------------------------------------------------------------------------------------------------------------
          63.    Range for BER=10-9, Zone H, vertical polarisation, availability of         X
                 99.99%, 30 Mbit/sector with 28 MHz  45 degree antenna at BS  and
                 standard antenna at TS is 3.5 km. 4.5 km can be reached using high
                 gain antenna. For more details, see availability statements below.
--------------------------------------------------------------------------------------------------------------------------------
          64.    The radio performance declines approximately 0.5 dB up to 55               X
                 degrees Celsius. Complies with ETSI 300 019 class T4.1
                 standard.
--------------------------------------------------------------------------------------------------------------------------------
          65.    As standalone base station with 28MHz allocation( 16 carriers):            X
                 4 sectors, Vertical, reuse 2, =>
                 2(reuse)*16(carriers)*4(Mbps) = 128Mbps 4 sectors, H+V, reuse
                 2, => 2(reuse)*16(carriers)*4(Mbps) = 128Mbps 8 sectors, H+V,
                 reuse 4, => 4(reuse)*16(carriers)*4(Mbps) = 256Mbps
--------------------------------------------------------------------------------------------------------------------------------
          66.    Deleted                                                                     X
--------------------------------------------------------------------------------------------------------------------------------
2.3              3.5 GHz SYSTEM RADIO PERFORMANCE
--------------------------------------------------------------------------------------------------------------------------------
          67.    The radio performance and capacity does not declines if all                 X
                 carriers of the available spectrum are used in one sector
--------------------------------------------------------------------------------------------------------------------------------
          68.    Minimum receive level for BER 10-3 is -90 dBm                               X
--------------------------------------------------------------------------------------------------------------------------------
          69.    Minimum receive level for BER 10-6 is -89 dBm                               X
--------------------------------------------------------------------------------------------------------------------------------
          70.    Minimum receive level for BER 10-9 is -87 dBm                               X
--------------------------------------------------------------------------------------------------------------------------------
          71.    C/I for BER 10-3 is 18 dB                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          72.    C/I for BER 10-6 is 19 dB                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          73.    C/I for BER 10-9 is 21 dB                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          74.    Max transmit power at the base station is 27 dBm and at the                 X
                 terminal is 18 dBm
--------------------------------------------------------------------------------------------------------------------------------
          75.    Range for BER=10-9, Zone H, availability of 99.99%,15                       X
                 Mbit/sector with 14 MHz standard antenna at BS (90 degree)                10 km
                 and TS is 10 km
--------------------------------------------------------------------------------------------------------------------------------
          76.    Range for BER=10-9, Zone H, availability of 99.99%, 15
                 Mbit/sector with 14 MHz 60 degree antenna at BS (90) and                    X
                 standard antenna at TS is 10 km                                           10 km
--------------------------------------------------------------------------------------------------------------------------------
          77.    As standalone base station with 14MHz allocation( 8 carries):               X
                 4 sectors, Vertical, reuse 2, => 2(reuse)*8(carriers)*4(Mbps) = 64Mbps
                 4 sectors, H+V, reuse 2, => 2(reuse)*8(carriers)*4(Mbps) = 64Mbps
                 6 sectors, Vertical, reuse 2, => 2(reuse)*8(carriers)*4(Mbps) = 64Mbps
                 8 sectors, H+V, reuse 4, => 4(reuse)*8(carriers)*4(Mbps) = 128Mbps
--------------------------------------------------------------------------------------------------------------------------------
          78.    Deleted.
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         5 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
3                TS (TERMINAL STATION) CHARACTERISTIC
--------------------------------------------------------------------------------------------------------------------------------
3.1              GENERAL
--------------------------------------------------------------------------------------------------------------------------------
          79.    The TS consist of the TS-RFU and the IDU (Indoor Unit)                      X
--------------------------------------------------------------------------------------------------------------------------------
          80.    The TS-RFU is connected via one coax cable with the IDU (Indoor             X
                 Unit) using t.b.d. connectors
--------------------------------------------------------------------------------------------------------------------------------
          81.    The RFU and antenna are attached. No cable is required except for           X
                 the IF cable.
--------------------------------------------------------------------------------------------------------------------------------
          82.    The system limitation on the IF cable loss is 20 dB.                        X
--------------------------------------------------------------------------------------------------------------------------------
          83.    The TS automatically find the appropriate frequency to transmit             X
                 after turning it on
--------------------------------------------------------------------------------------------------------------------------------
          84.    The terminal automatically changes to a frequency that provide
                 the best C/I This feature is not available
--------------------------------------------------------------------------------------------------------------------------------
3.2              TS-RFU 26 GHz
--------------------------------------------------------------------------------------------------------------------------------
          85.    The TS-RFU  includes an attached dish  antenna of 35dBi gain                X
                  and a  1 foot size
--------------------------------------------------------------------------------------------------------------------------------
          86.    The TS-RFU includes a 1 foot dish antenna of 35 dB gain. Antenna            X
                 beamwidth is 2.5 degree horizontal and vertical
--------------------------------------------------------------------------------------------------------------------------------
          87.    Additional antennae are available
--------------------------------------------------------------------------------------------------------------------------------
          88.    No. 1: 2"   feet parabolic antenna with 41 dB gain                                   X
--------------------------------------------------------------------------------------------------------------------------------
          89.    For optional antenna No 1 with size 2 feet the committed range              X
                 assuming 90 degree B/S and BER=10-9, Zone H, availability
                 due to radio propagation effects of 99.99%, 30 Mbit/sector with
                 28 MHz is 3.9 km
                 3.9 km can be reached using high gain antenna.
--------------------------------------------------------------------------------------------------------------------------------
          90.    All antennae are provided in horizontal and vertical polarisation                    X
--------------------------------------------------------------------------------------------------------------------------------
          91.    The dynamic power range of the TS-RFU varies from -30dBm to 10 dBm          X
--------------------------------------------------------------------------------------------------------------------------------
3.3              TS-RFU 3.5 GHz
--------------------------------------------------------------------------------------------------------------------------------
          92.    The TS-RFU includes and integrated flat panel antenna with 17.5             X
                 dBi and size of 25cmx25cm. Antenna beam width is 18 degree
                 horizontal and vertical
--------------------------------------------------------------------------------------------------------------------------------
          93.    Additional antennae are not available                                       -
--------------------------------------------------------------------------------------------------------------------------------
          94.    No. 1:  t.b.d. type of antenna with min 22,5 dB gain                        -
--------------------------------------------------------------------------------------------------------------------------------
          95.    With standard antenna the range assuming 90 degree antenna at               X
                 base station and BER=10-9, Zone H, availability of 99.99%,
                 is 10 km
--------------------------------------------------------------------------------------------------------------------------------
          96.    All antennae are provided in horizontal and vertical polarisation
--------------------------------------------------------------------------------------------------------------------------------
          97.    The dynamic power range varies from -22 dBm to 18 dBm                       X
--------------------------------------------------------------------------------------------------------------------------------
3.4              TS-COMBINER
--------------------------------------------------------------------------------------------------------------------------------
          98.    The combiner enables the combination of two IDU at one TS-RFU
                 Delivery will be 6 month after Purchaser's commitment of at
                 least 200 such units
--------------------------------------------------------------------------------------------------------------------------------
          99.    The combiner loss is less than 5dB
                 Note: the above number is estimated, since the feature was not
                 released yet.
--------------------------------------------------------------------------------------------------------------------------------
3.5              IDU (INDOOR UNIT)
--------------------------------------------------------------------------------------------------------------------------------
          100.   The IDU for 26 GHz and 3.5 GHz are not identical because the IF part is     -
                 different!
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
3.6              26 GHz TS MTBF
--------------------------------------------------------------------------------------------------------------------------------
          101.   Radio (ODU): 225.000 hours calculated acc. to Bellcore TR-332, Issue 5      X
--------------------------------------------------------------------------------------------------------------------------------
          102.   IDU: 180.000 hours  calculated acc. to Bellcore TR-332, Issue 5             X
--------------------------------------------------------------------------------------------------------------------------------
          103.   Combined ODU+IDU: 99.000 hours acc. to Bellcore TR-332, Issue 5             X
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         6 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
          104.
--------------------------------------------------------------------------------------------------------------------------------
3.7              3,5 GHz TS MTBF
--------------------------------------------------------------------------------------------------------------------------------
          105.   Radio (ODU): 225.000 hours calculated acc. to Bellcore TR-332, Issue 5      X
--------------------------------------------------------------------------------------------------------------------------------
          106.   IDU: 180.000 hours  calculated acc. to Bellcore TR-332, Issue 5             X
--------------------------------------------------------------------------------------------------------------------------------
          107.   Combined ODU+IDU: 99.000 hours acc. to Bellcore TR-332, Issue 5             X
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
4                BASE STATION (BS)
--------------------------------------------------------------------------------------------------------------------------------
4.1              GENERAL
--------------------------------------------------------------------------------------------------------------------------------
          108.   The system provide an integrated chassis with backplane that                                               X
                 interconnects most components of a sector
                 This is part of the WALKair 3000 broadband system
--------------------------------------------------------------------------------------------------------------------------------
          109.   The system provide a modular design without a common platform               X
                 and chassis. Each sector is independent
--------------------------------------------------------------------------------------------------------------------------------
          110.   The base station consist of 4 basic building blocks: the                    X
                 antenna, the BS-RFU (base station outdoor unit), the IF-Mux
                 (intermediate frequency mux) and the BS-BU (base station basic
                 unit). One of each is necessary to build a sector.
--------------------------------------------------------------------------------------------------------------------------------
          111.   The IF-Mux combines IF signals of 16 (8) BS-BU to be transmitted towards    X
                  a single BS-RFU
--------------------------------------------------------------------------------------------------------------------------------
          112.   The BS-RFU is connected via one coax cable with the IF-MUX using t.b.d.     X
                 connectors
--------------------------------------------------------------------------------------------------------------------------------
          113.   The cable loss of the coax cable provided (between RFU and                  X
                 antenna @ 3.5GHz) is 1/2 dB
--------------------------------------------------------------------------------------------------------------------------------
          114.   There system limitation on the IF cable loss is 20 dB.                      X
--------------------------------------------------------------------------------------------------------------------------------
          115.   The system supports BS-RFU redundancy providing a stand-by                           X
                 functionality in the IF-Mux between two connected BS-RFUs
--------------------------------------------------------------------------------------------------------------------------------
          116.   The basestation offering includes an external ATM Mux which will be                  X
                 integrated into management later.
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
4.2              BS-RFU (26 GHz)
--------------------------------------------------------------------------------------------------------------------------------
          117.   The RFU  includes an attached horn antenna                                  X
--------------------------------------------------------------------------------------------------------------------------------
          118.   The BS-RFU includes a 20cm diameter horn antenna                            X
--------------------------------------------------------------------------------------------------------------------------------
          119.   - for 90degree (15.5 dBi gain)                                              X
--------------------------------------------------------------------------------------------------------------------------------
          120.   - 60 degree                                                                 -
--------------------------------------------------------------------------------------------------------------------------------
          121.   - 45 degree (18 dBi gain)                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          122.   - 30 degree (20 dBi gain ) - 4 month ARO
--------------------------------------------------------------------------------------------------------------------------------
          123.   - 15 degree                                                                 -
--------------------------------------------------------------------------------------------------------------------------------
          124.   All antennae are provided in horizontal and vertical polarisation           X      X
                                                                                         vertica Horizontal
--------------------------------------------------------------------------------------------------------------------------------
          125.   The maximum transmit power is 24 dBm, being set by power setting with       X
                 the software of the WALKnet management system
                 Maximum transmit power is set per BU-BU
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         7 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
          126.   Committed Range for each Sectorisation for BER=10-9, Zone H,                X
                 availability due to propagation effects of 99.99%, 30
                 Mbit/sector with 28 MHz bandwith standard TS antenna is 3.0km.
                 3.9 km can be reached using high gain antenna at TS.
--------------------------------------------------------------------------------------------------------------------------------
          127.   180 degree                                                                  -
--------------------------------------------------------------------------------------------------------------------------------
          128.   90 degree = 3.0 km. 3.9 km can be reached using high gain antenna           X      X
                                                                                                   high
                                                                                                   gain
--------------------------------------------------------------------------------------------------------------------------------
          129.   60 degree                                                                   -
--------------------------------------------------------------------------------------------------------------------------------
          130.   45 degree = 3.5 km. 4.5 km can be reached using high gain antenna           X
--------------------------------------------------------------------------------------------------------------------------------
          131.   30 degree = 3.9 km - 4 months ARO
--------------------------------------------------------------------------------------------------------------------------------
          132.   15 degree                                                                   -
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
4.3              BS-RFU (3.5 GHz)
--------------------------------------------------------------------------------------------------------------------------------
          133.   RFU and Antenna are separated                                               X
--------------------------------------------------------------------------------------------------------------------------------
          134.   The BS-RFU includes a external antenna of 40x20x5 cm                        X
--------------------------------------------------------------------------------------------------------------------------------
          135.   180 degree                                                                  -
--------------------------------------------------------------------------------------------------------------------------------
          136.   90 degree (13.5 dBi gain)                                                   X
--------------------------------------------------------------------------------------------------------------------------------
          137.   60 degree (15 dBi gain)                                                     X
--------------------------------------------------------------------------------------------------------------------------------
          138.   45 degree - 8 sectors are provided via 60 degrees antenna
--------------------------------------------------------------------------------------------------------------------------------
          139.   30 degree                                                                   -
--------------------------------------------------------------------------------------------------------------------------------
          140.   All antennae are provided in horizontal and vertical polarisation           X
--------------------------------------------------------------------------------------------------------------------------------
          141.   The maximum transmit power is 27 dBm, being set by power                    X
                 setting with the software of the WalkNet management system
                 Transmit power is set per BS-BU (carrier) with nominal 18dBm
                 per BS-BU
--------------------------------------------------------------------------------------------------------------------------------
          142.   Predicted Range for each sectorisation for BER=10-9, Zone H,                X
                 availability of 99.99%, 15 Mbit/sector with 14 MHz bandwith
                 standard TS antenna is 10km
--------------------------------------------------------------------------------------------------------------------------------
          143.   180 degree                                                                  -
--------------------------------------------------------------------------------------------------------------------------------
          144.   90 degree =  10 km                                                          X
--------------------------------------------------------------------------------------------------------------------------------
          145.   60 degree =10 km                                                            X
--------------------------------------------------------------------------------------------------------------------------------
          146.   45 degree - 8 sectors are provided via 60 degrees antenna
--------------------------------------------------------------------------------------------------------------------------------
          147.   30 degree                                                                   -
--------------------------------------------------------------------------------------------------------------------------------
          148.   15 degree                                                                   -
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
4.4              IF-MUX
--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         8 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

<TABLE>
--------------------------------------------------------------------------------------------------------------------------------
<S>       <C>    <C>                                                                     <C>       <C>       <C>       <C>
          149.   The IF-MUX add 16 (8) IF signals towards the BS-RFU with a loss of 10dB     X
                 (Tx) and 2dB(Rx)
--------------------------------------------------------------------------------------------------------------------------------
          150.   All connectors have access via the front panel - except for                 X
                 power and Ntype towards the RFU
--------------------------------------------------------------------------------------------------------------------------------
          151.   Each BS-BU is connected via coax Jumper cables of coax type                 X
                 with SMA connector type
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
4.5              BS-BU
--------------------------------------------------------------------------------------------------------------------------------
          152.   Each BU BS (the main base station component) needs a carrier of 1.75 MHz    X
                 providing 4 Mbit/s of user bandwidth
--------------------------------------------------------------------------------------------------------------------------------
          153.   Each BU BS can handle 16 individual TS                                      X
--------------------------------------------------------------------------------------------------------------------------------
          154.   All base station indoor components (BS BU and IFMUX) can be                 X
                 installed in ETSI or 19" racks. The numbers of racks and
                 components depend on the available bandwidth and number of
                 sectors. With an available bandwidth of 1 x 28 MHz duplex
                 frequency WALKair can offer e.g. the following capacities:
                 4 sectors 8 carriers each :  2 ETSI racks (each 60x60x220cm) -  32 BS BU
                 (16 different carriers used )=  128 Mbit/s
                 8 sectors 8 carriers each:  4 ETSI racks  -  64 BS BU (16 different
                 carriers used)=  256 Mbit/s
--------------------------------------------------------------------------------------------------------------------------------
          155.   Power consumption of single base station modules for 26 and 3.5 GHz is:     X
                 BS BU:  40 W (indoor)
                 IF MUX:   8 W (indoor)
                 BS RFU: 80W @3.5GHz , 50W @ 26GHz (outdoor)
                 Calculation for 2 racks with 32 BS BU and a capacity of 128 Mbit/s:
                 4 x BS RFU + 4 x IF MUX + 32 x BS BU = 1632 W @ 3.5GHz
                 4 x BS RFU + 4 x IF MUX + 32 x BS BU = 1512 W @ 26GHz
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
4.6              BASE STATION MTBF 26 GHz AND 3.5 GHz
--------------------------------------------------------------------------------------------------------------------------------
          156.   MTBF of BS comprising BS-BU, IF MUX and BS RFU is 100.000  hours acc.       X
                 to Bellcore TR-332, Issue 5
--------------------------------------------------------------------------------------------------------------------------------
          157.   BS-BU are 220.000 hours calculated acc. to Bellcore TR-332, Issue 5         X
--------------------------------------------------------------------------------------------------------------------------------
          158.   IF MUX - 1.400.000 hours calculated acc. to Bellcore TR-332, Issue 5        X
--------------------------------------------------------------------------------------------------------------------------------
          159.   BS RFU  -  220.000 hours calculated acc. to Bellcore TR-332, Issue 5        X
--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------

--------------------------------------------------------------------------------------------------------------------------------
</TABLE>

REFERENCES TO STANDARDS

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS     DATE    TITLE
----------------------------------------------------------------------------------------------------------------------
<S>                  <C>        <C>     <C>
ITU-T G.703          Comply     04/91   Physical/Electrical characteristics of hierarchical digital interfaces
----------------------------------------------------------------------------------------------------------------------
ITU-T G.826          Comply     11/93   Error performance parameters and objectives for international constant bit
                                        rate digital paths at or above the primary rate
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
ETS 300 019          Comply     02/92   Environmental conditions and environmental tests for telecommunications
                                        equipment
                                        Part A:  introduction and terminology
                                        Part B: classification of environmental conditions
----------------------------------------------------------------------------------------------------------------------
ETS 300 253          Comply     01/95   Earthing and bonding of telecommunication equipment in telecommunication
                                        centres
----------------------------------------------------------------------------------------------------------------------
</TABLE>

                                                                         9 of 11
<PAGE>
                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution
<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
STANDARD             STATUS     DATE    TITLE
----------------------------------------------------------------------------------------------------------------------
<S>                  <C>        <C>     <C>
EN 41003             Comply     1991    Particular safety requirements for equipment to be connected to
                                        telecommunication network
----------------------------------------------------------------------------------------------------------------------
EN 55022             Comply     05/95   Grenzwerte und Me(beta)verfahren fur Funkstorungen von Einrichtungen der
                                        Informationstechnik
----------------------------------------------------------------------------------------------------------------------
DIN 47295            Comply             HF-Steckverbindung 1,6/5,6: Wellenwiderstand 75 Ohm
                     with
                     optional
                     external
                     adapters
----------------------------------------------------------------------------------------------------------------------
Reg TP 321 ZV 042               4.98    Zulassungsvorschrift fur Punkt zu Multipunkt Digital-Richtfunkanlagen des
                                        festen Funkdienstes im 3,5 GHz-Bereich mit verschiedenen Zugriffsverfahren
----------------------------------------------------------------------------------------------------------------------
                                        Zulassungsvorschrift  fur Punkt zu  Multipunkt  Digital-Richtfunkanlagen  des
                                        festen Funkdienstes im 26 GHz-Bereich mit verschiedenen Zugriffsverfahren
----------------------------------------------------------------------------------------------------------------------
EN 301 021 V1.2.1               5.99    ETSI EN 301 021 V1.2.1 (1999-05) Draft, Reference: REN/TM-04062, Title:
                                        Fixed Radio Systems; Point-to-multipoint equipment; Time Division Multiple
                                        Access (TDMA); Point-to-multipoint radio systems in the range 3 GHz to 11
                                        GHz
----------------------------------------------------------------------------------------------------------------------
EN 301 213-1 V1.1.11            11.99   ETSI EN 301 213-1 V1.1.1 (1999-11), Reference: DEN/TM-04050-1, Title: Fixed
                                        Radio Systems; Point-to-multipoint equipment; Point-to-multipoint digital
                                        radio systems in frequency bands in the range 24,25 GHz to 29,5 GHz using
                                        different access methods; Part 1: Basic parameters
----------------------------------------------------------------------------------------------------------------------
EN 301 213-3 V1.1.1             1.00    ETSI EN 301 213-3 V1.1.1 (2000-01) Final draft, Reference: DEN/TM-04050-3,
                                        Title: Fixed Radio Systems; Point-to-multipoint equipment;
                                        Point-to-multipoint digital radio systems in frequency bands in the range
                                        24,25 GHz to 29,5 GHz using different access methods; Part 3: Time Division
                                        Multiple Access (TDMA) methods
----------------------------------------------------------------------------------------------------------------------
EN 301 215-1 V1.1.1             11.99   EN 301 215-1 V1.1.1 (1999-11) Final draft, Reference: DEN/TM-04057-1,
                                        Title: Fixed Radio Systems; Point to Multipoint Antennas; Antennas for
                                        point-to-multipoint fixed radio systems in the 11 GHz to 60 GHz band; Part
                                        1: General aspects
----------------------------------------------------------------------------------------------------------------------
EN 301 215-2 V1.1.1             11.99   EN 301 215-2 V1.1.1 (1999-11) Final draft, Reference: DEN/TM-04057-2,
                                        Title: Fixed Radio Systems; Point to Multipoint Antennas; Antennas for
                                        point-to-multipoint fixed radio systems in the 11 GHz to 60 GHz band; Part
                                        2: 24 GHz to 30 GHz
----------------------------------------------------------------------------------------------------------------------
EN 301 390 V1.1.1               10.99   EN 301 390 V1.1.1 (1999-10) Draft, Reference: DEN/TM-04040, Title: Fixed
                                        Radio Systems; Point-to-point and Point-to-Multipoint Systems; Spurious
                                        emissions and receiver immunity at equipment/antenna port of Digital Fixed
                                        Radio Systems
----------------------------------------------------------------------------------------------------------------------
EN 302 085 V1.1.1               11.99   EN 302 085 V1.1.1 (1999-11) Final draft, Reference: DEN/TM-04049, Title:
                                        Fixed Radio Systems; Point-to-Multipoint Antennas; Antennas for
                                        point-to-multipoint fixed radio systems in the 3 GHz to 11 GHz band
----------------------------------------------------------------------------------------------------------------------
</TABLE>

STATEMENT ON LINK AVAILABILITY

Contractor warrants a link availability due to radio propagation effects of
****** in all planned rain zones in Germany as defined by the ITU standards in
place to date for all radio links installed within the committed range of the
radio system given in Table 1 and 3, below. For Information also the ranges for
a typical availability due to radio propagation effects of ****** are given in
Table 2 and 4. Outages due to equipment failure are not included in this
statement but are subject to the separate MTBF warranty.

If circumstances occur that result in a change of climatic conditions in
Germany, thereby affecting the links that have been deployed or engineered by
Contractor for Purchaser, then Force Majeur shall apply
-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.
                                                                        10 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

--------------------------------------------------------------------------------
               1.)  RANGE FOR A COMMITTED RAIN AVAILABILITY OF ****** BASED ON
                    BER THRESHOLD 10E-9

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
                     STANDARD ANTENNA AT TS                              2 FEET ANTENNA AT TS
----------------------------------------------------------------------------------------------------------------------
                  RAIN ZONE E      RAIN ZONE H      RAIN ZONE K      RAIN ZONE E      RAIN ZONE H      RAIN ZONE K
----------------------------------------------------------------------------------------------------------------------
<S>                    <C>              <C>              <C>              <C>              <C>              <C>
90DEG.SECTOR           3,3 km           3,0 km           2,5 km           4,2 km           3,9 km           3,2 km
----------------------------------------------------------------------------------------------------------------------
45DEG.SECTOR           3,8 km           3,5 km           2,9 km           4,8 km           4,5 km           3,6 km
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
</TABLE>

--------------------------------------------------------------------------------
               2.)  RANGE FOR AN TYPICAL RAIN AVAILABILITY OF ****** BASED ON
                    BER THRESHOLD 10E-9
--------------------------------------------------------------------------------

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
                     STANDARD ANTENNA AT TS                              2 FEET ANTENNA AT TS
----------------------------------------------------------------------------------------------------------------------
                  RAIN ZONE E      RAIN ZONE H      RAIN ZONE K      RAIN ZONE E      RAIN ZONE H      RAIN ZONE K
----------------------------------------------------------------------------------------------------------------------
<S>                    <C>              <C>              <C>              <C>              <C>              <C>
90DEG.SECTOR           4,4 km           3,9 km           3,2 km           5,7 km           5,1 km           4,1 km
----------------------------------------------------------------------------------------------------------------------
45DEG.SECTOR            5 km            4,5 km           3,7 km           6,5 km           5,8 km           4,7 km
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
</TABLE>

--------------------------------------------------------------------------------
               3.)  RANGE FOR A COMMITTED RAIN AVAILABILITY OF ****** BASED ON
                    BER THRESHOLD 10E-6 OR BASED ON PERFORMANCE PARAMETERS
                    ACCORDING TO ITU-T G.826/G.827
--------------------------------------------------------------------------------

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
                     STANDARD ANTENNA AT TS                              2 FEET ANTENNA AT TS
----------------------------------------------------------------------------------------------------------------------
                  RAIN ZONE E      RAIN ZONE H      RAIN ZONE K      RAIN ZONE E      RAIN ZONE H      RAIN ZONE K
----------------------------------------------------------------------------------------------------------------------
<S>                    <C>              <C>              <C>              <C>              <C>              <C>
90DEG.SECTOR           3,7 km           3,4 km           2,8 km           4,6 km           4,3 km           3,5 km
----------------------------------------------------------------------------------------------------------------------
45DEG.SECTOR           4,2 km           3,9 km           3,2 km           5,2 km           4,8 km           3,9 km
----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------------
</TABLE>

--------------------------------------------------------------------------------
               4.)  RANGE FOR A TYPICAL RAIN AVAILABILITY OF ****** BASED ON BER
                    THRESHOLD 10E-6 OR BASED ON PERFORMANCE PARAMETERS ACCORDING
                    TO ITU-T G.826/G.827
--------------------------------------------------------------------------------

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------------
                     STANDARD ANTENNA AT TS                              2 FEET ANTENNA AT TS
----------------------------------------------------------------------------------------------------------------------
                  RAIN ZONE E      RAIN ZONE H      RAIN ZONE K      RAIN ZONE E      RAIN ZONE H      RAIN ZONE K

----------------------------------------------------------------------------------------------------------------------
<S>                    <C>              <C>              <C>              <C>              <C>              <C>
90DEG.SECTOR           4,8 km           4,3 km           3,6 km           6,2 km           5,5 km           4,5 km
----------------------------------------------------------------------------------------------------------------------
45DEG.SECTOR           5,3 km           4,9 km           4,0 km            7 km            6,3 km           5,1 km
----------------------------------------------------------------------------------------------------------------------
</TABLE>

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                        11 of 11
<PAGE>

                               European Agreement
                                  Appendix 3a_1
           System Feature Description for the Contractor WLL solution

List of abbreviations :

<TABLE>
<CAPTION>
---------------------------------------------------------------------------
ABBREVIATION                   CONTENT
---------------------------------------------------------------------------
<S>                            <C>
TS                             WALKair terminalstation
---------------------------------------------------------------------------
BS                             WALKair basestation
---------------------------------------------------------------------------
BU                             WALKair base unit
---------------------------------------------------------------------------
RFU                            radio frequency unt
---------------------------------------------------------------------------
IDU                            WALKair indoor unit
---------------------------------------------------------------------------
ODU                            WALKair outdoor unit
---------------------------------------------------------------------------
IF                             Intermediate Frequency
---------------------------------------------------------------------------
FR                             Frame Relay
---------------------------------------------------------------------------
BER                            Bit Error Rate
---------------------------------------------------------------------------
</TABLE>

                                                                        12 of 11

<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

                    SYSTEM FEATURE DESCRIPTION OF CONTRACTOR

                             WLL MANAGEMENT SYSTEMS

------------------------- ------------------------------------------------------
DOCUMENT NAME             Appendix 3a_2 - SFD_WLL_Management_System 000510
------------------------- ------------------------------------------------------
DESCRIPTION               This document as part of the European Agreement
                          between Purchaser and Contractor describes the
                          features requested from the Contractor's WLL
                          Management Systems (including WALKnet and ACI
                          management of the Contractor's ONU).

------------------------- ------------------------------------------------------

                                                                         1 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

1        DEFINITIONS AND ABBREVIATIONS

API                  Applications Programmer Interface
BER                  Bit Error Ratio
CM                   Configuration Management
DCN                  Data Communication Network
EFD                  Event Forwarding Discriminator
EMS                  Element Management System
ESD                  Electro-static Discharge
FM                   Fault Management
GUI                  Graphical User Interface
ISO                  International Organisation for Standardisation
LAN                  Local Area Network
MIB                  Management Information Base
MTBF                 Mean Time Between Failure
NE                   Network Element
NOC                  Network Operations Centre
NMS                  Network (Layer) Management System
O&M                  Operation and Maintenance
OSS                  Operation Support System
PCB                  Printed Circuit Board
PM                   Performance Management
QoS                  Quality of Service
SNC                  Subnetwork Connection
TP                   Termination Points
UT                   Unavailable Time
WAN                  Wide Area Network

                                                                         2 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

2        REQUESTED FEATURES
<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
1                   MANAGED NE TYPES
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             1.     The management system supports the WALKair BSBU, TS                         V3*
                    Elements and "Tiny Router".
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             2.     The  management   system   supports  the  Contractor  ONU                                 X
                    product deployed
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             3.     The  management  system  supports the  Contractor  CMX II                                 X
                    system
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             4.     The  management  will  support  the ONU  and the  WALKair      TBD          TBD           X
                    system                                                                                  (ONU
                                                                                                             only)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
2                   GENERAL SYSTEM REQUIREMENTS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             5.     The NMS is based on Sun Solaris Operating System.                            V4
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             6.     The NMS is based on Microsoft NT O/S                                      Until V3        X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             7.     The NMS System is based on the SUN Solaris O/S                  X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             8.     The NMS hardware is a standard commercially available                       V4*
                    SUN ULTRA 10 Model 333 with non modified external
                    interfaces.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             9.     The NMS hardware consists of a standard commercially            X
                    available SUN ULTRA 60 Model 2360 and a SUN ULTRA 10 Model
                    333 with
                    Non modified external interfaces.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             10.    The NMS is a high-end server capable of meeting the                                       X
                    requirements outlined in this document, with standard
                    commerically available non modified interfaces.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             11.    The NMS based on a standard commercially available              X           V4            X
                    database systems.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             12.    The supplier shall specify the applied and supported           TBD        Oracle V4      ACI
                    type and release of all the proposed                                         no          V6.1:
                    database.                                                                 database      Versant
                                                                                              until V3       5.08
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             13.    Documentation of all database schemes/structures                X            V4           X(1)
                    utilised in the NMS will be provided upon request
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             14.    A failure in the NMS is in no case traffic affecting.           X            V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             15.    The downtime of the NMS is less than one hour per month         X            V4           X(2)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             16.    The NMS is a multi-user system.                                 X            V4           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             17.    The NMS each can be simultaneously operated by at least         X            V4           X
                    4 operators on different terminals.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

---------------
1 The ACI database structure is a pure system internal facility, not documented
on customer-level and subject of changes. It can be read on principle by Versant
means.
2 Provided a high-availability HW configuration (e.g. RAID system) and fast
repair (service contract), ACI achieves an availibility of ***, i.e. downtimes
about *** per year.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                         3 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             18.    All systems are Y2K compliant  and handle other  calendar       X            V3           X
                    events such as leap year, etc.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             19.    The NMS platforms are all capable of reporting logs and         X            V3           X
                    alarms to the Alarm Surveillance position in the NOC .
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             20.    Alarm burst will not cause loss of alarms at any system.        X            V3           X(3)
                    Overload conditions of the NEs and of the management                       The NE
                    systems will be reported at the management systems.                       saves all
                                                                                                open
                                                                                               alarms
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3                   USER INTERFACE
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3.1                 GENERAL
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             21.    The GUI is based on high  resolution  color  graphics  in       X            V3           X
                    the NMS Systems.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             22.    All NMS functionality is available from a GUI interface.        X            V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             23.    The NMS can be connected via a LAN to the Firstmark             X            V4           X
                    workstations with at least 4 simultaneous users.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             24.    Alarms can be monitored either directly from the element        X            V3            X
                    manager or from the INMS as required.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             25.    The INMS provides the capability of the system                  X                        n.a.
                    administrator to define the alarm displays so the
                    network can be divided according to the needs of
                    Purchaser. All displays can be edited and saved by the
                    system administrator.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             26.    The GUI is capable of immediately displaying  updates in        X            V3           X
                    case of MIB changes.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             27.    Dialogue boxes are used to confirm operator actions             X            V3           X4
                    which may affect network traffic.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             28.    The NMS provides a facility to select objects and               X            V3           X
                    initiate actions against the selected object.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             29.    The NMS provides a facility to modify applicable object         X            V3           X
                    attributes in parameter windows.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             30.    The execution of all operations is indicated to the             X            V3           X
                    operator during the execution. End of execution of
                    operations is immediately indicated to the operator.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             31.    The NMS shall allow to the user to cut and paste from           X            NA           X(5)
                    the various screens.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             32.    The NMS allows the user to provision services using the                      V3           X
                    GUI or text interface.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

----------------

3 The througput of alarms and control of bursts is mainly affected by given DCN
performance. The SISA-DCN provides flow control and buffering and thus is able
to control burst situations up to a certain limit. Provided that limits are not
exceeded, loss of alarms doesn't take place. Otherwise loss of alarms cannot be
stricted excluded. The FastLink NEs don't provide alarm buffering.
4 ACI provides a comfortable, efficient user interface, highly supporting secure
network operation. Actions can be terminated and reset at all important dialog
steps. In general, the OK or APPLY button has not to be confirmed again.
5 Drag and drop from DCN View to Network Map

                                                                         4 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             33.    All Information displayed at the GUI has to be                  X            V3           X
                    dynamically updated upon events spontaneously send by
                    the NEs (online).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3.2                 NETWORK PRESENTATION ON THE GUI
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             34.    The NMS supports an object-orientated graphical
                    representation of the network, showing the following network
                    layer objects on a geographical map:
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             35.             Location                                               X            V5           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             36.             NE (as icons on geographical map)                      X            V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             37.             Links                                                  X            V5           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             38.             Trails                                                          Not Clear
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             39.             Customer                                               X            V5
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             40.             Customer Circuit Number                                             V5
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             41.    Further layer representations, such as                                                    X(6)
                    -   NE equipment layer showing the equipment of a                          Port
                        NE in its full depth (sub-rack, module, card, ...)                  configuration
                    -   NE transmission layer showing the  transmission                         is
                        information of a NE (TPs, port configuration ...)                    available
                    shall be achieved by means of remote login.                             graphically
                                                                                               in V3
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             42.    The NMS provides a facility to edit, save and restore           X            NA           X
                    the graphical representation map with the help of a
                    network editor.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             43.    The NMS provides a facility to load maps of different           X            V3           X
                    geographical format.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             44.    The NMS provides a function for the operator to define          X            V4           X(7)
                    views which describe the part of the network that shall
                    be shown.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             45.    The NMS is able to display several thousand NEs in such         X            V5           X(7)
                    manner that the operator keeps an clear overview.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             46.    It is possible to group sets of NEs. These groups are           X           The           X(7)
                    presented by icons at the GUI. The Icon colour always                   grouping is
                    displays the highest severity alarm like on the NE                        fixed
                    icons. It shall be possible to zoom into these groups.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             47.    Each NE can be assigned to multiple groups.                     X       Only within
                                                                                               a Base
                                                                                              Station
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3.3                 OPERATOR INTERFACE MANAGEMENT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             48.    The NMS system administration provides facilities to            X            V4           X
                    create, delete and modify users and their access rights.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             49.    The NMS logs all actions during operator sessions               X            V6           X(8)
                    including login and logout operation.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

-------------------

6 Transmission information: Functional View (function blocks acc. SISA model)
7 Subnetworks as part of Network Map or a superior Subnetwork

                                                                         5 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             50.    The NMS provides a facility to generate a print out of          X            V3           X
                    any information stored within the system (e.g. alarm                       Alarms
                    logs, screen prints etc.).                                                   V5
                                                                                               Print
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             51.    The NMS provides a facility for print management                X       Part of the       X(9)
                    (cancel print jobs, select printer, ...)                                 Operating
                                                                                               System
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3.4                 STATUS PRESENTATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             52.    Status changes of network objects (such as operational          X            V3           X
                    state or alarm state) are displayed by means of clearly
                    visible and audible signals, especially on the graphical
                    network representation.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             53.    The change of the administrative state of a certain             X            V3           X(10)
                    object shall lead to according state modifications of
                    subordinate objects in the NMS management information
                    base (MIB) and vice versa.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             54.    The NMS  shall automatically update the state of the            X            V3           X
                    network layer objects due to state change of the element
                    layer objects which implement the network layer objects.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             55.    Alarms acknowledged at the upper layer NMS is reported         TBD           No
                    to the underlying NMS. The underlying NMS status must
                    reflect this change. Acknowledement of alarms at one
                    station will cause the alarm to be acknowledged at all
                    subordinate management layers.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             56.    Alarm and status changes of the NEs will be displayed           X            V3           X
                    immediately (online) at all management stations.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3.5                 TEXTUAL REPRESENTATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             57.    The NMS provides a textual representation of all                X            V3           X(11)
                    information in its MIB.                                                   Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             58.    The textual representation is a formatted list of MIB           X            V3           X(11)
                    contents (e.g. logs, object attributes).                                  Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             59.    The operator is able to choose between different levels         X            NA           X(11)
                    of detail in the textual representation.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             60.    The NMS provides scope and filter mechanisms to                 X            NA           X(11)
                    customize list representations.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             61.    The information is presented in a scrollable list with a        X            V3           X(11)
                    fixed visible headline.                                                   Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             62.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3.6                 HELP SYSTEM
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

------------------

8 via security logging of Windows NT
9 via Windows NT means
10 It is possible to lock/unlock Services and Paths. The related objects are
changed accordingly. Locking is only possible, if that function is supported by
concerned NEs.
11 Access to ACI's MIB is only possible by GUI. However, main contents of MIB
can be exported to ASCII file (mostly in "csv" format), e.g.
Service/Path/Subscr. Lists, logs or network topology. Certain filtering otions
are supported. By processing with MS Excel items 59 and 61 can be realized.

                                                                         6 of 20
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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             63.    The NMS provides a context sensitive on-line help system.       X            V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             64.    The User with the appropriate rights can edit the help          X        HTML files   s. note(12)
                    content.                                                                   can be
                                                                                               edited
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             65.    It is possible to insert to each single alarm a user           TBD           NA       s. note(12)
                    definable help text.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
3.7                 MML COMMANDS (MAN MACHINE LANGUAGE)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             66.    The NMS provides a MML Interface                                X        Not clear
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             67.    The NMS allows remote operation via MML.                       TBD       Not clear
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             68.    The NMS allows remote operation via terminal emulation.        TBD          It is
                                                                                               possible
                                                                                                 to
                                                                                               remotely
                                                                                               operate
                                                                                               NE via X
                                                                                               terminal
                                                                                                to the
                                                                                                NMS (V4)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             69.    MML commands allow to remotely test lines, diagnose all                     It is
                    Contractor's equipment remotely from the NOC.                              possible
                                                                                                  to
                                                                                               remotely
                                                                                               diagnose
                                                                                                NE via
                                                                                                WALKnet
                                                                                                 or X
                                                                                                terminal
                                                                                                  (V4)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             70.    MML commands allow to loop E-1 circuits at the BS-BU,                       Local,
                    TS and Contractor Mux to isolate faults before                              remote
                    dispatching Field people to the site. payload                                and
                                                                                               loopbacks
                                                                                                  are
                                                                                                possible
                                                                                                from the
                                                                                                NMS (V3)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
4                   MANAGEMENT SYSTEM INTERFACES
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
4.1                 NORTHBOUND INTERFACE
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

-------------------

12 ACI is delivered with fixed help texts. For alarms a context-related branch
to FastLink maintenance manual is possible. The help texts and the manuals can
be customized on principle by Windows NT tools and/or other SW (e.g. Adobe PDF
writer). However, one should consider that all these changes have to maintained
in a customer-specific manner. Each system update may be affected from that.

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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             71.    The (text) interface to a provisioning system is                             V6       s. note(13)
                    available. This interface is capable of accepting a                       Agreed DB
                    script file, executing the connection or disconnect and                   scheme is
                    responding with an indication if the operation was                         required
                    successful or failed. If the execution failed, a text
                    message indicating why the transaction failed is
                    required in the response.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             72.    Requested interface information is forwarded for the            X          Comply        X(14)
                    purpose of developing 3rd party software. Co-operation
                    with 3rd party vendors is committed when required.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             73.    The alarm logs, performance data and other database            TBD       Due after    s. note(15)
                    information is available via a CORBA                                      Further
                    interface                                                                definition
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             74.    It is possible to retrieve all configuration data by an        TBD         Can be     s. note(15)
                    external CORBA client.                                                   retrieved
                                                                                              via the
                                                                                              SQL DB
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             75.    It is possible to retrieve all equipment alarm data by         TBD       Due after    s. note(15)
                    an external CORBA client.                                                 Further
                                                                                             definition
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             76.    It is  possible  to  retrieve  all QoSData by an external                  Can be     s. note(15)
                    CORBA client.                                                            retrieved
                                                                                              via the
                                                                                              SQL DB
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             77.    It is possible to retrieve all service management data                     Can be     s. note(15)
                    by an external CORBA client.                                             retrieved
                                                                                              via the
                                                                                               SQL DB
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
4.2                 SOUTHBOUND INTERFACE
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             78.    The (TBD) allows a cut through (access) to the                 TBD          TBD       s. note(16)
                    underlying element manager.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
5                   PERFORMANCE REQUIREMENTS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
                    Under normal operating conditions, the worst case duration
                    for ....
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             79.    ... creating, copying, or deleting NEs is below 1 minute        X            V4           X(17)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             80.    ... retrieving & processing equipment alarm conditions          X            V3           X
                    is below 1 minute maximum for the worst condition.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

-----------------

13 ACI supports service activation via SNMP (service preconfigured) and service
creation by a batch file (normally this batch file is created using subscriber
definitions of the EWSD switch.
14 Information can be given on the prerequisite of according contractional
conditions.
15 The Corba interface of ACI provides a subnetwork-oriented view, which allows
service creation across an ACI domain. All internals of the ACI domain are
hidden. Just state changes, no alarms are reported.
16 The interface betweeen network level and element level is just ACI internal.
DCN interfaces to the NEs are: QD2 over RS-485, QD2 over TCP/IP (and/or OSI),
SNMP.
17 Assumed a DCN channel at 64 kbit/s, the upload of an ONU30 last in the range
of 1 minute. Copying is not possible. A NE can be deleted in the network map.
This is a pure ACI-internal action and lasts in seconds range.

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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             81.    ... backup of the complete data bases is below 1 h              X        Depends on       X
                                                                                             the backup
                                                                                            utility and
                                                                                            the DB size
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             82.    ... event logging is below 1 second                             X            V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             83.   The NMS is capable of managing 10,000 ONU30 muxes                                      s. note(18)
                   without impact on user response, alarm reporting or
                   provisioning.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             84.    The NMS is capable of managing >3000  fully equipped                         V4          n.a.
                    base station sites without impact on user response,                      Depends on
                    alarm reporting, configuration and performance data                         the
                    collection.                                                               Platform
                                                                                              strength
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6                   CORE FEATURES
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1                 CONFIGURATION MANAGEMENT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.1               SITE CREATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             85.    The NMS allows to assign a unique user friendly name to         X            V3           X
                    each site.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             86.    The NMS allows to create sites, regardless of whether it        X            V3           X
                    exists.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             87.    The NMS allows to perform checks to ensure unambiguous          X
                    user friendly site names.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.2               EQUIPMENT CREATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             88.    The NMS allows to select equipment types from a list            X            V3       s. note(19)
                    containing all valid NE types.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             89.    The NMS automatically retrieves configuration parameters                     V4           X
                    from the related Nes
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             90.    The NMS allows to assign a unique user friendly name to         X            V3           X
                    each NE.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             91.    The NMS allows the user to create an NE, regardless of          X            V3       s. note(19)
                    whether physical equipment exists.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             92.    The NMS notifies the user that equipment found in the           X        Not Clear    s. note(19)
                    network has not yet been created in the data
                    base.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

----------------------

18 ACI can manage up to 35000 subscribers today (ACI V3.4). Within that limits
more than 1000 ONU30 are possible. The capacity of the ACI will increase
stepwise by upgrade of the ACI server in the following ACI versions. In 06/2001
a multi-server structure is introduced which can handle large networks with
several 100000 subscribers and related NEs.
19 ACI detects and creates FastLink NEs always automatically. Manually created
are the so-called External NEs, which are not directly managed by ACI (e.g. a
ventilator). NEs can be removed from the network map.

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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             93.    The NMS allows to perform checks to ensure unambiguous          X         Customer
                    user friendly NE names.                                                    ID is
                                                                                              checked
                                                                                                for
                                                                                            duplication
                                                                                            only within
                                                                                              a BS-BU
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             94.    The NMS can create a list of all underlying EMS and Nes         X                        X(20)
                    connected to it.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             95.    The NMS can list all elements attached to it.                                V3          X(20)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             96.    NMS automatically retrieves topology information of the         X                        n.a.
                    connected management systems. No manual database access
                    is required.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             97.    It shall be possible to create NEs from templates at all                     V3       s. note(19)
                    EMS.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.4               CIRCUIT CREATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             98.    The NMS allows the user to configure the services                            V3          X(21)
                    manually through selection of the appropriate NE and
                    sub-units.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             99.    It is possible to trace circuits, if at least one of the                                 X(22)
                    below listed information is available:
                             Site name
                             BS-BU
                             TS
                             Circuit number
                             Circuit ID (individually configurable)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             100.   It is possible to detect the correlation of any                 X                        X(22)
                             port,
                             card,
                             network element,
                             site
                    to the corresponding service/trail which is using the
                    listed instance.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             101.   The NMS allows to assign a unique user friendly name to         X                        X(22)
                    each circuit/trail/service
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             102.   The NMS notifies the user of existing circuit numbers                                 s. note(23)
                    that have not yet been created in the data base.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

--------------------

20 The EMS function is integrated in ACI. A list of the NEs can be produced with
export of network topology.
21 ACI manages end-to-end services in a FastLink environment and across SDH
subnetworks (the latter with ACI V6.1). Then the endpoints of a service are
within ACI domain (and/or an integrated SDH subdomain). If one endpoint is
provided by WALKair, ACI has no knowledge of the endpoint and the path within
WALKair, i.e. ACI cannot construct the service. Then, the end-to-end service has
to be created part-by-part using ACI and WalkNet.
22 ACI provides that in it's domain. Please consider additional footnote 21.
23 ACI offers a learn service function (no notification provided)

                                                                        10 of 20
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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             103.   The NMS allows perform checks to ensure unambiguous circuit
                    numbers.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             104.   The NMS reports errors to the operator, especially              X            V3          X
                    unsuccessful operations and invalid attribute values.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             105.   It is possible to create circuits in the NMS without                         V6          X(22)
                    need to implement these in the network (planned state).                   Offline
                    The implementation of the trails shall be a separate                    configuration
                    command (implemented state).                                            is possible
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             106.   The state of the circuit shall be indicated in any                           V3          X(22)
                    representation.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             107.   It is possible to export the information on the                                          X(22)
                    configured circuits.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             108.   It is possible to export the information on the                                          X(24)
                    configured trails on bulk command
                    (APPLICATION: DATA BASE SYNCHRONISATION OF BETWEEN  NMS,
                    BILLING RECORDS AND THE NETWORK INVENTORY DATABASE)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             109.   Systems shall provide a list of created services/trails                                  X(24)
                    which contain the following information:
                             Trail / circuit ID
                             Service state (planned/implemented)
                             Fault status (alarms active)
                             Service type (bandwith, ...)
                             End/termination points
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.8               CIRCUIT  DELETION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             110.   The NMS allows the deletion of circuits in the database.                     V3          X(22)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             111.   Circuit object deletion needs to be confirmed by the                         V4          X(22)
                    operator.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             112.   If a network resource is physically removed, the                             V3          X(22)
                    corresponding circuit objects shall not be automatically
                    deleted in the database.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.9               EQUIPMENT DELETION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             113.   The NMS allows the user to delete NE objects in the             X            V4       s. note(19)
                    database.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             114.   NE object deletion needs to be confirmed by the operator.       X            V4          X(19)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

--------------------

24 This is possible by export of Service and Path List. Please consider
additional footnote 22.

                                                                        11 of 20
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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             115.   If a resource is physically removed, the corresponding          X            V4           X
                    equipment object is not automatically deleted in the
                    database.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             116.   After removing resources from the database the alarms of       TBD           NA           ?
                    this resource will automatically clear at all stations.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.10              ALARM CONFIGURATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             117.   The NMS allows to set alarm severity in accordance with         X           Alarm        X(25)
                    ITU-T Rec. X.721.                                                        Severity is
                                                                                               fixed
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             118.   The NMS allows the user to set the criteria for                TBD           V3           X
                    activating the audible alarm indication (e.g. alarm                       Via HPOV
                    priority).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             119.   The NMS shall provide a function for the operator to           TBD           V3           X(26)
                    manually assign a new severity.                                           Via HPOV

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.11              SYSTEM CONFIGURATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             120.   The NMS allows automatic download of all relevant
                    configuration data for the NE, no LCT is necessary for
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             121.    - ONU                                                                                    X

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             122.    - BS-BU                                                                     V4          n.a.

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             123.    - TS                                                                        V4          n.a.

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             124.    - CMX II                                                                                 X

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             125.   The NMS enables automatic configuration batch- download                     NA
                    to all managed network elements
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             126.   The NMS enables automatic optimization of network                         Not Clear       ?
                    resources in a freely selectable area
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             127.    - frequencies used by individual BS-BUs                                                 n.a.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

------------------

25 critcal, major, minor, warning
26 The severities can be changed on principle by editing the standard definition
files. However, one should consider that all these changes have to maintained in
a customer-specific manner. Each system update may be affected from that.

                                                                        12 of 20
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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             128.    - assignments of TS to BS-Bus                                                           n.a.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             129.   The customer services can be configured without service                      V3           ?
                    disturbence by the NMS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             130.   The NMS provides software download into all managed Nes                      V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.1.12              SOFTWARE DOWNLOAD
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             131.   The NMS supports remote SW download to all managed NEs                       V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             132.   Error-free transfer of system software download is                           V3       s. note(27)
                    ensured by verification procedures.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             133.   The NMS software update does not have any influence on                       V3           X
                    the network traffic
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2                 FAULT AND STATUS MANAGEMENT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.1               SUPPORT OF WALKNET AND ACI ALARMS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             134.   The upper layer NMS supports alarms supported by the            X                        X(28)
                    underlying NMS systems.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.2               ALARM AND STATUS INFORMATION RECEIVING
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             135.   The NMS supervises the connection to all underlying NMS         X         Possible       n.a.
                                                                                              via HPOV
                                                                                              AS an IP
                                                                                                node
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             136.   The NMS generates an alarm if the communication to the          X            V3          X(29)
                    element managers fails
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             137.   The NMS is capable of retrieving all active alarms once         X            V3          X
                    the connection is re-established.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             138.   The NMS supervises the DCN links towards and within the         X            NA
                    underlying transmission network
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

---------------------

27 Transfer across one DCN link is controlled by HDLC protocol with CRC means.
If a NE has received the last block of SW transmission, it sends an
acknowlegement back to ACI. Before restart with the new SW, a NE checks whether
the SW matches to the HW. With that procedure a correct SW download is highly
guaranteed.
28 ACI provides an SNMP alarm interface (NE alarms). This interface is an
optional feature.
29 An event is generated

                                                                        13 of 20
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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             139.   The NMS generates an alarm if communication with a              X            V3           X
                    network element is lost.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.3               ALARM ACKNOWLEDGEMENT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             140.   The NMS provides a facility to acknowledge alarms.              X            V3           X
                                                                                              Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             141.   When alarm acknowledgement is performed, acknowledgement        X            V3          X(30)
                    information shall be stored by the NMS:                                   Via HPOV
                         a) date and time of acknowledgement
                         b) type of alarm acknowledged
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             142.   The NMS allows to acknowledge one or more alarms                X            V3          X
                    simultaneously, e.g. multiple selection in alarm lists.                   Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             143.   The NMS provides alarm latching (alarm stays inside the         X            V3        s. note
                    active alarm list until it has been acknowledged - even                   Via HPOV
                    if this alarm is already cleared).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.4               ALARM LOGGING
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             144.   The NMS  provides alarm logs according to ITU-T Rec.                         V3       s. note(31)
                    X.735.                                                                   Alarm log
                                                                                              is HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             145.   The NMS stores all alarms in alarm logs.                        X            V3           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             146.   The NMS has access and can show contents of alarm logs          X            V3           X
                    created by the NEs.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             147.   The NMS alarm log contains the                                  X         Via HPOV    s. note(32)
                    -        the correlated alarm counter number                    X            NA
                    -        alarm ID number,                                       X            V3
                    -        alarm name,                                            X            V3
                    -        correlated object (NE name, slot, port, TP, ..),       X            V3
                    -        date and time of alarm status change,                  X            V3
                    -        alarm severity,                                        X            V3
                    -        date and time of acknowledgement(If                   TBD           V3
                             acknowledged)                                         TBD           V3
                    -        acknowledgement status
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             148.   Sorting criterion of the alarm lists can be time,               X            V3           X
                    affected instance, alarm type, ...                                        Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

-------------------

30 This function is planned for ACI V8.1 (planned for 12/00) with the feature
'Note Pad'. With the Note Pad a history of actions on alarms can be produced.
Different acknowledgements are not foreseen. Instead, the operator can type a
text into a Note Pad entry.
31 ACI provides efficient log control functions (e.g. log size, log full
actions), but doesn't strictly implement X.735
32 ACI supports: correlated object, date/time of occurence, severity, ack.
status (date/time of ack. status in ACI V8.1)

                                                                        14 of 20
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<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             149.   Contents of the NMS alarm lists are identical for all           X            V3           X
                    equipment types supported. The columns of the alarm
                    lists/tables have to be aligned and the columns of all rows
                    contain the same information type.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             150.   It is possible to apply filters to the alarm lists of           X         Via HPOV        X
                    all systems. Possible filter criteria are:                                            (except
                    -        Time range                                                          V3       time
                    -        Resource (NE name, instance, port, ...)                             V3         range)
                    -        Alarm severity                                                      V3
                    -        Acknowledge status                                                  V3
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.5               ALARM EXPORT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             151.   All alarm history data can be archived on external              X            V3           X
                    storage media (e.g. DAT tape) in ASCII or CSV format                      Via HPOV
                    and contain readable text.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             152.   All alarm history data can be retrieved from external           X            V3           X
                    storage media (e.g. DAT tape) in ASCII or CSV format.                     Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             153.   The list of new alarms,  the list of acknowledged  alarms       X            V3           X
                    and the list of  historical  alarms  can be  printed  and                 Via HPOV
                    contain readable text.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             154.   Selected parts of the list of new alarms, the list of           X            V3       X(33)
                    acknowledged alarms and the list of historical alarms                     Via HPOV
                    can be printed and contain readable text..
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.6               ALARM PRESENTATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.6.1             ALARM PRESENTATION FORMAT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             155.   The NMS presents active and acknowledged alarms in              X            V3           X
                    textual format.                                                           Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             156.   The NMS presents active alarms in graphical format (i.e.        X            V3           X
                    on the graphical network representation)                                   Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             157.   The NMS, Waknet and ACI provides an audible alarm               X            V3           X
                    indication in case of a received alarm event.                              Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             158.   The NMS displays a counter of the active and                   TBD           V3
                    acknowledged alarms.                                                      Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             159.   The NMS  displays a counter per each severity class.           TBD           V3           X
                                                                                              Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.6.2             LIST OF ACTIVE AND ACKNOWLEDGED ALARMS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

---------------------

33 Selection can be done by selection of network resources and filtering (not
e.g. by high-lightening of list/log columns)

                                                                        15 of 20
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                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             160.   The NMS  provides a facility to show active alarms.             X            V3           X
                                                                                              Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             161.   The Alarm list comprises                                        X         Via HPOV    s. note(34)
                        alarm  number                                                            V3
                        alarm short name                                                         V3
                        alarm description                                                        V3
                        alarm severity,                                                          V3
                        network element name and slot, port, TP                                  V3
                        network element location                                                 NA
                        alarm status                                                             V3
                        date and time of occurrence                                              V3
                        acknowledgement status                                                   V3
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             162.   It is possible to filter the lists of (new, current and        TBD        Via HPOV    s. note(35)
                    cleared) alarms according to
                        date of occurrence                                                       V3
                        time of occurrence                                                       V3
                        date of clearance                                                        V3
                        time of clearance                                                        V3
                        date of acknowledgement                                                  NA
                        time of acknowledgement                                                  NA
                        alarm counter number                                                     NA
                        alarm severity,                                                          V3
                        alarm acknowledgement status                                             V3
                        alarm (cleared/uncleared) status                                         V3
                        alarm name or description                                                V3
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             163.   It is possible to sort the alarms contained in the list        TBD        Via HPOV    s. note(36)
                    of (new, current and cleared) alarms
                    according to
                        Alarm type
                        Time of occurrence                                                       V3
                        Priority
                        Network element location                                                 NA
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             164.   Alarm history logs are exportable in ASCII or CSV format        X            V3           X
                                                                                              Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             165.   The alarm history log is capable of storing 30.000              X        Configurable     X(37)
                    entries but at minimum 30 days of                                         alarm log
                    data alarm                                                                  size
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             166.   The NMS allows to print the list of active and                 TBD           V3           X
                    acknowledged alarms.                                                      Via UNIX
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.6.3             DETAILED ALARM INFORMATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

------------------

34 Alarm attributes supported by ACI: date/time of occurence, origin
(NE/FUModule/TP), status (incl. ack.), alarm type, description, severity
35 ACI supports filtering for alarm type, severity, status
36 ACI supports sorting for most alarm attributes (s. footnote 34)
37 Size of the logs are adjustable. Limits are given be available disk space for
file system.

                                                                        16 of 20
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                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             167.   The NMS allows the User to detect the cause of an alarm         X            V3           X
                    by locating the alarm source in the graphical network
                    presentation (NE, link, etc.).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.6.4             ALARM FILTERING AND MASKING
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             168.   The NMS will provide an indication of all temporary                          NA           X(38)
                    blocked alarms currently in the system s the Operator
                    does not forget to re-activate these alarms when field
                    personnel leave the site.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             169.   The NMS will allow the authorised use to change the                          V3           X
                    priority of a particular alarm.                                           Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             170.   The authorised user may control which alarms are                X            V3
                    delivered to the alarm surveillance positions.                            Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             171.   All alarms occurring in the network are logged in the           X            V3           X(39)
                    alarm history log.                                                        Via HPOV
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             172.   It is be possible to prevent the entire NEs and single          X            V3
                    resources  (ports, ...) from reporting alarms (e.g.                       Via HPOV
                    during maintenance).  This status must be clearly visible                   The
                    to the operator at all management systems.                              granularity
                                                                                               is NE
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             173.   It is possible to mask each individual alarm.                                NA           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             174.   It is be possible to configure alarm masking be using                        NA
                    templates.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             175.   It is be possible to configure separate alarm masking                        NA           X
                    for the element management systems and for the NMS.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.2.7               ALARM CORRELATION
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             176.   The NMS performs alarm correlation across all of the            X
                    Purchaser WLL NEs and reports only the root cause alarm to
                    the Surveillance positions by default (without prior
                    configuration effort per single service).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             177.   NMS allows the user to change alarm correlation rules as        X
                    required.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             178.   Alarm correlation rules can be set on a per service type        X
                    basis in a user friendly manner.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

--------------------

38 The alarm status of an NE can be shown, including information whether an
alarm is disabled or not.
39 Logs have to be created manually. A log may contain all alarms.

                                                                        17 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             179.   Alarms are correlated to the affected services                  X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             180.   It is be possible to automatically generate actions             X            V3           X(40)
                    (alarms, mails, fax, TT, ..) upon the occurance of
                    certain events. These trigger events are user definable
                    (boolean expressions, ..).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
6.3                 PERFORMANCE MANAGEMENT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             181.   The performance management function allows to collect                        V4           X
                    and archive performance data every 15 minutes and 24
                    hour period. The max archive period is configurable (>
                    30 days).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             182.   It is possible to corelate performance history data to
                    services
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             183.   All performance data are exportable to a 3rd party                           V3           X
                    software package in ASCII or CSV format.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             184.   Management systems must be able to create PM reports per                     PM
                    customer and service/trail. PM data must be                                reports
                    correlated to the services/trails without any                             are stored
                    additional SW tools.                                                      on the DB
                                                                                              and can be
                                                                                              viewed from
                                                                                              the NMS or
                                                                                              exported as
                                                                                               explained
                                                                                               above (V4
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
                    In NMS, ACI Walknet performance data is available for
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             185.    - termination points of E1 trails (according G.826)                         V5       s. note(41)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             186.    - termination points of sub-E1 trails (according G.821)                     V5
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             187.   For the air-interface the NMS, ACI, Walknet provide
                    performance data for
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             188.    - receive power                                                             V3

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

-------------------

40 In Event Logs, system events can be recorded. User definable events are not
possible.
41 FastLink NEs support PM for 2 Mbit/s links (via CRC). The PM data can be read
and logged by ACI.

                                                                        18 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             189.    - transmit power                                                            V3

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             190.    - C/I                                                                       V3

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             191.    - BER                                                                       V5

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
7                   OPERATION AND MAINTENANCE
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
7.4.1               USER ACCESS CONTROL
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             192.   Security management shall follow the requirements              TBD           NA          X(42)
                    defined in the ITU-T Rec. X.736.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             193.   The NMS shall provide the ability to define different           X            V4           X
                    operator classes (e.g. normal operator, system
                    administrator, ...).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             194.   The definition of operator classes and related domain           X            V4           X
                    rights is restricted to the system administrator.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             195.   The NMS  provides an application to administer NMS              X            V4           X(43)
                    operators, their access rights and the definition of a
                    NE domain.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             196.   A user ID / password combination shall be available to          X            V4           X
                    get access to the Management System applications.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             197.   The NMS  locks an operator login after a configurable           X            NA           X
                    number of unsuccessful attempts and reports the attempt
                    to the System Administrator.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             198.   Password aging is available in the NMS systems.                 X            NA           X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
7.4.2               DATA MANAGEMENT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
7.4.2.1             DATA BACKUP
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

-------------------

42 Security mechanisms are based on Windows NT features
43 Windows NT domain management. NE Domains are not supported

                                                                        19 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             199.   The NMS offers facilities to backup and restore all             X         Not clear       X
                    relevant data.                                                           An external
                                                                                               backup
                                                                                             program can
                                                                                             back up DB.
                                                                                             NE data is
                                                                                            automatically
                                                                                             backed up
                                                                                             by the NMS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             200.   The NMS supports interfaces to printer, CD-ROM, streamer        X         Printer         X
                    and other types of standard removable storage                            interface
                    media.                                                                    Directly
                                                                                              from WA
                                                                                             Lkair will
                                                                                                 be
                                                                                             available
                                                                                              in next
                                                                                              versions
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             201.   The NMS allows manual backup and restore of the complete        X       All data is       X
                    data base..                                                              stored on
                                                                                               the DB
                                                                                            which shuld
                                                                                             be backed
                                                                                              uo by a
                                                                                              standard
                                                                                             backup SW
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             202.   The NMS provides a facility to log backup operations.           X        External.        X(44)
                                                                                            Not part of
                                                                                            the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             203.   The backup operation does not influence system                  X            V4           X
                    operations (online backup).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             204.   The result of the archiving operations is reported to           X            NA           X
                    the NMS operator.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             205.   Scheduled automatic archiving is configurable on all            X          External.      X(45)
                    systems.                                                                 Not part of
                                                                                             the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             206.   The operator interface of the archiving utilities is            X          External.      X
                    user friendly (e.g. no sequence of operating                             Not part of
                    system commands is required).                                            the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

------------------

44 Scheduled backup and restore of NE data and OS database are logged
45 Scheduling possible for NE Data and OS database. Backup of OS SW is manually
possible.

                                                                        20 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             207.   The NMS allows to manually backup and restore the               X          External.      X
                    complete management data.                                                Not part of
                                                                                             the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             208.   The NMS allows to automatically backup and restore the          X          External.      X
                    complete management data                                                 Not part of
                                                                                             the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             209.   The backup operation does not influence system                  X           Comply        X
                    operations.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             210.   The result of the archiving operations is reported to           X          External.      X(46)
                    the operator.                                                            Not part of
                                                                                             the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             211.   The NMS offers facilities to backup and restore all             X          External.      X
                    relevant data.                                                           Not part of
                                                                                             the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             212.   The NMS supports interfaces to printer, CD-ROM, streamer        X             NA          X
                    and other types of standard removable storage media.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             213.   The NMS allows manual backup and restore of the complete        X          External.      X
                     data base..                                                             Not part of
                                                                                             the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             214.   The NMS provides a facility to log backup operations.           X         External.       X(44)
                                                                                             Not part of
                                                                                             the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             215.   The backup operation does not influence system                  X          Comply         X
                    operations (online backup).
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             216.   The result of the archiving operations is reported to           X         External.       X
                    the NMS operator.                                                       Not part of
                                                                                            the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             217.   Scheduled automatic archiving is configurable on all            X         External.       X(45)
                    systems.                                                                Not part of
                                                                                            the WALKnet
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
7.4.2.2             SYSTEM UPGRADE
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             218.   In case of an NMS, Walknet or ACI software update               X          Comply         X
                    including a change of the configuration data model no
                    loss of data will occur.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             219.   An NMS, Walknet or ACI software update does not affect          X          Comply         X
                    the interfaces/services in any case.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

------------------

46 By means the of progress bar and message in window

                                                                        21 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
             220.   The software upgrade does not have any impact in the            X          Comply         X
                    useability of customised equipment or service
                    templates
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             221.   Future Upgrade of the management systems will not              TBD         Comply         X(47)
                    require new HW.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
7.4.3               NMS  SYSTEM SOFTWARE MANAGEMENT
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             222.   The NMS restart procedure performs data consistency             X         Available       X
                    checks between the NMS and the configuration
                    data of all subordinate NEs and management systems
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             223.   The NMS restart does not have any effects on the network        X         Available       X
                    traffic.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             224.   The NMS restart takes less than 10 minutes.                     X        Available        X(48)
                                                                                             Excluding
                                                                                             the UNIX
                                                                                              itself
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             225.   The NMS contains an recovery mechanism to control all           X         Via HPOV        X
                    concurrently running processes within the system and
                    restart any failed processes.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             226.   The recovery process is not traffic affecting.                  X        Available        X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
9                   ENVIRONMENTAL CONDITIONS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
9.1          227.   CLIMATIC CONDITIONS
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             228.   The Equipment allows error free operation in accordance         X            (49)         X
                    with ETSI Rec. prETS 300 019-2-3, Class T 3.1.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
9.2                 ELECTRO-MAGNETIC COMPATIBILITY (EMC)
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             229.   The Equipment is compliant with the standards EN 55022          X            (50)         X
                    and EN 50082, class B
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             230.   The Equipment is marked with the CE-compatibility sign.         X            (50)         X
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

---------------------

47 So far that the todays PC HW is supported by future OS (e.g. if Windows NT
has to be replaced)
48 Restart time is depending on network size, DCN structure and PC HW
performance.
49 WALKnet operates over a standard UNIX SUN Solaris platform

                                                                        22 of 20
<PAGE>

                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
              NO.   ITEM                                                        AVAILA-       AVAILA-      AVAILA-
                                                                                BILITY        BILITY       BILITY
                                                                                DATE ON       DATE ON      DATE ON
                                                                                  INMS           WN          ACI
---------------------------------------------------------------------------------------------------------------------
<S>          <C>    <C>                                                        <C>          <C>           <C>
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
9.3                 SAFETY
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             231.   The Equipment meets the electrical safety requirements          X            (50)         X
                    of EN 41003.
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
             232.   The equipment is designed to ensure operation without           X            (50)         X
                    hazard to personnel due to electrical commotion
------------ ------ ---------------------------------------------------------- ------------ ------------- -----------

------------ ------ ---------------------------------------------------------- ------------ ------------- -----------
</TABLE>

                                                                        23 of 20
<PAGE>
                               European Agreement
                                  Appendix 3a_2
        System Feature Description of Contractor's WLL Management Systems

3        REFERENCES
3.1      REFERENCES TO STANDARDS

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------
STANDARD                DATE      TITLE
----------------------------------------------------------------------------------------------------------
<S>                     <C>       <C>
ITU-T X.721             02/94     Information technology - OSI - Structure of management
                                  information: Definition of Management Information (63 pages) plus
                                  corrigendum
----------------------------------------------------------------------------------------------------------
ITU-T X.735             Sep 92    OSI Systems Management: Log control function (20 pages)
----------------------------------------------------------------------------------------------------------
ITU-T X.736             Jan 92    OSI Systems Management: Security Alarm Reporting Function (15 pages)
----------------------------------------------------------------------------------------------------------
ITU-T X.742             P         Information technology - Open systems interconnection - Systems
                                  management: Usage metering function
----------------------------------------------------------------------------------------------------------
PRETS 300 019           02/92     Environmental Conditions and Environmental Tests for
                                  Telecommunications Equipment Part A: Introduction and Terminology
                                  Part B: Classification of Environmental Conditions
----------------------------------------------------------------------------------------------------------
EN 41003                1993      Particular safety requirements to be connected to
                                  telecommunications network
----------------------------------------------------------------------------------------------------------
EN 55022                05/95     Grenzwerte und Me(beta)verfahren fur Funkstorungen von
                                  Einrichtungen der Informationstechnik
----------------------------------------------------------------------------------------------------------
EN 50082                          Elektromagnetische Vertraglichkeit - Fachgrundnorm Storfestigkeit
                        12/94     Part   1:    Elektromagnetische    Vertraglichkeit    -   Fachgrundnorm
                                  Storfestigkeit - Teil 1:  Wohnbereich,  Geschafts- und  Gewerbebereiche
                        02 /96    sowie Kleinbetriebe
                                  Part   2:    Elektromagnetische    Vertraglichkeit    -   Fachgrundnorm
                                  Storfestigkeit - Teil 2: Industriebereich
----------------------------------------------------------------------------------------------------------
</TABLE>

                                                                        24 of 20
end of document

<PAGE>

                               European Agreement
                                   Appendix 3b
                                Rollout Criteria

                                   WALKAIR-TM-

                  BROADBAND POINT TO MULTIPOINT WIRELESS SYSTEM

                    ROLLOUT CRITERIA (ROADMAP) FOR FIRSTMARK

    September 1999

--------------------------------------------------------------------------------
-C-FLOWARE Wireless Systems Ltd.    All rights reserved.
The material contained herein is proprietary, privileged, and confidential. No
disclosure thereof shall be made to third parties without the express written
permission of FLOWARE Wireless Systems Ltd.
No part of this publication shall be deemed to be part of any contract or
warranty unless specifically incorporated by reference into such contract or
warranty.
--------------------------------------------------------------------------------

<PAGE>

FLOWARE Wireless Systems Ltd                                        Confidential

Road Map for FMC

--------------------------------------------------------------------------------

                                TABLE OF CONTENTS

1. SCOPE....................................................................3

2. PRODUCT VERSIONS.........................................................3

   2.1. NOW.................................................................3
   2.2. VERSION 3.2.........................................................4
   2.3. VERSION 4.0.........................................................4
   2.4. VERSION 5.0.........................................................5
   2.5. VERSION 6.0.........................................................5

                                                                       2 of 5
<PAGE>

FLOWARE Wireless Systems Ltd                                        Confidential

Road Map for FMC

--------------------------------------------------------------------------------

1.       SCOPE

     This document provides the road-map for WALKair's versions and features
     which Siemens / Floware can commit to FirstMark ( FMC ). Availability dates
     as defined in this document are dates of availability for Type Acceptance
     Testing by FMC.

2.       PRODUCT VERSIONS

2.1.     NOW

     Features which are available now;

-  FREQUENCY BANDS: 3.5 GHz, 26 GHz, 10.5 GHz

-  CUSTOMER INTERFACES:

   -  E1 ( framed )

   -  PRI ( transparent )

   -  E1 / V5.1

   -  V.35 / X.21

-  NETWORK INTERFACES:

   -  E1 ( framed )

   -  PRI ( transparent )

   -  E1 / V5.2

-  SERVICES:

   -  PRI

   -  POTS ( using additional access MUX)

   -  E1

   -  Fractional E1

   -  IP ( non concentrated )

   -  FR ( non concentrated )

-  MAINTENANCE:

   -  Local craft interface

   -  Remote software download over the air

-  CONCENTRATION SUPPORT: Circuit switch based on V5.x

-  NIR - Network planning system with capacity optimization algorithm

                                                                       3 of 5
<PAGE>

FLOWARE Wireless Systems Ltd                                        Confidential

Road Map for FMC

--------------------------------------------------------------------------------

   -   MANAGEMENT - WALKNET

       -  HPOV over PC platform

       -  Alarm management

       -  Configuration management

       -  Air link performance monitoring

2.2.   VERSION 3.2

    Version 3.2 will be available for testing in December 1999.

    -  10 BASE-T ( BY TINY ROUTER )

    IP routing functionality is implemented by using very small size external
    device named Tiny Router. The Tiny Router has V.35 interface at its WAN side
    and 10 Base-T interface at its LAN connection side ( RJ 45 ).

    This device is directly attached to the BU-TS via the D-Type connectors (
    using V.35 interfaces ) . The Tiny Router enables the connection of the CPE
    or LAN to the IP network via its 10 Base-T port.

    -  V5 BRI

    BR ISDN is implemented over V5.1 (TS), V5.2 (BS) allowing for concentrated
    BR ISDN service via external MUX.

    -  ATM MUX

    External ATM MUX in the BS, providing ATM over STM-1 network interface.

2.3.   VERSION 4.0

    Version 4.0 will be available for testing in June 2000, and will comprise
    the following features:

    -  FRAME RELAY

    Frame Relay service is implemented via V35/X21 interface. Data
    concentration is achieved using Dynamic Bandwidth Allocation ( DBA ),
    utilizing bandwidth according to actual transferred data, and allowing
    other users to fully utilize the idle bandwidth.

    -  BS RFU REDUNDANCY

    Outdoor unit redundancy can be achieved by connecting 2 outdoor units to
    a single IF MUX. Upon a malfunction of the main RFU, a switching is
    performed, and the redundant RFU is activated, allowing for increased
    availability in the base station.

    -  MANAGEMENT - WALKNET

       -  HPOV over UNIX platform support

       -  Performance monitoring accumulated results presentation

       -  User security levels

                                                                       4 of 5
<PAGE>

FLOWARE Wireless Systems Ltd                                        Confidential

Road Map for FMC

--------------------------------------------------------------------------------

    -  Downloading  BS-BU configuration from the management system

2.4.   VERSION 5.0
    Version 5.0 will be available for testing in November 2000

    -  E1 FRAME RELAY
    Frame Relay service is implemented via E1 interface at the base station side

    -  10BASET
       Integrated Ethernet interface with bridging functionality

    -   MANAGEMENT

        -  Integrated management for WALKair and ATM MUX  under WALKnet

        -  E1 performance monitoring

2.5.   VERSION 6.0

      Version 6.0 will be available for testing in May 2001

      In this version, WALKair will support broadband link ( 26 GHz only ) with
the following features:

        -  34 Mb/s per carrier

        -  Dual modulation schemes - QAM / QPSK

        -  Services: E1s, IP

                                                                       5 of 5

<PAGE>
                               European Agreement
                                  Appendix 3 c
                          WALKair production ramp-up &
                        production capacity for Purchaser

                          WALKAIR PRODUCTION RAMP-UP &
                        PRODUCTION CAPACITY FOR PURCHASER

1.       CONTRACTOR PRODUCTION CAPACITY AND RAMP-UP PLAN
<TABLE>
<CAPTION>

---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
<S>                          <C>      <C>      <C>      <C>      <C>      <C>      <C>      <C>      <C>
Month                        12/99    01/00    02/00    03/00    04/00    05/00    06/00    07/00    08/00
----------------------------
Monthly production
Capacity
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
Total # of Terminals           250      250      300      400      600      800     1000     1250     1250
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
3.5 GHz Terminals              250      250      300      400      450      500      600      700      700
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
26 GHz Terminals                30       70      100      150      300      500      750      900      900
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
# of Sectors                   100      100      140      180      250      350      400      500      500
(90DEG. or 60DEG. or 45DEG.)
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
3.5 GHz Sectors                100      100      120      140      180      220      250      300      300
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
26 GHz Sectors                  15       40       70      120      170      250      300      400      400
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
</TABLE>

Notes:

1. the plan assumes a ratio of 1 BS-BU per sector. Additional BS-BUs, if needed,
   may be balanced with Terminal Stations.

2. Per each month there is a planned maximum number of terminals and maximum
   number of sectors. Part of the equipment is identical for both 3.5 GHz and 26
   GHz bands (i.e. the BU at both sides and the IF-Mux at the sector side) and
   the maximum number is defined according to these units. The RF heads, both at
   the terminal side and at the base station / sector side are frequency band
   depended. The sum of the planned production capacity of the terminal RF heads
   at 3.5 GHz plus the planned capacity of the terminal RF heads at 26 GHz is
   higher than the total number of terminals, in order to maintain frequency
   band capacity flexibility.

It should be noted that an increase in the production capacity involves mainly
duplication of the final testing stations, since Contractor's ramp-up plan is
based on working with 2 external sub-contractors for assembly of the boards and
boxes and final testing, and the capacity of these sub-contractors is
significantly higher than the above figures.

The Contractor and its subcontractor have agreed on manufacturing rights by
Contractor. The total production capacity is expected to grow substantially as a
result of manufacturing by the Contractor.

                                                                        1 of 2
<PAGE>
                               European Agreement
                                  Appendix 3 c

<TABLE>
<CAPTION>

2.       NET CAPACITY THAT CAN BE WARRANTED TO PURCHASER

---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
<S>                          <C>      <C>      <C>      <C>      <C>      <C>      <C>      <C>      <C>
Month                        12/99    01/00    02/00    03/00    04/00    05/00    06/00    07/00    08/00
----------------------------
Monthly warranted
capacity to Purchaser
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
# of Terminals                 100      100      120      140      150      200      250      300      300
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
3.5 GHz Terminals              100      100      120      120      120      150      150      150      150
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
26 GHz Terminals                10       30       40       60      100      150      200      300      300
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
# of Sectors                    30       40       50       80      100      150      170      200      200
(90DEG. or 60DEG. or 45DEG.)
--------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
3.5 GHz Sectors                 30       40       40       60       60       80       80      100      100
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
26 GHz Sectors                   5       10       20       40       60       90      120      150      150
---------------------------- -------- -------- -------- -------- -------- -------- -------- -------- --------
</TABLE>

Note # 2 of the first table is relevant also here: Per each month there is a
planned maximum number of terminals and maximum number of sectors. Part of
the equipment is practically identical for both 3.5 GHz and 26 GHz bands and
the maximum number is defined according to these units.

The sum of the planned production capacity of the terminal RF heads at 3.5
GHz plus the planned capacity of the terminal RF heads at 26 GHz is higher
than the total number of terminals, in order to maintain frequency band
capacity flexibility.

Following the above remarks, it should be emphasized that the allocated
production capacity to Purchaser may be further increased, while the response
time for such a change is 3-4 months.
Production capacity for the rest of 2000 is expected to further be increased
significantly.
<PAGE>

                               European Agreement
                                  Appendix 3 d
                        System Specification Commitments

1. ROADMAP VERSION 4.x

Purchaser will purchase only WALKair system components with DBA functionalities,
which will be ready for delivery in version 4.x.

Version 4.x is scheduled to be available for testing in 30, June 2000 (see
appendix 3b-Roadmap).

All previously delivered TS / BS components for data transmission based on FR
will be upgraded to version 4.x **************.

Service costs in relation to the upgrade to version 4.x have to be borne
**************.

A delay of delivery of the version 4.x as mentioned above is subject to a
penalty of 2% per month of the volume of the installed systems which has to be
upgraded. Maximum penalty is 10% of the volume of the installed systems which
has to be upgraded.

2. ROADMAP VERSION 6.x

Contractor commits to start immediately design review meetings in order to
define mutually the content and time schedule of release 6.x. Major features to
be achieved in the next WALKair Generation from Purchaser point of view are

a) High capacity per TS and
b) Low cost TS - IP based; QoS for VoIP.

Contractor underline there willingness to develop the WALKair product in these
direction.

3. TS CAPACITY EXTENSION FOR WHOLESALE E1 BUSINESS
3.1 CUSTOMIZED DEVELOPMENT

Purchaser will get a TS with a capacity of 4xE1 (high capacity TS / HC-TS) in a
timeframe which has to be agreed upon by all parties after mutually agreed
development specification. Contractor is offering the HC-TS based on the
existing TS product, where two TS-BU will be connected to one TS-RFU via an
IF-MUX. The additional path loss could be covered by higher gain antenna,
wherever it is necessary.

The customised development will be started

a) after mutual defined and committed system specification of the HC-TS and
b) Purchaser has given a firm order commitment of min. 200 of these HC-TS Less
   Than 180 Greater Than s in 12 month after the product will be available

3.2 UPGRADE PROCEDURE

Wherever more then 2xE1 capacity, up to max. 4xE1, per CPE will be needed,
Contractor will deliver the additional equipment (second TS-RFU + second TS-BU)
up to the moment the HC-TS will be available. The price for this expansion will
be calculated as follows:

list price (HC-TS) - list price (TS-BU + TS-RFU) = upgrade price

The cost for the capacity expansion will be borne by Purchaser.

<PAGE>

                               European Agreement
                                  Appendix 3 d
                        System Specification Commitments

If reasonable Contractor shall exchange the installed 2 x TS version for the
HC-TS. The related service cost of the replacement shall be borne by Contractor.
The replaced TS-BU equipment shall be checked and placed in the Purchaser
network in new CPE installations.

4. CAPACITY / RANGE CLAUSE

As described in the SFD Appendix 3a_1 item 54, Version 3 and 4 of WALKair 26 GHz
system allows for up to 6 carriers per BS RFU without performance degradation.
For larger capacity there is a trade off between range and the number of BS BU
Less Than 180 Greater Than s allocated to a single BS RFU. This dependency will
no longer apply from version 5.x of WALKair.

For the time being, Contractor as turn key provider will take care for a proper
allocation of TS Less Than 180 Greater Than s to the corresponding BS Less Than
180 Greater Than s in order to secure enough capacity and proper services for
all TS installations within the committed range during the planning process.

Should Purchaser see in a certain stage of the deployment a service affecting
constraint Contractor will replace the relevant BS RFU (with version 5 or
higher) at no additional cost in HW and service for Purchaser unless Contractor
can prove that this constraint is not caused by the above performance
degradation.

5. LINK AVAILABILITY

Contractor warrants a link availability due to radio propagation effects of
*** in all planned rain zones in Germany as defined by the ITU standards in
place to date for all radio links installed within the committed range of the
radio system given in SFD Appendix 3a. According to ITU-R recommendations the
availability shall be measured over a period of at least 12 month in accordance
to such standards.
If the warranted availability target is not met Contractor will provide free of
charge for FMCD the necessary technical measures and services as e.g. increased
antennas etc. in the respective links in order to improve the availability until
the agreed availability is reached. Prerequisite for this warrant is that the
Line of Sight condition is fulfilled. Contractor is not responsible for
obstacles which have been constructed or erected after deployment, of the base
station provided that Contractor has used its reasonable endeavours during the
planning phase.
If circumstances occur that result in a material change of climatic conditions
in Germany, thereby effecting the links that have been deployed or engineered by
Contractor for the Purchaser, then Force Majeure shall apply.
Outages due to equipment failure are not included in this statement but are
subject to the separate MTBF guarantee.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>
                               European Agreement
                                  Appendix 3 e
                                  MTBF Warranty

1. BASICS

The WALKair RFU as major transmitter/receiver part of the BS will warrant an
MTBF of 110.000 hours (12,7 years). This will allow the operator to serve his
customers with a high quality of reliability.

Failure BS-RFU will be recognized as a failed unit, only under the condition
that the unit was installed, commissioned and operated in conformity with its
user manual instructions, technical specifications, and environmental
conditions.

In order to prove this figure and to maintain a proper deployment in the initial
phase of the rollout Contractor would like to offers to Purchaser a two step
procedure as shown below (figures 2 and 3).

2. INITIAL DEPLOYMENT PERIOD OF 6 MONTH

During this period, where an exact statistical measurement of the MTBF could not
be fulfilled, the technicians of Contractor as turn-key providers will carry
spare RFU Less Than 180 Greater Than s in order to not affect the committed BZA
(ready for acceptance) dates. This will allow Purchaser to achieve the targets
of the roll-out plan.

However, the replacement related to service faults, will be according to the
mutual agreed MTTR procedures.

3. MATURE DEPLOYMENT PHASE
3.1. BASIC CONDITIONS

In this period, which will start 6 month after first PMP service, counting
minimum 500 sectors and will take min. 12 month for the calculation of the
committed MTBF as shown above, the MTBF will be measured as follows:

3.2.     MEASUREMENT FORMULA

MTBF     =        Operational Hours of RFU
                  -------------------------
                       Confirmed Faults

confirmed faults = hard faults (e.g. components of modules/units like I/C,
transistor, resistor, capacitor, crystals, diodes, fuse, inductor, transformer,
sub-units, soldering faults, open/short circuit, burnt)

Operational Hours = # of BS-RFU's x 24 h x 365 days

Example :

Sum of faults     =       500 RFU X 24 h X 365 d    = 40 RFU faults / annum
                          ----------------------
                          110.000 h

The counting of the faults will be based on a mutual agreed data base and
failure procedure between both parties.

     The mutually agreed measurement procedure will be verified by a third
     party. The expenses for such third party verification are not included in
     the prices and will be charged at actual outlay.

<PAGE>
                               European Agreement
                                  Appendix 3 e
                                  MTBF Warranty

3.3. TECHNICAL/COMMERCIAL PROCEDURE TO REACH GRANTED MTBF

If the deployed network of BS-RFU Less Than 180 Greater Than s will not reach
the committed MTBF as mentioned under section 1 and the faults will exceed the
value as calculated in 3.2. Contractor will deploy at no cost in the Purchaser's
PMP network a redundant BS-RFU in the sectors of the BS Less Than 180 Greater
Than s mentioned under 3.1. under the following conditions :

a) the base station was affected by a failure during the measurement period
b) there will be existing life traffic in the BS-sector

<PAGE>

<TABLE>
<CAPTION>

-----------------------------------------------------------------------------------------------------
<S>              <C>
SYSTEM           DOCUMENT TITLE

                 SYSTEM DESCRIPTIONS AND EXPLANATORY INFORMATION (FOR INFORMATION ONLY)

Sync.            WLL Synchronisation Guidelines

Walkair          System Description

Walkair          Version 3 Functional Description

Walknet          WALKnet Version 4 description

Walkair          WALKair Wideband / Broadband Point to MultiPoint Wireless System - Timing Mechanisms

Walkair          Bandwidth on Demand Description Concentrated Voice and Data Solution

Walkair          WALKair Broadband Point to MultiPoint Wireless System - Frame Relay Management

Walkair          V5 Solution Specification

ONU              Information about FastLink UNU 30 / ONU 20 for Firstmark network

ONU              Montage ONU 30 FTTB

CMXII            Information Cross Connect Multiplexer II A50010-A3-F102-2-7618

ACI              Access Integrator V5.1 Issue: 5.1.e.1 Product Description

DCN              Information on DCN concept with CMX II / ONU 30

<S>                 <C>
SYSTEM              FILE NAME

Sync.               02_WLL-sync.doc

Walkair             03_System Description.doc

Walkair             04_Version 3 Functional Description.doc

Walknet             05_WALKnet Version 4 description.doc

Walkair             06_Timing_and_Clock_Sources_in_WALKair.doc

Walkair             07_BOD S

Walkair             08_Frame Relay Management.doc

Walkair             09_V5spec.doc

ONU                 10_FM_Overview_FastLink_ONU_30_20.doc

ONU                 11_A00358439.pdf

CMXII               12_CMXII_en.pdf

ACI                 13_prdai51e.doc

DCN                 14_FM_Overview_Fastlink_DCN_000211.doc
-----------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

WLL Synchronisation Guidelines      WLL Synchronisation Guidelines / 1.0APPROVED
--------------------------------------------------------------------------------

                          WLL SYNCHRONISATION GUIDELINES

                          ------------------------------------------------------

ID                        WLL SYNCHRONISATION GUIDELINES
REVISION                  1.0 APPROVED
DATE                      17/03/2000
CONFIDENCE                FMCE CONFIDENTIAL

                          ------------------------------------------------------

                          DEPT.    PERSON               DATE     SIGNATURE

AUTHORS                   FMCE     Olaf Struck

APPROVED                  FMCE     Jorg Gimmler

REVIEW                    FMCD     Detlef Obiray

                          FMCD     Michael Strunz-Kroll

                          FMCE     Lorcan Burke

FILENAME                  Wll-synch.doc

                          ------------------------------------------------------

DESCRIPTION

                          ------------------------------------------------------

CHANGE LOG                0.1Draft   17/02/2000 / Olaf Struck
                               Initial Version
                          0.2Draft 10/03/2000 / Olaf Struck
                               Review comments
                          0.3Draft 16/03/2000 / Olaf Struck
                               ATM Switch or SDH Cross connects at the
                               concentration sites included
                          1.0Approved 17/03/2000 / Olaf Struck

                          ------------------------------------------------------

                                                                         1 of 22

<PAGE>

TABLE OF CONTENTS

--------------------------------------------------------------------------------

1     Introduction........................................................3
2     General Aspects.....................................................3
3     WalkAir Synchronisation Capabilities................................4
4     Network Architecture................................................4
   4.1    Via Local Access Provider.......................................4
      4.1.1  Via Clock Transparent Leased Lines...........................4
      4.1.2  Re-timed E1..................................................5
      4.1.3  T4 via Local Access Provider.................................6

   4.2    Via Radio Link..................................................6
   4.3    Co-location.....................................................7
   4.4    GPS Synchronisation.............................................8
5     Equipment Configurations............................................9
   5.1    WLL Sites.......................................................9

      5.1.1  Connected via Leased Lines...................................9
        5.1.1.1   Clock Transparent Leased Lines......................9
        5.1.1.2   T4.................................................10
        5.1.1.3   E1 Re-timing.......................................11

      5.1.2  Connected via SDH Radio Links...............................12
      5.1.3  Connected via PDH Radio Links...............................12
      5.1.4  Co-located to LambdaNet PoP.................................13

   5.2    Concentration Sites............................................13
      5.2.1  Connected to Core Network via SDH Radio.....................13
      5.2.2  Connected to the Core Network via Leased Lines..............14

        5.2.2.1   Connected to remote WLL sites via SDH radio........14
          5.2.2.1.1 Timing provided by LAP...........................14
          5.2.2.1.2 GPS System.......................................16

        5.2.2.2   Connected to remote WLL sites via PDH radio........17
        5.2.2.3   Entirely connected via Leased Lines................17

   5.3    TS and CPE.....................................................17
6     Conclusion.........................................................18

   6.1    Concentration Sites............................................18
      6.1.1  Connected to Core Network via SDH Radio.....................18
      6.1.2  Connected to the Core Network via Leased Lines..............18

        6.1.2.1   Connected to remote WLL sites via SDH radio........18
        6.1.2.2   Entirely connected via Leased Lines................18

      6.1.3  Co-located to LambdaNet PoP.................................18
   6.2    WLL sites......................................................19

      6.2.1  Connected via SDH radio.....................................19
      6.2.2  Connected via Leased Lines..................................19

7     Examples...........................................................20
   7.1    LambdaNet Clock carried over SDH radio.........................20
   7.2    GPS at Concentration Points....................................20
8     Abbreviations......................................................21

                                                                         2 of 22

<PAGE>

WLL Synchronisation Guidelines      WLL Synchronisation Guidelines / 1.0APPROVED
--------------------------------------------------------------------------------

1    INTRODUCTION

This document is intended to give guidelines for synchronising the wireless
local loop (WLL) equipment and the subsequent customer premises equipment (CPE).
It will give recommendations to synchronise the equipment for all possible
cases. This concept also applies to other terminating equipment, e. g. 64k Cross
Connects, Voice Switches.

This document is not intended to replace a detailed synchronisation planning
including documentation also considering the core network.

2    GENERAL ASPECTS

To avoid excessive frame/bit slips all equipment which is terminating the E1
frame has to be synchronised to a clock which is G.811 traceable. Real time
applications like voice are most sensitive to slips. Synchronising all
terminating equipment to a PRC (also applicable to several different PRCs)
ensures that the slip rate is kept at a minimum.

A clock transparent PDH/E1 signal traversing SDH network(s) will experience
excessive Jitter and Wander. This is due to the byte stuffing (pointer
adjustments) which may occur in SDH networks. This byte stuffing will cause
excessive wander at the de-synchroniser output which makes the PDH signal not
suitable for synchronising subsequent nodes deploying narrow bandwidth PLLs
(some mHz, like voice switches and SSUs). Access nodes deploying greater
bandwidth PLLs (ONUs, CMX, BS-BUs, ...) may be synchronised to clock transparent
E1 leased lines. Synchronising equipment to clock transparent E1 leased lines
assumes that the terminating equipment at the opposite end is synchronised to a
PRC (not from the same line).

To use E1 signals traversed an SDH network for all synchronisation purposes
(incl. voice switches) the E1 signal has to be re-timed with the SDH network
clock at PDH output of the last SDH node or an external re-timing device (e. g.
NE2SYNC). Re-timing won't be possible on unframed E1 signals. In case of
re-timing the network operator who provides its network clock (e. g. LAP via
re-timing or T4) has to guarantee the clock quality (Jitter, Wander) acc. to
ITU-T G.813 (option 1, locked mode, PRC traceable). The synchronisation
distribution inside the networks has to meet the requirements according to ITU-T
G.803.

Synchronous E1 signals traversing pure PDH network(s) are suitable to
synchronise the subsequent equipment. Due to the bit stuffing used in PDH
network only minor phase hits will occur. Care has to be taken when
synchronising equipment off clock transparent E1 signals. In this case one end
must act as the clock master the other end may be the clock slave synchronised
from the line. In case the equipment at both end is set to "slave" the "timing
loop" will cause loss of traffic. The same applies to clock transparent E1s
traversing SDH networks.

Care has to be taken on synchronising the WLL equipment to clock transparent E1s
connected to an ATM switch / network. An ATM network is only able to provide
clock transparent E1 services suitable to synchronise WLL equipment when the
SRTS mode of AAL1 (CBR) is used. The SRTS mode ensures that the adaption and
de-adaption function is in synch.

                                                                         3 of 22

<PAGE>

WLL Synchronisation Guidelines      WLL Synchronisation Guidelines / 1.0APPROVED
--------------------------------------------------------------------------------

3    WALKAIR SYNCHRONISATION CAPABILITIES

Each BS-BU provides one external 2MHz synchronisation input (T3) and one
external 2MHz synchronisation output (T4). These ports are compliant to
G.703/10. The T3 input has an high impedance (12kOhm||50pF) which allows to
connect about four inputs (more to be confirmed) to one output by applying
external 120 Ohm terminators.

It has been proven by Siemens that the WalkAir system is able to derive timing
from clock transparent E1s traversing SDH networks without any malfunction.

Each BS-BU can either be synchronised to one of the three E1 ports or from T3
input. In case of failure of all sources the BS-BU enters free running mode. In
automatic mode each BS-BU selects the highest priority from one of the three E1
sources. Timing from T3 is possible in manual mode only. In manual mode each
BS-BU is fixed to one source, if this source fails the BS-BU enters free
running. The T4 output can be configured on/off, automatic squelching is not
implemented.

Since T3 timing is possible in manual mode only, a proper automatic hierarchy
switching is possible via E1 signals only.

4    NETWORK ARCHITECTURE

There are several different options to connect the WLL stations to the core
network.

- Directly connected to LambdaNet Backbone or co-located to a feeder network
site
- Connected via local access provider network (leased lines)
- Connected via SDH/PDH radio link

Some concentration points also deploying BS will be used to concentrate traffic
from serveral BS and to carry the traffic to the core network.

The following describes the principles of the different synchronisation options.
Further details of the WLL sites considering all installed equipment are
described in chapter 5.

4.1  VIA LOCAL ACCESS PROVIDER

In case the WLL equipment is connected to the core network via an LAP there are
three options to consider. All options described below have to be negotiated
with each individual LAP. Clock transparent G.703 Leased Lines are the default
not causing any additional effort/cost.

4.1.1 VIA CLOCK TRANSPARENT LEASED LINES

If less than sixteen E1s (depending on the LAP and price of E1 / STM-1) are
required the LAP will usually provide separate E1s.

E1 Leased Lines used to synchronise the WLL equipment have to be clock
transparent end to end. The terminating equipment at the remote end has to
synchronised to a PRC traceable clock (not the same line). E1s terminated at
voice switches are most suitable for this purpose.

If the E1 is traversing ATM networks these network have to work in SRTS mode to
ensure clock transparent transmission. If the network is not in SRTS mode the
signal will experience wander of several hundred UIs which is not suitable for
synchronisation purposes.

                                                                         4 of 22

<PAGE>

WLL Synchronisation Guidelines      WLL Synchronisation Guidelines / 1.0APPROVED
--------------------------------------------------------------------------------

Figure 1: Clock transparent Leased Line

[html]

4.1.2 RE-TIMED E1

If less than sixteen E1s (depending on the LAP and price of E1 / STM-1) are
required the LAP will usually provide separate E1s. Compared to the transparent
Leased Lines the re-timing provides an higher accuracy clock signal.

In this case the LAP provides its network clock via E1 re-timing to clock at
least one CMX/BS-BU directly. Other BS-BUs have to be timed via T4 of the
CMXII/BS-BU. The remaining E1s do not need to be re-timed. An SSU may be used to
filter the clock (via CMXII) and to provide a better holdover performance.

Due to equipment restrictions some LAPs might not be able to offer re-timing.

Figure 2: LAP re-timing
[HTML]

                                                                         5 of 22

<PAGE>

WLL Synchronisation Guidelines      WLL Synchronisation Guidelines / 1.0APPROVED
--------------------------------------------------------------------------------

4.1.3 T4 VIA LOCAL ACCESS PROVIDER

If more than sixteen E1s (depending on the LAP and price of E1 / STM-1) are
required the LAP will provide an STM-1 terminal mux .

The LAP provides its network clock via STM-1 to synchronise the STM-1 mux. The
STM-1 mux will extract the clock and output the 2 MHz clock at the T4 port. This
T4 clock signal will be supplied to the T3 input at the CMXII/BS-BUs (bus
structure). In case other SDH/ATM nodes have to be synchronised an SSU may be
used to filter the clock and to provide a better holdover performance.

Figure 3: LAP STM-1

[HTML]

In case the STM-1 terminal mux is provided by FMC this mux has to derive timing
from the STM-1 signal provided by LAP.

4.2  VIA RADIO LINK

In case the WLL equipment is connected to the core network via SDH radio links
the clock from the core network can be supplied to the WLL equipment via the
radio links using SDH muxes which may be part of the radio equipment.

In case of SDH radio the SDH Mux which may be part of the radio equipment must
be synchronised to a PRC (traceable) clock at one end (usually the end which is
directing to the core network). The clock signal is carried on the STM-N signal
and is supplied to the CMXII/BS-BUs and other SDH/ATM nodes via the T4 output of
the SDH Mux. The SDH-Mux derives timing from the air interface.

Assuming the E1s carried via the SDH radio link are synchronised to a PRC (via
voice switch) at the remote end of the radio link, the E1s can also directly be
used to synchronise all subsequent equipment. This is due to the fact that it is
very unlikely to experience pointer justifications in a point to point link. The
E1s are exposed to mapping Jitter only. Carrying E1s via SDH radio links like
described above does not affect the suitability of these E1s for timing
purposes.

In case of PDH radio (16x2 Mbit/s) the clock is carried on the E1 signals
itself. The E1s will be carried transparently like on pure PDH networks and
therefore are suitable to derive timing. Carrying via PDH radio link does not
affect the suitability of these E1s for timing purposes. The E3 layer itself is
plesiochronous. The PDH radio equipment does not require a synchronisation
signal.

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Figure 4: Via PDH/SDH Radio

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4.3  CO-LOCATION

In case the WLL site is co-located to the LambdaNet or Core Network PoP the
scenario is like described in chapter 4.1.3. Depending on the location the 2 MHz
may be directly supplied by an GPS system.

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4.4  GPS SYNCHRONISATION

A GPS system will be required in concentration sites where no other clock is
available to synchronise the SDH /ATM nodes used for concentration the traffic
from other BSs. The synchronisation via GPS systems can be used in combination
with all options mentioned before (Leased Lines, Radio Links, ...).

All the FMC equipment (incl. CMXII) will be synchronised to the GPS clock.

Figure 5: GPS Synchronisation

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5        EQUIPMENT CONFIGURATIONS

5.1      WLL SITES

This chapter applies to WLL sites not acting as concentration points where no
other SDH/ATM equipment has to be supplied with clock.

At base stations/TS where ONUs are employed a CMX II is required for
consolidation of the 64k SISA-DCN channels. This CMX II can also be used to
distribute the clock to the connected BS-BUs . Since not all BS-BUs will have
ONUs at the TS sites the remaining BS-BUs have to be clocked via T4 (bus
structure).

5.1.1 CONNECTED VIA LEASED LINES

This chapter is applicable to WLL sites connected to the core/feeder network via
Leased Lines (E1 or STM-N) provided by a local access provider (LAP).

5.1.1.1 CLOCK TRANSPARENT LEASED LINES

In case no SDH/ATM equipment has to be synchronised at this site, the
preferred solution is to synchronise the CMXII to transparent E1s and to
distribute the clock to the BS-BUs via CMXII. Most suitable for
synchronisation are transparent E1s terminating at a voice switch at the
other end. If the option via CMXII is not possible each individual BS-BU has
to be supplied with at least one suitable E1.

For this purpose the CMXII has to be synchronised to the clock transparent E1
signals. Hence all outgoing E1s of the CMXII will be synchronised to this E1.
The BS-BUs connected to the CMXII must be synchronised to these E1s. The
remaining BS-BUs must be synchronised to the T4 output of the CMXII. A second
transparent E1 should be used to provide a standby synchronisation source to the
CMXII. If the number of T4 outputs at the CMXII is not sufficient each
individual BS-BU has to be synchronised to a clock transparent E1 leased line.

In case of failure of the E1(s) used for synch the CMX II enters free running.
Since the T4 is squelched the subsequent equipment will be free running also.
Figure 5 only shows the E1 signals used for SISA-DCN, the remaining E1s used for
traffic are not shown.

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Figure 6: Configuration for clock transparent leased lines

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5.1.1.2 T4

Compared to clock transparent E1 leased lines the T4 provides an higher accuracy
clock but causes higher cost/effort compared to clock transparent E1s.

The CMX II has to be synchronised to the 2MHz signal provided by the LAP. Hence
all outgoing E1s of the CMXII will be synchronised to this 2 MHz signal. The
BS-BUs connected to the CMXII must be synchronised to these E1s. The remaining
BS-BUs must be synchronised to the T4 output of the CMXII.

In case of failure of the 2 MHz signal(s) supplied by the LAP, the CMX II enters
free running. Since the T4 is squelched the subsequent equipment will be free
running also. Figure 6 only shows the E1 signals used for SISA-DCN, the E1s used
for traffic are not shown.

The same scenario applies in case the WLL BS-BUs are co-located to the
concentration sites or LambdaNet PoP sites. In both cases the clock might be
supplied by an GPS system. This scenario is also applicable to WLL sites
connected via SDH radio to the core network. In this case the T4 of the SDH
radio mux has to be used. In case another SDH / ATM equipment has to be supplied
with clock of a LAP an SSU shall be deployed. For details see 5.2.2.1.1.

In case the number of clock outputs is not sufficient due to the fanout
limitations an active clock distributor (without holdover capability) can be
deployed. The preferred system is the Siemens VTM-A1.

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Figure 7: Configuration for T4 timing

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5.1.1.3  E1 RE-TIMING

In case the LAP can not provide the network clock via T4 the clock should be
provided via re-timing. The clock quality of the T4 signal compared to the
re-timing option is identical.

In case of re-timing the CMXII has to be synchronised to the re-timed E1 signal
provided by the LAP. Hence all outgoing E1s of the CMXII will be synchronised to
the re-timed E1. The BS-BUs connected to the CMXII must be synchronised to these
E1s. The remaining BS-BUs must be synchronised to the T4 output of the CMXII. A
second re-timed E1 should be used to provide a standby synchronisation source to
the CMXII.

In case of failure of the re-timed E1(s) the CMX II enters free running mode.
Since the T4 is squelched the subsequent equipment will be free running also.
Figure 5 only shows the E1 signals used for SISA-DCN, the remaining E1s used for
traffic are not shown.

Care must be taken since some re-timing equipment overrides the traffic signal
with AIS upon failure of the synchronisation source (holdover).

In case another SDH/ATM node has to be supplied with a clock of a LAP an SSU
shall be deployed. For details see 5.2.2.1.1.

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Figure 8: Configuration for E1 re-timing

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5.1.2 CONNECTED VIA SDH RADIO LINKS

In case the WLL site is connected to the core/feeder network via SDH radio the
timing of the STM-N signal carried on the SDH radio link may be used to
synchronise the WLL equipment.

For this purpose the SDH mux which may be part of the radio equipment at the WLL
site has to output the clock signal at the T4 port. This signal has to be
supplied to the remaining equipment like described in chapter 5.1.1.3.

5.1.3 CONNECTED VIA PDH RADIO LINKS

In case the WLL site is connected to the core via PDH radio the E1s carried on
the radio link are handled like clock transparent leased lines. The timing
information is carried on the E1 signals itself. The E1s will be carried
transparently like on pure PDH networks and therefore are suitable to derive
timing. Carrying via PDH radio link does not affect the suitability of these E1s
for timing purposes. The E3 layer itself is plesiochronous. PDH radio equipment
does not require a synchronisation signal.

The synchronisation of the WLL equipment shall be done like described in chapter
5.1.1.1.

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5.1.4 CO-LOCATED TO LAMBDANET POP

Where the WLL equipment is co-located to a LambdaNet PoP the clock of the
transport network may be used via 2 MHz signals like described in chapter
5.1.1.3. The 2 MHz Clock (T4) should be extracted of the SDH NE supplying the
E1s to the BS-BUs/ CMX. Depending on the PoP the Clock may also be delivered by
an GPS system directly.

5.2  CONCENTRATION SITES

This chapter applies to concentration sites where the traffic of several BS is
concentrated and also WLL equipment might be deployed. Apart from the radio and
WLL equipment an ATM Switch or SDH Cross Connect will be used to concentrate the
traffic. The ATM nodes and/or the SDH muxes have to be supplied with an PRC
(traceable) clock.

In case the SDH XC interconnects to all SDH radio links (connecting remote WLL
sites) on STM-N level the SDH radio equipment does not comprise an SDH mux. An
ATM switch will interconnect to the SDH radio links on E1 level. Hence the radio
links have to comprise an SDH mux.

5.2.1 CONNECTED TO CORE NETWORK VIA SDH RADIO

In this case the clock of the LambdaNEt transport network shall be carried to
the concentration site via the SDH radio. This clock shall be supplied to the
SDH mux (radio) at the core PoP via 2 MHz signal or directly via an STM-N
signal. At the concentration sites the clock shall be distributed to the
remaining SDH/ATM nodes. Since the clock used to synchronise the SDH/ATM
equipment is under control of FMC, no SSU is required.

Figure 9: Supplying Core Network clock to the concentration / WLL sites

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The SDH radio equipment interconnects to the SDH cross connect on STM-1 level.
For this purpose the SDH radio equipment does not comprise an SDH mux. The SDH
XC derives timing from the STM-N coming from the core network. Hence all
outgoing STM signals are synchronised to the core network clock.

In case the nodes interconnect at the concentration site on E1 Level (ATM node
used for concentration) the radio links connecting the remote WLL sites will
include an SDH mux. The ATM node will extract timing from the STM-N signal from
the core network and will supply the to the corresponding SDH muxes (radio) via
2 MHz signals. Since the number of T4 outputs at the ATM

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node might be not sufficient an active clock distributor has to used to extend
the number of ports. The preferred system is the Siemens VTM-A1.

The local WLL equipment may be provided with a 2MHz clock of the SDH/ATM XC. The
preferred option is to synchronise the WLL equipment on clock transparent E1s.

5.2.2 CONNECTED TO THE CORE NETWORK VIA LEASED LINES

In case the concentration site is connected to the core network via leased lines
the clock has to be provided by the LAP via STM-N signal. The required traffic
capacity will usually be at least one STM-1.

The clock provided by the LAP/GPS has to synchronise the local SDH/ATM nodes.

In case no other SDH/ATM equipment has to be supplied with clock at the
concentration site no filtering of LAPs clock is required.

5.2.2.1 CONNECTED TO REMOTE WLL SITES VIA SDH RADIO

Not all remote WLL sites might be connected via SDH radio, some will be
connected via PDH radio or leased lines.

5.2.2.1.1  Timing provided by LAP

In this cas the clock has to be extracted from the SDH signal (leased line)
connecting to the core network and shall be filtered by an SSU. The SSU supplies
the SDH/ATM nodes with synchronisation via 2 MHz signals.

Since SDH radio equipment used to connect the WLL sites to the concentration
sites and the ATM/SDH cross connects require an PRC (traceable) clock source, an
SSU has to be deployed which filters the LAPs clock and provides a reasonable
holdover performance. In this case the clock can be distributed to the remote
WLL sites via SDH radio. This is applicable to re-timing and T4, both provided
by LAP.

The SDH/ATM node extracts the clock from the STM-N signal and outputs the clock
at the T4 interface. The T4 signal has to be connected to the SSU input. The SSU
has to feed all the subsequent SDH/ATM equipment. In case of failure the T4 has
to be squelched since the SSU provides the better holdover performance.

The used SSU should include an ovenized cristal quartz oscillator (OXCO).
Internal redundancy is not required. Dual power feed shall be used. The
preferred system is the XYZ.

The SSU has to be managed by the WLL equipment (incl. CMXII) via ext. Alarm
inputs.

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Figure 10: LAP timing deploying an SSU

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Only the signals used for synchronisation purposes are shown above.

In case an ATM switch is deployed the systems will interconnect on E1 level. The
clock of the SSU has to be supplied to the SDH muxes (radio links) via 2 MHz
signals.

If an SDH Cross Connect is used the connections between the SDH muxes of the
radio links and the SDH cross connect will be on STM-1 level and no further
SDH/ATM equipment has to be supplied with clock. Hence no SSU is required.

The local WLL equipment may be provided with a 2MHz clock of the SDH/ATM XC. The
preferred option is to synchronise the WLL equipment on clock transparent E1s.

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5.2.2.1.2 GPS System

In case the LAP is not able to provide a clock signal an GPS system has to be
deployed. A GPS system has the advantage of being independent of the LAP.
Depending on the extra cost for an GPS system compared to an SSU an GPS system
might be deployed even if the LAP could provide a clock signal.

The GPS systems used have to have an SSU to provide a suitable holdover
performance. In locked mode the system has to meet G.811 requirements. To limit
the additional cost for GPS equipment it will be sufficient when the GPS system
includes an ovenized cristal quartz oscillator (OXCO). Internal redundancy is
not required. Dual power feed shall be used. The GPS system has to provide 2MHz
signal(s) acc. to G.703/10. The system shall be able to supply at least ten 2MHz
outputs. To provide a minimum redundancy the BS-BUs should not be supplied by a
single GPS output. The maximum cable length between antenna and GPS system has
to meet the requirements of all WLL sites. 300 m will be sufficient. The
preferred system is the XYZ.

In case of failure of the GPS antenna the 2 MHz outputs must not be squelched
because the GPS system provides a much higher holdover performance than the
individual nodes.

The GPS system has to be managed by the WLL equipment (incl. CMXII) via ext.
Alarm inputs.

Figure 11: GPS configuration

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Only the signals used for synchronisation purposes are shown above.

If an SDH Cross Connect is used the connections between the SDH radio links and
the SDH cross connect will be on STM-1 level. In this case only the SDH XC has
to be supplied with clock

In case an ATM switch is deployed the systems will interconnect on E1 level. In
this case the clock of the GPS has to be supplied to the ATM and SDH muxes
(radio links).

5.2.2.2 CONNECTED TO REMOTE WLL SITES VIA PDH RADIO

The E1s carried on the PDH radio have to be handled like clock transparent E1s.
The PDH radio equipment does not require a synchronisation signal. Concentration
sites connected to the core network via leased lines and deploying PDH radio to
connect remote WLL sites are handled like described in chapter 5.2.2.1. Not all
remote WLL sites might be connected via PDH radio some of them might also be
connected via leased lines. 5.2.2.3 ENTIRELY CONNECTED VIA LEASED LINES

In this case the clock information carried on the STM-N (connecting to the
core network) does not have to be supplied to any other SDH/ATM node. Since
the STM-N signal supplied by the LAP always contains timing information this
signal has to be used to synchronise the ATM/SDH XC without using an SSU/GPS.
The local WLL equipment has to be synchronised to clock transparent leased
lines. If this is not possible the T4 clock of the ATM/SDH node can be used.

5.3  TS AND CPE

The following configuration of the terminal station and customer premises
equipment (CPE) is independent of the different scenarios described before.

The TS derives synchronisation from the air interface. The CPE (ONU, PABX,...)
shall derive synchronisation from the E1 supplied via TS.

Figure 12: TS and CPE configuration

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6    CONCLUSION

The following gives the recommendations to proceed with the synchronisation for
the different options used to connect the WLL to the feeder/core network. The
sequence of choices in each subsection reflects the hierarchy of choices (first
ones to be preferred).

It has to be distinguished between WLL sites acting as concentration sites and
"standalone" WLL sites. WLL sites connected via PDH radio links are handled like
connected via clock transparent leased lines.

6.1  CONCENTRATION SITES

6.1.1 CONNECTED TO CORE NETWORK VIA SDH RADIO

-    The Clock of the LambdaNet Transmission Network has to be carried to the
     concentration sites across the SDH radio link. This clock shall be used to
     synchronise the SDH/ATM nodes and shall be distributed to all remote WLL
     sites connected via SDH radio. Since this clock is under control of FMC no
     further SSU is required. For details see chapter 4.2, 5.2.1.

6.1.2 CONNECTED TO THE CORE NETWORK VIA LEASED LINES

6.1.2.1 CONNECTED TO REMOTE WLL SITES VIA SDH RADIO

-    The LAP should provide clock via T4 or re-timing (preferred T4). In case
     other SDH/ATM nodes have to be supplied with clock, this clock shall be
     filtered deploying an SSU. The clock of the SSU shall also be distributed
     to the remote WLL sites connected via SDH radio and has to be supplied to
     the local SDH/ATM nodes. Depending on the cost for the SSU the GPS solution
     may be preferred. For details see chapter 4.2, 4.1.3, 5.2.2.

-    If the LAP can not provide the clock an GPS system has to be used to supply
     the clock signal to the SDH/ATM nodes. This clock shall be distributed to
     all remote WLL sites connected via SDH radio. For details see chapter 4.4,
     5.2.2.1.

6.1.2.2 ENTIRELY CONNECTED VIA LEASED LINES

-    In this case only the ATM/SDH nodes used for traffic concentration have to
     be supplied with clock. The local WLL equipment may be provided with a 2MHz
     clock of the SDH/ATM XC. The preferred option is to synchronise the WLL
     equipment on clock transparent E1s. For details see chapter 5.2.2.3.

6.1.3    CO-LOCATED TO LAMBDANET POP

-    The clock of the LambdaNet transport network shall be used (via T4 or
     STM-N) and distributed to remote WLL sites connected via SDH radio. For
     details see chapter 4.3, 5.2.2.

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6.2  WLL SITES

This chapter applies to WLL sites not acting as concentration points. WLL sites
connceted via PDH radio are handled like connected via E1 leased lines.

6.2.1 CONNECTED VIA SDH RADIO

-    Use a clock transparent (end to end) E1 leased line terminating at voice
     switches to derive timing for CMX/BS-BU. For details see chapter 4.1.1,
     5.1.1.1.
-    The SDH clock of the SDH radio mux shall be used to synchronise the WLL
     equipment at this site. For details see chapter 4.2, 5.1.1.2.

6.2.2 CONNECTED VIA LEASED LINES

-    Use a clock transparent (end to end) E1 leased line terminating at voice
     switches to derive timing for the WLL equipment. For details see chapter
     4.1.1, 5.1.1.1.
-    Use re-timing or T4 provided by LAP (T4 preferred). In case of PDH radio
     re-timing and T4 might not be possible. In this case re-timing of the E1
     has to take place just before the E1 enters the radio link. If re-timing is
     done before the E1 can be handled like a clock transparent E1. For details
     see 4.1.2, 4.1.3, 5.1.1.2, 5.1.1.3.
-    BS-BU can temporarily be free running for pure data services.
-    Deploy a GPS system to supply the clock. Due to the cost for the additional
     equipment this should be avoided. For details see chapter 4.4, 5.2.2.1.2.

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7    EXAMPLES

7.1  LAMBDANET CLOCK CARRIED OVER SDH RADIO

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The LambdaNet clock is carried transparently to the WLL sites.

7.2  GPS AT CONCENTRATION POINTS

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The GPS clock is carried from the concentration site to the remote WLL site
transparently using SDH radio links.

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8        ABBREVIATIONS

      AAL1             ATM Adaption Layer 1 (constant bit rate)
      ADM              Add Drop Multiplexer
      AIS              Alarm Indication Signal (all ones)
      BS               Base Station
      BS-BU            Base Station Base Unit
      CBR              Constant Bit Rate
      CPE              Customer Premises Equipment
      FMC              Firstmark Communications
      GPS              Global Positioning System
      ITU-T            International Telecommunications Union -
                       Telecommunications Standardisation Sector
      NE               Network Element
      PDH              Plesiochronous Digital Hierarchy
      PoP              Point of Presence
      PRC              Primary Reference Clock
      TS               Terminal Station
      SDH              Synchronous Digital Hierarchy
      SEC              Synchronous Equipment Clock
      SSM              Synchronisation Status Message
      SRTS             Synchronous Residual Time Stamp
      SSU              Synchronisation Supply Unit
      STM              Synchronous Transport Module
      T3               Timing-Signal  2 MHz Synch-input
      T4               Timing-Signal 2 MHz Synch-output
      UI               Unit Interval, 488 ns in case of E1
      WLL              Wireless Local Loop
      XC               Cross Connect

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FLOWARE WIRELESS SYSTEMS LTD.                               COMPANY CONFIDENTIAL
WALKair-TM- SYSTEM DESCRIPTION
--------------------------------------------------------------------------------

   [LOGO]

                                   WALKair-TM-

            WIDEBAND / BROADBAND POINT TO MULTIPOINT WIRELESS SYSTEM

                               SYSTEM DESCRIPTION

         Revision 3.0
         January 2000

--------------------------------------------------------------------------------
-C- FLOWARE Wireless Systems Ltd.    All rights reserved.

The material contained herein is proprietary, privileged, and confidential. No
disclosure thereof shall be made to third parties without the express written
permission of FLOWARE Wireless Systems Ltd. FLOWARE Wireless Systems Ltd.
reserves the right to alter the equipment specifications and descriptions in
this publication without prior notice. No part of this publication shall be
deemed to be part of any contract or warranty unless specifically incorporated
by reference into such contract or warranty.
--------------------------------------------------------------------------------

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FLOWARE WIRELESS SYSTEMS LTD.                               COMPANY CONFIDENTIAL
WALKair-TM- SYSTEM DESCRIPTION
--------------------------------------------------------------------------------

                                TABLE OF CONTENTS

<TABLE>
<S>   <C>                                                                  <C>
1.    INTRODUCTION.........................................................1

2.    WALKAIR-TM- SYSTEM AND BUILDING BLOCKS...............................2
      2.1   BASE STATION (BS)..............................................3
        2.1.1   BASIC UNIT (BU)............................................3
        2.1.2   IF MUX.....................................................4
        2.1.3   RFU........................................................4
        2.1.4   ANTENNA....................................................4
        2.1.5   BS POWERING................................................4
      2.2   TERMINAL STATION (TS)..........................................5
      2.3   MANAGEMENT SYSTEM..............................................5
        2.3.1   MANAGEMENT COMMUNICATION...................................6

3.    SYSTEM FEATURES......................................................7

4.    WALKAIR-TM-  NETWORK APPLICATIONS....................................9
      4.1   THE BUSINESS CUSTOMER APPLICATION: HIGH GROWTH POTENTIAL
      SOLUTION OPTIMIZED FOR SME ACCESS....................................9
      4.2   THE RADIO TO THE BUILDING APPLICATION: BEST COST ACHIEVEMENT...10
      4.3   THE FEEDING APPLICATION:  EFFICIENT BACKHAUL TRANSMISSION......11

5.    TECHNICAL SPECIFICATIONS.............................................14
      5.1   GENERAL SPECIFICATIONS.........................................14
      5.2   TERMINAL STATION SPECIFICATIONS................................14
        5.2.1   RF @ 3.5 GHZ...............................................14
        5.2.2   RF @ 10.5 GHZ..............................................15
        5.2.3   RF @ 26 GHZ................................................15
        5.2.4   INTERFACES.................................................16
        5.2.5   SIZE AND STRUCTURE.........................................17
        5.2.6   POWER......................................................17
        5.2.7   ENVIRONMENTAL..............................................17
      5.3   BASE STATION SPECIFICATION.....................................18
        5.3.1   RF @ 3.5GHZ................................................18
        5.3.2   RF @ 10.5GHZ...............................................18
        5.3.3   RF @ 26GHZ.................................................19
        5.3.4   INTERFACES.................................................19
        5.3.5   SIZE AND STRUCTURE.........................................20
        5.3.6   POWER......................................................20
        5.3.7   ENVIRONMENTAL..............................................20

6.    THE WALKAIR ADVANTAGE................................................22

</TABLE>

                                TABLE OF FIGURES

<TABLE>
<S>                                                                        <C>
Figure 1. Typical  WALKair Application.....................................1

Figure 2: WALKair's System Architecture....................................2

Figure 3. Base Station General View........................................3

Figure 4. Terminal Station Overview........................................5

</TABLE>

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FLOWARE SYSTEM SOLUTIONS LTD.                              COMPANY CONFIDENTIAL
WALKair-TM- SYSTEM DESCRIPTION
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<TABLE>
<S>                                                                        <C>
Figure 5. WALKair serving the business customer PMP application............9

Figure 6. WALKair serving the RTTB/RTTO application........................11

Figure 7. WALKair serving as backhaul feeding of WLL/mobile base stations..12

</TABLE>

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FLOWARE WIRELESS SYSTEMS LTD.                               COMPANY CONFIDENTIAL
WALKair-TM- SYSTEM DESCRIPTION
--------------------------------------------------------------------------------
1.       INTRODUCTION

              WALKair-TM- is a state of the art Point-to-Multipoint (PMP)
              wireless system, designed to provide an optimal solution for a
              variety of wideband and broadband applications. Floware Wireless
              Systems Ltd., has developed WALKair to provide the new telecom
              operators with the best tools to successfully compete against
              incumbent operators.

              The system's innovative technology features fiber-optic quality
              telephony and data services for high-speed data and Internet
              applications . Small and Medium business (SME) as well as office
              and residential buildings (RTTO/RTTB) can benefit from high
              quality voice, high speed Internet access and other data services.

              WALKair also serves as an efficient feeder to wireless
              micro-cells, providing backhaul connectivity for base stations of
              mobile and fixed narrowband wireless systems. With our system, new
              operators can enjoy a successful, quick and cost-effective
              penetration process into the telecom market.

                                [GRAPHIC OMITTED]

                     FIGURE 1. TYPICAL WALKair APPLICATION

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WALKair-TM- SYSTEM DESCRIPTION
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2.       WALKair-TM- SYSTEM AND BUILDING BLOCKS

              The WALKair PMP system consists of a Base Station (BS) with
              multiple Terminal Stations (TS). The BS is connected by radio
              channels to all TS.

              The Base Station is a modular hub, connected to the Telecom
              switches on one side and to the service areas, via the Terminal
              Stations, on the other side. Each Terminal Station provides
              various Telecom services, such as leased line, ISDN, Frame Relay
              etc., utilizing a flexible bandwidth up to 4Mbps capacity. The
              entire base station provides a total network capacity of
              64E1@14Mhz, which is divided among the Terminal Stations as
              required, using flexible bandwidth allocation.

              The following diagram illustrates the system architecture.

                                [GRAPHIC OMITTED]

                     FIGURE 2: WALKAIR'S SYSTEM ARCHITECTURE

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2.1      BASE STATION (BS)

              Figure 3 shows a general view of the Base Station.

                                [GRAPHIC OMITTED]

                       FIGURE 3. BASE STATION GENERAL VIEW

              The Base Station consists of several sectors, up to 8/12 sectors
              (depending on frequency type) can cover a single cell. Each sector
              contains one or more (up to 16) Basic Units (BU), an IF MUX, RFU
              and an antenna.

2.1.1    BASIC UNIT (BU)

              The main building blocks of the BU are: the modem, the telecom
              interface cards and the IF module. Each BU converts the IF signal
              to telecom voice/data towards the telecom port, and vice verse

              Each BU contains up to three interfaces to the telecom interfaces
              (E1, V35, X21, Ethernet etc.) providing various voice and data
              services. The interface cards are implemented on daughterboards,
              and therefore allow maximum flexibility.

              Each BU contains an Ethernet port for Network Management purposes
              and a serial LCI port for local craft terminal.

              Each BU transmits and receives 1.75MHz carrier and, by employing
              TDMA mechanism, handles the traffic of several remote Terminal
              Station (typically 2-10, maximum 16). All BUs are loosely
              connected via the IF MUX, for monitoring and control purposes
              only; in this manner, malfunctioning of a single BU does not
              affect the others.

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2.1.2    IF MUX

              The IF MUX combines the IF signals from/to the various Bus + 48VDC
              into a single coax cable that goes up to the roof top, where the
              RF and antenna subsystem are located. Up to 8 (@3.5GHz ) or 16
              (@10.5GHz and 26GHz) BUs may operate together combined by the same
              IF-MUX.

2.1.3    RFU

              The RFU converts the IF to RF, amplifies the signal to its right
              level and transmits it through the antenna. It is mounted near the
              antenna. The system has several types of RFUs, each serving a
              different radio frequency band. WALKair supports 3.5Ghz, 10.5Ghz
              and 26Ghz bands. The RFU is connected to the indoor equipment via
              a single coax cable.

2.1.4    ANTENNA

              A sector antenna may cover an angular service area (cell) using:

                   -    4, 6, or 8 sectors @ 3.5GHz and 10.5GHz

                   -    4 or 8 sectors @ 26GHz

              Each sector antenna is connected to an RFU.

2.1.5    BS POWERING

              The BS is powered by a DC standard source (48V) to the indoor
              unit.

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2.2      TERMINAL STATION (TS)

              Figure 4 shows a general view of the Terminal Station.

                                [GRAPHIC OMITTED]

                       FIGURE 4. TERMINAL STATION OVERVIEW

              A Terminal Station consists of a single BU (adapted to TS
              operation) and an integrated RFU and antenna subsystem.

              Each BU contains up to three interfaces to the telecom interfaces
              (E1, V35, X21, Ethernet etc.) providing various voice and data
              services.. The interface cards and the are implemented on
              daughterboards, and therefore allow maximum flexibility

              Each BU contains LCI port to be used by local craft terminal for
              installation and maintenance purposes.

              The BU operation is similar to the one at the Base Station. A
              single coax cable carries IF signal, that connects it to the RFU,
              which is installed at the rooftop. The RFU converts IF to RF. The
              antenna, which is an integral part of the RFU, is directed towards
              the BS location.

              The TS is powered either by a DC standard source (48V) or an AC
              source to the indoor unit.

2.3      MANAGEMENT SYSTEM

              WALKnet, WALKair PMP Access management system, runs on a
              commercial workstation, on top of Standard Network Management
              Platform package (HPOV). This station is capable of managing
              thousands of Network Elements (NE) concurrently, e.g Base Stations
              and their relating Terminal Stations.

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              WALKnet provides graphical visualization of WALKair Network
              Elements concerning the status, performance and configuration
              parameters.

              WALKnet PMP Access management may be located locally, in the cell,
              or remotely, in the control center. WALKnet allows for
              comprehensive configuration and maintenance tasks including
              testing, fault management and remote software download.

              Configuration Data Base is located in a central SQL Data base. The
              DB can be approached from several management Stations.
              Provisioning data that is stored on the DB can be retrieved by
              WALKnet and sent to the NE

              WALKair management Architecture is fully distributed: each BS-BU
              (BS stackable unit) is treated by the manager as an independent
              entity, allowing for flexible management tasks and simplified
              design. This architecture comprises of three main objects:

              -    SNMP-based PMP Access Management System (EMS)

              -    SNMP Management Agent in a Base Station's Base Unit (BU)

              -    Remote, Non-SNMP Management Agent in a Terminal Station

2.3.1    MANAGEMENT COMMUNICATION

              Each BS-BU is assigned with an IP address. The NMS and the BS-BU
              communicates using TCP/IP protocol stack. The NMS Manager at the
              central/regional site may communicate with the various SNMP agents
              using the following ways:

              In-band - One of the DS0 time-slots of the E1 channels in a
              specific BS-BU is dedicated for management. This BS-BU processes
              packet destined to its IP address and forwards the rest towards
              the LAN connecting al BS-BUs.

              Out of band - IP traffic is sent and received via the Ethernet
              port. All BS-BUs are connected to Ethernet hub. Each BS-BU
              processes only the IP traffic destined to it, according to the
              assigned IP address. The NMS may be local or remotely connected
              via router and any DCN network such as Frame Relay, Leased Line
              etc.

              Local communication is also available using Local Craft terminal
              via the serial interface in the BS-BU and TS-BU. user can use
              local LCI menus, which reside in the BU in order to configure,
              maintain or test the system.

              The remote TS is managed via a remote agent, residing in the
              TS-BU. The communication between the BS_BU SNMP agent and its
              remote TS_BU agents is done over the air link, using OUT OF BAND
              proprietary protocol that better utilizes the air link.

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3.       SYSTEM FEATURES

              SUPPORTS ALL PMP ETSI BANDS: 3.5, 10.5, 26 GHz

              These bands are certified in Europe for PMP systems by ETSI. The
              various regulatory authorities in Europe (and other countries as
              well) license either one or two of these bands.

              ACCESS METHOD: MULTI CARRIER TDMA / FDD

              The system uses a TDMA access scheme shared by a group of users at
              a radio bandwidth of 1.75MHz. There is one frequency for uplink
              and another one dedicated to the downlink (FDD). Multi-carrier is
              derived from the stackable structure of multiple 1.75MHz carriers.

              HIGH RELIABLE RADIO LINK

                   -    High radio utilization using 64QAM modulation, with
                        trellis FEC for coding gain. Spectral efficiency is 2.5
                        bit/sec/Hz.

                   -    Fiber-optics equivalent quality of BER less than 10(-9),
                        99.99% availability

                   -    Reliable radio link in cluttered environment using modem
                        equalizer and Trellis coding

                   -    Optional redundant RFU for increased availability

              DYNAMIC BW ALLOCATION VIA TDMA CELL BASED PROTOCOL

                   -    Air protocol specially designed for Wireless PMP, Multi
                        service and BW optimization (low and high rate)

                   -    Flexible and Dynamic Bandwidth per User: 64Kbps - 2xE1

                   -    Dynamic Bandwidth Assignment Based on Traffic Type and
                        Magnitude: packet switching for data, circuit switching
                        for voice.

                   -    Asymmetric BW Assignment for Uplink & Downlink

                   -    Quality of Service using bandwidth reservation and
                        priority schemes .

                   -    Built -In Security and Authentication

              CAPACITY

                   -    High spectral efficiency of 2.5 bit/sec/Hz

                   -    User's net payload is 2xE1 and can be doubled to 4xE1

                   -    Optimized cell planning allows for reuse of 2- 4

                   -    The useful net bandwidth per cell depends on the
                        allocated spectrum. As an example, the net capacity for
                        a typical 14Mhz x 2 allocation @ 3.5GHz is 324xE1 and
                        may be doubled to 64xE1 using dual polarization.

                   -    High concentration ratio using dynamic Bandwidth
                        Allocation

              MODULAR AND SCALEABLE STRUCTURE OF THE BASE-STATION

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                   -    The Base Station composes modular Basic Units, each
                        supporting 4Mbps over 1.75MHz carrier. This modularity
                        reduces startup costs, minimizes initial investment and
                        maximizes gradual growth capabilities.

              INTERFACES AND SERVICES

                   -    At the Terminal WALKair offers variety of Telecom
                        interfaces for voice data and Internet applications:
                        E1/PR ISDN, V35, X21 and Ethernet. BR ISDN is supported
                        via external MUX.

                   -    The Base Station is connected to the backbone via E1
                        (G.703/G.704) , V35 and X21. STM-1 is supported via
                        external ATM MUX

                   -    WALKair Multi service includes Leased Line, , Frame
                        Relay, BR/PR ISDN and IP.

                   -    WALKair supports leased line services via variety of
                        interfaces such as transparent E1, Fractional E1, V35
                        and X21 interfaces. Traffic is transparently transferred
                        over a predefined bandwidth, determined by the
                        management station.

                   -    Voice traffic is received via E1 interface at the
                        Terminal Station (CPE) using V5.1 protocol. The V5.1
                        traffic is then converted to V5.2 traffic and
                        concentrated over the air using V5.2 signaling. The V5.2
                        signalling is monitored by WALKair BW manager, allowing
                        for service oriented dynamic BW allocation, which grants
                        extremely efficient concentration ratio for the
                        operating services.

                   -    Frame Relay packets are received via X21/V35 interface
                        in the Terminal Station (CPE equipment) and transmitted
                        over the air using dynamic bandwidth allocation. At the
                        Base Station, Frame Relay packets are transmitted
                        towards the network using V35/X21 or E1 interface

                   -    Ethernet packets are received via 10BaseT interface in
                        the Terminal Station (CPE equipment) ans and transmitted
                        over the air using dynamic bandwidth allocation.
                        Bridging and static routing functionality ensures
                        optmized IP connectivity.

                   -    VoIP packets are identified and prioritized over the air
                        using special queuing mechanism. Constant delay is
                        maintained using cell based transmission.

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      WALKair-TM- NETWORK APPLICATIONS

              WALKair is designed to meet a set of requirements that are common
              to PMP applications in many cases. The specific requirements of a
              certain Telecom operator may vary, however, according to the
              profile of its specific application. Different priorities may be
              given to different requirements as a result of differences in
              needs, competitive environment, regulation, etc.

4.1      THE BUSINESS CUSTOMER APPLICATION : HIGH GROWTH POTENTIAL SOLUTION
OPTIMIZED FOR SME ACCESS

              Business customers are typically located in independent customer
              sites over an urban/suburban area. The covered area may be large -
              several hundred square kilometers, or small - a few square
              kilometers. The average capacity requirement per customer may vary
              significantly from one area to another. The number of customer
              sites and the average capacity per customer are expected to grow
              significantly within few years.

              WALKair is designed to suit WLL applications for business
              customers. The system directly connects locations of small- and
              medium-business customers providing wireline quality service of
              PABX, data and high speed Internet connection.

                                [GRAPHIC OMITTED]

         FIGURE 5. WALKair SERVING THE BUSINESS CUSTOMER PMP APPLICATION

              WALKair provides substantial technical, economical and competitive
              advantages to the Operators:

              BETTER BANDWIDTH EFFICIENCY

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                   -    Spectral efficiency of 2.5bits/s/Hz

                   -    Flexible and dynamic real time allocation per user for
                        high-speed Internet access

                   -    Voice and data concentration using Dynamic Bandwidth
                        allocation for increased radio efficiency, capacity, and
                        higher throughput

              QUALITY OF SERVICE

                   -    Fiber Optics equivalent voice and data service

                   -    Efficient traffic management including Bandwidth
                        reservation and priority mechanisms for sensitive & high
                        priority traffic

              COST EFFECTIVENESS

                   -    All-in-one wireless access network for all business
                        applications with full range of Telecom services such as
                        Leased Line (from fractional E1/T1 to full E1/T1),
                        BR-ISDN to PR-ISDN, Frame Relay, Ethernet and ATM

                   -    Variety of IP services: Internet access, LAN-to-LAN
                        connectivity etc

                   -    Cost structure tailored to the new operator needs: low
                        start-up cost, linear growth, low life cycle costs

                   -    Best cost achievement using radio-to-building

                   -    Outstanding economical performance

                   -    Future proof with high growth potential

              ROBUSTNESS

                   -    Modular and fault tolerant architecture

                   -

4.2      THE RADIO TO THE BUILDING APPLICATION: BEST COST ACHIEVEMENT

              Small business customers and Residential buildings typically
              require low Bandwidth. Several such customers that reside on the
              same building can be served using a single radio connection to the
              building.

              WALKair provides an ideal solution for the Radio To The Building
              (RTTB) and Radio To The Office (RTTO) application. The operator
              can provide voice and data services to the entire building, using
              a single CPE unit (radio link).

              In addition to the SME application advantages, the RTTB/RTTO
              application offers the best cost effective service to the
              operator.

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                                [GRAPHIC OMITTED]

               FIGURE 6. WALKair SERVING THE RTTB/RTTO APPLICATION

4.3      THE FEEDING APPLICATION: EFFICIENT BACKHAUL TRANSMISSION

                   -    The PMP can be used for feeding the Base Stations of
                        narrowband wireless network, typically in urban and
                        suburban areas, where continuous area coverage and high
                        capacity requirements call for PMP backhaul transmission
                        system. PMP allows for a more cost-effective area
                        coverage than the traditional Point To Point microwave
                        links.

              WALKair is designed to meet a set of requirements that are common
              to many backhaul transmission applications, regardless of the type
              of narrowband wireless network that it feeds.

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                                [GRAPHIC OMITTED]

    FIGURE 7. WALKair SERVING AS BACKHAUL FEEDING OF WLL/MOBILE BASE STATIONS

              WALKair is a typical solution for this application, which offers
              substantial advantages:

              SIMPLE BACKHAUL STRUCTURE

                   -    Simpler of the backhaul structure with superior area
                        coverage and flexible bandwidth support (fractional E1
                        to 2xE1), ensuring traffic averaging

                   -    Simple and easy planning and installation.

                   -    Transparent access for all traffic and signaling

              COST EFFICIENCY

                   -    Significant cost reduction of overall backhaul network
                        compared to PTP alternative

                   -    Modular architecture allows expedient feeding for
                        various network capacities

              HIGH CAPACITY

                   -    Large backhaul capacity per area, enabled by the
                        excellent spectral efficiency of the WALKair radio
                        interface.

                   -    Cost and traffic averaging is enabled using flexible
                        bandwidth allocation, ranging from a 64Kbps to 4Mbps,
                        which provides a mixed capacity channels to different
                        base stations while efficiently utilizing the available
                        bandwidth.

                   -    Flexible and more efficient bandwidth management
                        allowing for varied capacities to the same base stations
                        in different hours of the day:

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              QUALITY

                   -    Backhaul transmission by highly reliable radio links and
                        additional redundancy options

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--------------------------------------------------------------------------------
5.       TECHNICAL SPECIFICATIONS

5.1      GENERAL SPECIFICATIONS

<TABLE>
            <S>                                       <C>
            STANDARD COMPLIANCE                       ETSI TM4 (EN 301 021)

                                                      ETSI TM4/2

            RADIO ACCESS METHOD                       Multi-carrier TDMA/FDD

            MODULATION & CODING TECHNIQUE             64QAM @ convolutional coding, rate 2/3

            SPECTRAL EFFICIENCY                       2.5bit/sec/Hz

            NUMBER OF TERMINAL STATIONS PER ONE       up to 256.
            SECTOR

            NET PAYLOAD  PER SINGLE USER              64Kbps to 4.096Mbps

            SYSTEM CAPACITY PER ONE BASE STATION      64xE1@14MHz  allocation

                                                      128xE1@28MHz allocation

            SUPPORTED DISTANCE                        3.5Ghz: 10Km at near line of sight.

                                                      10.5Ghz: 10Km at line of sight.

                                                      26GHz: 4km at line of sight

</TABLE>

5.2      TERMINAL STATION SPECIFICATIONS

5.2.1    RF @ 3.5 GHz

<TABLE>
            <S>                                       <C>
            GUIDING STANDARD                          CEPT/ERC Rec. 14-03

            FREQUENCY BAND                            3.5GHz.

                                                      Transmit: A: 3.40-3.44 GHz

                                                                B: 3.43- 3.47 GHz

                                                                C: 3.46 - 3.5 GHz

                                                      Receive:  A: 3.50 -3.54 GHz

                                                                B: 3.53- 3.57 GHz

                                                                C: 3.56 - 3.60 GHz

            OUTPUT POWER                              Dynamic range:  -22dBm to +18dBm

</TABLE>

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<TABLE>
            <S>                                       <C>
            RECEIVER SENSITIVITY                      -87dBm  (@ BER 10(-9))

            RF BANDWIDTH                              1.75MHz

            ANTENNA SIZE                              25x25 cm.

            ANTENNA BEAMWIDTH                         18DEG. vertical and horizontal.

            ANTENNA GAIN                              18dBi

            STANDARD COMPLIANCE                       EN 302 085, Range 3, class TS2 and TS3

</TABLE>

5.2.2    RF @ 10.5 GHz

<TABLE>
            <S>                                       <C>
            GUIDING STANDARD                          CEPT/ERC Rec. 14-03

            FREQUENCY BAND                            10.5GHz

                                                      Transmit: 10.50-10.65GHz

                                                      Receive: 10.15-10.30GHz

            OUTPUT POWER                              Dynamic range:  -25dBm to +15dBm

            RECEIVER SENSITIVITY                      -87dBm  (@ BER 10(-9))

            RF BANDWIDTH                              1.75MHz

            ANTENNA SIZE                              25x25 cm.

            ANTENNA BEAMWIDTH                         8DEG. vertical and horizontal.

            ANTENNA GAIN                              25dBi

            STANDARD COMPLIANCE                       EN 302 085, Range 3, class TS2 and TS3

</TABLE>

5.2.3    RF @ 26 GHz

<TABLE>
            <S>                                       <C>                        <C>
            GUIDING STANDARD                          T/R 13-02

                                                              TRANSMIT                RECEIVE

            FREQUENCY BAND

                                                      Band A:  25557 to 25669    24549 to 24661 MHz
                                                      Band B:  25669 to 25781    24661 to 24773 MHz
                                                      Band C:  25781 to 25893    24773 to 24885 MHz
                                                      Band D:  25893 to 26005    24885 to 24997 MHz
                                                      Band E:  26005 to 26117    24997 to 25109 MHz
                                                      Band F:  26117 to 26229    25109 to 25221 MHz
                                                      Band G:  26229 to 26341    25221 to 25333 MHz
                                                      Band H:  26341 to 26453    25333 to 25445 MHz

            OUTPUT POWER                              Dynamic range  -30dBm to +10dBm

            RECEIVER SENSITIVITY                      -85dBm  (@ BER 10(-9))

</TABLE>

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<TABLE>
            <S>                                       <C>
            RF BANDWIDTH                              1.75MHz

            ANTENNA SIZE                              30CM DISH

            ANTENNA BEAMWIDTH                         2.50 vertical and horizontal.

            ANTENNA GAIN                              35dBi

            STANDARD COMPLIANCE                       EN 301 215-1 and EN 301 215-2, Type TS1

</TABLE>

5.2.4    INTERFACES

              Up to 3 Telecom ports available with the following interfaces: E1,
              V35/X21, Ethernet. RS232 LCI port exists for maintenance purposes

5.2.4.1  E1

              The E1 interface comply with ETS 300 011, and is in accordance
              with ITU-T Rec. G.703, Section 6. It is a symmetrical-pair 120ohm
              balanced interface. The signal bit rate input should be 2048
              kbit/s +/-50 ppm. The line code is HDB3.

              Frame Structure is according to CCITT G.704 Section 5 and Section
              2.3 with or without CRC-4, according to operator selection.

              The jitter performance is in accordance with ITU-T G.823, and the
              parameters given in ITU-T Rec. G.736 and I.431.

              E1 intreface is used for the following services:

              -    PR ISDN

              -    Leased line

              -    Frame Relay with Dynamic Badwidth Allocation for optimized
                   air utilization

              -    V5.1

5.2.4.2  V35/X21

             The V.35/X.21 leased line interface provides the WALKair BU with a
             serial synchronous data interface that connects to a data switch or
             router and supports either V.35 or X.21 signals in DCE or DTE mode.
             The V.35/X.21 interface supports user data rates of full duplex N x
             64kbps up to 2.048 Mbps (N = 1,...,32).

             When the interface is configured as V.35, the electrical
             definitions of the pins comply with CCITT Rec. V.35 (Red Book).
             Balanced signals comply with V.35 Annex.II. Unbalanced signals
             comply with ITU-T Rec. V.28.

             When the interface is configured as X.21, the functional and
             electrical definitions of the pins comply with ITU-T Rec. X.21.

             V35/X21 intreface is used for the following services:

              -    Leased line

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              -    Frame Relay with Dynamic Badwidth Allocation for optimized
                   air utilization

5.2.4.3  ETHERNET

              Ethernet interfcae is impleamented via a 10BaseT interface in the
              Terminal Station (CPE equipment). Bridging functionality ensures
              that packets destined to the local LAN will not be forwarded. Only
              packets destined to remote location e.g ISP or remote LAN will be
              forwarded towards the Telecom backbone. Static IP routing ensures
              proper IP conectivity.

5.2.5    SIZE AND STRUCTURE

              -    Indoor device: 44cm (19") Width, 4.4cm (1U) height, 23cm
                   Depth. Weight: 3Kg. Either rack mount or wall mount.

              -    3.5 & 10.5GHz outdoor device: 25x25x8 cm, including the
                   antenna. Weight: 4Kg. 26GHz outdoor device: 28x20x10 cm, not
                   including the antenna. Weight 4.5Kg.

                   Pole mount antenna.

              -    A single Coaxial cable (type LMR400 or better) connects the
                   indoor to outdoor device, at distances of more than 150m.

5.2.6 POWER

              -    Powering is 48V DC or 110/220V AC, supplied to the indoor
                   device only, from an external power supply.

              -    Power consumption is 40W, Heat dissipation is 30W.

5.2.7    ENVIRONMENTAL

              -    The indoor device is subject to normal indoor temperature and
                   humidity conditions, complies with EN 300 019 , class 3.2E
                   standard (-5DEG.C to 45DEG.c).

              -    The outdoor device is subject to standard European outdoor
                   conditions, complies with EN 300 019, class 4.1E (-45DEG.C to
                   +55DEC.C). The sealing outdoor device complies with the IP-65
                   standard.

              -    System safety complies with EN 60950

              -    Wind loadiing complies with EN 302 085 ,(3.5GHz, 10.5GHz) and
                   EN 301 215 (26GHz)

              -    Vibration complies with EN 301 021

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5.3      BASE STATION SPECIFICATION

5.3.1    RF @ 3.5GHz

<TABLE>
            <S>                                       <C>
            GUIDING STANDARD                          CEPT/ERC Rec. 14-03

            FREQUENCY BAND                            3.5GHz

                                                      Transmit: A: 3.50 -3.54

                                                                B: 3.53- 3.57

                                                                C: 3.56 - 3.60

                                                      Receive:  A: 3.40-3.44

                                                                B: 3.43- 3.47

                                                                C: 3.46 - 3.5

            OUTPUT POWER                              up to 27dBm

            RECEIVER SENSITIVITY                      -87dBm  (@ BER 10(-9))

            RF BANDWIDTH                              Multiple 1.75MHz (1 to 8)

            ANTENNA COVERAGE                          4,6,8 sectors.

            ANTENNA SIZE                              40x20x5 cm.

            ANTENNA GAIN                              13.5dBi(90DEG.) , 15.5 dBi(60DEG.)

            STANDARD COMPLIANCE                       EN 302 085, class CS3

</TABLE>

5.3.2    RF @ 10.5GHz

<TABLE>
            <S>                                       <C>
            GUIDING STANDARD                          CEPT/ERC Rec. 14-03

            FREQUENCY BAND                            10.5GHz.

                                                      Transmit: 10.15-10.30

                                                      Receive:  10.50-10.65

            OUTPUT POWER                              up to 27dBm

            RECEIVER SENSITIVITY                      -87dBm  (@ BER 10(-9))

            RF BANDWIDTH                              Multiple 1.75MHz (1 to 16)

            ANTENNA COVERAGE                          4,6,8 sectors.

            ANTENNA SIZE                              75x11x10 cm.

</TABLE>

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<TABLE>
            <S>                                       <C>
            ANTENNA GAIN                              15.5dBi(90DEG.),  18dBi(60DEG.)

            STANDARD COMPLIANCE                       EN 302 085, class CS3

</TABLE>

5.3.3    RF @ 26GHz

<TABLE>
            <S>                                      <C>                        <C>
            GUIDING STANDARD                          T/R 13-02

                                                            TRANSMIT                RECEIVE

            FREQUENCY BAND

                                                     Band A:  24549 to 24661    25557 to 25669 MHz
                                                     Band B:  24661 to 24773    25669 to 25781 MHz
                                                     Band C:  24773 to 24885    25781 to 25893 MHz
                                                     Band D:  24885 to 24997    25893 to 26005 MHz
                                                     Band E:  24997 to 25109    26005 to 26117 MHz
                                                     Band F:  25109 to 25221    26117 to 26229 MHz
                                                     Band G:  25221 to 25333    26229 to 26341 MHz
                                                     Band H:  25333 to 25445    26341 to 26453 MHz

            OUTPUT POWER                             up to 24dBm

            RECEIVER SENSITIVITY                     -85dBm  (@ BER 10(-9))

            RF BANDWIDTH                             Multiple 1.75MHz (1 to 16)

            ANTENNA COVERAGE                         4, 8, 12 sectors.

            ANTENNA SIZE                             20CM DIAMETER HORN

            ANTENNA GAIN                             18dBi (45DEG.), 15.5dBi (90DEG.),

            STANDARD COMPLIANCE                      EN 301 215-1, and EN 301 215-2, Type CS1

</TABLE>

5.3.4    INTERFACES

              Up to 3 Telecom ports available with the following interfaces: E1
              and V35/X21. RS232 LCI port exists for maintenance purposes. ATM
              connectivity to the backbone is supported via an additional ATM
              MUX with integtrated management.

5.3.4.1  E1

              The E1 interface comply with ETS 300 011, and is in accordance
              with ITU-T Rec. G.703, Section 6. It is a symmetrical-pair 120ohm
              balanced interface. The signal bit rate input should be 2048
              kbit/s +/-50 ppm. The line code is HDB3.

              Frame Structure is according to CCITT G.704 Section 5 and
              Section 2.3 with or without CRC-4, according to operator
              selection.

              The jitter performance is in accordance with ITU-T G.823, and the
              parameters given in ITU-T Rec. G.736 and I.431.

              E1 intreface is used for the following services:

--------------------------------------------------------------------------------
                                                                         PAGE 19
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FLOWARE SYSTEM SOLUTIONS LTD.                              COMPANY CONFIDENTIAL
WALKair-TM- SYSTEM DESCRIPTION
--------------------------------------------------------------------------------

              -    PR ISDN

              -    Leased line

              -    Frame Relay with Dynamic Badwidth Allocation for optimized
                   air utilization

              -    V5.2 with Dynamic Badwidth Allocation for optimized air
                   utilization

5.3.4.2  V35/X21

             The V.35/X.21 leased line interface provides the WALKair BU with a
             serial synchronous data interface that connects to a data switch or
             router and supports either V.35 or X.21 signals in DCE or DTE mode.
             The V.35/X.21 interface supports user data rates of full duplex N x
             64kbps up to 2.048 Mbps (N = 1,...,32).

             When the interface is configured as V.35, the electrical
             definitions of the pins comply with CCITT Rec. V.35 (Red Book).
             Balanced signals comply with V.35 Annex.II. Unbalanced signals
             comply with ITU-T Rec. V.28.

             When the interface is configured as X.21, the functional and
             electrical definitions of the pins comply with ITU-T Rec. X.21.

             V35/X21 intreface is used for the following services:

              -    Leased line

              -    Frame Relay with Dynamic Badwidth Allocation for optimized
                   air utilization

5.3.5    SIZE AND STRUCTURE

              -    Indoor device: 44cm (19") Width, 4.4cm (1U) height, 23cm
                   Depth. Weight:3Kg. These are rack mount devices.

              -    3.5 & 10.5GHz outdoor device: 36x15x24 cm, not including the
                   antenna. Weight 9.5Kg. 26GHz outdoor device: 28x25x12 cm, not
                   including the antenna. Weight 5.5Kg. Pole mount device.

              -    A single coaxial cable (type LMR400 or better) connects the
                   indoor to outdoor devices, at distances of more than 150m.

5.3.6 POWER

              -    Powering is 48V DC, supplied to the indoor device only, from
                   an external power supply.

              -    each stackable Base Station unit has Power consumption of 40W
                   and Heat dissipation of 36W.

5.3.7    ENVIRONMENTAL

              -    The indoor device is subject to normal indoor temperature and
                   humidity conditions, complies with EN 300 019 , class 3.2E
                   standard (-5DEG.C to 45DEG.c).

--------------------------------------------------------------------------------
                                                                         PAGE 20
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FLOWARE WIRELESS SYSTEMS LTD.                               COMPANY CONFIDENTIAL
WALKair-TM- SYSTEM DESCRIPTION
--------------------------------------------------------------------------------

              -    The outdoor device is subject to standard European outdoor
                   conditions, complies with EN 300 019, class 4.1E (-45DEG.C to
                   +55 DEG.C). The sealing outdoor device complies with the
                   IP-65 standard.

              -    System safety complies with EN 60950

              -    Wind loadiing complies with EN 302 085 ,(3.5GHz, 10.5GHz) and
                   EN 301 215 (26GHz)

              -    Vibration complies with EN 301 021

--------------------------------------------------------------------------------
                                                                         PAGE 21
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FLOWARE SYSTEM SOLUTIONS LTD.                              COMPANY CONFIDENTIAL
WALKair-TM- SYSTEM DESCRIPTION
--------------------------------------------------------------------------------

6.       THE WALKair ADVANTAGE

              SPECTRAL ASPECTS

              A winning combination for positive business case:

              -    Wide city coverage using large 3.5GHz frequency cells
                   (GREATER THAN 10Km radius), allowing good capacity with small
                   no. of cells.

              -    Hot spots coverage using small 26GHz frequency cells (~3Km
                   radius), allowing high capacity for industrial parks and
                   business centers.

              CAPACITY PERSPECTIVE

              Hundreds of voice and data customers in just 14MHz:

              -    HIGH SPECTRAL EFFICIENCY (2.5bit/sec/Hz) with
                   state-of-the-art 64QAM modem allows for more users per area
                   and more bandwidth per user. This enables a much higher
                   capacity under the licensed bandwidth limitation and
                   significantly reduces the number of required base stations.

              -    EFFICIENT SERVICE-ORIENTED DATA AND VOICE CONCENTRATION
                   through patent-pending air protocol, facilitates better
                   utilization of the infrastructure, which substantially
                   increases the number of subscribers in one geographical area.

              -    OPTIMIZED CELL PLANNING facilitates high frequency re-use

              PAY-AS-YOU-GROW COST STRUCTURE

              WALKair's modular architecture provides a flexible pay-as-you-grow
              cost arrangement tailored to suite the new operator's needs. This
              is evident through low start-up cost, linear growth, minimal
              life-cycle costs and excellent cash-flow performance.

              FUTURE PROOF

              WALKair's efficient sectorization scheme, optimized cell
              planning, high capacity and efficient concentration guarantees
              long lasting future proof life cycle. WALKair's high growth
              potential enables cost effective operation in the rapidly
              increasing environment of the data and Internet applications.

              SUMMARY

              WALKair presents competitive standing for SME access using
              Efficient Packaging of high speed data and telephony services

              WALKair presents an optimized, low risk business case with Lowest
              up-front investment, Linear, demand driven growth and best
              combination of capacity, frequency bands, modularity

--------------------------------------------------------------------------------
                                                                         PAGE 22
<PAGE>

FLOWARE Wireless Systems Ltd                              Company Confidential
Version 3 Functional Description
--------------------------------------------------------------------------------

   [OBJECT OMITTED]

                                    WALKAIR-TM-

                  WIDEBAND POINT TO MULTIPOINT WIRELESS SYSTEM

                        VERSION 3 FUNCTIONAL DESCRIPTION

    Revision 1.0
    October 1999

--------------------------------------------------------------------------------
-C-FLOWARE Wireless Systems Ltd.    All rights reserved.
The material contained herein is proprietary, privileged, and confidential. No
disclosure thereof shall be made to third parties without the express written
permission of FLOWARE Wireless Systems Ltd.
--------------------------------------------------------------------------------

                                     Page 1

<PAGE>

FLOWARE Wireless Systems Ltd                              Company Confidential
Version 3 Functional Description
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
FLOWARE Wireless Systems Ltd. reserves the right to alter the equipment
specifications and descriptions in this publication without prior notice. No
part of this publication shall be deemed to be part of any contract or warranty
unless specifically incorporated by reference into such contract or warranty.
--------------------------------------------------------------------------------

                                     Page 2
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Version 3 Functional Description
--------------------------------------------------------------------------------

                                TABLE OF CONTENTS

<TABLE>
<S>   <C>                                                         <C>
1.    DOCUMENT CONTROL.............................................4
      1.1.  PUBLICATION HISTORY....................................4

2.    GENERAL......................................................5
      2.1.  ABBREVIATIONS..........................................5

3.    26GHZ........................................................6

4.    V5.2/V5.1....................................................8
      4.1.  GENERAL................................................8
      4.2.  DEFINITIONS............................................8
        4.2.1.   V5 INTERFACE......................................9
        4.2.2.   V5 SUBSCRIBER.....................................9
      4.3.  CONFIGURATION..........................................10
      4.4.  SIGNALLING.............................................11
      4.5.  VOICE TRAFFIC..........................................12
        4.5.1.   VOICE TRAFFIC MULTIPLEXING........................12
        4.5.2.   CONCENTRATION.....................................12
      4.6.  CONTROL AND MAINTENANCE................................13

5.    V.35/X.21 LEASED LINE INTERFACE..............................14
      5.1.  V.35/X.21 SPECIFICATIONS...............................15
      5.2.  ADAPTER CABLES.........................................15
      5.3.  LOOP BACKS.............................................15

6.    AIR PERFORMANCE MONITORING...................................17
      6.1.  PERFORMANCE MEASUREMENTS...............................17
      6.2.  MODEM PERFORMANCE PARAMETERS...........................18
        6.2.1.   BASE STATION MODEM PERFORMANCE PARAMETERS.........18
        6.2.2.   TERMINAL STATION MODEM PERFORMANCE PARAMETERS.....19

7.    MANAGEMENT...................................................20
      7.1.  LCI MANAGEMENT.........................................20
      7.2.  REMOTE LCI MANAGEMENT..................................20
      7.3.  REMOTE CPE MANAGEMENT..................................20
      7.4.  WALKNET................................................21
        7.4.1.   GENERAL...........................................21
        7.4.2.   GRAPHICAL VIEW....................................22
        7.4.3.   CONFIGURATION MANAGEMENT..........................22
        7.4.4.   MAINTENANCE MANAGEMENT............................22

</TABLE>

                                     Page 3
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--------------------------------------------------------------------------------
1.   DOCUMENT CONTROL

<TABLE>
<CAPTION>

      ------------------------------------------------------------------------------
      FLOWARE WIRELESS SYSTEMS LTD.
      ------------------------------------------------------------------------------
      <S>                     <C>
      Project:                WALKAIR[TM] POINT TO MULTIPOINT WIRELESS ACCESS SYSTEM
      ------------------------------------------------------------------------------
      Document:               VERSION 3 FUNCTIONAL DESRIPTION
      ------------------------------------------------------------------------------
      Document Location:      MARKETING\PRE-SALE\FUNCTIONAL DESCRIPTION\
                              VERSION3_FUNCTIONAL_DESCRIPTION.DOC
      ------------------------------------------------------------------------------

</TABLE>

1.1. PUBLICATION HISTORY

<TABLE>
<CAPTION>

      ---------------------------------------------------------------------------
          REV.            DATE                 AUTHOR                   NOTES
      ---------------------------------------------------------------------------
          <S>       <C>                     <C>                  <C>
          1.0       31 October, 1999        Refaela Segdan       Original Version
      ---------------------------------------------------------------------------

      ---------------------------------------------------------------------------

      ---------------------------------------------------------------------------

</TABLE>

                                     Page 4

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Version 3 Functional Description
--------------------------------------------------------------------------------
2.  GENERAL

This document details the functional description of WALKair version 3.0
features. It includes both 3.02 and 3.1 WALKair SW versions' features as well as
the WALKnet functionality.

2.1. ABBREVIATIONS

BS     Base Station
BS BU  Basic Unit in the BS
TS     Terminal Station
LCI    Local Craft Interface
NMS    Network Management System
OOS    Out Of Service
AN     Access Network
LE     Local Exchange
L3     Layer 3 address
AFC    Automatic Frequency Control
AS     Available Seconds
CBR    Constant Bit Rate
CRC    Cyclic Redundancy Check
DM     Degraded Minutes
EB     Errored Block
EDC    Error Detection Code
ES     Errored Second
FER    Frame Error Rate
LOF    Loss of Frame Alignment
LOS    Loss of Signal
MBS    Monitoring Block Size
PEP    Path End Point
SES    Severely Errored Second
UAS    Unavailable Seconds

                                     Page 5

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3.  26GHZ

    26GHz radio heads were designed according to CEPT/ERC T/R 13-02. The entire
    26GHz frequency is divided to 112MHz x 8 RF heads (band A - band H). Sub
    band edges on 112 boundaries according to T/R 13-02 Annex B.

<TABLE>
    <S>                                         <C>
    RADIO ACCESS METHOD                         Multi carrier TDMA/FDD
    SUPPORTED DISTANCE                          .26GHz: 3-4km at line of sight
    SPECTRAL EFFICIENCY                         2.5bit/sec/Hz
    NUMBER OF TERMINAL STATIONS PER ONE BASE    up to 256.
    STATION
    BANDWIDTH PER SINGLE USER                   64Kbps to 4.096Mbps
    SYSTEM CAPACITY PER ONE BASE STATION        128xE1@28MHz  allocation
    GUIDING STANDARD                            CEPT/ERC T/R 13-02
    FDD SEPARATION                              1008MHz according to T/R 13-02
    TERMINAL STATION SPECIFICATIONS              Annex B.
    FREQUENCY BAND
                                                         TRANSMIT                RECEIVE

                                                 Band A:  25557 to 25669    24549 to 24661 MHz
                                                 Band B:  25669 to 25781    24661 to 24773 MHz
                                                 Band C:  25781 to 25893    24773 to 24885 MHz
                                                 Band D:  25893 to 26005    24885 to 24997 MHz
                                                 Band E:  26005 to 26117    24997 to 25109 MHz
                                                 Band F:  26117 to 26229    25109 to 25221 MHz
                                                 Band G:  26229 to 26341    25221 to 25333 MHz
                                                 Band H:  26341 to 26453    25333 to 25445 MHz
    OUTPUT POWER                                 Dynamic range  -30dBm to +10dBm
    ANTENNA SIZE                                 30CM DISH
    ANTENNA BEAMWIDTH                            2.50 vertical and horizontal.
    ANTENNA GAIN                                 35dBi
    STANDARD COMPLIANCE                          ETSI TM4
    RF BANDWIDTH                                 1.75MHz
    RECEIVER SENSITIVITY                         -85dBm  (@ BER 10-9)
    BASE STATION SPECIFICATIONS

</TABLE>

                                     Page 6

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<TABLE>
    <S>                                          <C>
    FREQUENCY BAND                                      TRANSMIT                RECEIVE

                                                 Band A:  24549 to 24661    25557 to 25669 MHz
                                                 Band B:  24661 to 24773    25669 to 25781 MHz
                                                 Band C:  24773 to 24885    25781 to 25893 MHz
                                                 Band D:  24885 to 24997    25893 to 26005 MHz
                                                 Band E:  24997 to 25109    26005 to 26117 MHz
                                                 Band F:   25109 to 25221   26117 to 26229 MHz
                                                 Band G:  25221 to 25333   26229 to 26341 MHz
                                                 Band H:  25333 to 25445   26341 to 26453 MHz

    OUTPUT POWER                                 up to 24dBm

    ANTENNA COVERAGE                             Sector antenna of 900 , 450, 300  per sector.
    ANTENNA SIZE                                 20CM DIAMETER HORN
    ANTENNA GAIN                                 20dBi (300), 18dBi (450), 15.5dBi (900),

    STANDARD COMPLIANCE                          ETSI TM4

    RF BANDWIDTH                                 Multiple 1.75MHz (1 to 16) per sector
     RECEIVER SENSITIVITY                        -85dBm  (@ BER 10-9)

</TABLE>

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4.  V5.2/V5.1

4.1. GENERAL

The WALKair V5 solution provides PSTN services over V5 interface. V5.1 is
implemented between the Terminal Station and a CPE (MUX or PABX) and V5.2
signaling is implemented between the BS and the LE. The WALKair V5 solution is
based on layer 3 termination of V5 protocol, where WALKair actually serves as
V5.1/V5.2 gateway.

WALKair dynamically assigns air timeslots according to the actual requirement.
WALKair implementation complies with the following standards:

V5.1 at the TS: ETS 300 324-1

V5.2 at the BS: ETS 300 324-1 and ETS 300 347-1

4.2.   DEFINITIONS

The following paragraphs generally define V5 terms and attributes. In order to
better understand the V5 terms, The definitions details are sometimes broader
that the WALKair implementation. WALKair V3 support is specifically described in
the table 5-1.

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4.2.1. V5 INTERFACE

V5 interface is defined by VARIANT. Variant is a set of provisioning data of
V5.x interface, which includes an information about interface:

-   Interface Id,

-   Variant Id,

    The above 2 parameters are agreed between the BS and the LE

-   Link information. Link is defined as WALKair's E1 port.

-   C-Channel information,

-   PSTN port information. Port is defined as Subscriber's L3 address (PSTN) or
    EF address (ISDN) + assigned time slot (V5.1)

    Theoretically, each interface can have several variants. Variant can be
    added, deleted, updated etc. by the user via LCI/WALKnet

4.2.2. V5 SUBSCRIBER.

V5 subscriber is a logical object, which is represented by 2 pairs of
parameters:

-   Interface Id and address Id at BS

-   Interface Id and address Id at TS

    Address Id can be L3 address in PSTN or EF address in ISDN. L3 address is a
    logical number, which represents a subscriber at V5 interface.

    User can define new V5 subscriber or delete an existing subscriber via
    LCI/WALKnet

    SUBSCRIBERS' TYPES

    V5 subscribers provides the user with several service types:

-   ON-DEMAND service where connection is set up at the start of each call.

-   LEASED service, which can be divided to permanent, SEMI-PERMANENT or
    PERMANENTLY LEASED SERVICES:

    / /  PERMANENT service is handled by leased-line network that is separate
         from LE. However such user ports are under control of V5 Control
         Protocol. This implies that information about the ports must be
         available in LE.

   / /   SEMI-PERMANENT service is routed through LE via V5 interface.

  / /    PERMANENTLY LEASED service has no effect on the V5 interface. However
         the access capacity of link decreases from the point of V5 view.

    The table 5-1 specifically describes WALKair V5 support road map.

                                     Page 9

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<TABLE>
<CAPTION>

       ---------------------------------------------------------------------------------------
       SERVICE TYPE         SERVICE     SIGNALING       V5 CONTROL      LE             WALKAIR
                            TYPES         TYPE                          SWITCHED/      SUPPORT
                                                                        NON-
                                                                        SWITCHED
       ---------------------------------------------------------------------------------------
       <S>                  <C>         <C>             <C>             <C>            <C>
       On-demand            PSTN        Out of band     Controlled      switched        V3
       ---------------------------------------------------------------------------------------
       On-demand            ISDN BRA    Out of band     Controlled      switched        V4
       ---------------------------------------------------------------------------------------
       Semi-permanent       ISDN BRA    Out of band     Controlled      switched        Future
       ---------------------------------------------------------------------------------------
       Permanent line       ISDN BRA    In-band         Controlled      bypass LE       Future
       ---------------------------------------------------------------------------------------
       Semi-permanent       analog      In band         Controlled      switched        Future
                            /digit
       ---------------------------------------------------------------------------------------
       Permanently leased   analog      In-band         Non             bypass LE       future
       line                 /digit                      controlled
       ---------------------------------------------------------------------------------------
                                     TABLE 5-1: WALKAIR'S V5 SUPPORT

</TABLE>

4.3. CONFIGURATION
Each BS-BU is a single V5.2 interface with up to 3 E1 links connected to Public
Switch. BS-BU V5.x software includes V5Core (AN side, V5.2) and set of V5
applications. Theoretically, Up to 3 V5.2 interfaces can be configured. However,
current SW version provides only 1 V5.2 interface (see restrictions). Each BS-BU
can communicate with a maximum of 16 TS's each connected to PABX or V5 MUX by
V5.1 interface. Each TS can support up to 3 V5.1 interfaces. All V5
configurations (BS and TS) are located in the BS V5 database. V5 database is
placed at BS BU non-volatile memory and includes in general 3 tables:

                                     Page 10

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-   Interface (or Variant) table

-   Subscriber (or Port) table

-   Routing table - PSTN Call Control application uses this table for routing of
    signaling messages. The table is automatically built. Routing process takes
    place only at BS side of V5 application, thus only one Routing table
    exists-at the BS side.

Figure 1 depicts WALKair V5 configuration:

                                [OBJECT OMITTED]

FIGURE 1: WALKAIR V5 CONFIGURATION

User ports associated with the same V5.2 interface link at BS can be distributed
between the different TSs.

RESTRICTIONS:

-   Maximum number of subscribers is 600 per BS-BU

-   Only one V5.2 interface can be configured in each BS-BU. Please note that
    each V5.2 interface can be configured with multiple links (BS-BU physical)
    ports.

-   C-Channel can be configured only on time slot 16at each per V5.2 link. This
    implies the support of "protection group 1".

-   There is no re-provisioning (the ability to include few variants or
    configuration sets per interface with on-line change) at the V5.2
    interfaces.

4.4.   SIGNALLING
V5.1/V5.2 signalling is transferred, out of band, via the EOC (Embedded
Operation Channels). V5.1 signalling is accepted by the Ts and transferred via
the EOC channels to the BS.

At the uplink (from TS to BS) each received signaling message is routed to a
specific V5.2 interface over one of the two uplink EOC channels. The BS
multiplexes all the

                                     Page 11

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received signaling messages from the EOC channel to the C-channel of V5.2
interface.

At the downlink (from BS to TS), each received Signaling message is sent to a
specific TS V5 interface, over one of the downlink EOC channels. .

Signaling messages are routed using user port identifier: Layer 3 address for
PSTN port. User Port at WALKair is uniquely represented by the following:

-   L3 address & Interface Id at BS V5.2 interface

-   TS customer Id

-   L3 address & Interface Id at TS V5.1 interface

The PSTN signalling is transferred transparently over the air. Only the
Destination Id is changed while data is transferred as is. This allows for
implementation free of national variant specific adaptation.

4.5.   VOICE TRAFFIC

4.5.1. VOICE TRAFFIC MULTIPLEXING
Voice Traffic multiplexing is performed by transferring a voice channel between
a specific bearer channel in one of the BS E1 ports and another specific channel
at a corresponding TS E1 port. The association between bearer channels at BS E1
port and TS E1 port must be fixed at TS V5.1 interface and dynamic at BS V5.2
interface.

4.5.2. CONCENTRATION.
Voice Traffic concentration is the capability to allocate air bandwidth only to
active circuits. V5.2 protocol supports concentration by definition. It means
that association between user port and bearer channel on the interface is not
predefined, but bearer channel is allocated dynamically on demand. V5.2 controls
relationship between bearer time slots on the interface and corresponding E1
channels at the user port. This functionality is provided by V5 Bearer Channel
Connection (BCC) protocol of interface. BCC controls dynamic
allocation/releasing of time slots of interface according to the demand. Dynamic
air channels allocation is triggered by BCC protocol inputs at BS. The use of
BCC in order to identify call establishment (off hook) and disconnection allows
for transparent path of the PSTN signalling, instead of PSTN signalling
analysis.

                                     Page 12

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4.6.   CONTROL AND MAINTENANCE
Each V5 interface has 2 parameters, which describe its current status:

-   Administrative status - Enable/Disable

-   Operational status - In-Service/ Out-of-service

Administrative status determines the operational status of the interface. A
disabled interface will always be Out-of-Service. Operational status is
determined as follows:

-   In Service - enabled administrative status and successful interface
    establishment with the external equipment (CPE or LE)

-   Out-of-service - disabled administrative status or faulty interface
    establishment due to faulty E1, faulty CPE equipment etc.

BS and TS interface statuses are independent, e.g. the status of TS interface
does not affect the status of BS interface and vice verse. However TS/BS status
affects one another as follows:

-   TS V5.1 Interface is Disabled/Out of Service

    TS out of service causes blocking of the relevant BS interface port, which
    are connected to the Disable/Out-of-Service TS. After service resuming,
    WALKair invokes ports unblocking.

-   BS V5.2 interface is Disabled/Out of Service

    BS out of service causes port blocking of all TS interfaces connected to the
    disabled/Out-of-Service BS interface.

Usually, the Local Exchange initiates Port Control processes (port
blocking/unblocking). However, several events trigger port blocking/unblocking
by WALKair V5 implementation:

-   Air Link Loss.

    Air Link Loss causes blocking of the relevant user ports at BS V5 interface
    and shutdown to the relevant TS V5 interface. After Air Link is
    re-established, WALKair invokes TSs interface restart and ports unblocking.

-   Layer 1 failure.

    Whenever layer 1 failure is detected in one of the V5.1 links, V5.1
    operational status is set to Out-of-Service and all ports associated with
    defected link at BS V5 interface are blocked.

    Whenever layer 1 failure is detected in one of the V5.2 links, all active
    calls in this link are cleared. Detected layer 1 failures relating to
    physical C-channels within a failed V5.2 link shall result in the protection
    protocol reassigning these C-channels. No port blocking is required. The
    states of associated ports are not changed.

-   All Trunks Busy

    Whenever BW manager identifies that there are no free air time slots for
    call establishment, it ignores a BCC "allocation request" command.

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5.  V.35/X.21 LEASED LINE INTERFACE
The V.35/X.21 leased line interface provides the WALKair BU with a serial
synchronous data interface that connects to a data switch or router and supports
either V.35 or X.21 signals in DCE or DTE mode. The interface supports Leased
Line Point-to-Point services and can be used in the BS or in the TS. The
V.35/X.21 interface supports user data rates of full duplex N x 64kbps up to
2.048 Mbps (N = 1,...,32).

A typical application is an N x 64Kbps Point-to-Point leased line data from a
company headquarters to a branch office. In this application the interface at
the customer premises could be V.35 or X.21 N x 64Kbps, installed in the WALKair
TS. The base station interface carrying the service could be an E1 or a V.35 /
X.21 interface. When using the V.35/X.21 leased line interface in the base
station, it is limited to a Point-to-Point service.

The interface is designed to fit into any of the 3 Telecom slots in the BS or TS
BU.

The V.35/X.21 interface configuration and maintenance is performed via the
management interfaces of the WALKair - locally via the Local Craft Interface
connected on the front panel of the BS/BU and TS/BU or via the NMS. The
interface can be configured as V.35 or as X.21, and as DCE or DCE.

When the interface is configured as V.35, the electrical definitions of the pins
comply with CCITT Rec. V.35 (Red Book). Balanced signals comply with V.35
Annex.II. Unbalanced signals comply with ITU-T Rec. V.28.

When the interface is configured as X.21, the functional and electrical
definitions of the pins comply with ITU-T Rec. X.21.

The mechanical interface is via a female DB-25 connector. Both the V.35 and X.21
signals are supported on the same mechanical connector. Selection of the V.35 or
X.21 is done by software means, via management ports. To operate the interface
as either X.21/V.35/DTE/DCE, an external cable adapter should be used. The
cables may also be used if standard-compliance connectors are required for
connection to the interface. The interface can be configured in the following
configuration:

<TABLE>
<CAPTION>

---------------------------------------------------
TYPE         TIMING MODE           DTE         DCE
---------------------------------------------------
<S>          <C>                   <C>         <C>
V.35         Internal              Yes         Yes
---------------------------------------------------
V.35         External              Yes         Yes
---------------------------------------------------
X.21         Internal              No          Yes
---------------------------------------------------
X.21         External              Yes         No
---------------------------------------------------
</TABLE>

                                     Page 14

<PAGE>

When in V.35 - DCE mode, Tx Data timing (signal 114) can be configured to be
external. If external Tx Data timing is used and the interface is the source for
the WALKair system timing, the existence of this timing signal is checked
(checked if changing). No changes for 64ms time of this signal will considered a
loss of this clock and will cause the timing source algorithm of the WALKair to
change source.

5.1.   V.35/X.21 SPECIFICATIONS

-   The mechanical interface is a female DB-25 connector. The pin assignment of
    the connector is as in EIA/TIA-530-A. o The signal bit rate is N x 64kbp/s
    +/-50 ppm. When external Tx Data timing is used, the clock rate should be N
    x 64kbp/s +/-50 ppm.

-   The jitter performance is in accordance with recommendation G.823 as
    specified for 2 Mbits/s. When external Tx Data timing is used, jitter should
    not exceed the standard limits.

-   The V.35/X.21 leased line interface front panel has a single LED that
    displays the status of the interface.

5.2.   ADAPTER CABLES

Four optional types of cable adapters may be used:

- X.21-DCE - Standard D-Type 15 Pin female connector for the X.21 in accordance
with ISO - 4903 on one end of the cable, and a D-Type 25 Male adapter on the
other end.

-   X.21-DTE - Standard D-Type 15 Pin male connector for the X.21 in accordance
    with ISO - 4903 on one end of the cable, and a D-Type 25 Male adapter on the
    other end.

-   V.35-DCE - Winchester 34 Pin female connector for the V.35 in accordance
    with ISO - 2593 on one end of the cable, and a D-Type 25 Male adapter on the
    other end.

-   Winchester 34 Pin male connector for the V.35 in accordance with ISO - 2593
    on one end of the cable, and a D-Type 25 Male adapter on the other end.

5.3.  LOOP BACKS

The operator, via the management tools can operate the following loop backs, as
depicted in figure 3:

-   Local (L) loop back - In Local loop back, the data transmitted to the line
    outputs is routed back to the receive path. The line inputs are disconnected
    from the receive path. This loop back is used to test the air link.

-   Remote (R) loop back - In Remote loop back, the clock and data recovered
    from the line inputs are routed back to the line outputs via the analog or
    digital transmitter. This loop back is used for remote self-testing the TS.

-   Payload (P) loop back - Payload loop back loops the data stream from the
    receiver path back to the transmitter path. The looped data passes the
    complete telecomm

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--------------------------------------------------------------------------------
    port receiver including the wander and jitter compensation in the receive
    elastic store.

                                [OBJECT OMITTED]

                           FIGURE 2: WALKAIR LOOPBACKS

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6.  AIR PERFORMANCE MONITORING

Air Performance Monitoring in the WALKair enables monitoring and display of
performance of the air link with all connected Terminal Stations and other link
related parameters. WALKair provides performance measurements for each air link
(between a Base Station and a Terminal Station), for upstream and downstream
directions.

The Air PM raw data is collected in BS BUs and reported to the management tools,
the LCI and the management station. The raw data include counters for time
intervals of the current 15 minutes and last 24 hours.

The LCI allows reviewing of the raw access.

The management station software (WALKnet) gives also graphical views, with the
option of creating formatted reports of detailed air performance parameters for
selected measured performance.

Air Link definitions

-   Air Link Path - The bi-directional air link path is defined by the
    connection between the two Path End Points (PEP), BS and TS in accordance
    with Recommendation G.703 [1].

-   Definition and Measurement of Air Frame - Performance measurements based on
    the error performance measurement of 5 msec fixed size Air Frames.
    Consistent with the generic definition of the term "block" as requested in
    the ITU-T Recommendation G.826, sec 4.1

-   In-Service Monitoring of Air Frames- Each Air Frame is monitored by means of
    Cyclic Redundancy Check (CRC). It is not normally possible to determine
    whether an Air Frame or its controlling EDC bits are in error. If there is a
    discrepancy between the EDC and its Air Frame, it is always assumed that the
    Air Frame is in error as requested in the ITU-T Recommendation G.826, sec
    4.4

6.1.   PERFORMANCE MEASUREMENTS
Centralized monitoring control is enabled simultaneously from the BS BU for all
of its TSs, allowing for n measurements upstream and n measurements downstream.

The following table describes the Performance Parameters.

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PERFORMANCE PARAMETERS                               DESCRIPTION
--------------------------------------------------------------------------------
<S>                                             <C>
Frame                                           Error Ratio (FER) The ratio of
                                                errored Air Frames referred to
                                                the total number of Air Frames
                                                transmitted in a given time
                                                interval of 15 minutes.
--------------------------------------------------------------------------------
Errored                                         Seconds (ES) A one-second time
                                                period with one or more CRC
                                                errors over the Air Link Path.
                                                This parameter is not
                                                incremented during an
                                                Unavailable Second.
--------------------------------------------------------------------------------
</TABLE>

                                     Page 17
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<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PERFORMANCE PARAMETERS                               DESCRIPTION
--------------------------------------------------------------------------------
<S>                                             <C>
Severely                                        Errored Seconds (SES) A
                                                one-second time period
                                                containing above 30% errored Air
                                                Frames or at least one defect (a
                                                second with 60 or more errored
                                                Air Frames). SES is a subset of
                                                ES.
--------------------------------------------------------------------------------
Unavailable                                      Seconds (UAS) Unavailable
                                                 Seconds are calculated by
                                                 counting the number of seconds
                                                 that the Air Link Path is
                                                 unavailable. The Air Link Path
                                                 is considered unavailable from
                                                 the onset of 10 contiguous SESs
                                                 or the onset of the condition
                                                 leading to a failure.
--------------------------------------------------------------------------------
Available                                       Seconds (AS) Error free seconds
                                                are those seconds that are not
                                                Unavailable as described above.
--------------------------------------------------------------------------------
Degraded                                        Minutes (DM) A one minute time
                                                period in which the estimated
                                                frame error rate exceeds 1E-6
                                                but does not exceed 1E-3 (see
                                                G.821 [1].
--------------------------------------------------------------------------------

</TABLE>

6.2.   MODEM PERFORMANCE PARAMETERS
Modem performance parameters are accumulated regardless of CRC Errors provided
that the Air Link is available and no Failure States are detected. Different
sets of Modem Performance Parameters are recorded and calculated for each
upstream and downstream directions or the Air Link Path

6.2.1. BASE STATION MODEM PERFORMANCE PARAMETERS

    Base Station Modem performance parameter are listed below:

    -    The following Modem performance parameters are recorded every 1 sec:

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PERFORMANCE PARAMETERS                               DESCRIPTION
--------------------------------------------------------------------------------
<S>                                             <C>
Signal to Noise Ratio (SNR)                     This is an estimation of the
                                                signal to noise ratio the Base
                                                modem sees. Measuring units are
                                                dB
--------------------------------------------------------------------------------
Receive                                         Power (Rx Pwr) This is an
                                                estimation of the received
                                                signal power measured at the
                                                antenna port of the
                                                Base.Measuring units are dBm.
--------------------------------------------------------------------------------
</TABLE>

    -    The following Modem performance parameters are calculated every 15 min:

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PERFORMANCE PARAMETERS                               DESCRIPTION
--------------------------------------------------------------------------------
<S>                                             <C>
Signal to Noise Ratio (SNR)                     Minimum, maximum and average
                                                values.
--------------------------------------------------------------------------------

</TABLE>

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<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PERFORMANCE PARAMETERS                               DESCRIPTION
--------------------------------------------------------------------------------
<S>                                             <C>
Receive Power (Rx Pwr)                          Minimum, maximum and average
                                                values.
--------------------------------------------------------------------------------

</TABLE>

6.2.2. TERMINAL STATION MODEM PERFORMANCE PARAMETERS Terminal Station Modem
       performance parameter are listed below:

    -    The following Modem performance parameters are recorded every 1 sec:

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PERFORMANCE PARAMETERS                               DESCRIPTION
--------------------------------------------------------------------------------
<S>                                        <C>
Signal to Noise Ratio (SNR)                This is an estimation of the signal
                                           to noise ratio the Base modem sees.
                                           Measuring units are dB

--------------------------------------------------------------------------------
Receive                                    Power (Rx Pwr) This is an estimation
                                           of the received signal power measured
                                           at the antenna port of the
                                           Base.Measuring units are dBm.
--------------------------------------------------------------------------------
Transmit Power (Tx Pwr)                    This is an estimation of the transmit
                                           signal power measured at the antenna
                                           port of the Terminal RF unit.
                                           Measuring units are in dBm
--------------------------------------------------------------------------------
Carrier Frequency Offset (AFC)             This is the sum of synthesizer's
                                           frequency offsets in the Base
                                           Station, for the transmit path and in
                                           the Terminal Station for the receive
                                           path. Measuring units are in Hz.
--------------------------------------------------------------------------------

</TABLE>

    -    The following Modem performance parameters are recorded every 15 min.:

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------
    PERFORMANCE PARAMETERS                   DESCRIPTION
--------------------------------------------------------------------------------
<S>                                   <C>
Signal to Noise Ratio (SNR)           Minimum, maximum and average values.
--------------------------------------------------------------------------------
Receive Power (Rx Pwr)                Minimum, maximum and average values.
--------------------------------------------------------------------------------
Transmit Power (Tx Pwr)               Minimum, maximum and average values.
--------------------------------------------------------------------------------
Carrier Frequency Offset (AFC)        Minimum, maximum and average values.
--------------------------------------------------------------------------------
</TABLE>
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7.  MANAGEMENT

7.1.   LCI MANAGEMENT

WALKair provides complete configuration and maintenance functions via Local
Craft Interfaces (LCI) connected to PC with VT100 emulation. The LCI screens
utilizes a layered, menu driven screens that enables the operator to manage the
WALKair V3.0 system equipment and telecommunications services. The LCI
management functions include:

-   Configuration Management

    / /  Radio Link Management

    / /  Administrative Parameters

    / /  Services Management

-   Maintenance Management

    / /  Version Control

    / /  Alarm Management

    / /  System Testing

    / /  Air Performance Monitoring

    / /  Modem Management

WALKair's BS LCI provides remote configuration and maintenance functions for all
of its connected TS enabling full monitoring and remote control over each of the
TSs

7.2.   REMOTE LCI MANAGEMENT
A BS LCI session can also take control over a specific TS's LCI session, thus
saving expensive field maintenance. This can be also used for on-line help to a
field technician.

In order to control specific TS, the operator has to type the TS customer Id and
a password. While the BS LCI is controlling specific TS, the TS operator can
view the same screens as displayed on the BS LCI.

The TS operator can resume control over the TS's LCI by pressing any key on its
keyboard. The system automatically terminates the remote connection.

7.3.   REMOTE CPE MANAGEMENT
WALKair provides the means to transfer management data to the remote CPE unit,
located after the Terminal Station. The remote CPE unit can be connected to the
LCI port (RS232) at the TS side and transfer its management traffic, out of
band, via WALKair's management channels.

Remote CPE functionality has 2 modes of operations:

-   Display the Local Craft Terminal menus of the remote CPE device on the
    BS/TS

                                     Page 20

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--------------------------------------------------------------------------------
    Local Craft Terminal.

-   Send remote CPE device alarms to the management system. Alarms are
    identified using pre-defined prefix. Each such alarm is sent as a trap to
    the management system and to the BS LCI .

                                [OBJECT OMITTED]

                     FIGURE 3: WALKAIR REMOTE CPE MANAGEMENT

7.4.   WALKNET

7.4.1. GENERAL
WALKnet management system runs on a standard PC, on top of Standard Network
Management Platform package (HPOV). WALKnet is an SNMP, GUI based network
management system for manages WALKair access networks.

WALKnet communicates with the Network elements (BS-BUs) via standard SNMP V1
protocol. Each BS communicates with its remote TSs using optimized proprietary
protocol, which is transferred out-of-band, via EOC channels. WALKnet PC
application is capable of managing 100 Network Elements (NE) concurrently, e.g
Base Stations, and their relating Terminal Stations.

WALKnet uses polling mechanism in order to constantly check all its managed
network elements. Whenever a NE does not react to the poling request,

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--------------------------------------------------------------------------------
Currently WALKnet support only supervisor security level, which allows all
configuration and maintenance functionality in addition to password change.

7.4.2. GRAPHICAL VIEW
WALKair equipment is displayed using bitmaps representing the actual front panel
of the equipment. WALKair graphical view includes:

-   Cell view according to its defined parameters

-   Sectors view in each cell

-   Rack view for each sector

-   Registered terminals view per each BS-BU in a sector.

7.4.3. CONFIGURATION MANAGEMENT

WALKair configuration parameters includes all the configuration parameter
required for operating the system:

-   Radio Link Management includes all radio parameters required for radio link
    such as RFU type, cable gain etc. in addition informational parameters are
    also included such as antenna type, antenna altitude

-   Telecom Interfaces Parameters includes all Telecom port specific parameters
    such as signalling mode for E1 and interface type for X21/V35 interface

-   Administrative Parameters controls the status of each BS-BU and its Terminal
    Station. A disabled service can be configured but cannot be established.

-   Services Management controls all service specific parameters such as the
    leased line path, V5 variants, V5 quality of service parameters etc.

7.4.4. MAINTENANCE MANAGEMENT

WALKair maintenance parameters includes all the parameter required for
maintaining, testing and fault isolating the system:

-   SW download is performed remotely from the management system, via TFTP
    server located on the management system, to a list of BS_BUs and its
    registered Terminal stations. The download is performed out-of-band, using
    management channels, to all TS concurrently. The new version is downloaded
    to the stand by image of each of WALKair elements without service
    interruption. .

-   Version Control displays the 2 SW versions (Current, Stand-by) located in of
    each WALKair element. The user can switch the current and stand-by version
    at any time.

-   Alarm Management is presented both graphically and as a list. Each WALKair
    alarm is sent as a trap to the management system ad displayed in an alarm
    list using the HPOV. Alarms can be filtered, forwarded or cause an event
    such as send a mail etc. Each alarm is associated with a specific LED and
    color. Alarms are reflected graphically as a change of color of the cell,
    sector and a specific LED on

                                     Page 22

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--------------------------------------------------------------------------------
    the front panel of the faulty TS/BS-BU.

-   System Testing s includes various port specific loopbacks that can be
    remotely performed for each BS-BU and TS.

-   Air Performance Monitoring results can be displayed as a alphanumerically
    and graphically using all parameters as defined in chapter 6.

                                     Page 23

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FLOWARE Wireless Systems Ltd                               Company Confidential
WALKnet V4 description
--------------------------------------------------------------------------------

   [OBJECT OMITTED]

                                   WALKAIR-TM-

                  WIDEBAND POINT TO MULTIPOINT WIRELESS SYSTEM

                          WALKNET VERSION 4 DESCRIPTION

    Revision 1.0
    December, 99

--------------------------------------------------------------------------------
-C-FLOWARE Wireless Systems Ltd.    All rights reserved.
The material contained herein is proprietary, privileged, and confidential. No
disclosure thereof shall be made to third parties without the express written
permission of FLOWARE Wireless Systems Ltd.
--------------------------------------------------------------------------------

                                                                         Page 1
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FLOWARE Wireless Systems Ltd                               Company Confidential
WALKnet V4 description
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
FLOWARE Wireless Systems Ltd. reserves the right to alter the equipment
specifications and descriptions in this publication without prior notice. No
part of this publication shall be deemed to be part of any contract or warranty
unless specifically incorporated by reference into such contract or warranty.
--------------------------------------------------------------------------------

                                                                         Page 2
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FLOWARE Wireless Systems Ltd                               Company Confidential
WALKnet V4 description
--------------------------------------------------------------------------------

                                TABLE OF CONTENTS

<TABLE>
<S>  <C>                                                       <C>
1.   DOCUMENT CONTROL...........................................4
     1.1.   PUBLICATION HISTORY.................................4

2.   OBJECTIVE..................................................5

3.   GENERAL....................................................5

4.   DATA BASE..................................................5

5.   SECURITY...................................................5

6.   GRAPHICAL VIEW.............................................6

7.   CONFIGURATION MANAGEMENT...................................6

8.   MAINTENANCE MANAGEMENT.....................................6

</TABLE>

1.

                                                                         Page 3
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--------------------------------------------------------------------------------
1.  DOCUMENT CONTROL

<TABLE>
      <S>                    <C>
      -----------------------------------------------------------------------------
      FLOWARE WIRELESS SYSTEMS LTD.
      -----------------------------------------------------------------------------
      Project:               WALKAIR[TM] POINT TO MULTIPOINT WIRELESS ACCESS SYSTEM
      -----------------------------------------------------------------------------
      Document:              WALKNET V4
      -----------------------------------------------------------------------------
      Document Location:     MARKETING\PRODUCT_PLANNING\ROAD_MAP\WALKNET V4.DOC
      -----------------------------------------------------------------------------

</TABLE>

1.1. PUBLICATION HISTORY

<TABLE>
<CAPTION>

          -----------------------------------------------------------------------------------
          REV.           DATE                       AUTHOR                       NOTES
          -----------------------------------------------------------------------------------
          <S>       <C>                           <C>                       <C>
          1.0       DECEMBER 7, 1999              Refaela Segdan            Original Version

                                                  Rina Nathaniel
          -----------------------------------------------------------------------------------

          -----------------------------------------------------------------------------------

          -----------------------------------------------------------------------------------

</TABLE>

                                                                         Page 4
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--------------------------------------------------------------------------------
2.  OBJECTIVE

This document details WALKnet version 4 functionality description.

3.  GENERAL

WALKnet management system runs on 2 operating systems on top of Standard Network
Management Platform package (HPOV Network Node Manager Version 6):

-   Win NT

-   Sun Solaris 2.6 UNIX

WALKnet is an SNMP, GUI based network management system for manages WALKair
access networks.

WALKnet communicates with the Network elements (BS-BUs) via standard SNMP V1
protocol. Each BS communicates with its remote TSs using optimized proprietary
protocol, which is transferred out-of-band, via EOC channels.

WALKnet uses polling mechanism in order to constantly check all its managed
network elements. Whenever a NE does not react to the poling request,.

4.  DATA BASE

WALKnet stores configuration and performance data using one of the following
ways:

-   SQL data base ( Oracle , Informix). Version 4 will support Oracle database.
    WALKnet can use a local or remote database. One database can serve several
    WALKnet systems.

-   Local file system,. In case the user installs WALKnet without an external
    SQL database, WALKnet will use the local file system in order to save
    information. Performance data will be saved in Excel Format.

5.  SECURITY

WALknet supports 4 secur4ity levels as follows:

-   Monitor - allows for monitoring functions only

-   Maintenance - allows for monitoring and testing functions such as loopbacks.

-   Administrator - allows for configuration, maintenance and monitoring

-   Supervisor - allow for administrator functionality and WALKnet user
    administration (add/remove users, change password)

                                                                         Page 5
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--------------------------------------------------------------------------------
6.  GRAPHICAL VIEW

WALKair equipment is displayed using bitmaps representing the actual front panel
of the equipment. WALKair graphical view includes:

-   Cell view according to its defined parameters

-   Sectors view in each cell

-   Rack view for each sector including the BS-BU in the specific sector

-   Registered terminals view per each BS-BU in a sector. Numeric Customer ID
    and Alphanumeric Node name is presented for each terminal .

7.  CONFIGURATION MANAGEMENT

WALKair configuration parameters includes all the configuration parameter
required for operating the system:

-   Radio Link Management includes all radio parameters required for radio link
    such as RFU type, cable gain etc. in addition informational parameters are
    also included such as antenna type, antenna altitude

-   Administrative Parameters controls the status of each BS-BU and its Terminal
    Station. A disabled service can be configured but cannot be established.

-   Telecom Interfaces Parameters includes all Telecom port specific parameters
    such as signalling mode for E1 and interface type for X21/V35 interface

-   Services Management controls all service specific parameters as follows:

/ / Leased line service parameters,

/ / V5 PSTN /ISDN  service parameters, V5 quality of service parameters,

/ / Frame Relay service parameters

8.  MAINTENANCE MANAGEMENT

WALKair maintenance parameters includes all the parameter required for
maintaining, testing and fault isolating the system:

-   SW DOWNLOAD is performed remotely from the management system, via TFTP
    server located on the management system, to a list of BS_BUs and its
    registered Terminal stations. The download is performed out-of-band, using
    management channels, to all TS concurrently. The new version is downloaded
    to the stand by image of each of WALKair elements without service
    interruption. .

-   CONFIGURATION DOWNLOAD/UPLOAD- Configuration data can be downloaded from
    each BS-BU to the management system, which stores the configuration files on
    the local file system. The user can upload the configuration from the
    management system to any BS-BU.

                                                                         Page 6
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--------------------------------------------------------------------------------
-   VERSION CONTROL displays the 2 SW versions (Current, Stand-by) located in of
    each WALKair element. The user can switch the current and stand-by version
    at any time.

-   ALARM MANAGEMENT is presented both graphically and as a list. Each WALKair
    alarm is sent as a trap to the management system and displayed in an alarm
    list using the HPOV. Alarms can be filtered, forwarded, acknowledged or
    cause an event such as send a mail etc. Each alarm is associated with a
    specific LED and color. Alarms are reflected graphically as a change of
    color of the cell, sector and a specific LED on the front panel of the
    faulty TS/BS-BU.

-   SYSTEM TESTING includes various port specific loopbacks that can be remotely
    performed for each BS-BU and TS.

-   AIR PERFORMANCE MONITORING results can be displayed as a alphanumerically
    and graphically using PM parameters such as Errored Seconds, Severely
    errored seconds, SNR, FER etc. Air PM data is collected once in 24 hours
    from all BS-BUs and saved on the local file system/SQL database for
    exporting to external reporting system.

-   SERVICE PERFORMANCE MONITORING - The following service specific PM is
    presented alphanumerically and graphically:

/ / V5 call statistics such as blocked calls, unblocked calls, busiest hour etc

/ / Frame Relay DLCI statistics according to RFC 1604.

                                                                         Page 7
<PAGE>
FLOWARE Wireless Systems Ltd.                              Company Confidential
--------------------------------------------------------------------------------

   [GRAPHIC]

                                    WALKair-TM-

                              WIDEBAND / BROADBAND

                       POINT TO MULTIPOINT WIRELESS SYSTEM

                                TIMING MECHANISMS

Revision 1.0
September 1999
--------------------------------------------------------------------------------
-C-FLOWARE Wireless Systems Ltd. All rights reserved. The material contained
herein is proprietary, privileged, and confidential. No disclosure thereof shall
be made to third parties without the express written permission of FLOWARE
Wireless Systems Ltd. FLOWARE Wireless Systems Ltd. reserves the right to alter
the equipment specifications and descriptions in this publication without prior
notice. No part of this publication shall be deemed to be part of any contract
or warranty unless specifically incorporated by reference into such contract or
warranty.
--------------------------------------------------------------------------------
September 1999                                                      Page 1 of 1
<PAGE>

FLOWARE Wireless Systems Ltd                               Company Confidential
WALKair Timing Mechanisms
-------------------------------------------------------------------------------

TABLE OF CONTENTS

1.    SCOPE...................................................................3

2.    SYSTEM TIMING MECHANISM.................................................3

   2.1.  TIMING BLOCK DIAGRAM.................................................3
   2.2.  SYSTEM TIMING DESCRIPTION............................................3
   2.3.  SLIP BUFFERS.........................................................4
   2.4.  SYSTEM CLOCK SOURCES.................................................4

3.    EXAMPLES................................................................4

   3.1.  SIMPLIFIED TIMING DIAGRAM............................................4
   3.2.  EXAMPLE 1 - TWO DIFFERENT INPUT CLOCKS IN BS_BU......................5
   3.3.  EXAMPLE 2 - CPE WORKS WITH DIFFERENT CLOCK THAN WALKair..............5

TABLE OF FIGURES

Figure 1. WALKair Timing......................................................3
Figure 2. Simplified Timing diagram for examples..............................4
--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------

1.   SCOPE
The purpose of this document is to describe WALKair's timing mechanisms. The
timing mechanisms in WALKair include the system and user timing signals, and the
way the system handles different timing scenarios.

2.   SYSTEM TIMING MECHANISM

     2.1. TIMING BLOCK DIAGRAM The following block diagram describes the timing
signals and the model of timing handling in WALKair.

[GRAPHIC]

                            FIGURE 1. WALKAIR TIMING

2.2. SYSTEM TIMING DESCRIPTION
Each Base station BU has an independent timing mechanism and a single system
clock. The mechanism allows several timing sources to serve as the system clock.
The system source is derived from one of the sources, and is used as a timing
signal for data transmission in both base station towards the telecomm network
(Uplink direction), and the terminal station towards the CPE (downlink and
uplink directions).

--------------------------------------------------------------------------------
September 99                                                       Page 3 of 3

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--------------------------------------------------------------------------------

2.3. SLIP BUFFERS Since WALKair has one system clock, it is
recommended that all data inputs have the same frequency, and that the CPE is
working in "loop timing" mode (CPE TX towards WALKair is derived from timing
supplied from WALKair). If the data streams do not have the same frequency as
recommended, controlled slips will occur. For this reason, controlled slip
buffers are implemented in each interface's input, so that if voice traffic is
used, the slips will occur on frame boundary. When a framed signal is used, the
slips will always occur on a frame boundary, and a full E1 frame will be
repeated or skipped in the event of a controlled slip. When an unframed 2Mbps is
used, there is no frame boundary, and therefore a block of 256 bit is repeated
or skipped.

2.4. SYSTEM CLOCK SOURCES
WALKair system clock can be synchronize to one of the following sources:

-    One of three telecomm port input signals (and shall be 2,048KHz
     plus/minus 50ppm, with Jitter characteristics according to G.823)

-    Internal source which is 2,048KHz plus/minus 50ppm, and jitter
     characteristics according to ITU-T Rec. G.823.

-    An external clock source, which complies with ITU-T Rec. G.703 Section 10.

The system clock source can be manually forced to be one of the available
sources, or the WALKair software can automatically select one of the sources, so
that in case of a signal loss, a secondary source is selected as the system
source.

3.   EXAMPLES

     3.1. SIMPLIFIED TIMING DIAGRAM

The following block diagram is a simplified diagram, which shows different
clocks in the different inputs. In this diagram, the system clock source is
telecomm port 0 at the base station, and only one other clock source, telecomm
port 1, is shown.

                                   [GRAPHIC]

                Figure 2. Simplified Timing diagram for examples
--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------

     3.2. EXAMPLE 1 - TWO DIFFERENT INPUT CLOCKS IN BS_BU
In this example, the input to telecomm port 1 of base station, marked f1 in
figure 2 has a different frequency than the system clock, which is f0, the input
timing of telecomm port 0. The E1 transmitted from WALKair's telecomm port 1 has
the frequency f0, the system clock. At the terminal station, the E1 signal
transmitted from WALKair towards the CPE has the frequency f0, the system clock.
Since f1 is not equal to f0, slips will occur in the slip buffer of telecomm
port 1 at the base station. Telecomm port 0 will work error free, without any
slips.

     3.3. EXAMPLE 2 - CPE WORKS WITH DIFFERENT CLOCK THAN WALKAIR
In this example, the input to the terminal station, marked f2 in figure FEHLER!
KEINE GULTIGE VERKNUPFUNG. has a different frequency than the system clock, f0
The E1 transmitted from the terminal station to the CPE has the frequency f0,
the system clock. Since f2 is not equal to f0, slips will occur in the slip
buffer of the telecomm port at the terminal station. Telecomm ports 0 and 1 in
the base station will work error free, without any slips.
--------------------------------------------------------------------------------
September 99                                                       Page 5 of 5
<PAGE>
S

WALKAIR-TM-

WIDEBAND POINT TO MULTIPOINT WIRELESS SYSTEM

BANDWIDTH ON DEMAND DESCRIPTION
CONCENTRATED VOICE AND DATA SOLUTION

REVISION 1.0
JANUARY 1999

<PAGE>

S                                                        Bandwidth on Demand
                                                                  WALKair-TM-
-----------------------------------------------------------------------------

                  Contents

1   Dynamic BW Allocation...................................................3
2   Service Oriented Dynamic Allocation.....................................4
3   Voice Concentration.....................................................4
4   Data Concentration......................................................5

<PAGE>

S                                                        Bandwidth on Demand
                                                                 WALKair-TM-
-------------------------------------------------------------------------------

1    DYNAMIC BW ALLOCATION

               WALKair's efficient dynamic BW allocation is achieved using its
               patent pending air protocol. By fully exploiting TDMA
               capabilities, a Terminal Station can be assigned with additional
               air time slots upon demand. As demand decreases, the air time
               slots are reassigned to another Terminal Station with minimal
               delay, which does not affect the traffic.

             [GRAPHIC OMITTED]
                                                                               3
<PAGE>

S                                                        Bandwidth on Demand
                                                                 WALKair-TM-
-------------------------------------------------------------------------------

2    SERVICE ORIENTED DYNAMIC ALLOCATION

               Dynamic BW allocation is service oriented, implementing various
               concentration types according to the active services. For
               example, voice is concentrated using v5.2 or Q.931 and data is
               concentrated using queue mechanism, which initiates a request for
               additional air time slot upon queue status. Service oriented
               dynamic BW allocation grants the best efficient concentration
               ratio for the operating services.

           [GRAPHIC OMITTED]

                                                                               4
<PAGE>

S                                                        Bandwidth on Demand
                                                                 WALKair-TM-
-------------------------------------------------------------------------------

3    VOICE CONCENTRATION

               Efficient voice concentration is performed via V5.2 protocol in
               the Base Station. The CPE side provides ISDN , V5.1 and Leased
               Line interfaces, connecting various types of equipment such as
               PABX , Multiplexers (for POTS, ISDN BRI, nx64 etc. interfcaes (in
               addition to the non concentrated Leased Lines),) and micro cell
               Base Stations. The V5.2 concentration abilities utilize the
               system's Bandwidth On Demand capabilities, which maximize the
               subscribers capacity within the licensed spectrum.

           [GRAPHIC OMITTED]

                                                                               5
<PAGE>

S                                                        Bandwidth on Demand
                                                                 WALKair-TM-
-------------------------------------------------------------------------------

4    DATA CONCENTRATION

                    Data concentration is a crucial issue in every PMP system.
                    Since data is bursty in its nature, large concentration
                    ratio can be provided using an efficient air protocol with
                    the appropriate service.
                    CPE SERVICES:
                    Ethernet service is destined to small business providing
                    built in router with Ethernet interface to the customer IP
                    (such and Internet Intranet) and non-IP traffic. This is a
                    value added service, also known as IP service, frees the
                    customer from the need to buy and maintain additional
                    DataCom equipment (e.g. router)
                    Frame Relay service is more suitable for medium business
                    traffic (Internet, Intranet and other ) , providing PVC type
                    of connectivity with simple billing (fixed fee similar to
                    the Leased Line). However., Frame Relay is superior to
                    leased line in terms of concentration, since it relies on
                    statistical multiplexing, where the PVC is actually virtual
                    momentary Leased Line. Frame Relay concentration ratio is
                    practically unlimited and depends on the grade of service
                    decided by the operator. Furthermore, Frame Relay offers
                    Quality of Service mechanisms (CIR) that can be charged
                    accordingly using the higher fixed fees, without any special
                    billing means.
                    BASE STATION INTERFACE:
                    The concentrated data is transferred , via the Base Station,
                    to either a DataCom equipment, e.g. router with Frame
                    Relay interface, or to a Telecom equipment, e.g. Frame Relay
                    switch.
                    ALL IN ONE SOLUTION
                    For a complete, cost effective solution, mixed services of
                    voice, concentrated data and Leased Lines should be offered
                    using the same Base Station equipment.
                                                                               6
<PAGE>
S                                                        Bandwidth on Demand
                                                                 WALKair-TM-
-------------------------------------------------------------------------------

                  [GRAPHIC OMITTED]
                                                                               7
<PAGE>

FLOWARE Wireless Systems Ltd                               Company Confidential
Frame Relay Management
--------------------------------------------------------------------------------

[GRAPHIC OMITTED]

                                    WALKAIR-TM-

                  BROADBAND POINT TO MULTIPOINT WIRELESS SYSTEM

                             FRAME RELAY MANAGEMENT

Revision 1.0

September 1999

--------------------------------------------------------------------------------
-C-FLOWARE Wireless Systems Ltd. All rights reserved. The material contained
herein is proprietary, privileged, and confidential. No disclosure thereof shall
be made to third parties without the express written permission of FLOWARE
Wireless Systems Ltd.
FLOWARE Wireless Systems Ltd. reserves the right to alter the equipment
specifications and descriptions in this publication without prior notice. No
part of this publication shall be deemed to be part of any contract or
warranty unless specifically incorporated by reference into such contract or
warranty.
--------------------------------------------------------------------------------

<PAGE>
FLOWARE Wireless Systems Ltd                               Company Confidential
--------------------------------------------------------------------------------

                                TABLE OF CONTENTS

1.       DOCUMENT CONTROL

================================================================================
      FLOWARE SYSTEM SOLUTIONS
-------------------------------------------------------------------------------
      WALKair[TM]                   Point to Multi-point Wireless Access System
-------------------------------------------------------------------------------
      Project:                      WALKair
-------------------------------------------------------------------------------
      Document:                     Frame Relay  Management  description
================================================================================

1.1.     PUBLICATION HISTORY

================================================================================
      REV.                    DATE                     AUTHOR             NOTES
-------------------------------------------------------------------------------
      1.0                     November 1999            Klara
-------------------------------------------------------------------------------
      1.0                     January 2000             Refaela
-------------------------------------------------------------------------------

===============================================================================

                                                                    Page 2 of 2
<PAGE>

FLOWARE Wireless Systems Ltd                               Company Confidential
--------------------------------------------------------------------------------

2.   SCOPE
This document specifies WALKnet functionality for the management of WALKAir
Frame Relay service support. It contains the description of the Frame Relay
configuration procedure, clarification of manageable parameters and definition
of WALKNet screens.

3.   OVERVIEW
WALKair system provides a full Frame Relay access network, where BS-BU
implements a Network to Network Interface (NNI) and User to Network Interface
(UNI) to the Frame Relay Network and TS-BU implements User to Network Interface
(UNI) to the FRAD (Router). In case of UNI interface Network side only is
supported.

The picture below describes WALKair Frame Relay application configuration.

                                [OBJECT OMITTED]

WALKair Frame Relay interface is running on the dedicated Telecom card over the
V35/X21 physical interface. In the next software versions Frame Relay card will
be also utilized for the Leased Line service.

 .
Configuration and Maintenance of the WALKAir Frame Relay application involves
the management of the following MIB objects:

-        Frame Relay Logical Port Table
-        Frame Relay Management VC Signaling Table
-        Frame Relay PVC End-Point table
-        Frame Relay PVC Connection table

                                                                    Page 3 of 3
<PAGE>
FLOWARE Wireless Systems Ltd                               Company Confidential
--------------------------------------------------------------------------------

4.   FRAME RELAY MANAGEMENT
Frame Relay parameters can be configured on BS-BU and all registered TS-BUs.
BS-BU keeps the FR configuration and transfers it to the Terminal after
connection establishment. In case that configuration mismatch the installed
hardware, TS-BU transmits Configuration mismatch trap.

4.1. FR MENUS
Frame Relay Configuration menus can be reached from the Configuration menu, from
the Base Station view screen BS-BU menu or from the Terminal Station View
screen, Terminal menu.

FR CONFIGURATION -> FR Port
                    FR Service

From the "Configuration" menu operator should select BS-BU or TS-BU using common
WALKNet navigation procedure. Required FR screen of the selected device is
displayed.
Using the menu of the BS-BU view or TS-BU view, operator receives the
selected FR menu of the current device.

4.2. BS-BU VIEW AND TS-BU VIEW DISPLAY
FR card telecom port definitions are displayed on the BS-BU view and TS-BU view
screens. FR card telecom port is identified by the ifType = Frame Relay and in
this case Detected Type is "V35/X21 - FR". Configured Type is the type of FR
card physical interface: V35 or X21.
In the current version user can not configure E1 interface on the Frame Relay
card.

4.3. FR PORT CONFIGURATION WALKair supports single FR Port per FR card.
WALKNet enables the FR Port configuration for the telecom interfaces configured
as V35 or X21.
FR port configuration menu can be reached from the BS-BU or TS-BU or from the
Configuration menu. When reached from the BS-BU or Configuration menus FR
ports defined on BS and all registered TSs are displayed.
When reached from the TS view - FR ports defined on the specified TS are
displayed.

DIALOG TITLE: Frame Relay Ports
----------- ----------- ---------------- -------------------- --------------
DEVICE      PORT #      PORT TYPE        DLCI LENGTH          SIGNALING
                                                              PROTOCOL

----------- ----------- ---------------- -------------------- --------------
----------- ----------- ---------------- -------------------- --------------

----------- ----------- ---------------- -------------------- --------------

Following table describes fields.

                                                                    Page 4 of 4
<PAGE>
FLOWARE Wireless Systems Ltd                               Company Confidential
--------------------------------------------------------------------------------
<TABLE>
<CAPTION>

---------------------- ---------------------------------------------------------------------- ----------------
<S>                    <C>                                                                    <C>
NAME                   DESCRIPTION                                                            ACCESS
---------------------- ---------------------------------------------------------------------- ----------------
Device                 BS-BU or                                                               RC
                       TS (System Name or
                              Customer Id)
---------------------- ---------------------------------------------------------------------- ----------------
Port #                 Telecom port number                                                    RC
---------------------- ---------------------------------------------------------------------- ----------------
Port Type              Type of the network interface supported by this logical port :         RW
                       UNI - User to Network
                                interface , should be
                               defined as default on TS
                               ports and can not be
                               changed by user

                       NNI - Network To Network
                                interface, should be
                               defined as default on
                                BS ports and can be
                                configured by user

---------------------- ---------------------------------------------------------------------- ----------------
DLCI Length            Identifies the Q.922 Address field length and DLCI length for this     RO
                       logical port.

                       WALKAir supports : twoOctets10Bits
---------------------- ---------------------------------------------------------------------- ----------------
Signaling              Identifies the Local                                                   RW
Protocol               In-Channel Signaling Protocol that is used for this logical port :
                       WALKAir supports the following signaling protocols :
                       -        none
                       -        LMI
                       -        ANSI T1617 D - Default
                       -        CCITT Q933 A
---------------------- ---------------------------------------------------------------------- ----------------
</TABLE>

Dialog menu contains the following options:
         Add Port
         Edit Port
         View Port
         Delete Port

Operator selects the line in the port table and option from the menu.

4.3.1. ADD PORT
Using the Add Port dialog operator defines new FR port.
Dialog contains the following elements:
- DEVICE - operator selects device from the drop list containing BS-BU and list
of registered TSs. In case that FR Port dialog was reached from the TS view -
Device column is not displayed

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FLOWARE Wireless Systems Ltd                               Company Confidential
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- PORT - operator selects telecom port from the list of ports configured as
V35/X21.

- PORT TYPE - selection is enabled only for BS. Operator selects from the drop
list containing NNI/UNI

- DLCI LENGTH - this field is read only.

- SIGNALING PROTOCOL - operator selects signaling protocol from the drop list

4.3.2. EDIT PORT

The dialog is like the Add Port , but only Port Type and Signaling Protocol can
be changed.

4.3.3. DELETE PORT

User should receive the Warning message : Frame Relay service defined over the
port will be deleted.

4.4. FR SERVICE CONFIGURATION
WALKAir Frame Relay service is presented by the PVC connection established
between FR Logical Port on BS and FR Logical Port on TS and is identified by
DLCI.
In the current version BS and TS DLCI involved in the connection have the
same value.

FR Service configuration dialog can be reached from BS-BU view, TS-BU view and
Configuration menus. When reached from BS-BU view, it displays all connections
defined in the system on BS-BU and all registered TSs.
Addition of the FR connection can be done only from the BS-BU view.
When reached from TS-BU view it displays connections defined on the selected TS.

DIALOG TITLE: Frame Relay Service
<TABLE>
<CAPTION>

-------- ------------- ----------- ----------- ------------- --------------------- ----------- ------------
<S>      <C>           <C>         <C>         <C>           <C>                   <C>         <C>
         BS PORT       TS ID       TS PORT     DLCI ID       ENDPOINT RCV          OPER        ADMIN
                                                             SIGNALING STATUS      STATUS      STATUS
-------- ------------- ----------- ----------- ------------- --------------------- ----------- ------------
1
-------- ------------- ----------- ----------- ------------- --------------------- ----------- ------------

By default connections should be displayed in sorted by: BS port ,TSs Customer
Id, TS port. Double click on one of the title: BS port, TS Id, TS port and DLCI
will cause WALKNet to redisplay connections sorted according the selected
variable.

Following table describes dialog fields:

------------------------------- ------------------------------------------------------------- -------------
<S>                            <C>                                                            <C>
NAME                            DESCRIPTION                                                   ACCESS
------------------------------- ------------------------------------------------------------- -------------
BS port                         BS Telecom port participating in connection                   RW
                                (Port-1,Port-2,Port-3)
------------------------------- ------------------------------------------------------------- -------------
TS Id                           TS Customer Id                                                RW
------------------------------- ------------------------------------------------------------- -------------
TS port                         TS Telecom port participating in connection                   RW
------------------------------- ------------------------------------------------------------- -------------
DLCI Id                         DLCI on BS and TS port have the same value                    RW
------------------------------- ------------------------------------------------------------- -------------
Endp Rcv Signaling              Endpoint Receive Signaling Status :                           RO
------------------------------- ------------------------------------------------------------- -------------

                                                                    Page 6 of 6
<PAGE>
<CAPTION>

FLOWARE Wireless Systems Ltd                               Company Confidential
--------------------------------------------------------------------------------

------------------------------- ------------------------------------------------------------- -------------
Status                          Deleted
                                Active
                                Inactive
                                None
------------------------------- ------------------------------------------------------------- -------------
Oper Status                     Operational status of connection                              RO
------------------------------- ------------------------------------------------------------- -------------
Admin Status                                                                                  RW
------------------------------- ------------------------------------------------------------- -------------
</TABLE>

Dialog menu contains the following options:
         Add FR Service
         Edit FR Service
         Delete FR Service

Operator selects the line in the DLCI table and option from the menu.

4.4.1.   ADD FR SERVICE
Using this dialog operator defines new FR service. Dialog contains the following
elements:

-    BS PORT - operator selects telecom port from the list of ports configured
as FR Ports on BS.
-    TS ID - operator selects from the drop list containing System Name/Customer
Id of registered terminals with defined FR ports.
-    TS PORT - operator selects from the drop list of ports defined as FR Ports
on TS.
-    DLCI - operator defines DLCI
-    BC - operator defines Committed Burst Size
-    BE - operator defines Excess Burst Size
-    CIR - operator defines Committed Information Rate

Following table describes dialog fields:

<TABLE>
<CAPTION>

------------------------------- ------------------------------------------------------------- ------------------
<S>                            <C>                                                            <C>
NAME                            DESCRIPTION                                                   ACCESS
------------------------------- ------------------------------------------------------------- ------------------
Bc                              Committed burst size (Bc) measured in bits for this PVC       RW
                                end-point
------------------------------- ------------------------------------------------------------- ------------------
Be                              Excess  burst size (Be) measured in bits for this PVC         RW
                                end-point
------------------------------- ------------------------------------------------------------- ------------------
CIR                             Committed Information Rate (CIR) measured in bits per         RW
                                second for this PVC end-point
------------------------------- ------------------------------------------------------------- ------------------
</TABLE>

4.4.2. EDIT FR SERVICE

The dialog is similar to the Add DLCI, but only Bc, Be ,CIR and Admin Status
fields can be changed.
Bc, Be ,CIR fields can be changed only if Admin Status of FR service is not
active.

                                                                    Page 7 of 7
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FLOWARE Wireless Systems Ltd                               Company Confidential
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4.4.3. VIEW FR SERVICE
The dialog is similar to the Add DLCI , but nothing can be changed.

4.4.4. DELETE FR SERVICE
Selected Connection is deleted. Only FR service with Admin Status which is Not
Active can be deleted.

4.5. FR PERFORMANCE MONITORING
FR Performance Monitoring is activated from the Performance menu.
PERFORMANCE ->FR PERFORMANCE -> SIGNALING
                                PVC CONNECTIONS

FR PM screens are organized similar to the APM screens and have the following
columns:
-    Parameter - contains counter description
-    Graph - check box for the graphical display selection
-    Value - displays last received value
-    Minimum/Maximum - counter range used for the graphical display. It can be
     changed by the Edit Range context menu.
-    Get Data/Stop button toggles beginning and termination of the monitoring
     operation.

4.5.1.    SIGNALING

Signaling counters are displayed per FR port selected from the list of FR ports
for the specified BS or TS.

Signaling Error counters are described below:

----------------------------------------- --------------------------------------
NAME                                      DESCRIPTION
----------------------------------------- --------------------------------------
Link Reliability Error                    The number of user-side local
                                          in-channel signaling link reliability
                                          errors (i.e., non-receipt of
                                          status/Status Enquiry messages or
                                          invalid sequence numbers in a Link
                                          Integrity Verification Information
                                          Element) for this UNI/NNI logical port
----------------------------------------- --------------------------------------
User Side Protocol Error                  The number of user-side local
                                          in-channel signaling protocol errors
                                          (i.e.,protocol discriminator, message
                                          type, call reference, and mandatory
                                          information element errors) for this
                                          UNI/NNI logical port.
----------------------------------------- --------------------------------------
Channel Inactive                          The number of times the user-side
                                          channel was declared inactive (i.e.,
                                          N392 errors in N393 events) for this
                                          UNI/NNI logical port.
----------------------------------------- --------------------------------------
Link Reliability Error                    The number of network-side local
                                          in-channel signaling links reliability
                                          errors (i.e., non-receipt of
                                          Status/Status Enquiry messages or
                                          invalid sequence numbers in a Link
                                          Integrity Verification Information
                                          Element) for this UNI/NNI logical
                                          port.
----------------------------------------- --------------------------------------

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FLOWARE Wireless Systems Ltd                               Company Confidential
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----------------------------------------- --------------------------------------
Network Side Protocol Error               The number of network-side local
                                          in-channel signaling protocol errors
                                          (i.e.,protocol discriminator, message
                                          type, call reference, and mandatory
                                          information element errors) for this
                                          UNI/NNI logical port.
----------------------------------------- --------------------------------------
Network Side Channel Inactive             The number of times the network-side
                                          channel was declared inactive (i.e.,
                                          N392 errors in N393 events) for this
                                          UNI/NNI logical port.
----------------------------------------- --------------------------------------

4.5.2.   PVC CONNECTION

PVC connection counters accumulated on BS and TS are displayed concurrently.
User is able to monitor up to 5 connections on the same screen.

When this option is selected from the BS-BU view - user receives screen
containing all connections defined on BS and registered TSs. In case that dialog
was reached from TS view - connections defined on the specified TS are
presented. User selects connections to be monitored and presses "OK" button. PM
screen is opened.

PM screen Value column can be scrolled horizontally to enable display of the
last received value for each selected connection counters. The Label over each
value column contains Index of selected connection.

PVC connection counters are described in the following table. Uplink counters
are accumulated on the BS. Downlink counters are accumulated on.
In case that TS is disconnected , only BS counters are displayed.

-------------------------------- -----------------------------------------------
NAME                             DESCRIPTION
-------------------------------- -----------------------------------------------
BS In frames                              The number of frames received by the
TS In frames                              network (ingress) for this PVC
                                          end-point. This includes any frames
                                          discarded by the network due to
                                          submitting more than Bc + Be data or
                                          due to any network congestion recovery
                                          procedures.
-------------------------------- -----------------------------------------------
 BS Out frames                            The number of frames sent by the
 TS Out frames                            network (egress) regardless of whether
                                          they are Bc or Be frames for this PVC
                                          end-point
-------------------------------- -----------------------------------------------
BS In DE frames                           The number of frames received by the
TS In DE frames                           network (ingress) with the DE bit set
                                          to (1) for this PVC end-point
-------------------------------- -----------------------------------------------
BS In Excess frames                       The number of frames received by the
TS In Excess frames                       network (ingress) for this PVC
                                          end-point which were treated as excess
                                          traffic. Frames which are sent
                                          to the network with DE set to zero are
                                          treated as excess when more than Bc
                                          bits are submitted to the network
                                          during the Committed Information Rate
                                          Measurement Interval (Tc). Excess
                                          traffic may or may not be discarded at
                                          the ingress if more than Bc + Be bits
                                          are submitted to the network during
                                          Tc. Traffic discarded at the ingress
                                          is not
-------------------------------- -----------------------------------------------

                                                                    Page 9 of 9
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-------------------------------- -----------------------------------------------
                                          recorded in frPVCEndptInExcessFrames.
                                          Frames, which are sent to the network
                                          with DE set to one, are also treated
                                          as excess traffic.
-------------------------------- -----------------------------------------------
 BS Out Excess frames                     The number of frames sent by the
 TS Out Excess frames                     network (egress) for this PVC
                                          end-point which were treated as excess
                                          traffic. (The DE bit may be set to
                                          one.)
-------------------------------- -----------------------------------------------
BS In Discards frames                     The number of frames received by the
TS In Discards frames                     the network (ingress) that were
                                          discarded due to traffic enforcement
                                          for this PVC end-point
-------------------------------- -----------------------------------------------
BS In Octets                              The number of octets received by the
TS In Octets                              network (ingress) for this PVC
                                          end-point. This counter should only
                                          count octets from the beginning of the
                                          frame relay header field to the end of
                                          user data.
-------------------------------- -----------------------------------------------
BS Out Octets                             The number of octets sent by the
TS Out Octets                             network (egress) for this PVC
                                          end-point. This counter should only
                                          count octets from the beginning of the
                                          frame relay header field to the end of
                                          user data.
-------------------------------- -----------------------------------------------

                                                                   Page 10 of 10

<PAGE>

Floware Wireless Systems Ltd.                                WALKair V5 Solution
--------------------------------------------------------------------------------

[OBJECT OMITTED]                                   FLOWARE WIRELESS SYSTEMS LTD.
                                                   28 Hacharoshet St., P.O.B 812
THE BUSINESS CUSTOMERS WLL COMPANY                 Or Yehuda 60250 Israel
                                                   Tel: 972-3-5332324
                                                   Fax: 972-3-5332678

                                    WALKAIR-TM-

                  WIDEBAND POINT TO MULTIPOINT WIRELESS SYSTEM

                           V5 SOLUTION SPECIFICATION.

--------------------------------------------------------------------------------
-C- 1996-1999 FLOWARE Wireless Systems Ltd.    All rights reserved.
The material contained herein is proprietary, privileged, and confidential. No
disclosure thereof shall be made to third parties without the express written
permission of FLOWARE System Solutions Ltd. FLOWARE System Solutions Ltd.
reserves the right to alter the equipment specifications and descriptions in
this publication without prior notice. No part of this publication shall be
deemed to be part of any contract or warranty unless specifically incorporated
by reference into such contract or warranty.
--------------------------------------------------------------------------------

                             Confidential                     Page 1 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                 WALKair V5 Solution Specification.
--------------------------------------------------------------------------------

                                TABLE OF CONTENTS

<TABLE>
<S>                                                                        <C>
Y1P. DOCUMENT CONTROL.......................................................3

Y2P. PUBLICATION HISTORY....................................................3

Y3P. ABBREVIATIONS..........................................................3

Y4P. GENERAL................................................................4

Y5P. DEFINITIONS............................................................4

   Y5P.YY1P. V5 INTERFACE...................................................4
   Y5P.YY2P. V5 SUBSCRIBER..................................................5
   Y5P.YY3P. V5 SERVICE.....................................................5

Y6P. CONFIGURATION..........................................................5

Y7P. SIGNALING MULTIPLEXING.................................................6

Y8P. VOICE TRAFFIC..........................................................7

   Y8P.YY1P. VOICE TRAFFIC MULTIPLEXING.....................................7
   Y8P.YY2P. CONCENTRATION..................................................7

Y9P. CONTROL & MAINTENANCE..................................................7

   Y9P.YY1P. INTERFACE CONTROL & PORT CONTROL...............................7
   Y9P.YY2P. LAYER 1 FAILURE................................................8
   Y9P.YY3P. AIR LINK LOSS..................................................8
   Y9P.YY4P. ALL TRUNK BUSY.................................................8
   Y9P.YY5P. AUDITING.......................................................9
     Y9P.YY5P.YY1P. BS V5 AUDIT APPLICATION.................................9
     Y9P.YY5P.YY2P. TS V5 AUDIT APPLICATION................................10

Y10P. ISDN BRA PORTS SUPPORT...............................................11

Y11P. QUALITY OF SERVICE...................................................11

Y12P. V5 NETWORK MANAGEMENT................................................11
</TABLE>

                             Confidential                     Page 2 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                 WALKair V5 Solution Specification.
--------------------------------------------------------------------------------

1.    DOCUMENT CONTROL.

<TABLE>
<CAPTION>
      -----------------------------------------------------------------------------------------------
      FLOWARE WIRELESS SYSTEMS LTD.
      -----------------------------------------------------------------------------------------------
      <S>                                <C>
      Project:                           WALKAIR[TM] POINT TO MULTIPOINT WIRELESS ACCESS SYSTEM
      ---------------------------------- ------------------------------------------------------------
      Document:                          V5 SOLUTION SPECIFICATION
      ---------------------------------- ------------------------------------------------------------
      Document Location :
      ---------------------------------- ------------------------------------------------------------
</TABLE>

2.   PUBLICATION HISTORY.

<TABLE>
<CAPTION>
      ------------- --------------------- -------------------- -------------------------
          REV.               DATE               AUTHOR                       NOTES
      ------------- --------------------- -------------------- -------------------------
      <S>           <C>                   <C>                  <C>
          1.0       2 November, 1999      Lena Marina,         Original Version
                                          Refaela Segdan
      ------------- --------------------- -------------------- -------------------------

      ------------- --------------------- -------------------- -------------------------

      ------------- --------------------- -------------------- -------------------------

      ------------- --------------------- -------------------- -------------------------
</TABLE>

3.    ABBREVIATIONS.

BS            Base Station
BS BU         Basic Unit in the BS
TS            Terminal Station
LCI           Local Craft Interface
NMS           Network Management System
EMS           Element Management Station
OoS           Out of Service
AN            Access Network
LE            Local Exchange
L3 address    Layer 3 address
EF address    Envelope Function address
EOC           Embedded Operation Control

                             Confidential                     Page 3 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                 WALKair V5 Solution Specification.
--------------------------------------------------------------------------------

4.    GENERAL.

Since the WALKair system has a Point to Multi-Point architecture, using V5 for
telephony services provides significant capability in terms of concentration and
efficient air link usage. The WALKair V5.x system is intended to provide PSTN &
ISDN BRA services over V5 interface.

The WALKair V5.x solution is based on the following definitions:
-    V5.2 interface is implemented between the BS and the LE;
-    V5.1 interface is implemented between the Terminal Station and a CPE;
-    The WALKair V5 solution is based on layer 3 termination of V5 protocol.
-    WALKair implementation complies with the following standards:
ETS 300 324-1
ETS 300 347-1

The WALKair V5.x solution provides signaling multiplexing capability between the
Base Station and the Terminal Stations.
The WALKair V5.x solution provides concentration for traffic and thus allows the
support of much more customer ports then the available air capacity.
The WALKair V5.x solution provides additional QoS setting to enable the operator
to define Minimum and Maximum traffic capacity per V5.1 interface at TS*.
The WALKair V5.x system handles the V5 signaling to pass it over the air
protocol internal embedded operational channels (EOC) without reducing traffic
capacity.
The WALKair V5.x handles "Air Link Loss" situation, "All Trunks Busy" condition,
E1 failure using Control Protocols of V5.2/V5.1 interfaces, Protection and BCC
Protocols of V5.2 interface.
The WALKair V5.x system can be configured & handled by NMS/LCI.

5.    DEFINITIONS.

The following paragraphs generally define V5 terms and attributes.

5.1.    V5 INTERFACE.

V5 interface is defined by variant. Variant is a set of provisioning data
parameters, which includes an information about interface:

-    Interface Id;
-    Variant Id;
-    E1 link parameters (Physical Number, Logical Number, ... etc.);
-    C-Channels attributes (Logical Id, Logical Number of associated link,
     provided service bit mask, ...etc.);
-    PSTN & ISDN ports attributes; V5 port is defined by L3 address (PSTN) or EF
      address (ISDN) + assigned time slot (V5.1).

Theoretically, each interface can have several variants.
Interface parameters set can be added, deleted and updated etc. by user via
NMS/LCI.

-------------------------------
* It is not provided by the current software release.

                             Confidential                     Page 4 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                 WALKair V5 Solution Specification.
--------------------------------------------------------------------------------

5.2.     V5 SUBSCRIBER.

V5.x subscriber is a logical object, which is uniquely defined by the following
parameters set:
-    Subscriber type (ISDN/PSTN);
-    Interface Id and address Id at BS;
-    Interface Id and address Id at TS;
-    TS Customer ID;
-    E1 time slot number at TS interface.

Address Id can be L3 address of PSTN port or EF address of ISDN
port*. User can define new V5 subscriber or delete an existing subscriber via
LCI/NMS.

5.3.     V5 SERVICE.

V5 service type is one from Subscriber's attributes. V5 subscribers provides the
following types of services:

-    ON-DEMAND service, where connection is set up at the start of each call.

-    LEASED service, which can be divided to permanent, semi-permanent or
     permanently leased services.

PERMANENT service is handled by leased-line network that is separate from LE,
however such user ports are under control of V5 Control Protocol. This implies
that information about the ports must be available in LE.

SEMI-PERMANENT service is routed through LE via V5 interface.

PERMANENTLY LEASED service has no effect on the V5 interface. However the access
capacity of link decreases from the point of V5 view.

<TABLE>
<CAPTION>
------------------------ ---------------- -------------- --------------- ---------------- -----------------
SERVICE TYPE             PORT TYPES       SIGNALING      V5 CONTROL      LE SWITCHED/NO   WALKAIR
                                          TYPE                                            SUPPORT
------------------------ ---------------- -------------- --------------- ---------------- -----------------
<S>                      <C>              <C>            <C>             <C>              <C>
On-demand                PSTN             Out of band    Controlled      switched         Version 3.0
------------------------ ---------------- -------------- --------------- ---------------- -----------------
On-demand                ISDN BRA         Out of band    Controlled      switched         Version 4.0
------------------------ ---------------- -------------- --------------- ---------------- -----------------
Semi-permanent           ISDN BRA         Out of band    Controlled      switched         Future
------------------------ ---------------- -------------- --------------- ---------------- -----------------
Permanent line           ISDN BRA         In-band        Controlled      bypass LE        Future
------------------------ ---------------- -------------- --------------- ---------------- -----------------
Semi-permanent           analog/          In band        Controlled      switched         Future
                         digital
------------------------ ---------------- -------------- --------------- ---------------- -----------------
Permanently leased line  analog/          In-band        Non             bypass LE        Future
                         digital                         controlled
------------------------ ---------------- -------------- --------------- ---------------- -----------------
</TABLE>

6.    CONFIGURATION.

Each BS-BU is a single V5.2 interface with up to 3 links connected to Public
Switch. BS-BU V5.x software includes V5Core (AN side, V5.2) and set of V5
applications. Theoretically, up to 3 V5.2 interfaces can be configured. However,
current software version provides only 1 V5.2 interface (see restrictions). Each
BS

-----------------------------
* L3 address/EF address is a logical number, which represents an actual
subscriber at V5.x interface.

                             Confidential                     Page 5 of eleventh

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Floware Wireless Systems Ltd.                 WALKair V5 Solution Specification.
--------------------------------------------------------------------------------

BU can communicate with a maximum of 16 TS's each connected to PABX or V5 MUX
by V5.1 interface. Each TS can support up to 3 V5.1 interfaces. All V5
configurations (BS and TSs) are located in the BS V5 database.

V5 database is placed at BS BU non-volatile memory and includes in general 3
tables:

-    Interface (or Variant) table;
-    Subscriber (or Port) table;
-    Routing table; V5 applications uses this table for routing of PSTN or ISDN
     signaling messages, Port Control events and so on. This table is
     automatically built. Routing process takes place only at BS side of V5
     application, thus only one Routing table exists - at the BS side.

Figure 1 depicts an example of WALKair V5 configuration:

[OBJECT OMITTED]

User ports associated with the same V5.2 interface link at BS can be distributed
between the different TSs.

Restrictions:

-    Maximum number of subscribers is 600 per BS-BU.

-    Only one V5.2 interface can be configured in each BS-BU. Please note that
     each V5.2 interface can be configured with multiple links.

-    C-Channel can be configured only on time slot 16 at V5.2 link. This implies
     the support of "protection group 1".

-    There is no re-provisioning (the ability to include few variants or
     configuration sets per interface with on-line change) at the interfaces.

7.    SIGNALING MULTIPLEXING.

V5.1/V5.2 signaling is transferred, out of band, via the EOC (Embedded Operation
Channels). At the downlink direction (from BS to TS) each received signaling
message is routed (see earlier Routing Table definition) and transferred to it's
corresponding TS. At TS the signaling message is directed to appropriate V5.1

                             Confidential                     Page 6 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                  WALKair V5 Solution Specification
--------------------------------------------------------------------------------

interface. At the uplink direction each V5.1 signaling message is transferred as
is to BS BU via the EOC channels. At the BS, V5.1 signaling is routed and
directed to V5.2 interface.

Signaling messages are routed using following user port identifiers:

-    L3/EF address & Interface Id at BS V5.2 interface
-    TS customer Id
-    L3/EF address & Interface Id at TS V5.1 interface

As a result of routing process the destination address parameters of the message
header are changed (Interface ID and L3/EF address).

Signaling data (Information Elements) is transferred transparently over the
WALKair, thus overcomes the national variant specific adaptation.

8.    VOICE TRAFFIC

8.1.     VOICE TRAFFIC MULTIPLEXING

Voice Traffic multiplexing is performed by transferring a voice channel between
a specific bearer channel in one of the BS E1 ports and another specific channel
at a corresponding TS E1 port. The association between bearer channels at BS E1
port and TS E1 port must be fixed at TS V5.1 interface and dynamic at BS V5.2
interface.

8.2.     CONCENTRATION.

Voice Traffic concentration is the capability to allocate air bandwidth only to
active circuits. V5.2 protocol supports concentration by definition. It means
that association between user port and bearer channel on the interface is not
predefined, but bearer channel is allocated dynamically on demand. This
functionality is provided by V5.2 Bearer Channel Connection (BCC) protocol of
interface. BCC controls dynamic allocation/releasing of time slots of interface
according to the demand. Dynamic air channels allocation/release is performed by
BS software and triggered by inputs of the BCC protocol.

9.    CONTROL & MAINTENANCE.

9.1.     INTERFACE CONTROL & PORT CONTROL.
Each V5 interface has two types for interface status:

-    Administrative status, this status is a result of explicit management
     action, and can get two values: ENABLE/DISABLE;

-    Operational status this is the current state of the interface, which can
     get two values: In-Service/Out-of-service.

Administrative status determines the desire status of the interface. If
Administrative Status is changed to ENABLE then Operational Status should change
to IN-SERVICE as a result of successful interface restart and the interface is
ready to transmit and receive traffic. It should remain in the OUT-OF-SERVICE
state if and only if there is a fault that

                             Confidential                     Page 7 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                  WALKair V5 Solution Specification
--------------------------------------------------------------------------------

prevents it from successful restart. If Administrative Status is DISABLE
operational status must be OUT-OF SERVICE.
BS and TS interface statuses are independent; e.g. the status of TS interface
does not affect the status of BS interface and vice verse. However TS/BS status
affects the status of ports.

V5 Port has only one status attribute - Operational status. The reason is that
WALKair operator is not allowed to control Port status. Operational status of
Port can be BLOCKED or UNBLOCKED AND are controlled by Public Switch or CPE.
Usually WALKair V5 application is responsible only to route an appropriate
request (block/unblock) from BS to TS and vise versa.

However, several events trigger Port Block/Unblock by initiative of V5
application:

-    Change the Administrative status of specific TS V5.1 interface to DISABLE
     causes shutdown of the interface. Operational status of the V5.1 interface
     turns to OUT-OF-SERVICE. WALKair can not provide V5 service for the
     subscribers, which are associated with the TS Interface. V5 application
     initiates BLOCK the relevant BS interface ports. After service resuming,
     WALKair invokes ports unblocking.

9.2.     LAYER 1 FAILURE.

Whenever layer 1 failure is detected in one of the V5.1 operational status ports
associated with defected V5 interface are blocked.

Whenever layer 1 failure is detected in one of the V5.2 links, all active calls
in this link are Detected layer 1 failures relating to physical C-channels
within a failed V5.2 link shall result in the protection protocol reassigning
these C-channels. No port blocking is required. The states of associated ports
are not changed.

9.3.    AIR LINK LOSS.

Air Link Loss causes blocking of the relevant user ports at BS V5 interface and
shutdown to the relevant TS V5 interface. After Air Link is re-established,
WALKair invokes configuration to the TSs.

9.4.    ALL TRUNK BUSY.

In the case of All Trunk Busy situation their WALKair V5 application does not
react. This solution is relied on V5 protocol standard. LE side repeats request
to connect traffic channel and in the case of "no response" LE disconnects the
signaling path. The behavior of WALKair V5 application is identical for both
outgoing call and incoming call. The picture below illustrates this situation in
the case of outgoing call.

                             Confidential                     Page 8 of eleventh

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Floware Wireless Systems Ltd.                  WALKair V5 Solution Specification
--------------------------------------------------------------------------------

[OBJECT OMITTED]

9.5.     AUDITING.

V5 Auditing application is responsible to prevent the following situations:

-    Ports of V5 Interfaces can stay permanently blocked. Reason: some racing
     conditions which happen during BS & TS V5 Interfaces internal control
     processes.
-    Non-consistency between states of TS V5.1 and BS V5.2 Ports which represent
     the same subscriber. Reason: some racing conditions which happen during
     WALKair V5 control processes.
-    Non-consistency between Administrative status and Operational status of
     specific Interface.

BS auditing process is triggered by timer and performed by BS Auditing
application. TS auditing process is triggered by BS Auditing application.

9.5.1.   BS V5 AUDIT APPLICATION.

<TABLE>
<CAPTION>
---------------------- --------------------------------------------- -------------------------------------------------
NUMBER OF STEP         CONDITION                                     ACTION
---------------------- --------------------------------------------- -------------------------------------------------

<S>                    <C>                                           <C>
1. BS Interface audit  BS interface Administrative status is         Initiate "Restart BS interface". Skip ports
                       "Enable" and interface operational status     audit (steps 5 and 6).
                        is "Out Of Service"
---------------------- --------------------------------------------- -------------------------------------------------
2. BS Interface audit  BS interface Administrative status is         Initiate "Shutdown BS interface". Skip ports
                       "Disable" and interface operational status    audit (steps 5 and 6).
                       is "In Service"
---------------------- --------------------------------------------- -------------------------------------------------
3. TS Interface audit  TS interface Administrative status is         Initiate "Restart TS interface".
                       "Enable" and interface operational
                       status is "Out Of Service"
---------------------- --------------------------------------------- -------------------------------------------------
4. TS Interface audit  TS interface administrative status is         Initiate "Shutdown Interface"
                       "Disable" and interface operational status
                       is "In-service".
---------------------- --------------------------------------------- -------------------------------------------------
</TABLE>

                             Confidential                     Page 9 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                  WALKair V5 Solution Specification
--------------------------------------------------------------------------------

<TABLE>
<S>                    <C>                                           <C>
---------------------- --------------------------------------------- -------------------------------------------------
5. Port audit          BS Interface Administrative status is         Make sure subscriber is in state "unblocked";
                       "Enable" and interface operational status     if not, initiate for it "block" and immediately
                       is "In-service" - go over all subscribers:    "unblock" process.
                       Subscriber belongs to a TS interface that
                       is "enabled" and "in-service"
---------------------- --------------------------------------------- -------------------------------------------------
6. Port audit          Subscriber belongs to a TS interface that     Make sure subscriber is in state "removed"; if
                       is "out of service"                           not initiate for it "remove" process.
---------------------- --------------------------------------------- -------------------------------------------------
7. Initiate TS V5      -                                             Send message to all TSs to start TS audit.
audit application                                                    Note: this message will contain the BS
                                                                     interface operational state.
---------------------- --------------------------------------------- -------------------------------------------------
</TABLE>

9.5.2.   TS V5 AUDIT APPLICATION.

<TABLE>
<CAPTION>
---------------------- --------------------------------------------- -------------------------------------------------
NUMBER OF STEP         CONDITION                                     ACTION
---------------------- --------------------------------------------- -------------------------------------------------
<S>                    <C>                                           <C>
1. Port audit          BS interface operational status is "In        Make sure subscriber is in state "unblocked";
                       Service"                                      if not, initiate for it "unblock" process.
---------------------- --------------------------------------------- -------------------------------------------------
2. Port audit          BS interface operational status is "Out Of    Make sure subscriber is in state "removed"; if
                       Service"                                      not, initiate for it "remove" process.
---------------------- --------------------------------------------- -------------------------------------------------
</TABLE>

                             Confidential                    Page 10 of eleventh

<PAGE>

Floware Wireless Systems Ltd.                  WALKair V5 Solution Specification
--------------------------------------------------------------------------------

10.   ISDN BRA PORTS SUPPORT.

RESTRICTIONS:

-    Current V5 software version provides only On-demand ISDN service type;
-    Current V5 software version supports only Ds-data type transfer.

For On-demand service Activation/Deactivation of user port (access) is under
control of LE (Public Switch). Access Activation can be initiated by LE or CPE.
Deactivation is initiated only by LE.

V5.x system supports Access Activation/Deactivation processes and Port Status
indication by transferring appropriated messages from BS to TS and vice versa
via EOC. Such messages are routed by Routing Table using Interface Id and EF
address.

11.    QUALITY OF SERVICE*.

V5 guarantees quality of service using BW reservation mechanism Each customer
can be allocated with a minimal guaranteed airtime slots. These airtime slots
will be reserved for it at all times. This customer calls can reach up to a
pre-determined maximum using V5 on-demand service, e.g. incoming calls will be
assigned with air time slots while air time slots that were used by disconnected
calls, will return to the global pool.

12.    V5 NETWORK MANAGEMENT.

The FLOWARE WALKnet EMS using SNMP protocol will manage WALKair V5 application.
The following functionality will be supported:

-    Fault management (see below traps definition);
-    Maintenance & Configuration of V5 interfaces on BS and TS's;
-    Maintenance & Configuration of subscribers parameters;
-    Definitions of quality of service per TS or per

V5 system is responsible to notify the EMS about fault conditions. Current V5
software version uses only 2 following traps:

-    "Interface Restart Failure"
-    "Link Id Process Failure".

The first one is sent in the following cases:

-    "Variant Invalid" indication (when variant is not loaded or has become
     corrupt);
-    "Variant Not Loaded" indication (when variant does not fit interface);
-    error report, concerning V5 interface control errors (for example,
     SYS_C_IdNotIdentical, SYS_C_VariantNotIdentical etc.).

When a trap is sent, the NMS displays a proper message to user.

-----------------------
* This functionality will be implemented in future version.

                             Confidential                    Page 11 of eleventh
<PAGE>
[OBJECT OMITTED]                                             [OBJECT OMITTED]

INFORMATION ABOUT FASTLINK ONU 30 / ONU 20 FOR FIRSTMARK NETWORK

OVERVIEW GENERAL PARAMETERS

                               ONU 20 FTTO                  ONU 30 FTTB
-------------------------------------------------------------------------------
case                           desktop case                  wall case

power consumption          avg.  Less Than  56 W       avg.  Less Than  92 W

dimensions (W x H x D)   370 mm x 165 mm x 247 mm    440 mm x 535 mm x 260 mm

subscriber max                      20                          30

ONU 20 / STRUCTURE

ONU 20 is only available as indoor variant ONU 20 FTTO (Fiber to the Office). It
contains the following modules and plug-in units:
Multiplexer AMX/FMX2

-    with 1 central unit CUA/CUD and 1 to 2 line cards (LC)

-    1 line terminating unit LTC (LTCOH or LT12CM/LT22CM) or LTO/NT

-    Integrated supervision module COSU

-    Central terminal panel

-    Terminal panels for the LCs.

The ONU is installed in a compact case. It can be operated as a desktop model or
with a wall mounting set as a wall model. Fig. 3.12 shows the installation of
the ONU.

[HTML]

                                                                    Page 1 of 6

<PAGE>

[OBJECT OMITTED]                                             [OBJECT OMITTED]

ONU 20 / PICTURE

[html]

ONU 20 / REMOTE MANAGEMENT DESCRIPTION

All the internal connections are made via a backplane. The supervision module
COSU is secured separately in the case. If an LC terminal panel is not required,
an empty case is made available for it.
The case is grounded via a separate conductor.

In principle, ONU 20 FTTO is supplied for remote control and supervision. By
setting the switch, one of the following transmission routes can be selected for
QD2 information:
-    Overhead channel of a line terminating unit
-    X.21 interface of the digital signal channel DSC2-nx64.
If the X.21 interface is used as QD2 access, plug-in position 4 has to be
equipped with digital signal channel DSC2-nx64. In this case, one of the X.21
interfaces of DSC2-n(180)64X (the second one) is used to transfer the control
information and is no longer available as subscriber interface. Transport of ECC
in an used V5.1 connection as separate leased line channel is not possible.

ONU 20 / POWER SUPPLY

An external power pack (115 V AC /230 V AC primary, 56 V DC secondary) provides
the local power supply and loads the battery which can be connected optionally.
In the case of mains failure, there is a battery-backup for approx. 4 hours at
0.6 Erlang.

                                                                    Page 2 of 6

<PAGE>

[OBJECT OMITTED]                                             [OBJECT OMITTED]

As an alternative to the external power pack, a battery voltage in
the range from -48 V to -60 V can also be introduced via the Sub-D jack (3W3).
In this case the battery may not be connected.

ONU 30 / STRUCTURE

ONU 30 is used as indoor variant (FTTB). It contains a system module AMX and,
depending on the available line tract, plug-in unit LTO or LTC as an
alternative. The ONU 30 FTTB is accommodated in a wall case and contains the
following modules:
-    AMX-Mini shelf (AMXMS), equipped with a system module AMX and a line
     terminating unit LTO or LTC
-    main distribution frame with 7 LSA-Plus terminal strips
-    Power supply
-    Battery unit
-    Fan.

                                                                    Page 3 of 6

<PAGE>

[OBJECT OMITTED]                                             [OBJECT OMITTED]

AMXMS is central multiplexer shelf of ONU30. The AMXMS accommodates the
following double Eurocard units without front panel:
-    One central unit CUA
-    One supervision unit MSUE
-    Up to three line cards LC
-    One line terminating unit LTC, LTCP (HDSL) or LTO (optical)
The backplane interconnects the units via external and internal interfaces.

                                                                    Page 4 of 6

<PAGE>

ONU 30 / PICTURE

[HTML]
[HTML]

                                                                    Page 5 of 6
<PAGE>

ONU 30 / REMOTE MANAGEMENT DESCRIPTION

The AMX including the various line cards forms a SISA network element. The
addressing of the network element is assigned by backplane coding with five bits
for the card that provides the access to the network element. Access via a OS or
a LCT is provided to this network element via the CUA or the MSU/MSUE.
The interfaces are:
-    QD2 interface of the CUA with 1.2 kbit/s, 9.6 kbit/s and 64 kbit/s
-    QD2 interface of the MSU/MSUE with 1.2 kbit/s, 9.6 kbit/s and 64 kbit/s
-    ECC interface of the MSUE with 64 kbit/s.
Automatic interface and bit rate detection is provided by the operating program
of the relevant card. The MSU/MSUE can be accessed, for example, via a
transparent overhead channel of the line termination or, in case of the MSUE,
via an ECC included in the PCM signal. Fig. 4.3 shows an example of OS access.
Local operator control of the AMX is effected via the F interface of the
MSU/MSUE.

[HTML]

ONU 30 / POWER SUPPLY

The power is supplied via the local mains. The power line (110/230 V AC) is
connected with the AC terminal clamps in a wall case and is protected by a 10 A
mains fuse. In the case of mains failure, the battery unit (48 V/2.5 Ah) takes
over the power supply and makes possible further operation of the ONU for at
least 4 h.

                                                                    Page 6 of 6

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

SIEMENS

INSTALLATION

OPTICAL NETWORK UNIT
IMN:ONU 30 FTTB

A50010-A3-E108-2-31

A50010-A3-E108-2-31                                                            1

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

IMPORTANT NOTE REGARDING PRODUCT SAFETY

In electrical systems, it is inevitable that certain parts of the devices are
energized / live. Several parts can also have a high operating temperature.

Not paying attention to this situation and not following the warning remarks
can lead to personal injury and material damage.

For this reason, the precondition is made that only trained and qualified
personnel may perform the installation and maintenance of the systems.

The system complies with the requirements of EN 60950 / IEC 60950. Connected
devices must fulfill the relevant safety regulations.

COPYRIGHT (C) SIEMENS AG 1997

Published by the Siemens group Information and Communication Networks
Hofmann Stasse 51
D-81359 Munich
GERMANY

Subject to technical changes.
Technical specifications and performance features are only legally binding If
they are specifically and explicitly agreed in a written contract.

A50010-A3-E108-2-31                                                           2

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

This document consists of 14 pages. All pages are of the version 2.

TABLE OF CONTENTS

<TABLE>
<CAPTION>

<S>        <C>
1          Structure and assembly / installation
1.1.       Structure of the ONU 30 FTTB
1.2        Installation
2          Scope of delivery
3          Components of the ONU 30 FTTB
4          Prerequisites for installation
5          Tools and auxiliary materials
6          Installation of the ONU 30 FTTB
6.1        Connecting the external cables
6.1.1      Connecting the copper telecommunications cables
6.1.2      Connecting the tracer leads of subscriber lines
6.1.3      Glass-fibre connection cable and pigtail
6.1.4      Connection the power supply cable
6.2        Installation of the battery
7          Connection assignment
8          Plugging in the plug-in modules
9          Over-voltage protection
10         Electromagnetic compatibility
11         Appendix

</TABLE>

A50010-A3-E108-2-31                                                           3

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

A50010-A3-E108-2-31                                                           4

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

STRUCTURE AND ASSEMBLY / INSTALLATION

1.1  STRUCTURE OF THE ONU 30 FTTB

     The Optical Network Unit ONU 30 FTTB is contained in a wall housing for
     indoor operation and contains the following functional units:
     - AMX (muliplex function with 30 subscriber interfaces)
     - LTO (optical line termination equipment having 2 x 2 Mbit/s)
     - LTCOH/LT12CM/LT22CM (HDSL line termination equipment having 1 (2) x 2
       Mbits/s)

     FIGURE 1.1 shows the ONU 30 FTTB

<TABLE>

<S>                                    <C>

                                       Compartment for fibre-optic-cable reserves
Power supply unit
                                       Fibre optic connection cable
Mains fuse

                                       Splicing cassette
           Battery unit

LSA connection for LC
(when data cards V35,
V36 and X21 with a front
connection panel are
deployed)
                                       AMXMS

                                       Pigtail

                                       Screw location for glass-fibre earthing
AC connection terminals

                                       EGB clip socket

                                       Fibre optic cable lead-in

Connection terminal for tracer leads

Separate earthing for MS nut on bolts    Network lead-in   Cable lead-ins   Cover contact

</TABLE>

Figure 1.1 View of an ONU 30 FTTB

1.2  INSTALLATION

THE ONU IS INSTALLED IN ROOMS IN THE PRELIMINARY AREA OF THE SUBSCRIBERS TO
BE SUPPLIED. The telecommunications cables are inserted into the ONU housing
through the openings intended for this purpose and connected to the LSA-Plus
strips.  A glass-fibre cable can also be inserted and twisted together in the
splicing cassette with a glass-fibre connection cable (pigtail).  Finally,
the plug-in modules are plugged into the card cage and the pigtail screwed
on.  If HDSL lines are used for the connection of the ONU, they are to be
deposited on a LSA-Plus strip.

The transport weight of the ONU is 20 kg max.

A50010-A3-E108-2-31                                                            5

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

2  SCOPE OF DELIVERY

The scope of delivery includes the components specified in the project list.

3  COMPONENTS OF THE ONU 30 FFTB

The ONU 30 FFTB contains the following components:

-  AMX mini-shelf (AMXMS) loaded with a system module AMX and a line
   termination plug-in module LTO or LTCOH/LT12GM/LT22CM

-  connection panel with 7 LSA-Plus connection stripes for the connection of.
        - 30 DLs for subscriber connection (2-wire) or
        - 20 DLs for subscriber connection (4-wire) and 2 x 10 DLs for
          (2-wire)
        - 1(2) x 2 DLs for HDSL interface (H1,H2)
-  Power supply
-  Battery SBS15
-  Splicing cassette (only where LTO deployed)

4  PREREQUISITES FOR INSTALLATION

The ONU can be attached to a wall or another suitable support.  For the wall
attachment, please follow the following steps:

- Mark the wall using a drilling template
- Drill holes of DIAMETER 12 mm and depth 50 mm at the marked locations
  using a percussion drill
- Insert plugs into the holes (e.g. Fischer plugs M6)
- Screw hexagonal screws of type ISO 4017-M6 x 45 into the upper pegs
  as far as required until the distance from the head of the screw to
  the wall is around 10 mm
- Attach the ONU
- Screw hexagonal screws of type ISO 4017-MG x 45-8.8 into the lower
  pegs through the attachment holes in the back of the ONU
- Tighten all four attachment screws with 7 Nm

5  TOOLS AND AUXILIARY MATERIALS

The tools and auxiliary materials are not included in the delivery.

<TABLE>
<CAPTION>

DESCRIPTION                                                    APPLICATION
<S>                                                            <C>
Toolbox H89999-B512 (available from OEN SP)                    Installation of the ONU

Splicer for fibre-optic cable e.g. FUSIONS SPLICER             Splicing fibre-optic cables
S46999-M7-A80

Cable binders 2.4 x 92                                         Attachment of the cables in the cassette housing

Paper towels                                                   Cleaning of the glass fibres

Sagrosept towels by Schuetke & Mayr GmbH, D-22840              Degreasing of connection cables filled with petrolatum
Norderstadt, Germany                                           after stripping the insulation

Glass-fibre-reinforced-plastic earthing unit Gfk-EB 2/D by     Earthing of glass-fibre cables
Walter Rose GmbH & Co. KG, D-58093 Hagen, Germany

</TABLE>

TABLE 5.1  Tools and auxiliary materials for the installation of the
           ONU 30 FTTB.

A50010-A3-E108-2-31                                                           6

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

6   INSTALLATION OF THE ONU 30 FTTB

6.1 CONNECTING THE EXTERNAL CABLES

The external cables include the copper telecommunications cables, the
glass-fibre connection cable and the power-supply cable.

6.1.1  Connecting the copper telecommunications cables

<TABLE>
<CAPTION>

LOWER EDGE OF THE ATTACMENT BINDER          COPPER LEADS
<S>                                         <C>
30-50(1)                                    35-50(2)

</TABLE>

Interior telecommunications cable

1)  Measurement from lower edge of the attachment binder to the stripping
    point.
2)  Length as per connection location in the MDF              Measurements in mm

FIGURE 6.1  Interior telecommunications cable

The following procedure is necessary:

-  Insert the connection lines from below into the ONU and take the
   measurement up to the connection panel
-  Strip the insulation as shown in FIGURE 6.1
-  Count the double leads (DLs)
-  Attach the DLs on the LSA-Plus connection strips in accordance with the
   project plan (use the attachment tools for LSA-Plus strips).
-  Attach the copper telecommunications cable with the aid of relief straps
   on the cable lead-in of the housing, see FIGURE 1.1
-  Cover the cable if the diameter is low

Numeric sequences of the connection strips is from left to right
Within a given strip, it is from bottom to top.

6.1.2  CONNECTING THE TRACER LEADS OF SUBSCRIBER LINES

If tracer leads are integrated in the connection cables, they are to be
joined together and crimped at the ends.  The end is to be connected to the
connection terminal for tracer leads.

6.1.3  Glass-fibre connection cable and pigtail

       - Prepare glass-fibre connection cable and pigtail
         - Cut the glass-fibre connection cable to the appropriate length and
           prepare it as shown in FIGURE 6.2 all the way to the bundle lead
         - Insert the bundle lead into the fibre-optic-cable lead-in and
           relieve the glass-fibre connection cable
         - Prepare the bundle lead as shown in FIGURE 6.2 all the way to the
           fibre
         - Take out the splicing cassette
         - Make room for splicing
         - Prepare the pigtail as shown in FIGURE 6.3

A50010-A3-E108-2-31                                                           7

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

       - Splice the glass-fibre connection with the pigtail
         - Splice the fibre of the glass-fibre connection cable with the
           fibre of the pigtail
         - Check the splicing connection
         - Insert the fibre of the pigtail and the fibres of the glass-fibre
           connection cable into the splicing cassette, see FIGURE 6.4
         - Close the cassette housing
       - Attach the splicing cassette
         - Insert the splicing cassette in its holder, see Figure 1.1
         - Insert a reserve of the glass-fibre connection cable in the
           compartment for fibre-optic-cable reserves, see FIGURE 1.1

<TABLE>
<S>             <C>                              <C>              <C>        <C>
Pull relief     Glass-fibre connection cable     Bundle lead      Fibre      Measurements in mm
</TABLE>

Figure 6.2  Glass-fibre connection cable

<TABLE>
<S>                      <C>                               <C>       <C>        <C>
FC-PC plug connector     Glass-fibre cable with sheath     Lead      Fibre      Measurements in mm
</TABLE>

Figure 6.3  Pigtails with FC-PC plug connector

<TABLE>

<S>                                    <C>
                                       Cover

                                       Pull relief

Glass-fibre connection cable

Splice insertion

                                       Pigtail c. 400 mm to the FC-PC plug connector, sheath attached

                                       Splicing cassette

</TABLE>

Figure 6.4  Splicing cassette (schematic diagram)

6.1.4  CONNECTION THE POWER SUPPLY CABLE

- Follow the safty regulations in accordance with VBG 4
       - Enable
       - Protect against switching on again
       - Make sure the voltage is switched off (idle state)
       - Earth and short-circuit
       - Cover or encase adjacent parts which are energised / live
- Prepare the cable as shown in FIGURE 6.5
- Guide the cable through the left-hand cable channel to the mains connection
  terminals
- Pull out the mains connection terminals out to the limit
- Connect the cable to the mains connection terminals as shown in Figure 6.6
- Push back the mains connection terminals
- Relieve the cable using the relief strap

A50010-A3-E108-2-31                                                           8

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

Cable(1)  Lower edge of the attachment terminal

<TABLE>
<S>              <C>                          <C>
                                              (3)
200              80(2)

</TABLE>

1)   Maximum diameter 9 mm
2)   Leads 2.5 mm(2) maximum
3)   Protective wire 20 mm longer

FIGURE 6.6  Stripping measurement of the power supply cable in mm

Mains connection terminals

Mains-connection cable

Figure 6.6 Connection of the power-supply cable

6.2  INSTALLATION OF THE BATTERY

The installation of the battery is performed as shown in FIGURE 6.7.  The
ventilation tube must be attached to the ventilation valve of the battery.  The
tube terminates before a ventilation opening in the reverse side of the ONU.

<TABLE>
<S>                      <C>                                            <C>
Ventilation tube pulled out through the back of the housing          To the power supply

red                      black
</TABLE>

Figure 6.7  Connection of the battery set to the battery block

A50010-A3-E108-2-31                                                           9

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

7  CONNECTION ASSIGNMENT

The connection between the AMXMS and the connection panel is made at the
factory.  The assignment of plug-in location in the AMXMS and the relevant
connections is shown in FIGURE 7.1, TABLE 7.1 and TABLE 7.2.  The copper
telecommunications cables for the subscribers must be attached to the
connection panel in accordance with the project plan.

<TABLE>
<S>                                         <C>                 <C>
                                            AMXMs

Internal connection panel (via LSA strips)                      LTO/LTCx deployed
viewed from below                                               A - 2 X G.703, QD2M, QD2S
                                                                A' - H1/H2
                                                                Deployment of data cards
                                                                B data1
                                                                C data2
                                                                D data3
                                                                Line cards deployed
                                                                C - c/d 1 to 10 from LC1
                                                                D - a/b 1 to 10 from LC1
                                                                E - a/b 11 to 20 from LC2
                                                                F - a/b 21 to 30 from LC3

LSA-Plus strips                             Ventilation module

</TABLE>

FIGURE 7.1  Connection assignment in the AMXMS

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------------------
Plug-in module                              Plug-in location in      LSA-Plus strip                   Front connect, Sub-D
                                                  AMXMS                                               module
                                            -----------------------------------------------------
                                            1   2   3   4   5   6    1   2(2)  3(2)  4   5   6   7
--------------------------------------------------------------------------------------------------------------------------
<S>                   <C>                   <C> <C> <C> <C> <C> <C>  <C> <C>   <C>   <C> <C> <C> <C>  <C>
MSUE                  S42024-A1841-A2       x
--------------------------------------------------------------------------------------------------------------------------
CUA                   S42024-A1789-B101(1)      x
--------------------------------------------------------------------------------------------------------------------------
LLA 102/104 (2-wire)  S42024-A1810-A1               x   y   z                            x   y   z
--------------------------------------------------------------------------------------------------------------------------
SUB 102               S42024-A1804-A1               x   y   z                            x   y   z
--------------------------------------------------------------------------------------------------------------------------
I4UK2V5               S42024-A1814-A1               x   y   z                            x   y   z
--------------------------------------------------------------------------------------------------------------------------
LLA 102/104 (4-wire)  S42024-A1810-A1               x                                x   x
--------------------------------------------------------------------------------------------------------------------------
DSC nx64G             S42024-A1767-A1               x                                x   x
--------------------------------------------------------------------------------------------------------------------------
LTCOH                 S42024-A1791-A1                           x    x
--------------------------------------------------------------------------------------------------------------------------
LT12CM (NT)           S42024-A1882-A201                         x    x
--------------------------------------------------------------------------------------------------------------------------
LT22CM (NT)           S42024-A1849-B101                         x    x
--------------------------------------------------------------------------------------------------------------------------
LTO/NT                S42024-A1799-B302                         x
--------------------------------------------------------------------------------------------------------------------------
DSC2-nx64 X21         S42024-A1757-A1(1)            x                                                 S42022-A768-S19
--------------------------------------------------------------------------------------------------------------------------
DSC2-nx65 V35         S42024-A1757-A2(1)            x                                                 S42022-A768-S18
--------------------------------------------------------------------------------------------------------------------------
DSC2-nx64 V36         S42024-A1757-A3(1)            x                                                 S42022-A768-S17
--------------------------------------------------------------------------------------------------------------------------
</TABLE>

1) The subscriber connection is realised via a front-connection module with
   Sub-D;
2) Separator strips for over-voltage protection of ISDN connections used
   (optional)
3) V5.1 or CAS

TABLE 7.1 Loading variations for AMXMS

A50010-A3-E108-2-31                                                          10

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

<TABLE>
<S>      <C>       <C>   <C> <C>         <C>      <C>
CUA                LTx
----------------------------------------------------------------

----------------------------------------------------------------
F2outA             F2inA     F2outB(1)            F2outA(1)
----------------------------------------------------------------
F2outB             F2inB     F2outB2(2)           F2outA2(2)
----------------------------------------------------------------
F2inA              F2outA    QD2MoutB             QD2MoutA
----------------------------------------------------------------
F2inB              F2outB    F2inB(1)             F2inA(1)
----------------------------------------------------------------
                             F2inB2(2)            F2inA2(2)
----------------------------------------------------------------
                             QD2SoutB(4)          QD2SoutA(4)
----------------------------------------------------------------
                             QD2SinB(4)           QD2SinA(4)
----------------------------------------------------------------
                   F2inA2
----------------------------------------------------------------
                   F2inB2
----------------------------------------------------------------
                   F2outA2   QD2MinB              QD2MinA
----------------------------------------------------------------
                   F2outB2
----------------------------------------------------------------

----------------------------------------------------------------
                                         Plug(3)
----------------------------------------------------------------
</TABLE>

                                       LSA strip with EMC module
                                       (2 x HDSL e.g. with LT22CM)

1)  The signal description refers to the CUA proper
2)  The signal description refers to the LTx circuit card proper
3)  The interfaces are accessible at plug connector A, see FIGURE 7.1
4)  The QD2 slave bus is connected in the AMXMS with the ECC of the MSUE

FIGURE 7.2  G.703, GDQ2M/QD2S and HDSL interfaces

<TABLE>
    <S>                      <C>                <C>                      <C>
    Channel A                Channel B          Channel A                Channel B

    Shield                   Shield             Shield                   Shield

    Front connection V.35,                      Front connection V.36,
    ISO4902 37-pole, socket                     ISO4902 37-pole, socket

</TABLE>

FIGURE 7.3  V.35 and V.36 front connection in the ONU 30 FTTB (optional)

A50010-A3-E108-2-31                                                          11

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

<TABLE>
-----------------------------------------------------------------------------------------------------------
CONNECTION ASSIGNMENT OF THE LSA-PLUS STRIPS IN ACCORDANCE WITH THE AMXMS CONFIGURATION, SEE ALSO TABLE 7.1
-----------------------------------------------------------------------------------------------------------
CONNECTION            LLA104            DSC nx64G       LLA 102/SUB102     I4UK2V5(1)      LTCOH/LT22CM
-----------------------------------------------------------------------------------------------------------
<S>   <C>       <C>       <C>        <C>       <C>      <C>                <C>             <C>
      a         F2out A1  F2in C1    D2out A1               F2 A1            D2 A1             H1A1
-----------------------------------------------------------------------------------------------------------
    1 b         F2out B1  F2in D1    D2out B1               F2 B1            D2 B1             H1B1
-----------------------------------------------------------------------------------------------------------
      a         F2out A2  F2in C2    T21 A1    D2in A1      F2 A2                              H2A1
-----------------------------------------------------------------------------------------------------------
    2 b         F2out B2  F2in D2    T21 B1    D2in B1      F2 B2                              H2B1
-----------------------------------------------------------------------------------------------------------
      a         F2out A3  F2in C3    T22 A1                 F2 A3            D2 A2             H1A2
-----------------------------------------------------------------------------------------------------------
    3 b         F2out B3  F2in D3    T22 B1                 F2 B3            D2 B2             H1B2
-----------------------------------------------------------------------------------------------------------
      a         F2out A4  F2in C4    D2out A2  D2in A2      F2 A4                              H2A2
-----------------------------------------------------------------------------------------------------------
    4 b         F2out B4  F2in D4    D2out B2  B2in B2      F2 B4                              H2B2
-----------------------------------------------------------------------------------------------------------
      a         F2out A5  F2in C5    T21 A2                 F2 A5
-----------------------------------------------------------------------------------------------------------
    5 b         F2out B5  F2in D5    T21 B2                 F2 B5
-----------------------------------------------------------------------------------------------------------
      a         F2out A6  F2in C6    T22 A2    D2in A3      F2 A6            D2 A3
-----------------------------------------------------------------------------------------------------------
    6 b         F2out B6  F2in D6    T22 B2    D2in B3      F2 B6            D2 B3
-----------------------------------------------------------------------------------------------------------
      a         F2out A7  F2in C7    D2out A3   D2in A4      F2 A7
-----------------------------------------------------------------------------------------------------------
    7 b         F2out B7  F2in D7    D2out B3   D2in B4      F2 B7
-----------------------------------------------------------------------------------------------------------
      a         F2out A8  F2in C8    D2out A4   D2in A5      F2 A8
-----------------------------------------------------------------------------------------------------------
    8 b         F2out B8  F2in D8    D2out B4   D2in B5      F2 B8
-----------------------------------------------------------------------------------------------------------
      a         F2out A9  F2in C9    D2out A5   D2in A6      F2 A9
-----------------------------------------------------------------------------------------------------------
    9 b         F2out B9  F2in D9    D2out B5   D2in B6      F2 B9
-----------------------------------------------------------------------------------------------------------
      a         F2out A10 F2in C10   D2out A6    Tan A        F2 A10           D2 A4
-----------------------------------------------------------------------------------------------------------
   10 b         F2out B10 F2in D10   D2out B6    Tan B        F2 B10           D2 B4
-----------------------------------------------------------------------------------------------------------
</TABLE>

1)   If the power contact protection is deployed, shunting must take place to
     the separator stripts 1 and 2

TABLE 7.2   Connection of AMXMS to the LSA-Plus strips

If the LTO is deployed, both the G.703 signal (twice) and also the OD2M and
OD2S signal can be taken from the Sub-D plug connector A, see Figure 7.1 and
Figure 7.2.  The connection to the data inputs is effected via the
appropriate connection module. The mounting base with the front connections
is attached to the bars of the connection panel.  The 25-pole Sub-D plug
connectors of modules X.21, V.35 and V.36 are plugged into plug connectors B
to D, 1 to B, 2 to C and 3 to D, see Figure 7.1.

A50010-A3-E108-2-31                                                          12

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

<TABLE>
<S>                          <C>
Front connection X.21

Socket A1                    Socket A2
</TABLE>

FIGURE 7.4  X.21 Front connecteion in the ONU 30 FTTB (optional)

8  PLUGGING IN THE PLUG-IN MODULES

Before unpacking the plug-in modules from the delivered package, put on the
earthing strap.

Earthing takes place via the clip socket on the ONU 30 FTTB to the right of
the cover contact, see Figure 1.1. Remove the packaging around the plug-in
modules and plug them in as per project plan.

9  OVER-VOLTAGE PROTECTION

The wall housing must be included in the potential equalisation.  For the
over-voltage protection and the lightening protection, the protective
elements included in the delivery must be plugged into the subscriber-side
LSA-Plus strips of the connection panels.  The over-voltage dissipaters must
be ordered separately.  In this connection, over-voltage dissipaters for ISDN
are different from over-voltage dissipaters of other line cards.

<TABLE>
<CAPTION>
PROTECTIVE ELEMENT        PLUG-IN TYPE
<S>                       <C>
S42023-A810-S21           ISDN and HDSL
S42023-A810-S22           AB (2-wire, 4-wire)
S42023-A810-S23           Power contact for ISDN
</TABLE>

TABLE 9.1  Assignment of the protective elements to the respective plug-in
type of the AMXMS

A50010-A3-E108-2-31                                                          13

<PAGE>

IMN:ONU 30 FTTB                                                     Installation
                                                            Optical Network Unit

10  ELECTROMAGNETIC COMPATIBILITY

To fulfil the EMC norm ETS 300 386-1, EMC filters must be plugged into the
Sub-D plug connectors in the connection panel of the AMXMS as shown in
TABLE 10.1.

<TABLE>
<CAPTION>
MODULE                    PLUG-IN TYPE
<S>                       <C>
S42023-A810-S20           AB (2-wire, 4-wire)
S42023-A810-S21           ISDN
S42023-A810-S22           HDSL
</TABLE>

TABLE 10.1  Assignment of the EMC modules to the respective plug-in type of
the AMXMS

11  APPENDIX

<TABLE>
<CAPTION>
<S>                                    <C>
           DESCRIPTION                                       APPLICATION
S46999-M7-B60                          Operating manual on splicing glass-fibre connection cables,
                                       e.g. belonging to the thermal splicer S46999-M7-A80
Installation instructions for glass-   Earthing of external glass-fibre cables in accordance with
fibre-cable earthing unit, type 2      TL No. 6015-3006/-3007/-3008
</TABLE>

TABLE 11.1  Installation instructions and operating manuals to be used

A50010-A3-E108-2-31                                                          14

<PAGE>

SIEMENS

INFORMATION

CROSSCONNECT MULTIPLEXER II

SSD: CMXII

A50010-A3-F102-2-7618

<PAGE>

SSD:CMXII                                                       INFORMATION
                                                CROSSCONNECT MULTIPLEXER II
---------------------------------------------------------------------------

Copyright (C) Siemens AG 1998

Issued by the Information and Communication Networks Group
HolmannstraBe 51
D-81359 Muchen

Technical modifications possible.
Technical specifications and features are binding only insofar as
they are specifically and expressly agreed upon in a written contract.

2

<PAGE>

INFORMATION                                                       SSD:CMXII
CROSSCONNECT MULTIPLEXER II
---------------------------------------------------------------------------

<TABLE>

This document consists of a total of 58 pages. All pages are issue 2.

CONTENTS

<S>     <C>                                                                                <C>
1       Application.........................................................................9

2       System Design......................................................................12

2.1     Overview...........................................................................12

2.1.1   V5C Interface......................................................................14

2.1.2   Conference Operation...............................................................14

2.1.3   Unit PUSISA........................................................................14

2.2     External Interfaces................................................................15

2.2.1   2-Mbit/s Interfaces................................................................15

2.2.2   T3-Interface.......................................................................15

2.2.3   QD2 Slave Interface................................................................15

2.2.4   QD2 Master Interface (ECC).........................................................15

2.2.5   F-Interface........................................................................16

2.2.6   QSa Interface......................................................................16

2.2.7   Alarm Contacts.....................................................................16

2.2.8   Power Supply.......................................................................16

2.3     Internal Interfaces................................................................17

2.3.1   PCI Interfaces.....................................................................17

2.3.2   PCI* Interface.....................................................................18

2.3.3   HXC Interface......................................................................18

2.3.4   LSI Interface......................................................................18

2.3.5   CC Interface.......................................................................19

2.3.6   MFA Interface......................................................................19

2.3.7   Supervision Buses and Static Signal Lines..........................................19

2.4     Clock Synchronization..............................................................20

2.5     Redundancy Concept.................................................................21

2.5.1   Unit Redundancy....................................................................21

2.5.2   Protection Switching at the V5C Interface..........................................22

2.5.3   Standby Path Switching in the CMXII-CAS............................................23

2.6     Power Supply.......................................................................23

3       Functions..........................................................................25

3.1     Crossconnect Unit CCU..............................................................25

3.1.1   Overview...........................................................................25

3.1.2   Interfaces.........................................................................25

3.1.3   Monitoring and Alarm Signaling.....................................................26

3.2     CAS Unit CASU......................................................................26

3.2.1   Overview...........................................................................27

3.2.2   Interfaces.........................................................................28

3.2.3   Digital Conferencing...............................................................28

3.2.4   Monitoring and Alarm Signaling.....................................................28

3.3     V5.2 Frame Relay Unit V52FR........................................................29

3.3.1   Overview...........................................................................29

3.3.2   Interfaces.........................................................................30

3.3.3   Monitoring and Alarm Signaling.....................................................30
</TABLE>

                                                                             3
<PAGE>

SSD:CMXII                                                       INFORMATION
                                                CROSSCONNECT MULTIPLEXER II
---------------------------------------------------------------------------

<TABLE>

<S>     <C>                                                                                <C>
3.4     2-Mbit/s Port Units PU2 and PU2+...................................................31

3.4.1   Overview...........................................................................31

3.4.2   Interfaces.........................................................................33

3.4.3   Monitoring and Alarm Signaling.....................................................33

3.5     SISA Port Unit PUSISA...............................................................35

3.5.1   Functional Overview................................................................35

3.5.2   Interfaces.........................................................................36

3.5.3   Monitoring and Alarm Signaling.....................................................36

3.6     Supervision Unit MCU...............................................................37

3.6.1   Overview...........................................................................37

3.6.2   Interfaces.........................................................................38

3.6.3   Monitoring and Alarm Signaling.....................................................38

3.7     Power Supply Unit PSC..............................................................39

3.7.1   Overview...........................................................................39

3.7.2   Interfaces.........................................................................39

3.7.3   External Filtering.................................................................39

3.7.4   Monitoring and Alarm Signaling.....................................................40

4       Control and Monitoring.............................................................41

4.1     Access to the CMXII................................................................41

4.2     Operator Control...................................................................42

4.3     Monitoring.........................................................................42

4.4     Diagnostic Functions...............................................................43

5       Mechanical Design..................................................................44

5.1     General............................................................................44

5.2     CMXII-CS Shelf.....................................................................45

5.2.1   Equipment Configuration............................................................45

5.2.2   Interfaces.........................................................................46

5.3     CMXII-2S Shelf.....................................................................46

5.3.1   Equipment Configuration............................................................46

5.3.2   Interfaces.........................................................................46

5.3.3   Functional Assignment of PU2, PU2+ and PUSISA Mounting Slots.......................47

5.4     CMXII-LS Shelf.....................................................................50

5.4.1   Equipment Configuration............................................................50

5.4.2   Interfaces.........................................................................51

5.4.3   Functional Assignment of PU2, PU2+ and PUSISA Mounting Slots.......................51

6       Software...........................................................................53

6.1     Memory Structure...................................................................53

6.2     Initialization.....................................................................53

7       Technical Data.....................................................................54

7.1     CMXII System Module................................................................54

7.1.1   Environmental Conditions...........................................................54

7.1.2   Power Supply.......................................................................54

7.2     Crossconnect Unit CCU..............................................................54

7.2.1   T3 Interface.......................................................................54

7.2.2   Power Supply.......................................................................54
</TABLE>

4

<PAGE>

INFORMATION                                                       SSD:CMXII
CROSSCONNECT MULTIPLEXER II
---------------------------------------------------------------------------

<TABLE>

<S>     <C>                                                                                 <C>
7.3     V5.2 Frame Relay Unit V52FR.........................................................55

7.4     CAS Unit CASU.......................................................................55

7.5     2-Mbit/s Port Units PU2 and PU2+....................................................55

7.5.1   F1 Interfaces.......................................................................55

7.5.2   QSa Interfaces......................................................................56

7.5.3   Power Supply........................................................................56

7.6     SISA Port Unit PUSISA...............................................................56

7.7     Supervision Unit MCU................................................................56

7.7.1   F Interface.........................................................................56

7.7.2   QD2 Interface.......................................................................57

7.7.3   Alarm Contacts......................................................................57

7.7.4   Power Supply........................................................................57

7.8     Power Supply Unit PSC...............................................................57
</TABLE>

                                                                             5
<PAGE>

SSD:CMXII                                                       INFORMATION
                                                CROSSCONNECT MULTIPLEXER II
---------------------------------------------------------------------------

<TABLE>

ILLUSTRATIONS

<S>          <C>                                                                          <C>
Fig. 1.1     Operation as Concentrating CMXII with V5.2 Interfaces to LE Side.............10

Fig. 1.2     Operation as CMXII with V5.1 Interfaces to the LE Side.......................11

Fig. 1.3     Operation as CMXII with Channel-Associated Signaling.........................11

Fig. 2.1     Functional Diagram of the CMXII with V5 Processing...........................12

Fig. 2.2     Functional Diagram of the CMXII with CAS Signaling...........................13

Fig. 2.3     V5C Interface between CMXII and AMXC.........................................14

Fig. 2.4     Structure of the CMXII with PUSISA...........................................14

Fig. 2.5     Relay Provisioning for Alarm Contacts........................................16

Fig. 2.6     Provisioning of the PCI AND PCI* Links........................................17

Fig. 2.7     Synchronization of the CMXII.................................................21

Fig. 2.8     Redundancy Concept...........................................................22

Fig. 2.9     Power Supply in the CMXII-CS Shelf...........................................23

Fig. 2.10    Power Supply in the CMXII-2S Shelf...........................................24

Fig. 2.11    Power Supply in the CMXII-LS Shelf...........................................24

Fig. 3.1     Functional Diagram of the CCU................................................25

Fig. 3.2     Functional Diagram of the CASU...............................................27

Fig. 3.3     Functional Diagram of the V52FR..............................................29

Fig. 3.4     Functional Diagram of the PU2/PU2+...........................................31

Fig. 3.5     Local and Remote Loopbacks...................................................34

Fig. 3.6     Functional Diagram of the PUSISA.............................................35

Fig. 3.7     Functional Diagram of the MCU................................................37

Fig. 3.8     Functional Diagram of the PSC................................................39

Fig. 4.1     Control Interfaces of the CMXII..............................................41

Fig. 5.1     Arrangement of the Three Shelves Inside the Rack.............................44

Fig. 5.2     CMXII-CS Shelf...............................................................45

Fig. 5.3     CMXII-2S Shelf...............................................................47

Fig. 5.4     CMXII-LS Shelf...............................................................50
</TABLE>

6

<PAGE>

INFORMATION                                                       SSD:CMXII
CROSSCONNECT MULTIPLEXER II
---------------------------------------------------------------------------

<TABLE>

TABLES

<S>           <C>                                                                         <C>
Tab. 1.1      Granularity of the V5.2 Interfaces..........................................10

Tab. 2.1      Structure of a PCI Time Slot................................................17

Tab. 2.2      PCI Frame Structure.........................................................18

Tab. 2.3      Supervision Buses...........................................................19

Tab. 2.4      Static Signal Lines.........................................................20

Tab. 3.1      Signaling the CCU Operating Status..........................................26

Tab. 3.2      Operating States Signaled on the CASU.......................................28

Tab. 3.3      Signaling the V52FR's Operating Status......................................30

Tab. 3.4      Functionalities of the PU2 and PU2+ Units...................................31

Tab. 3.5      Operating States Signaled on the PU2........................................33

Tab. 3.6      Signaling of the PUSIA's Operating Status...................................36

Tab. 3.7      Signaling of the MCU Operating Status.......................................38

Tab. 3.8      Displaying the Operating Status of the CMXII System Module..................38

Tab. 3.9      Signaling of the PSC Operating Status.......................................40

Tab. 5.1      Functional Assignment of the PU2, PU2+ and PUSISA
              in the 2-Shelf Variant (in the V5.2-CMXII)..................................47

Tab. 5.2      Functional Assignment of the PU2, PU2+ and PUSISA
              in the 3-Shelf Variant AN-side Shelf (in the V5.2-CMXII)....................48

Tab. 5.3      Functional Assignment of the PU2, PU2+ and PUSISA
              in the 3-Shelf Variant LE-side Shelf (in the V5.2-CMXII)....................48

Tab. 5.4      Functional Assignment of the PU2, PU2+ and PUSISA
              in the 2-Shelf Variant (in the V5.1 or CAS-CMXII)...........................48

Tab. 5.5      Functional Assignment of the PU2, PU2+ and PUSISA in the
              3-Shelf Variant, AN-side Shelf (in the V5.1 or CAS-CMXII)...................49

Tab. 5.6      Functional Assignment of the PU2, PU2+ and PUSISA in the
              3-Shelf Variant LE-side Shelf (in the V5.1 or CAS-CMXII)....................49

Tab. 5.7      Functional Assignment of the PU2, PU2+ and PUSISA in the
              1- and 2-Shelf Variant (in the V5.2-CMXII)..................................51

Tab. 5.8      Functional Assignment of the PU2, PU2+ and PUSISA
              in the 1- and 2-Shelf Variant (in the V5.1- or CAS-CMXII)...................52
</TABLE>

                                                                          7

<PAGE>

SSD:CMXII                                                            Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

8                                                          A50010-A3-F102-2-7618

<PAGE>

Information                                                            SSD:CMXII
Crossconnect Multiplexer II
--------------------------------------------------------------------------------

1    APPLICATION

     The CMXII is designed principally for the following applications:
     -  Concentrating crossconnect multiplexer for 2-MBit/s signals with V5
        protocol, concentrating V5C interface on the subscriber side and/or
        concentrating V5.2 interface or V5.1 interface on the exchange side
     -  Crossconnect multiplexer for 2-Mbit/s signals with V5.1 protocol
     -  Crossconnect multiplexer for channel-associated signalling (CAS), it
        does not available yet at the moment.

     All ports of the CMXII allow equipment to be connected that has 2-Mbit/s
     interfaces per ITU-T G.703/6. The 2-Mbit/s signals are connected at time
     slot level (64 kbit/s).

     The CAS crossconnect multiplexer can transmit both 2-Mbit/s signals and
     individual 64-kbit/s signals either bidirectionally or unidirectionally.
     Unframed 2-Mbit/s signals can also be cross-connected.

     The CMX II is suitable for making rapid changes in all network
     configurations. It provides the following facilities:

     -  Optional cross-connecting of the payload from up to 184 interfaces
        with 2 Mbit/s each; The maximum number of 2-Mbit/s interfaces can be
        adapted to the network configuration with different shelf variants, see
        Fig. 1.1 to Fig 1.3.
     -  Configurable assignment of the 2-Mbit/s ports towards the subscribers
        (AN) or towards the exchange (LE)
     -  Optional processing of CAS or V5.1 signaling information on the AN
        side, or implementation of a FastLink-internal V5C protocol to
        increase the subscriber concentration; Mixed V5.1 and V5C operation
        is possible. Mixed CAS and V5 operation is not possible.
     -  Optional implementation of the 2-Mbit/s interfaces with CAS, V5.1 or
        V5.2 on the LE side; Mixed operation is not possible
     -  Transmission of leased lines (LL) in the structure n x 64 kbit/s
        (n = 1 to 31) Loopbacks with n x 64 kbit/s (n = 1 to 31) are possible
        on the AN-side.
     -  Support for the following V5 subscriber types
        - PSTN
        - ISDN basic access with configurable number of B-channels (0 to 2)
          and configurable C-channel (p- and f-data)
        - permanent ISDN nailed-up circuits with configurable number of
          B-channels (0 or 1) and configurable C-channel (p- and f-data)
        - semi-permanent nailed-up circuits, analog or digital with 1 or 2
          B-channels ISDN subscribers with primary rate access are not
          supported.
     -  In the CMXII-CAS, digital conference circuits for up to 128x 64-kbit/s
        channels
     -  Provision of up to 128 ECC channels (inband 64 kbit/s) for remote
        control and monitoring of remote network elements
        This reduces the number of 2-Mbit/s interfaces on the LE side by four.
     -  Extraction of an ECC port for remote devices (using only PU2+ unit
        S42024-A1829-A1). This reduces the available transmission channels by
        one.
     -  Facility for remote monitoring of remote network elements via Sa-bit
        interfaces (using only PU2 unit S42024-A1820-A1, outband 1.2 kbit/s)
     -  High service reliability due to extensive redundancy concept.

     The CMXII is configured, controlled and monitored by means of software.
     For this purpose it is provided with suitable interfaces for connection
     to a TMN. Local control is exercised by means of a local craft terminal
     (LCT).

A50010-A3-F102-2-7618                                                          9

<PAGE>

SSD:CMXII                                                            Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

     CMXII WITH V5.2 INTERFACES TOWARDS EXCHANGE (CMXIIR3-V5.2)

     AN SIDE                LE SIDE
     2 Mbit/s               2 Mbit/s
     (G.703/6)              (G.703/6)

           [GRAPHIC OMITTED]

<TABLE>

     ------------------------------------------------------------------------------------------------------------------
        IF type            1 shelf                 2 shelves                  2 shelves                 3 shelves
        AN side            CMXII-LS             CMXII-CS u.-2S             CMXII-LS undCM-            CMXII-CS u.2x
                                                                               XII-2S                   CMXII-2S
     ------------------------------------------------------------------------------------------------------------------
                      2 Mbit/s     Sub         2 Mbit/s     Sub           2 Mbit/s     Sub          2 Mbit/s     Sub
     ------------------------------------------------------------------------------------------------------------------
   <S>               <C>          <C>            <C>       <C>              <C>        <C>          <C>       <C>
     V5.1 with        AN: 32       960          AN: 36     1080            AN:124     3720(1)        AN:128     3840(1)
     30 sub. each     LE: 16                    LE: 32                     LE: 16                    LE: 32
     ------------------------------------------------------------------------------------------------------------------
     V5C with         AN: 32       960          AN: 36     1080            AN:124     3720(1)        AN:128     3840(1)
     120 sub. each    LE: 16                    LE: 32                     LE: 16                    LE: 32
     ------------------------------------------------------------------------------------------------------------------
     V5C with         AN: 32      2048          AN: 36     2304(1)         AN:108     6912(1)        AN:128     8192(1)
     250 sub. each    LE: 16                    LE: 32                     LE: 32                    LE: 32
     ------------------------------------------------------------------------------------------------------------------

</TABLE>

     1) The maximum number of ISDN subscribers (with 1 or 2 B channels) that
        can be arranged is limited to 2048.

     FIG. 1.1   Operation as Concentrating CMXII with V5.2 Interfaces to LE Side

     The four V5.2 Interfaces on the LE side are assigned altogether up to
     32 x 2-Mbit/s interfaces with the following granularity:

<TABLE>
<CAPTION>

     -------------------------------------------------------------------------------------------
     NUMBER OF V5.2 INTERFACES            MAXIMUM NUMBER OF 2-Mbit/s PORTS PER V5.2 INTERFACE
     -------------------------------------------------------------------------------------------
             <S>                                            <C>
               4                                               8
               2                                              16
             2 + 1                                          8 + 16
     -------------------------------------------------------------------------------------------

</TABLE>

     TAB. 1.1  Granularity of the V5.2 Interfaces

     The bearer channels of a V5.1 or V5C interface on the AN side can be
     freely assigned to the V5.2 interfaces on the LE side. Underequipping
     relating to the number of interfaces and the number of 2-Mbit/s ports
     for one V5.2 interface each is possible.

     The remaining number of 2-Mbit/s ports available on the LE side (up to
     24 in the variant with 3 shelves) can be used for through-connecting
     leased lines (LL) or for embedded control channels (ECC) to remote
     devices.

     The resource management for connecting 64-kbit/s channels with
     signaling is controlled dynamically from the exchange using the V5.2
     protocol, leased lines are configured via the management system.

10                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                            SSD:CMXII
Crossconnect Multiplexer II
--------------------------------------------------------------------------------

     CMXII WITH V5.2 INTERFACES TOWARDS EXCHANGE (CMXIIR3-V5.1)

     AN SIDE                LE SIDE
     2 Mbit/s               2 Mbit/s
     (G.703/6)              (G.703/6)

            [GRAPHIC OMITTED]

<TABLE>
<CAPTION>

     -------------------------------------------------------------------------------------------------------
      IF TYPE             1 SHELF             2 SHELVES             2 SHELVES              3 SHELVES
      AN SIDE             CMXII-LS         CMXII-CS u. -2S       CMXII-LS u. 2x -2S    CMXII-CS u. 2 x 2S
                      2 Mbit/s    SUB.     2 Mbit/s    SUB.      2 Mbit/s   SUB.       2 Mbit/s     SUB.
     -------------------------------------------------------------------------------------------------------
     <S>              <C>         <C>      <C>         <C>      <C>         <C>        <C>           <C>
     V5.1 with 30     AN: 24      720      AN: 24      1080     AN: 72      2040       AN:  92       2760(1)
     sub. each        LE: 24               LE: 56               LE: 68                 LE:  92
     -------------------------------------------------------------------------------------------------------
     V5C with 30      AN: 24      720      AN: 36      1080     AN: 72      2040       AN:  92       2760(1)
     20 sub. each     LE: 24               LE: 56               LE: 68                 LE:  92
     -------------------------------------------------------------------------------------------------------
     V5C with 30      AN: 16      960      AN: 32      1080     AN: 48      2760(1)    AN:  60       3720(1)
     20 sub. each     LE: 32               LE: 60               LE: 92                 LE: 124
     -------------------------------------------------------------------------------------------------------
</TABLE>

     1) The maximum number of ISDN subscribers (with 1 or 2 B channels) that
        can be arranged is limited to 2048.

     FIG. 1.2  Operation as CMXII with V5.1 Interfaces to the LE Side

     The bearer channels of a V5.1 or V5C Interface of the AN side can be
     freely assigned to the V5.1 interfaces on the LE side.

     CROSSCONNECT MULTIPLEXER FOR CHANNEL-ASSOCIATED SIGNALING (CMXII-CAS)

     2 Mbit/s               2 Mbit/s
     (G.703/6)              (G.703/6)

            [GRAPHIC OMITTED]

<TABLE>
<CAPTION>

     -------------------------------------------------------------------------------------------------------
      IF TYPE             1 SHELF             2 SHELVES             2 SHELVES              3 SHELVES
      AN SIDE             CMXII-LS         CMXII-CS u. -2S       CMXII-LS u. -2S        CMXII-CS u. 2 x 2S
                      2 Mbit/s    SUB.     2 Mbit/s    SUB.      2 Mbit/s    SUB.       2 Mbit/s     SUB.
     -------------------------------------------------------------------------------------------------------
     <S>              <C>         <C>      <C>         <C>      <C>         <C>        <C>           <C>
     CAS with
     30 sub. each     48          720      92          1380     140         2100       184           2760
     -------------------------------------------------------------------------------------------------------

</TABLE>

     FIG. 1.3  Operation as CMXII with Channel-Associated Signaling

     The CAS signaling frame conforms to ITU-T G.704.

A50010-A3-F102-2-7618                                                         11
<PAGE>

SSD:CMXII                                                            Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

  2  SYSTEM DESIGN

2.1  OVERVIEW

                                [GRAPHIC OMITTED]

     FIG 2.1  Functional Diagram of the CMXII with V5 Processing

     For V5 processing CMXII is equipped as follows, See Fig. 2.1:
     -   One or two crossconnect units CCU, product number: S42024-A1819-A2
     -   Up to 46 Port Units 2 Mbit/s PU2 or PU2+
         Only the PU2+ unit can be used for the V5C concentrator function.
         Other aspects in which PU2+ differs from the PU2 are:
         -  PU2+ has no Sa-bit interface on the AN side
         -  PU2+ (product number S42024-A1829-A2) is cost reduced
         -  PU2+ (product number S4024-A1829-A1) provides inband transmission
            of TMN data via an ECC channel including ECC extraction
         -  The ensuing text uses the term PU2 to refer to both PU2 and PU2+.
            In situations where the difference is relevant, special reference
            will be made to this.

12                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                            SSD:CMXII
Crossconnect Multiplexer II
--------------------------------------------------------------------------------

     -   A SISA interface unit PUSISA (Port Unit SISA) one of which can be
         optionally provided in the CMXII in place of a PU2/PU2+ unit on the
         LE side
     -   One or two V5.2 frame relay units V52FR (V5.2 Frame Relay Unit)
     -   One management control unit MCU
     -   Two to four power supply units PSC.

                                 [GRAPHIC OMITTED]

     FIG. 2.2  Functional Diagram of the CMXII with CAS Signaling

     For CAS signaling the CMXII comprises:
     -   One or two crossconnect units CCU, product number: S42024-A1819-A2
     -   Up to 46 2-Mbit/s interface units PU2+ (Port Unit 2 Mbit/s)
         Two unit variants are available:
         -  S42024-A1829-A1 with ECC extraction
         -  S42024-A1829-A2 cost-reduced, but without ECC extraction
     -   One SISA interface unit PUSISA (Port Unit SISA) one of which can be
         optionally provided in the CMXII in place of a PU2+ unit on the LE
         side
     -   One or two CAS units CASU
     -   One management control unit MCU
     -   Two to four power supply units PCS.

A50010-A3-F102-2-7618                                                         13

<PAGE>

SSD:CMXII                                                            Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

2.1.1 V5C INTERFACE
      The V5C interface is a proprietary interface based on the V5.1 protocol
      with additional implementation of a BCC* protocol. The V5C protocol is
      exchanged between the system modules CMXII and AMXC and permits
      concentration on the subscriber line as well as protection switching of
      the communication channels. Only the PU2+ unit provides V5C interfaces.
      A DIL switch on the unit is used for selecting the required
      functionality.

                              [GRAPHIC OMITTED]

      FIG. 2.4  V5C Interface between CMXII and AMXC

2.1.2 CONFERENCE OPERATION
      In the CMXII with CAS signaling it is possible to establish digital
      conferences between 128 termination points. The 128 64-kbit/s channels
      from which these digital conferences can be established are obtained by
      the CASU from the connection matrix of the CCU.

      Between 3 to 64 channels can be interconnected to form a conference.
      This produces a maximum number of 42 switchable conferences. The
      conferences are configured by means of the software. The necessary data
      are stored in the file system of the MCU unit (non-volatile).

2.1.3 UNIT PUSISA

      How the SISA information for remote devices is distributed via the
      PUSISA is shown in FIG. 2.4.

                              [GRAPHIC OMITTED]

      FIG. 2.4  Structure of the CMXII and PUSISA

14                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                            SSD:CMXII
Crossconnect Multiplexer II
--------------------------------------------------------------------------------

      The SISA information for remote devices is fed in via the QD2 slave
      port or the F interface of the MCU and transferred to the PUSISA via a
      supervision bus. There the information is embedded in a PCI link,
      transferred via the CCU connection matrix to the PU2 on the AN side and
      mapped onto the ECC slot in the 2-Mbit/s frame structure. In the remote
      device which disassembles the 2-Mbit/s frame the relevant ECC is mapped
      out and applied transparently to an ECC port that corresponds to a QD2
      master port. The number of ECCs to be served by the PUSISA is identical
      to the number of devices to be monitored.

      Using a PUSISA unit reduces the number of 2-Mbit/s ports available for
      leased lines on the LE side by 4.

  2.2 EXTERNAL INTERFACES

2.2.1 2-Mbit/s INTERFACES

      The 2-Mbit/s interfaces (F1) are provided by the PU2 units. The
      F1-interfaces are used for receiving and transmitting the HDB3-coded
      PCM signals. They comply with ITU-T Recommendation G.703/6.
      Four F1in and four F1out interfaces are present on each PU2 unit. The
      unbalanced 75-Ohms line impedance or balanced 120-Ohms line impedance
      can be set separately for each interface using dip-fix switches.

2.2.2 T3-INTERFACE

      To synchronize the clock, it is possible to supply a clock signal via
      the T3in interface and output a clock signal via the T3out interface.
      The interface is located on the CCU unit and complies with ITU-T
      Recommendation G.703/10.

      A dip-fix switch can be used to set the input impedance of T3in to low
      impedance (120 OMEGA) or high impedance (1.6 kOhms II LESS THAN 120 pF).
      A clock signal can be transmitted at T3out if the crossconnection is
      synchronized from T3in or from F1in of a 2-Mbit/s port.

2.2.3 QD2 SLAVE INTERFACE

      The MCU unit is equipped with a QD2 slave interface complying to EIA
      RS485 which is used for transmitting control and monitoring data
      between the CMXII and the superordinate network components within a TMN
      system.
      This interface is also used for transmitting the control data to remote
      devices.

2.2.4 QD2 MASTER INTERFACE (ECC)

      The QD2 master interface is located on the PU2+ (-A1) unit on the LE
      side. It is used for transmitting control information to remote OLTs
      not connected to the TMN (no SISAK function). The control information
      is inserted in an ECC channel of the fourth 2-Mbit/s port on the unit
      if the functionality has been selected with the 2-position switch on
      the PU2+. The time slot occupied by the ECC channel is set with a
      5-position DIL switch (TS 1 to 15 and 17 to 31). The QD2 master
      interface is accessible via the terminal panel of the LE-side shelf
      CMXII-2S or the shelf CMXII-LS and conforms to EIA RS485.

A50010-A3-F102-2-7618                                                         15

<PAGE>

SSD:CMXII                                                            Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

2.2.5 F-INTERFACE

      The F-interface is accessible via a 9-contact SUB-D socket as per
      IEC807-2 located on the front panel of the MCU. The F-interface is used
      for connecting a LCT (local craft terminal) which performs OA&M
      functions on a local level. The interface is designed in accordance
      with ITU-T V.24/V.28.

2.2.6 QSa INTERFACE

      The QSa interfaces are implemented on the PU2 units of the AN side of
      the CMXII. There are no QSa interfaces on the PU2+ units. The QSa
      interface allows the transparent transmission of an overhead signal
      required for monitoring remote devices which are connected to the CMXII
      via 2-Mbit/s line terminating units. By way of a transport medium, the
      service word bits of the PCM frame Sa6 (activation for the transmit
      drivers of the distant station if Sa6 = Low) and Sa7 (data) are used.

      The QSa interface signals are switched by the PU2 to a total of three
      RS485 buses. These buses are located at SUB-D connectors in the
      terminal panel of the CMXII-2S shelf on the AN side from where they can
      be connected to the QD2 master port of a SISA concentrator. The
      assignment of the QSa interface for each 2-Mbit/s port is set
      individually by means of the software configuration.

2.2.7 ALARM CONTACTS

      The alarm contacts are arranged on the backplane and are used for
      signaling alarm states in the CMXII system module. The alarm contacts
      are implemented in the form of floating relay contacts which are
      accessible to the user via the terminal panel.

                              [GRAPHIC OMITTED]

      FIG. 2.5  Relay Provisioning for Alarm Contacts

      The user can assign the contacts freely as either normally-open or
      normally-closed contacts. The driver circuits for the relays are
      located on the MCU.

      Alarm contact AZ signals urgent alarm (A-alarm). Alarm contact BZ
      signals non-urgent alarm (B-alarm). The criteria for initiating
      A-alarm  and B-alarm are listed in the alarm table, see installation
      and test manual ITMN. FIG. 2.5 shows the connection of the relays to
      the MCU unit.

2.2.8 POWER SUPPLY

      A input voltage of -48 V/-60 V is fed to the MCU, CCU, CASU/V52FR and
      PSC units of the CMXII.

16                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

2.3     INTERNAL INTERFACES

2.3.1   PCI INTERFACES

        The PCI interfaces are used for transmitting user data between the
        CCU and the peripheral PU2 units. They are also responsible for
        distributing the master clock from the CCU to the periphery.

        The hardware is implemented on the CCU and on the PU2 units in
        conjunction with the resistor provisioning specified in FIG. 2.6.

        One PCI link implements a point-to-point connection between the CCU
        and the periphery via two balanced pairs (separately in the upstream
        and downstream directions) within a cable shield. Each balanced pair
        is used for transmitting data signals with balanced levels from which
        the frame and clock information is extracted.

        The PCI frame contains 162 time slots each with a width of 10 bits.
        The CAS bit is not used in the CMXII and is set to a fixed potential.

        [Graph omitted]

        FIG. 2.6     Provisioning of the PCI and PCI* Links

        The PCI time slots are assigned in TAB. 2.1:

<TABLE>
<CAPTION>
        -------------------------------------------------------------
        BIT          1    2    3    4    5    6    7    8     9    10
        -------------------------------------------------------------
        <S>          <C>  <C>  <C>  <C>  <C>  <C>  <C>  <C>  <C>   <C>
        TS 1 ..161   D1   D2   D3   D4   D5   D6   D7   D8   CAS   P
        -------------------------------------------------------------
        TS 162       R    1    1    1    0    0    1    1     0    P
        -------------------------------------------------------------
</TABLE>

        D1 ... D8:   PCM data
        CAS      :   Bit for CAS signaling (not used here)
        P        :   Parity bit
        R        :   Reserved bit (in PCI downstream direction: Activity
                     status of the CCU displayed)

        TAB. 2.1     Structure of a PCI Time Slot

        A payload of 4 x 2-Mbit/s links each with 32 PCM time slots is mapped
        into each PCI frame according to the following pattern:

A50010-A3-F102-2-7618                                                         17
<PAGE>

SSD: CMXII                                                           Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

<TABLE>
<CAPTION>
        -----------------------------------------------
          PCI              PCM                   PCM
        time slot          link               time slot
        -----------------------------------------------
        <S>                <C>                    <C>
           1                1
        -----------------------------------------------
           2                2                     0
        -----------------------------------------------
           3                3
        -----------------------------------------------
           4                4
        -----------------------------------------------
           5                1
        -----------------------------------------------
           6                2                     1
        -----------------------------------------------
           7                3
        -----------------------------------------------
           8                4
        -----------------------------------------------
                            ...
        -----------------------------------------------
         125                1
        -----------------------------------------------
         126                2                     31
        -----------------------------------------------
         127                3
        -----------------------------------------------
         128                4
        -----------------------------------------------
         129
        -----------------------------------------------
         ...                       Free
        -----------------------------------------------
         161
        -----------------------------------------------
         162                       FSW
        -----------------------------------------------
</TABLE>

        TAB. 2.2     PCI Frame Structure

2.3.2   PCI* INTERFACE

        The PCI* interface is implemented between the CCU and V52FR unit
        respectively between the CCU and CASU unit, and is used for
        transporting time slots with signaling and conference information.
        Each PCI* interface consists of 4 lines (PCI* data in upstream
        direction, PCI* data in downstream direction, PCI* clock and PCI*
        frame synchronization pulse in downstream direction), see FIG. 2.6.

        The frame structure of the PCI* links corresponds to the PCI
        interface.

2.3.3   HXC INTERFACE

        The HXC Interface is implemented between CCU and V52FR. It includes
        12 HDLC channels which are needed for the transport of V5 messages.
        Each HXC port consists of a clock line (from CCU to V52FR) and one
        data line in each direction (upstream and downstream).

2.3.4   LSI INTERFACE

        The LSI interface is implemented on the PU2 (transmitter) and on the
        CCU (receiver). It consists of 7 balanced line pairs and is used for
        transmitting the F1 in timing clock from the PU2 units on the LE side
        to the CCU.

        Only one clock source per LSI line may be activated by the 23 PU2,
        the other transmit drivers are switched to high impedance. The
        hardware is implemented via the terminal panels and connecting cables
        between the CMXII shelves, see Section 5. The LSI interfaces are
        activated on the basis of a clock priority list via the software, see
        Section 2.4.

18                                                         A50010-A3-F102-2-7618
<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

2.3.5   CC INTERFACE

        The CC interface (cross-coupling interface with CC_R and CC_T) is
        implemented on both CCUs and is used for synchronizing the standby
        CCU by the clock master. The clock contains the frequency reference,
        and the position of the central frame synchronization pulse is
        injected via a pulse width modulation function.

2.3.6   MFA INTERFACE

        The MFA interface (Multiframe Alignment Interface) is implemented on
        both CASU units and permits multiframe synchronization of the standby
        CASU by the active CASU. The clock contains the position of frame 15.

2.3.7   SUPERVISION BUSES AND STATIC SIGNAL LINES

        Data are transmitted on all the buses in the manner defined in the
        HDLC protocol. The bus concept is designed such that the traffic
        signal is still transmitted even if one of the bus systems fails. The
        buses are terminated on the units by means of HDLC controllers and,
        where appropriate, RS485 drivers.

<TABLE>
<CAPTION>
        ------------------------------------------------------------------------------------------------------------
        Desig-                         Function                                                    Attributes
        nation
        ------------------------------------------------------------------------------------------------------------
        <S>          <C>                                                                        <C>
        SVB1 to      Supervision buses (one per shelf) for transmitting configuration           Level: RS485
        SVB3         data to the units, for SW download and for acknowledging status            Bit rate: 768 kbit/s
                     information
                     The SVB consists of one point-to-multipoint connection:
                     Master: MCU
                     Slaves: SVB1:     PU2 on the AN side
                             SVB2:     PU2 on the LE side
                             SVB3:     either CCU, CCUS, CASU and CASUS
                                       or CCU, CCUS, V52FR AND V52FRS.
        ------------------------------------------------------------------------------------------------------------
        STSB         Status standby bus for requesting and confirming a switchover of           Level: RS485
                     the standby mode                                                           Bit rate: 128 kbit/s
                     It constitutes a point-to-point connection between CCU and CCUS.
        ------------------------------------------------------------------------------------------------------------
        DTC          Dynamic time slot control bus (one per standby block) for reporting        Level: RS485
                     the seizure of the PCI* links by the CCU to the CASU or to the V52FR.      Bit rate: 128 kbit/s
                     It constitutes a point-to-point connection between the CCU and the
                     CASU or the V52FR of a failure unit.
        ------------------------------------------------------------------------------------------------------------
        UFR          Update frame relay standby bus for configuration data update of the        Level: RS485
                     standby unit by the active unit. This bus is also used to synchronize      Bit rate: 128 kbit/s
                     the internal states of both units, which is necessary for the
                     redundancy concept.
                     The UFR bus provides a direct connection between the two CASU units
                     or between the two V52FR units.
        ------------------------------------------------------------------------------------------------------------
</TABLE>

        TAB. 2.3     Supervision Buses

A50010-A3-F102-2-7618                                                         19
<PAGE>

SSD: CMXII                                                           Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

        In addition static signal lines are implemented with the following
        functions:

<TABLE>
<CAPTION>
        -----------------------------------------------------------------------------------------------
        DES.                         FUNCTION                                     ATTRIBUTES
        -----------------------------------------------------------------------------------------------
        <S>      <C>                                                         <C>
        SEI      Switching the relays for the standby control of the T-3     +5 V via relay contact at
                 interface (2 relays)                                        connector strip of the CCU
        -----------------------------------------------------------------------------------------------
        STPS     For each PSC, a seizure signal (STPSI:PSC Inserted) and     CMOS/pull up
                 an alarm signal (STPSA:PSC Alarm) are transmitted.          two lines for each PSC
                 Low potential means the unit is present and error-free.
        -----------------------------------------------------------------------------------------------
        CCUR     Two static lines (CCUR_T and CCUR_R) are available          +5 V, CMOS level
                 between the CCU/CCUS and the PU2 units which are used
                 for logging on and off from each other. The signalling
                 activates the standby CCU, and the previously active CCU
                 is automatically switched to standby.
        -----------------------------------------------------------------------------------------------
</TABLE>

        TAB. 2.4     Static Signal Lines

2.4     CLOCK SYNCHRONIZATION

        In order for the CMXII to function properly, it is necessary that all
        the 2-Mbit/s F1in and F1out signal flows on both the LE and AN
        sides occur with the same frequency-synchronized clock signal. This
        requirement is fulfilled for the LE side if the signals at the output
        of an exchange are extracted from the same synchronization clock. On
        the AN side, this requirement must be satisfied by implementing clock
        loops in all the connected subscriber equipment NT (NT transmit clock
        = recovered receive clock). If this principle is violated, frame
        slips occur which cause disturbances in the signal transmission.

        The active CCU is always the clock master for all the other units of
        the CMXII except for the MCU.

        The 2-MHz timing clock can be extracted from the following clock
        sources, see FIG. 2.7:

        -   T3in interface for injecting an external synchronization clock

        -   Regenerated clock signal which has been recovered from the F1in
            data at one of the interfaces on the LE side

        -   Internal oscillator on the CCU unit

        7 balanced pairs LSI1 to LSI7 (Line Synchronization Input) are
        available for transmitting F1in timing clock from the PU2 units on
        the LE side to the CCU unit. The source for the timing clock can be
        freely selected from the 92 F1 ports via the software on the basis of
        a priority list. This list determines which of the receive clocks of
        the F1in ports are assigned to which of the 7 timing clock lines.

        If a disturbance in the F1in signal is detected on the PU2 that
        provides a timing clock, the corresponding clock source is switched
        off. The CCU then detects a clock failure and initiates the
        switchover to the clock source with the next lowest priority (see
        alarm table of the CCU in the installation and test manual ITMN). If
        all the external clock sources fail, the PLL of the CCU is switched
        to free-running mode and an urgent alarm is triggered.

        If, during operation with a low-priority standby clock, a clock
        source with a higher priority becomes available, the timing clock is
        automatically switched over to this source.

20                                                         A50010-A3-F102-2-7618
<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

        [Graph omitted]

        FIG. 2.7     Synchronization of the CMXII

        Requirements regarding the phase synchronism of the G.703 interface
        signals originate from the ITU-T Recommendations G.823 and ETS
        TBR-12, and are implemented using buffer stores and jitter reducers
        on the PU2 units. Frame synchronism is realized by means of an
        elastic store.

        The synchronization clocks on the PU2, PUSISA, CASU and V52FR units
        are extracted via PLL from the PCI/PCI* downstream signal. The MCU
        unit generate the necessary clock signal itself, irrespective of the
        CCU.

        The active CCU provides a 2.048-MHz synchronization clock (T3out) for
        the following equipment. This clock is synchronized to the current
        system clock.

        The T3in and T3out lines are switched by a relay (controlled by the
        CCU) located on the backplane of the CMXII-CS and CMXII-LS shelves in
        the event of a switchover to standby mode.

2.5     REDUNDANCY CONCEPT

2.5.1   UNIT REDUNDANCY

        Units CCU, CASU/V52FR and PSC can be equipped with redundancy (CCUS,
        CASUS/V52FRS and PSCS) in such a way that, if one of these units
        fails, the CMXII continues to operate, see FIG. 2.8. One CCU and one
        CASU or one CCU and one V52FR belong to a failure unit together
        switching over between active and standby state. Switchover in the
        event of a fault is done within the CMXII without using on central
        supervision units. The automatic switchover is only possible,
        however, if units CCU and CASU or CCU and V52FR have been plugged
        into both failure units.

        Redundantly plugged PSCs supply the PU2 of a shelf via diode circuit,
        see Section 2.6.

        The failure of a PU2 with V5.1 interfaces or of a PU2 for leased
        lines results in the failure of a maximum 128 x 64-kbit/s subscribers.

A50010-A3-F102-2-7618                                                         21
<PAGE>

SSD: CMXII                                                           Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

        [Graph omitted]

        FIG. 2.8     Redundancy Concept

        If a PU2 with a V5.2 interface fails on the LE side, the
        communication channels can be switched over to standby by the V5.2
        protocol. Current connections passed via the faulty PU2 are cut off.
        The total number of the time slots on the V5.2 interface is reduced
        by 128. This leads to a higher concentration on the V5.2 interface.

/!/     When PU2+ hardware version -A1 is used in the CMXII-CAS, the
        automatical switch over from the active to the standby units can
        result in releasing subscriber connections. If an switch over is
        required (e.g. for unit replacement), the standby units have to be
        activated via the OS menu before the active units will be drawn.

        For the standby operation, the PCI and PCI* buses are duplicated. The
        central units of the two failure units are each connected to separate
        bus systems (PCIS to the standby unit), while the decentral units PU2
        are connected to the two bus systems.

        As regards communication path for redundancy operation, the DTC bus
        is available for the units of a failure unit, while STSB and CCUR are
        available between the two CCUs, see Section 2.3.7.

        In accordance with a clock priority list, the clock sources for the
        synchronous clock of the CMXII are switched standby, see Section 2.4.
        The T3 interfaces of the CCUs are connected to sockets in the
        terminal panel of the CMXII-CS and CMXII-LS shelves via selection
        switches. The selection switches are composed of bistable relays
        which are controled by the CCU. They connect either the CCU or the
        CCUS to the T3 interface.

2.5.2   PROTECTION SWITCHING AT THE V5C INTERFACE

        If a V5C communication channel fails at a V5C interface, it can be
        switched over to a standby if another 2-Mbit/s link is provided. To
        enhance reliability further, the data of a subscriber can also be
        transported via another 2-Mbit/s link. This changeover cannot be
        performed without interruption. The protection switching increases
        the concentration

22                                                         A50010-A3-F102-2-7618
<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

        factor at the V5C interface. If a failed transmission link becomes
        available, the 2-Mbit/s link can be used again without additional
        operator action being necessary.

2.5.3   STANDBY PATH SWITCHING IN THE CMXII-CAS

        For each connection it is possible to configure a standby path to
        which operation is transferred if the following alarm criteria occur:

        - LOS, AIS, SYN, SYNK,
          BER-3, Remote Loop             in all operating modes,

        - AISK, BER-5/6,                 if for alarm criteria with (yes)

        - D-Bit, D(k)-Bit                only for bidirectional connections,

        - Local Loop                     only for unidirectional connections.

        The standby path must be entered in the operations menu.

2.6     POWER SUPPLY

        The input voltage (-48V/-60V) is supplied via a socket in the shelf's
        terminal panel. For standby operation, a second socket (S) is
        available for supplying the input voltage for the standby units. The
        input voltages are supplied via the backplane of the shelves to the
        load circuits.

        [Graph omitted]

        FIG. 2.9     Power Supply in the CMXII-CS Shelf

A50010-A3-F102-2-7618                                                         23
<PAGE>

SSD: CMXII                                                           Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

        [Graph omitted]

        FIG. 2.10     Power Supply in the CMXII-2S Shelf

        The PSC supplies all the PU2 of the CMXII-2S and CMXII-LS shelves
        with the +5-V operating voltage. To comply with the EMC requirements,
        EMC filters are located between the connecting sockets and each PSC.
        When used in conjunction with a second PSC unit, it is possible to
        realize standby operation for the power supply of the shelf in
        question. If two PSCs are equipped, the power required by the shelf
        is divided up symmetrically between both power supply units. If one
        PSC fails, the undisturbed PSC supplies all PU2 in the shelf.

        FIG 2.11     Power Supply in the CMXII-LS Shelf

24                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

    3  FUNCTIONS

  3.1  CROSSCONNECT UNIT CCU

3.1.1  OVERVIEW

       The crossconnect unit CCU is used within the CMXII system module
       for crossconnecting 64-kbit/s channels to the exchange side (LE) and
       subscriber side (AN). For each direction, it is possible to connect
       23 PU2 units to the CCU. This produces a total capacity of 5520
       channels with 64 kbit/s. There are two different CCU units. From
       this version only the CCU with product number S42024-A1819-A2 is
       used.

                                [GRAPHIC OMITTED]

       FIG. 3.1  Functional Diagram of the CCU

       The CCU unit performs the following functions:
       - crossconnection of 64-kbit/s channels and management of the
         database required for this
       - implementation of alarm evaluation and subsequent activation of
         the standby units The active CCU generates the signal CCUR for all
         units of the system. The two CCU units (active and standby) are
         loaded with the same software version and with the same configuration
         data. Each configuration activity for the CCU is followed by the
         configuration of both the active and the standby units being
         updated via the DTC bus.
       - Generation of a system-internal data format for data transfer
         between the CCU and PU2 and of a system-internal data format
         between CCU and V52FR/CASU
       - Clock control via clock priority list
         Controlling the LSI lines to select the F1 in timing clock
       - Implementation of the T3in/T3out interfaces as per G.703/10
         A dip-fix switch is used to switch the input impedance of T3in
         between low impedance (120 Ohms) and high impedance (1,6k Ohms II
         LESS THAN 120 pF)

A50010-A3-F102-2-7618                                                      25

<PAGE>

SSD:CMXII                                                          Information
                                                   Crossconnect Multiplexer II
------------------------------------------------------------------------------

       The connection matrix hardware connects 46 PCI links, two PCI* links
       and two HXC links. Synchronization to the frame alignment signal
       and parity error monitoring are implemented.

       Once the CCU has been inserted, the unit performs a self-test.
       Following a successful self-test and SW download, the unit assumes
       normal operation.

       The CCU software and configuration data are stored in the MCU flash.

3.1.2  INTERFACES

       The CCU units comprises the following interfaces:
       - 46 PCI interfaces to the PU2 units
       - 2 PCI* interfaces to the CASU or V52FR unit
       - 2 HXC interfaces to the CASU or V52FR unit
       - T3in and T3out interfaces as per ITU-T G.703/10
       - SEI line for switching over the T3 interfaces
       - 7 LSI interfaces of the PU2 units on the LE side of the CMXII
       - SVB interface (SVB3) to the MCU unit
       - CC interface to the standby CCU
       - STSB interface to the standby CCU
       - DTC interface to the CASU or to the V52FR and for
         connecting the central units of the standby block
       - CCUR interface to the units of the standby block
       - Slot ID
       - -48-V/-60-V power supply.

3.1.3  MONITORING AND ALARM SIGNALING

       The status of the CCU can be diagnosed using the LED signals
       and the alarm table.

       The front panel of the unit is equipped with 5 SMD-LEDs
       which are only visible when the shelf panel is removed. These
       LEDs indicate the operating status of the CCU.

<TABLE>
<CAPTION>

        LED          COLOR         STATUS                     SIGNIFICANCE
       -----------------------------------------------------------------------------------------
       <S>           <C>           <C>           <C>

       ON            Green         On            Unit OK, active operating status

                                   Flashing      Unit OK, standby status

                                   Off           No power supply or unit failure

       EXTERNAL      Red           On            Alarm status of the external T3 interface

       SYSTEM        Red           On            Alarm status of the system-internal interfaces
                                                 (e.g. parity error or loss of signal on the PCI
                                                 links, double seizure of PCI links)

       INTERNAL      Red           On            Unit fault
                                                 (e.g. self-test error, faults in the +3.3-V supply)

                                   Flashing      Software has not yet been loaded onto unit following
                                                 power up

       SERVICE       Yellow        On            Active service status on the unit
                                                 (e.g. SW download active)
</TABLE>
       TAB. 3.1  Signaling the CCU Operating Status

26                                                       A50010-A3-F102-2-7618

<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

  3.2  CAS UNIT CASU

3.2.1  OVERVIEW

       The CASU unit handles the cross-connection of up to 5520 items of
       signaling information in the CAS crossconnect multiplexer. This
       signaling information is fed to the CASU from the CCU unit via two
       PCI* interfaces.

       In addition the CASU can establish digital conferences between a
       maximum of 128 64-kbit/s channels. The channels to be set in
       conference mode are received by the CASU via the PCI* interfaces.
       The number of 64-kbit/s channels per conference can be between
       3 and 64.

                                [GRAPHIC OMITTED]

       FIG. 3.2  Functional Diagram of the CASU

       The unit performs the following functions:
       - Signaling frame alignment for up to 184 2-Mbit/s ports
       - AIS detection and D-bit evaluation for every signaling frame
         and detection of multiframing failure
       - Cross-connection of the maximum of 5520 CAS signals as well
         as management of the database required for this
       - Assembly of the signaling frame for up to 182 2-Mbit/s ports
       - D-bit and AIS insertion for every signaling frame
         During the startup phase when the CAS configuration table is
         not yet loaded, CAS time slots can be filled by a control
         signal with 1111 (AIS).
       - Establishing up to 42 conferences
       - Switching over to the standby CASU by means of the CCUR signal
         from the CCU
         The two CASU units are loaded with the same software version and
         configuration data. Any configuring of the CASU automatically
         results in updating of the configuration both for the active
         and the standby unit via the UFR bus. The standby CASU is
         also continuously synchronized relative to the multiframe.

       The CASU software and configuration data are stored in the flash of
       the MCU.

A50010-A3-F102-2-7618                                                       27

<PAGE>

SSD:CMXII                                                          Information
                                                   Crossconnect Multiplexer II
------------------------------------------------------------------------------

3.2.2  INTERFACES

       The following interfaces are provided:
       - PCI*1 and PCI*2 interface from the CCU unit
       - MFA interface (FRAME 15) to the standby CASU
       - SVB interface (SVB3) to the MCU unit
       - UFR to the standby CASU
       - DTC from the CCU unit
       - CCUR interface from the CCU unit
       - Card slot address
       - -48V/-60-V power supply.

3.2.3  DIGITAL CONFERENCING

       The data received in burst mode are converted in the CASIC to two
       continuously operating PCM64 signals (64 time slots each, 4.096
       Mbit/s) and forwarded to the conference circuit.

       Digital conferences can be established in two modes:
       - Conferencing full mode
         bidirectional data exchange between all termination points
         involved
       - Point-to-multipoint mode
         bidirectional data exchange between one particular termination
         point and all other termination points involved in the conference.

3.2.4  MONITORING AND ALARM SIGNALING

       The status of the CASU can be diagnosed from the LED signaling
       and the alarm reports.

       On the front of the unit are 5 SMD-LEDs which can be seen only
       after removing the shelf cover. They indicate the operating
       state of CASU.

<TABLE>
<CAPTION>

        LED          COLOR         STATUS                     MEANING
       ----------------------------------------------------------------------------------------------------
       <S>           <C>           <C>           <C>

       EIN (ON)      Green         On            Unit OK, active operating state

                                   Flashing      Unit OK, standby state

                                   Off           No power supply, unit failed or still in initializing mode

       EXTERN        Red           On            See alarm table in the ITMN

       SYSTEM        Red           On            Alarm status of system-internal interfaces e.g. UFR,
                                                 DTC, SVB

       INTERN        Red           On            Unit faults which are not due to external faults,
                                                 e.g. self-test, fault during SW download

                                   Flashing      Unit has not yet been loaded with SW and configuration
                                                 data after power-on

       SERVICE       Yellow        On            Active service state on the unit e.g. SW download active
</TABLE>

       TAB. 3.2  Operating States Signaled on the CASU

28                                                       A50010-A3-F102-2-7618

<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

  3.3  V5.2 FRAME RELAY UNIT V52FR

3.3.1  OVERVIEW

       The V52FR is used in the CMXII system module for processing and
       distributing the signaling information as defined by the V5
       protocol. The information is transmitted as HDLC frames via the
       PCI* AND HXC interfaces to the V52FR.

                                [GRAPHIC OMITTED]

              FIG. 3.3  Functional Diagram of the V52FR

       The unit performs the following functions:
       - Processing of the PCI* receive signals (including testing of the
         CRC checksum, testing for parity)
       - HDLC framing
       - Parity insertion
       - Transmission of the synchronous PCI* signals to the CCU
       - Dealing with the layer 2
         Completion of the V5.2 information with BCC, PSTN, control,
         link-control and protection protocols
       - Frame relay of ISDN information
       - Generation of information for dynamic controlling of the
         connection matrix via the BCC protocol
         This information is transmitted to the CCU via the DTC bus.
       - Generation of information to monitor the 2-Mbit/s ports
       - Switching to standby for failed communication channels
       - Generation of internal PSTN and control information which is
         transmitted to the PU2

A50010-A3-F102-2-7618                                                      29

<PAGE>

SSD:CMXII                                                          Information
                                                   Crossconnect Multiplexer II
------------------------------------------------------------------------------

         - Standby circuit to the second V52FR via the CCUR signal from the
           CCU unit
           The two V52FR units are loaded with the same software version and
           the same configuration data. Each configuration activity for the
           V52FR is followed by the configuration of both the active and the
           standby units being updated via the UFR bus.

       The V52FR software and configuration data are stored in the MCU
       flash.

3.3.2  INTERFACES

       The following interfaces are available:
       - PCI*1 and PCI*2 interfaces from the CCU unit
       - HXC1 and HXC2 interfaces from the CCU unit
       - SVB interface (SVB3) to the MCU unit
       - UFR to the standby V52FR
       - DTC from the CCU unit
       - CCUR interface from the CCU unit
       - Slot ID
       - -48-V/-60-V power supply.

3.3.3  MONITORING AND ALARM SIGNALING

       The status of the V52FR can be diagnosed from the LED signals
       and different alarm reports.

       The front panel of the unit is equipped with 5 SMD LEDs which
       are only visible when the shelf panel is removed. These LEDs
       indicate the V52FR's operating status.

<TABLE>
<CAPTION>

        LED          COLOR         STATUS                     SIGNIFICANCE
       -----------------------------------------------------------------------------------------
       <S>           <C>           <C>           <C>

       ON            Green         On            Unit OK, active operating status

                                   Flashing      Unit OK, standby status

                                   Off           No power supply, unit failure or unit still in
                                                 initialization mode

       EXTERNAL      Red           On            see alarm table in the ITMN

       SYSTEM        Red           On            system-internal interfaces UFR, DTC or SVB are failed

       INTERNAL      Red           On            Unit faults which cannot be traced back to external
                                                 faults, e.g. self-test, frame relay function, unit
                                                 processor

                                   Flashing      SW still not loaded onto unit after switching on

       SERVICE       Yellow        On            Active service status on the unit, e.g. SW download active
</TABLE>

       TAB. 3.3  Signaling the V52FR's Operating Status

30                                                       A50010-A3-F102-2-7618

<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

  3.4  2-MBIT/S PORT UNITS PU2 AND PU2+

3.4.1  OVERVIEW

       The PU2 and PU2+ units are each used for connecting four 2-Mbit/s ports
       with interfaces as per ITU-T G.703 on the AN and LE side of the system
       module CMXII. Assignment to the AN or LE side is effected through the
       backplane contacts.

                                  [GRAPHIC OMITTED]

       FIG. 3.4  Functional Diagram of the PU2/PU2+

       The PU2+ is available in two variants. Unit (-A1) comprises all the
       PU2+ functionalities. Unit (-A2) provides a low-cost alternative.
       A choice must be made between the units according to the application:

<TABLE>
<CAPTION>
       UNIT                             AN SIDE                         LE SIDE
                                 V5.1   V5.C   CAS   Sa bit        V5.2   V5.1   CAS   ECC
       -----------------------------------------------------------------------------------
       <S>                       <C>    <C>    <C>   <C>           <C>    <C>    <C>   <C>

       PU2                        x                    x            x      x

                                    1)    1)     1)                  1)     1)     1)    1)2)
       PU2+ (S42024-A1829-A1)     x      x      x                   x      x      x     x

                                          1)     1)                         1)     1)
       PU2+ (S42024-A1829-A2)     x      x      x                   x      x      x
</TABLE>

       1) A DIL switch is used to select either normal operation
          (V5.1/V5.2/CAS), concentrating AN interface (V5C) or remote
          monitoring (ECC extraction).
       2) If the unit has been configured for remote monitoring, the
          time slots not used as an ECC can be used for leased Lines,
          for V5.1 or for CAS channels.

       TAB. 3.4  Functionalities of the PU2 and PU2+ Units

A50010-A3-F102-2-7618                                                      31

<PAGE>

SSD:CMXII                                                          Information
                                                   Crossconnect Multiplexer II
------------------------------------------------------------------------------

       The PU2/PU2+ unit incorporates four sets of functional groups:
       - for recovering the receive-side data and timing signal from the
         HDB3-coded signal F1in
       - for frame aligning the F1in signal
       - for stripping the frame structure of the F1in signal (recovery of
         the 64-kbit/s signals for further processing on the CCU)
       - for evaluating the CRC4 procedure (CRC4 decoding procedure)
       - for buffering the data signal derived from the F1in signal for the
         purpose of frame alignment within the CMXII
       - for assembling the HDB3-coded 2-Mbit/s signal F1out from the
         transmit-side data and timing signal
       - for forming the frame structure for the F1out signal (including
         CRC4 encoding procedure)
       - for the add/drop function in time slot 16 for V5.1 or CAS
         processing
       - for monitoring the F1in signal in accordance with an alarm table
       - for forming a system-internal data format for the transfer of data
         between PU2/PU2+ and CCU
       - for access to bits Sa6 and Sa7 in the frame service word of any
         F1 interface by means of a serial bus system per EIA RS485
         Sa7 can be sent as well as received. Sa6 is additionally used as
         the enable signal for the transmitters in the CMXII. This
         functionality is usable only on the PU2 units located in the
         CMXII-2S shelf on the AN side. The PU2+ unit has no Sa-bit
         interfaces.
       - for access to bit Sa7 for checking the 2-Mbit/s links on the LE
         side by means of the V5.2 protocol
       - Dip-Fix switches allowing the line impedance to be set to 75
         Ohms unbalanced or 120 Ohms balanced separately for each F1
         interface.

       In addition the unit incorporates the functional groups:
       - for forming a system-internal data format for data transfer
         between PU2/PU2+ and CCU
       - for terminating four V5 links or for terminating four CAS
         links to the AN side or to the LE side
       - for managing the database required for the four interfaces
       - for performing initialization and monitoring functions for
         the functional groups of the four 2-Mbit/s ports
       - for selecting the F1in reference clock
         This function is usable only on the PU2/PU2+ on the LE side.
       - for evaluating the CCUR signal from the CCU for changing over
         the PCI links in redundancy operation
       - for the add-drop function of the ECC channel in the signal
         stream of a 2-Mbit/s port
         The ECC can be inserted in the time slot of the 2-Mbit/s signal
         via the QD2 master interface for remote control of a remote
         OLT and can be connected to the fourth port of the PU2+. The
         position of the ECC within the 2-Mbit/s frame is set using a
         5-position DIL switch on the PU2+.

       The PU2 software and configuration data are stored in the flash of
       the MCU.

32                                                       A50010-A3-F102-2-7618

<PAGE>

Information                                                           SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

3.4.2  INTERFACE

       The following interfaces are served:
       - 4 F1 interfaces as per ITU-T G.703
       - 2 PCI interfaces (active and standby) to the CCU units (CCU
         and CCUS)
       - LSI interfaces to the CCU,
         used only on the PU2 on the LE side
       - QSa interfaces as per EIA RS485 for 8a-bit channel,
         used only on the PU2 on the AN side, these interfaces are
         not provided on the PU2+ units
       - QD2-M interface as per EIA RS485 for ECC channel,
         used only on the PU2+ (-A1) on the LE side, this interface
         is not provided on the PU2 and PU2+ (-A2) units
       - SVB interface (SVB1/SVB2) to the MCU
       - card slot address, unit type and shelf identification
       - CCUR, CCURS to the CCU
       - +5-V operating voltage.

3.4.3  MONITORING AND ALARM SIGNALING

       The status of the PU2 can be diagnosed from alarm reports.

       On the front panel of the unit SMD-LEDs which are only
       visible with the shelf panel removed. They indicate the
       operating state of the PU2.

<TABLE>
<CAPTION>

        LED          COLOR         STATUS                     MEANING
       -----------------------------------------------------------------------------------------
       <S>           <C>           <C>           <C>

       ON            Green         On            Unit OK

                                   Off           No power supply or unit failed

       EXTERNAL      Red           On            Alarm status of the F1 interfaces

       SYSTEM        Red           On            Alarm status of system-internal interfaces (PCI
                                                 link, SVB1/SVB2)

       INTERNAL      Red           On            Unit fault

                                   Flashing      Unit has not yet been loaded with SW after power-on

       SERVICE       Yellow        On            Active service state on the unit
                                                 (SW download active, loop activated)
</TABLE>

       TAB. 3.5  Operating States Signaled on the PU2

       MONITORING THE TRANSMISSION QUALITY AT F1IN

       The PCM signals received at the F1 ports can be continuously
       analyzed to ITU-T G.826 and the values obtained can be stored
       in quality data records. It is possible to view both the current
       quality counter and any stored record.

       In addition a counter also records the framing slips. The counter
       can be interrogated via the user interface.

A50010-A3-F102-2-7618                                                      33

<PAGE>

SSD:CMXII                                                          Information
                                                   Crossconnect Multiplexer II
------------------------------------------------------------------------------

       LOOP CIRCUITS

       For maintenance purposes, loops can be activated to facilitate
       fault location in the event of trouble. The loops can be controlled
       individually for each 2-Mbit/s port. The following loops can be
       established:
       - Local Loop (LL)
         The signal at the transmit port of the 2-Mbit/s interface is
         connected to the receive port, AIS signal is produced in the
         F1out direction. It is thus possible to locate faults within
         the CMXII system module.
       - Remote Loop (RL)
         The signal at the receive port of the 2-Mbit/s interface is
         connected to the transmit port. In the PCI upstream direction
         the AIS signal is inserted in the relevant time slots in place
         of the payload. It is thus possible to locate faults in the
         external connecting lines.

                                  [GRAPHIC OMITTED]

         FIG. 3.5   Local and Remote Loopbacks

         The loop is activated or disconnected by SISA commands via the
         LCT or the OS. The loop status is not stored in the EEPROM.
         The current loopback status can be viewed by means of SISA
         queries. In addition an activated loopback is indicated on
         the unit by the SERVICE-LED. The responses obtained with
         activated loopbacks are given in the alarm table.

         A 2-Mbit/s link, transmitting an ECC channel of the PU2+ for
         remote monitoring, cannot be looped.

34                                                      A50010-A3-F102-2-7618

<PAGE>

Information                                                        SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------------

3.5      SISA PORT UNIT PUSISA

3.5.1    FUNCTIONAL OVERVIEW

         The PUSISA is used for implementing the inband transmission of TMN
         data between the OLT and remote ONUs. By way of a transmission
         medium, for each ONU an ECC is used which seizes one of the 30
         traffic channels of a 2-Mbit/s link framed according to ITU-T
         Recommendation G.704. The transmission rate in an ECC is 64 kbit/s.
         The ECC is switched via the management.

         The PUSISA unit can be used once in the CMXII instead of a PU2 unit
         in the CMXII-2S shelf on the LE side.

                                    [GRAPH OMITTED]

         FIG. 3.6   Functional Diagram of the PUSISA

         The PUSISA unit performs the following functions:

         -  Reception from the MCU of the data for all ECCs to be controlled

         -  Generation of four SISA-V
            Each SISA-V operates up to 32 ECCs.

         -  PCI framing and transmission of the PCI links
            The TMN information is transmitted in a PCI link to the CCU,
            mapped into position in a 2-Mbit/s signal as per ITU-T G.704 in
            the CCU-crossconnect matrix and transmitted to the remote
            equipment.

         -  Frame synchronization of the PCI receive signal

         -  Recovery of the ECC data

         -  Transmission of the data via the SVB1 to the MCU

         -  Evaluation of the signal CCUR signal from the CCU unit to switch
            over the PCI links in standby operation.

         The PUSISA software and configuration data are stored in the MCU
         flash.

A50010-A3-F102-2-7618                                                     35

<PAGE>

SSD:CMXII                                                        Information
                                                 Crossconnect Multiplexer II
----------------------------------------------------------------------------

3.5.2    INTERFACES

         The following interfaces are available:

         -  2 PCI interfaces (active and standby) to the CCU units (CCU and
            CCUS)

         -  SVB1 interface to the MCU

         -  Control signals CCUR, CCURS to the CCU

         -  Slot ID and shelf ID

         -  +5-V operating voltage

3.5.3    MONITORING AND ALARM SIGNALING

         The status of the PUSISA can be diagnosed from the LED signals and
         different alarm reports.

         The front panel of the unit is equipped with 5 SMD LEDs which are
         only visible when the shelf panel is removed. These display the
         operating status of the PUSISA.

<TABLE>
<CAPTION>
         -------------------------------------------------------------------------------------------------------
            LED         COLOR             STATUS                        SIGNIFICANCE
         -------------------------------------------------------------------------------------------------------
        <S>           <C>                <C>            <C>
          ON           Green               On            Unit OK
                                          ----------------------------------------------------------------------
                                           Off           No power supply or unit failure
         -------------------------------------------------------------------------------------------------------
         EXTERNAL      Red                 Off           -
         -------------------------------------------------------------------------------------------------------
         SYSTEM        Red                 On            Alarm status of the system-internal interfaces
                                                         (PCI link, SVB1 or WPIP)
         -------------------------------------------------------------------------------------------------------
         INTERNAL      Red                 On            Unit error
                                          ----------------------------------------------------------------------
                                           Flashing      SW has not yet been loaded onto unit following power up
         -------------------------------------------------------------------------------------------------------
         SERVICE       Yellow              On            Active service status of the unit (SW download active)
         -------------------------------------------------------------------------------------------------------
</TABLE>

         TAB. 3.6  Signaling of the PUSISA's Operating Status

36                                                     A50010-A3-F102-2-7618

<PAGE>

Information                                                        SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------------

3.6      SUPERVISION UNIT MCU

3.6.1    OVERVIEW

         The MCU constitutes a central management unit. There is only one MCU
         present within the CMXII. The MCU is connected via system-internal
         supervision buses to all the units of the CMXII.

         The MCU unit is equipped with a QD2 interface and an F interface.
         The QD2 interface is used for connecting to a operating system,
         while the F interface is used for connecting a LCT. These interfaces
         allow installation data, configuration data, alarm data and test
         data between operating terminal and the CMXII to be exchanged.

                                [GRAPH OMITTED]

         FIG. 3.7  Functional Diagram of the MCU

         The MCU performs the following functions:

         -  Processing of the messages received from either the LCT or the OS

         -  Storing of software and configuration data for all the units of
            the CMXII
            In addition to the flash for its own firmware (bootstrap), the
            MCU processor comprises two other non-volatile memory blocks in
            which the configuration data for all units (size: 512 kBytes, No.
            of write cycles: GREATER THAN 10(5)) and the software files for
            all unit types (size: 2048 kBytes, No. of write cycles: GREATER
            THAN 10(4)) are stored centrally for the entire CMXII.

         -  Polling of the units located on the supervision buses

         -  Generating and outputting messages for the QD2 interface and the
            F interface

         -  Provision of the system time.

A50010-A3-F102-2-7618                                                     37

<PAGE>

SSD:CMXII                                                        Information
                                                 Crossconnect Multiplexer II
----------------------------------------------------------------------------

3.6.2    INTERFACES

         The following interfaces are available:

         -  QD2 interface (slave port) as per EIA RS485

         -  F interface as per ITU-T V.24/V.28

         -  Alarm contacts A_alarm and B_alarm

         -  SVB interface (SVB1 to SVB3) to all the CMXII units

         -  STPSI (status power supply inserted) and
            STPSA (status power supply alarm) from the PSC units

         -  Slot address

         -  -48-V/-60-V power supply.

3.6.3    MONITORING AND ALARM SIGNALING

         The front panel of the unit is equipped with 5 SMD LEDs which are
         only visible when the shelf panel is removed. These display the
         operating status of the MCU.

<TABLE>
<CAPTION>
         -------------------------------------------------------------------------------------------------------
            LED         COLOR             STATUS                        SIGNIFICANCE
         -------------------------------------------------------------------------------------------------------
        <S>           <C>                <C>            <C>
          ON           Green               On            Unit OK
                                          ----------------------------------------------------------------------
                                           Off           No power supply or unit failure
         -------------------------------------------------------------------------------------------------------
         EXTERNAL      Red                 Off           -
         -------------------------------------------------------------------------------------------------------
         SYSTEM        Red                 On            Alarm status of the system-internal interfaces
         -------------------------------------------------------------------------------------------------------
         INTERNAL      Red                 On            Unit error (e.g. self-test error)
         -------------------------------------------------------------------------------------------------------
         SERVICE       Yellow              On            MCU link to the OS or to the LCT
         -------------------------------------------------------------------------------------------------------
</TABLE>

         TAB. 3.7  Signaling of the MCU Operating Status

         The MCU also accommodates one green and one red LED which are both
         visible when the shelf panel is closed. These LEDs are used to
         indicate the operating status of the entire CMXII system module in
         accordance with the alarm table (see installation and test manual
         ITMN).

<TABLE>
<CAPTION>
         ---------------------------------------------------------------------
         CMXII OPERATING STATUS              RED LED             GREEN LED
         ---------------------------------------------------------------------
        <S>                                 <C>                 <C>
         Normal operation                    Off                 On
         ---------------------------------------------------------------------
         A-alarm                             On                  Off
         ---------------------------------------------------------------------
         B-alarm                             Flashing            On
         ---------------------------------------------------------------------
         S-alarm                             On                  On
         ---------------------------------------------------------------------
</TABLE>

         TAB. 3.8  Displaying the Operating Status of the CMXII System Module

38                                                     A50010-A3-F102-2-7618

<PAGE>

Information                                                        SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------------

3.7      POWER SUPPLY UNIT PSC

3.7.1    OVERVIEW

         The PSC power supply unit uses an input voltage in the range of
         -36 V to -72 V to generate the +5-V operating voltage required for
         the PU2 inside the CMXII-2S and CMXII-LS shelves.

                                    [GRAPH OMITTED]

         FIG. 3.8  Functional Diagram of the PSC

         The output voltage is shut down if the input voltage falls below a
         value which lies in the range of -27 V to -33 V.

         The front panel of the unit is equipped with an isolated test jack
         for checking the +5-V operating voltage.

         When used in conjunction with a second PSC unit, standby operation
         for the power supply of the shelf is available.

3.7.2    INTERFACES

         The following interfaces are available on the unit:

         -  Input voltage -36 V to -72 V (PUP and MUP)

         -  Operating voltage +5 V/13 A to the PU2 units

         -  Status power supply inserted (STPSI) to the MCU

         -  Status power supply alarm (STPSA) to the MCU

3.7.3    EXTERNAL FILTERING

         To satisfy the EMC requirements, a filter is connected between the
         connecting sockets of the input voltage and each power supply unit.
         These filters are arranged inside the shelf and are connected to the
         backplane PCB. They also contain the overvoltage protection for the
         equipments.

A50010-A3-F102-2-7618                                                     39

<PAGE>

SSD:CMXII                                                        Information
                                                 Crossconnect Multiplexer II
----------------------------------------------------------------------------

3.7.4    MONITORING AND ALARM SIGNALING

         The PSC is equipped with one green and one red SMD-LED which are
         only visible when the shelf panel is removed. They indicate the
         operating status of the PSC:

<TABLE>
<CAPTION>
         ---------------------------------------------------------------------------------------
         CMXII OPERATING STATUS             LED RED                           LED GREEN
         ---------------------------------------------------------------------------------------
        <S>                                 <C>                             <C>
         Normal operation                    Off                              On
         ---------------------------------------------------------------------------------------
         Fault in the unit                   On                               Off
                                             if signaling is still possible
         ---------------------------------------------------------------------------------------
</TABLE>

         TAB. 3.9  Signaling of the PSC Operating Status

         It is possible to interrogate the presence and correct functioning
         of the unit via a system-internal interface within the CMXII.
         For this purpose, the static signaling lines (open collectors)
         connect the PSC to the MCU unit:

         -  STPSI    "Low" unit present,
                     "High" unit not present,

         -  STPSA    "Low" unit OK,
                     "High" unit faulty (if signaling is still possible).

40                                                     A50010-A3-F102-2-7618

<PAGE>

Information                                                        SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------------

  4      CONTROL AND MONITORING

4.1      ACCESS TO THE CMXII

         The configuration, operator control and the operation monitoring of
         the CMXII are performed via the software. For this purpose, the MCU
         unit is equipped with a QD2 slave interface to the OS and an F
         interface for connecting a LCT. The QD2 interface can be accessed
         via the terminal panel of the CMXII-CS or the CMXII-LS shelves. For
         the F interface, a 9-contact SUB-D socket is located on the front
         panel of the MCU unit.

         Inside the system module, the SW files, configuration data and the
         monitoring information are transmitted between the units via
         supervision buses, see also Section 2.3.7.

                                  [GRAPHIC OMITTED]

         FIG. 4.1  Control Interfaces of the CMXII

         For remote control of remote devices the following facilities are
         available:

         -  Transmission of TMN information via ECC channels (inband
            64 kbit/s)
            If the shelf on the LE side is provided with a PUSISA unit in
            place of a PU2/PU2+ unit for V5.1 or leased lines, it is then
            possible for remote devices having an ECC port to be controlled
            remotely via the CMXII. The PUSISA incorporates the TMN information
            in a 64-kbit/s channel (ECC) that is transmitted in the 2-Mbit/s
            signal from the PU2/PU2+ on the AN side, see Section 3.5.

         -  Access to the Sa-bit channels on the AN side (outband 1.2 kbit/s)
            There are QSa interfaces on the AN-side PU2 units.
            The QSa interface signals are applied by the PU2 to a total of
            three RS485 buses which are terminated on SUB-D connectors in the
            terminal panel of the CMXII-2S shelf on the AN-side, see Fig. 5.3,
            and can be connected there to the QD2 slave port of a SISA
            concentrator.

A50010-A3-F102-2-7618                                                     41

<PAGE>

SSD:CMXII                                                        Information
                                                 Crossconnect Multiplexer II
----------------------------------------------------------------------------

         -  Access to the ECC channel of a 2-Mbit/s signal on the PU2+
            (inband 64 kbit/s) In the "remote monitoring" mode, the PU2+ unit
            offers a QD2-master interface which can be used to transmit
            control information to a remote OLT which does not have direct
            access to the SISA transport network. To achieve this
            functionality, the ECC is inserted in a time slot of a 2-Mbit/s
            signal stream and connected to the fourth F1 port of the PU2+.
            The ECC is transmitted transparently to the QD2-M interface. The
            QD2-M interface signals pass from the unit to the (QSa) D-Sub
            connectors in the terminal panel of the LE-side shelf CMXII-2S or
            CMXII-LS.

4.2      OPERATOR CONTROL

         No control elements are present on the MCU, CASU, V52FR and PUSISA
         units. All the necessary settings for commissioning, operator
         control and servicing are performed via the software using either
         the LCT or the OS, see UMN, UMN:OMN.

         The CCU unit is equipped with a dip-fix switch. This switch is used
         to set the impedance of the T3in interface either to low impedance
         (120 Ohms) or to high impedance (1.6 k Ohms II LESS THAN
         120 pF).

         The PU2/PU2+ units incorporate Dip-Fix switches for setting the
         impedances of the F1 interfaces. The line impedance of each F1
         interface can be set separately to either 75 Ohms unbalanced or
         120 Ohms balanced. The PU2+ unit additionally has a switch for
         setting the functionality (normal operation/V5C on the AN
         side/remote monitoring), as well as a switch for selecting the time
         slot to be used as the ECC.

         The CMXII-CS and CMXII-LS shelves are equipped with a 5-position DIL
         switch for setting the SISA address of the system module.

         The installation and test manual ITMN gives detailed information of
         the switch settings and assignments of connectors.

4.3      MONITORING

         The operating status of each unit is signaled via LEDs, see Sections
         3.1 to 3.7.

         The F1, PCI, PCI*, HXC and LSI interfaces are monitored in
         accordance with the alarm tables on the units in question, see
         installation and test manual ITMN.

         -  The PCI and LSI links between the CCU and the PU2 or PUSISA are
            monitored by the CCU.

         -  The F1 interfaces are evaluated by the PU2 unit.

         -  The CASU/V52FR monitors both PCI* upstream signals which are
            transmitted to the CCU. In addition, the V52FR monitors the both
            HXC signals.

         The MCU unit collects the alarm reports of the various units and
         forwards these in the form of system alarms and SISA0 alarms. The
         system alarms are routed via relay contacts to the terminal panel of
         the CMXII-CS and CMXII-LS shelves. The SISA0 alarms are reported to
         the OA&M processor. LEDs on the MCU unit are used to indicate the
         system alarms.

42                                                     A50010-A3-F102-2-7618

<PAGE>

Information                                                        SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------------

4.4      DIAGNOSTIC FUNCTIONS

         Directly after the input voltage has been switched on, self-test
         routines are run on the software programs and different hardware
         components on the units.

         The PCM signals received at the F1 ports can be constantly analyzed
         as per ITU-T G.826 and the obtained values are stored in performance
         data records. It is possible to display both the current quality
         counter and any of the records which have been stored.

         The number of frame slips which have occurred at a 2-Mbit/s port can
         be interrogated via the operating terminal.

         For maintenance purposes, it is possible to implement loops on the
         PU2 units, see also Section 3.4:

         -  Local loop for fault location within the CMXII system module,

         -  Remote loop for fault location of the external 2-Mbit/s
            connections.

         Maintenance Manual UMN, UMN:MMN gives a detailed description of the
         alarm procedures.

A50010-A3-F102-2-7618                                                     43

<PAGE>

SSD:CMXII                                                           Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

  5    MECHANICAL DESIGN

5.1    GENERAL

       The mechanical design of the CMXII is based on 19-inch shelves with
       associated terminal panel. The maximum number of 2-Mbit/s interfaces
       can be adapted to the network configuration using different shelf
       variants:

       -  Three shelves for up to 184 2-Mbit/s interfaces, one CMXII-CS shelf
          and two CMXII-2S shelves

       -  Two shelves for up to 140 2-Mbit/s interfaces, one CMXII-LS shelf
          and one CMXII-26 shelf, or one CMXII-CS shelf and one CMXII-2S
          shelf

       -  One shelf for up to 48 2-Mbit/s interfaces, one CMXII-LS shelf.

       The shelves themselves are designed such that they can be accommodated in
       19-inch or ETS standardized racks. All units are in the form of double
       Eurocards. A backplane PCB interconnects all the units within a shelf and
       implements the connections to the terminal panel.

                                 [GRAPHIC OMITTED]

       FIG. 5.1  Arrangement of the Three Shelves inside the Rack

44                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                            SSD:CMXII
Crossconnect Multiplexer II
--------------------------------------------------------------------------------
       The shelves are arranged on top of each other inside the racks, see FIG.
       5.1. The connections required between the shelves (PCI, LSI and SVB) are
       made via the terminal panels. Connectorized lines are available for that,
       see installation Manual IMN.

       The external interface cables are connected to connectors which are
       provided for them in the terminal panels, see so in FIG. 5.2 and FIG.
       5.3. The assignments of the connectors can be found in the installation
       and test manual ITMN.

  5.2  CMXII-CS Shelf

5.2.1  EQUIPMENT CONFIGURATION

       The shelf accommodates the central units of the CMXII.

                               [GRAPHIC OMITTED]

       FIG. 5.2  CMXII-CS Shelf

       For the CMXII with V5 processing, the shelf is equipped following:

       -    One MCU

       -    Either one or two V52FR

       -    Either one or two CCU (product number: S42024-A1819-A2).

       Two CCU and V52FR units have to be equipped for operation in standby
       mode.

       For the CMXII with CAS processing, the shelf is equipped in the following
       way:

       -   One MCU

       -   Either one or two CASU

       -   Either one or two CCU (product number: S42024-A1819-A2).

       Two CCU and CASU units have to be equipped for operation in standby mode.

A50010-A3-F102-2-7618                                                         45

<PAGE>

SSD:CMXII                                                           Information
                                                     Crossconnect Multiplexer II
--------------------------------------------------------------------------------

5.2.2. INTERFACES

       The following interfaces are available on the shelf:

       -   Supervision buses from the CMXII-2S shelves on the LE side (SVB1)
           and on the AN side (SVB2)

       -   QD2 slave interface from the OS to the MCU unit

       -   F interface as per ITU-T V.24/V.28 on the MCU unit

       -   Interfaces T3in(down arrow) and T3in/T3out(up arrow, down arrow)
           to the CCU unit

       -   Alarm interfaces for urgent (A-alarms) and non-urgent alarms
           (B-alarms)

       -   PCI buses from the PU2 of the CMXII-2S shelves on the AN side (1
           to 23)(1) and on the LE side (24 to 46)(1)

       -   PCI standby buses from the PU2 of the CMXII-2S shelves on the AN
           side (1S to 23S)(1) and on the LE side (24S to 46S)(1)

       -   F1in timing clock LSI from the PU2 of the CMXII-2S shelf on the
           LE side to the CCU

       -   5-position DIL switch for setting the SISA address of the system
           module

       -   -48-V input voltage for MCU, CCU and CASU/V52FR units;
           -48-V-S input voltage for standby units

  5.3      CMXII-2 SHELF

5.3.1      EQUIPMENT CONFIGURATION

       The CMXII-2S shelf is equipped with:

       -   Up to 23 PU2 units

       -   Either one or two PSC

       -   Optionally one PUSISA, once at any PU2 mounting slot on the LE
           side.

       For standby mode, it is possible to equip two PSC units.

5.3.2      INTERFACES

           The following interfaces are available on the shelf:

       -   Supervision bus from the CMXII-CS shelf (SVB1 on the LE side and
           SVB2 on the AN side)

       -   2-Mbit/s interfaces (P1 to P92) as per ITU-T G.703 to the PU2 units

       -   QSa interfaces to the PU2 on the AN side for monitoring remote
           devices. The are no QSa interfaces on the PU2+ units.

       -   QD2-M (ECC) interface to the PU2+ of the LE side for monitoring
           remote devices. The interface is only available on the PU2+
           unit (-A1).

       -   PCI bus from the PU2 on the AN side (1 to 23)(1) and from the PU2
           of the LE side (24 to 46)(1)

       -   PCI standby bus from the PU2 on the AN side (1S to 23S)(1) and
           from the PU2 of the LE side (24S to 46S)(1)

       -   F1in timing clock LSI from the PU2 of the LE side to the CCU unit

       -   -48-V input voltage for PSC and -48-V-S input voltage for PSC
           standby unit.

       1)  In CMXII-CAS the mounting slots for the PU2/PU2+ are not
           pre-assigned to the AN or LE side and therefore there is no fixed
           assignment of the PCI buses.

46                                                        A50010-A3-F102-2-7618

<PAGE>

Information                                                  SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------

                            [GRAPHIC OMITTED]

       FIG. 5.3  CMXII-2S Shelf

5.3.3  FUNCTIONAL ASSIGNMENT OF PU2, PU2+ AND PUSISA MOUNTING SLOTS

       CONCENTRATING CMXII WITH V5.2 INTERFACES TO THE LE SIDE

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------
FUNCTION OF THE UNITS             EQUIPPING OPTIONS (W. CMXII-CS)            EQUIPPING OPTIONS (W. CMXII-LS)
---------------------------------------------------------------------------------------------------------------
<S>                               <C>                                        <C>
V5.2 interfaces on the LE side    4 x PU2/PU2+, slots 21 to 24               8 x PU2/PU2+, slots 2 to 9
---------------------------------------------------------------------------------------------------------------
V5.1 interfaces on the AN side    23 x PU2/PU2+, slots 2 to 24               9 x PU2/PU2+, slots 16 to 24
---------------------------------------------------------------------------------------------------------------
V5C interfaces on the AN side     23 x PU2+, slots 2 to 24                   9 x PU2+, slots 16 to 24
---------------------------------------------------------------------------------------------------------------
Leased lines on the LE side       not possible                               15 x PU2/PU2+, slots 10 to 24
---------------------------------------------------------------------------------------------------------------
Leased lines on the AN side       23 x PU2/PU2+, slots 2 to 24               9 x PU2/PU2+, slots 16 to 24
---------------------------------------------------------------------------------------------------------------
ECC with PUSISA for TMN           not possible                               1 x PUSISA, slots 2 to 24
---------------------------------------------------------------------------------------------------------------
ECC extraction with PU2+          not possible                               1 x PU2+, slots 10 to 24
---------------------------------------------------------------------------------------------------------------
Sa-bit channel with PU2           23 x PU2, slots 2 to 24                    not possible
---------------------------------------------------------------------------------------------------------------
</TABLE>

      TAB. 5.1  Functional Assignment of the PU2, PU2+ and PUSISA in the
                2-Shelf Variant (in the V5.2-CMXII)

A50010-A3-F102-2-7618                                                         47

<PAGE>

SSD:CMXII                                                        INFORMATION
                                                 CROSSCONNECT MULTIPLEXER II
----------------------------------------------------------------------------
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
FUNCTION OF THE UNITS                           SLOT EQUIPPING OPTIONS
-----------------------------------------------------------------------------------------
<S>                                             <C>
V5.2 interfaces on the LE side                  not possible
-----------------------------------------------------------------------------------------
V5.1 interfaces on the AN side                  23 x PU2/PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
V5C interfaces on the AN side                   23 x PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
Leased lines on the LE side                     not possible
-----------------------------------------------------------------------------------------
Leased lines on the AN side                     23 x PU2/PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
ECC with PUSISA for TMN transmiss.              not possible
-----------------------------------------------------------------------------------------
ECC extraction with PU2+                        not possible
-----------------------------------------------------------------------------------------
Sa-bit channel with PU2                         23 x PU2, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
</TABLE>

      TAB. 5.2  Functional Assignment of the PU2, PU2+ and PUSISA
                in the 3-Shelf Variant, AN-side Shelf (in the V5.2-CMXII)

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
FUNCTION OF THE UNITS                           SLOT EQUIPPING OPTIONS
-----------------------------------------------------------------------------------------
<S>                                             <C>
V5.2 interfaces on the LE side                  8 x PU2/PU2+, mounting slots 2 to 9
-----------------------------------------------------------------------------------------
V5.1 interfaces on the AN side                  9 x PU2+, mounting slots 16 to 24
-----------------------------------------------------------------------------------------
V5C interfaces on the AN side                   9 x PU2+, mounting slots 16 to 24
-----------------------------------------------------------------------------------------
Leased lines on the LE side                     15 x PU2/PU2+, mounting slots 10 to 24
-----------------------------------------------------------------------------------------
Leased lines on the AN side                     9 x PU2/PU2+, mounting slots 16 to 24
-----------------------------------------------------------------------------------------
ECC with PUSISA for TMN transmiss.              1 x PUSISA, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
ECC extraction with PU2+                        1 x PU2+, mounting slots 10 to 24
-----------------------------------------------------------------------------------------
Sa-bit channel with PU2+                        not possible
-----------------------------------------------------------------------------------------
</TABLE>

      TAB. 5.3  Functional Assignment of the PU2, PU2+ and PUSISA
                in the 3-Shelf Variant, LE-side Shelf (in the V5.2-CMXII)

CMXII WITH V5.1 OR CAS INTERFACES TO THE LE SIDE

<TABLE>
<CAPTION>

---------------------------------------------------------------------------------------------------------------------------------
FUNCTION OF THE UNITS                                EQUIPPING OPTIONS (W. CMXII-CS)              EQUIPPING OPTIONS (W. CMXII-LS)
---------------------------------------------------------------------------------------------------------------------------------
<S>                                                  <C>                                          <C>
V5.1 Interfaces on the LE side                       15 x PU2/PU2+, slots 10 to 24                23 x PU2/PU2+, slots 2 to 24
---------------------------------------------------------------------------------------------------------------------------------
V5.1 Interfaces on the AN side                       23 x PU2/PU2+, slots 2 to 24                 9 x PU2/PU2+, slots 16 to 24
---------------------------------------------------------------------------------------------------------------------------------
CAS Interfaces(1)                                    23 x PU2+, slots 2 to 24                     23 x PU2/PU2+, slots 2 to 24
---------------------------------------------------------------------------------------------------------------------------------
V5C interfaces on the AN side                        23 x PU2+, slots 2 to 24                     9 x PU2+, slots 16 to 24
---------------------------------------------------------------------------------------------------------------------------------
Leased lines on the LE side                          15 x PU2/PU2+, slots 10 to 24                23 x PU2/PU2+, slots 2 to 24
---------------------------------------------------------------------------------------------------------------------------------
Leased lines on the AN side                          23 x PU2/PU2+, slots 2 to 24                 9 x PU2/PU2+, slots 16 to 24
---------------------------------------------------------------------------------------------------------------------------------
ECC with PUSISA for TMN                              not possible                                 1 x PUSISA, slots 2 to 24
---------------------------------------------------------------------------------------------------------------------------------
ECC extraction with PU2+                             not possible                                 1 x PU2+, slots 2 to 24
---------------------------------------------------------------------------------------------------------------------------------
Sa-bit channel with PU2                              23 x PU2, slots 2 to 24                      not possible
---------------------------------------------------------------------------------------------------------------------------------
</TABLE>

1)  In CMXII-CAS the mounting slots for the PU2/PU2+ are not pre-assigned to
    the AN or LE side

      TAB. 5.4  Functional Assignment of the PU2, PU2+ and PUSISA
                in the 2-Shelf Variant, (in the V5.1 or CAS-CMXII)

48                                                    A50010-A3-F102-2-7618

<PAGE>

Information                                                  SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
FUNCTION OF THE UNITS                           SLOT EQUIPPING OPTIONS
-----------------------------------------------------------------------------------------
<S>                                             <C>
V5.1 interfaces on the LE side                  8 x PU2/PU2+, mounting slots 17 to 24
-----------------------------------------------------------------------------------------
V5.1 interfaces on the AN side                  23 x PU2/PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
CAS interfaces(1)                               23 x PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
V5C interfaces on the AN side                   23 x PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
Leased lines on the LE side                     8 x PU2/PU2+, mounting slots 17 to 24
-----------------------------------------------------------------------------------------
Leased lines on the AN side                     23 x PU2/PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
ECC with PUSISA or PU2+                         not possible
-----------------------------------------------------------------------------------------
Sa-bit channel with PU2                         23 x PU2, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
</TABLE>

      TAB. 5.5  Functional Assignment of the PU2, PU2+ and PUSISA
                in the 3-Shelf Variant, AN-side Shelf (in the V5.1 or
                CAS-CMXII)

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
FUNCTION OF THE UNITS                           SLOT EQUIPPING OPTIONS
-----------------------------------------------------------------------------------------
<S>                                             <C>
V5.1 interfaces on the LE side                  23 x PU2/PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
V5.1 interfaces on the AN side                  9 x PU2/PU2+, mounting slots 16 to 24
-----------------------------------------------------------------------------------------
CAS interfaces(1)                               23 x PU2/PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
V5C interfaces on the AN side                   9 x PU2+, mounting slots 16 to 24
-----------------------------------------------------------------------------------------
Leased lines on the LE side                     23 x PU2/PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
Leased lines on the AN side                     9 x PU2/PU2+, mounting slots 16 to 24
-----------------------------------------------------------------------------------------
ECC with PUSISA for TMN transmiss.              1 x PUSISA, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
ECC extraction with PU2+                        1 x PU2+, mounting slots 2 to 24
-----------------------------------------------------------------------------------------
Sa-bit channel with PU2+                        not possible
-----------------------------------------------------------------------------------------
</TABLE>

      TAB. 5.6  Functional Assignment of the PU2, PU2+ and PUSISA
                in the 3-Shelf Variant, LE-side Shelf (in the V5.1 or
                CAS-CMXII)

1)  In CMXII-CAS the mounting slots for the PU2/PU2+ are not pre-assigned to
    the AN or LE side

A50010-A3-F102-2-7618                                                      49

<PAGE>

SSD:CMXII                                                        INFORMATION
                                                 CROSSCONNECT MULTIPLEXER II
----------------------------------------------------------------------------

     5.4   CMXII-LS SHELF

   5.4.1   EQUIPMENT CONFIGURATION

                             [GRAPHIC OMITTED]

           FIG. 5.4  CMXII-LS SHELF

           For the CMXII with V5 processing the shelf is equipped as follows:

           -  One MCU

           -  One or two V52FR

           -  One or two CCU (product number: S42024-A1829-A2).

           -  Up to 12 PU2

           -  One or two PSC

           -  Optionally one PUSISA unit, one in the shelf at any mounting slot
              for a PU2 on the LE side.

           For redundant operation two CCU and two V52FR must be inserted. Two
           PSC units are provided when the PU2 are powered redundantly.

50                                                    A50010-A3-F102-2-7618

<PAGE>

Information                                                  SSD:CMXII
Crossconnect Multiplexer II
----------------------------------------------------------------------

         For the CMXII with CAS processing the shelf is equipped as follows:
         -  One MCU

         -  One or two CASU

         -  One or two CCU (product number: S42024-A1819-A2)

         -  Up to 12 PU2

         -  One or two PSC

         -  Optionally one PUSISA unit, one in the shelf at any mounting slot
            for a PU2 on the LE side

         For redundant operation two CCU and two CASU must be inserted. Two
         PSC units are provided when the PU2 are powered redundantly.

  5.4.2  INTERFACES

         The following interfaces are provided on the shelf:

         -  Supervision bus (SVB1) from the PU2 units on a shelf CMXII-2S

         -  QD2-slave interface from the OS to the MCU unit

         -  QD2-M (ECC) interface to the PU2+ (-A1) of the LE side

         -  F interface as per ITU-T V.24/V.28 on the MCU unit

         -  Interfaces T3in(DOWN ARROW) and T3in/T3out(DOWN ARROW AND UP ARROW)
            to the CCU unit

         -  Alarm interfaces for urgent (A-alarm) and non-urgent alarm
            (B-alarm)

         -  PCI buses from the PU2 of a shelf CMXII-2S

         -  PCI standby buses of the PU2 of a shelf CMXII-2S

         -  F1in reference clock LSI from the PU2 on the LE side to the CCU
            unit

         -  5position DIL switch for setting the SISA address

         -  input voltage -48 V for MCU, CCU and CASU/V52FR and

         -  input voltage -48 V-S for standby units.

  5.4.3  FUNCTIONAL ASSIGNMENT OF PU2, PU2+ AND PUSISA MOUNTING SLOTS

         CONCENTRATING CMXII WITH V5.2 INTERFACES TO THE LE SIDE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
FUNCTION OF THE UNITS                           SLOT EQUIPPING OPTIONS
-----------------------------------------------------------------------------------------
<S>                                             <C>
V5.2 interfaces on the LE side                  4 x PU2/PU2+, mounting slots 13 to 16
-----------------------------------------------------------------------------------------
V5.1 interfaces on the AN side                  8 x PU2/PU2+, mounting slots 3 to 8
                                                and 17, 18
-----------------------------------------------------------------------------------------
V5C interfaces on the AN side                   8 x PU2+, mounting slots 3 to 8 and 17, 18
-----------------------------------------------------------------------------------------
Leased lines on the LE side                     2 x PU2/PU2+, mounting slots 17 and 18
-----------------------------------------------------------------------------------------
Leased lines on the AN side                     8 x mounting slots, 3 to 8 and 17, 18
-----------------------------------------------------------------------------------------
ECC with PUSISA for TMN transmiss.              1 x PUSISA, mounting slots 13 to 18
-----------------------------------------------------------------------------------------
ECC extraction with PU2+                        1 x PU2+, mounting slots 17 and 18
-----------------------------------------------------------------------------------------
Sa-bit channel with PU2                         not possible
-----------------------------------------------------------------------------------------
</TABLE>

      TAB. 5.7  Functional Assignment of the PU2, PU2+ and PUSISA
                in the 1- and 2-Shelf Variant (in the V5.2 CAS-CMXII)

A50010-A3-F102-2-7618                                                        51

<PAGE>

SSD:CMXII                                                        INFORMATION
                                                 CROSSCONNECT MULTIPLEXER II
----------------------------------------------------------------------------

                 CMXII WITH V5.1 OR CAS INTERFACES TO THE LE SIDE

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------
FUNCTION OF THE UNITS                           SLOT EQUIPPING OPTIONS
-----------------------------------------------------------------------------------------
<S>                                             <C>
V5.1 interfaces on the LE side                  8 x PU2/PU2+, mounting slots 7, 8 and 13
                                                to 18
-----------------------------------------------------------------------------------------
V5.1 interfaces on the AN side                  8 x PU2/PU2+, mounting slots 3 to 8 and
                                                17, 18
-----------------------------------------------------------------------------------------
CAS interfaces(1)                               12 x PU2+, mounting slots 3 to 8 and
                                                13 to 18
-----------------------------------------------------------------------------------------
V5C interfaces on the AN side                   8 x PU2+, mounting slots 3 to 8 and 17, 18
-----------------------------------------------------------------------------------------
Leased lines on the LE side                     8 x PU2/PU2+, mounting slots 7, 8 and
                                                13 to 18
-----------------------------------------------------------------------------------------
Leased lines on the AN side                     8 x PU2/PU2+, mounting slots 3 to 8 and
                                                17, 18
-----------------------------------------------------------------------------------------
TMN transmission in ECC with PUSISA             1 x PUSISA, mounting slots 13 to 18
-----------------------------------------------------------------------------------------
ECC extraction with PU2+                        1 x PU2+, mounting slots 13 to 18
-----------------------------------------------------------------------------------------
Sa-bit channel with PU2                         8 x PU2, mounting slots 13 to 18
-----------------------------------------------------------------------------------------
</TABLE>

      TAB. 5.8  Functional Assignment of the PU2, PU2+ and PUSISA
                in the 1- and 2-Shelf Variant (in the V5.1 or CAS-CMXII)

52                                                    A50010-A3-F102-2-7618

<PAGE>

Information                                                          SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------

          6  SOFTWARE

             A local craft terminal or a central operating terminal of an OS
             are required for the initialization of the CMXII components.
             Configuration and SW download can be implemented using these
             terminals via the V.24 interface or via the RS-485 interface
             respectively. For each unit of the CMXII, except for the PSC,
             SW is available in the form of a file.

        6.1  MEMORY STRUCTURE

             Each unit has a unit processor for managing the software and
             data. This processor consists of a microcontroller and various
             memory circuits (FEPROM, EEPROM, RAM). The microcontroller
             controls the internal functional sequence on the individual units.
             The memory circuits are used for performing SW and data backups.

             The entire software (SW) and all the configuration data of the
             CMXII network element are stored in the backup system (FEPROM) of
             the MCU. So as to recover the configuration in the event of a
             fault, backup versions are also stored in the OS which can be
             reinstalled later.

             Each unit contains firmware which in turn comprises the bootstrap
             program, the self-test programs and the nameplate data. The
             firmware is stored in the EEPROMs on the units and can only be
             modified by replacing this component. The MCU unit incorporates
             a second FEPROM for that.

             The RAM contains the current SW which is loaded from the FEPROM
             of the MCU by the bootstrap program.

        6.2  INITIALIZATION

             Following the power-up routine, each unit starts the bootstrap
             program contained in the EEPROM. The IPL implements the self-test
             routines of the unit (duration max. 30 s) and the logging on
             procedure at the supervision bus. Once the software has been
             successfully downloaded and started, the units read their
             configuration data from the MCU backup system and, if necessary,
             distribute data to other modules.

             In the event of a SW update, the current SW version continues to
             work in the RAM. Once new SW has been loaded, a reset must always
             be performed to reboot the unit.

             The initial procedure is described in detail in the installation
             and Test Manual ITMN.

A50010-A3-F102-2-7618                                                        53

<PAGE>

SSD:CMXII                                                           Information
                                                    Crossconnect Multiplexer II
-------------------------------------------------------------------------------
<TABLE>
<S>         <C>                                  <C>
          7  TECHNICAL DATA

        7.1  CMXII SYSTEM MODULE

      7.1.1  ENVIRONMENTAL CONDITIONS

             Operation ........................... ETS 300 019 Part 1-3,
                                                   environment class 3.1
             Transport ........................... ETS 300 019 Part 1-2,
                                                   environmental class 2.3
             Storage ............................. ETS 300 019 Part 1-1,
                                                   environmental class 1.2
             EMC ................................. ETX 300 386

      7.1.2  POWER SUPPLY

             Input voltage ....................... -36 V to -72 V
             Power consumption
               CMXII-CS shelf with standby mode
               for CCU and CASU/V52FR units ...... LESS THAN OR EQUAL TO 42 W
               CMXII-2S shelf with standby mode
               for PSC units ..................... LESS THAN OR EQUAL TO 90 W
               CMXII-LS shelf with standby mode
               for CCU and CASU/V52FR units ...... LESS THAN OR EQUAL TO 90 W

        7.2  CROSSCONNECT UNIT CCU

      7.2.1  T3 INTERFACE

             Frequency ........................... 2048 kHz PLUS OR MINUS 50 ppm

             T3in
             Impedance, selectable
               High impedance .................... 1,6 kOhms II LESS THAN 120 pF
               Low impedance ..................... 120 Ohms
             Input voltage ....................... 0.5 V(o-p) to 1.9 V(o-p)
             Cable loss at 2048 kHz .............. LESS THAN OR EQUAL TO 6 dB
             Return loss at 2048 kHz ............. GREATER THAN OR EQUAL TO 15 dB
             Jitter tolerance .................... as per ETS TBR-12, Fig. 3
             T3out
             Impedance ........................... 120 Ohms, balanced
             Level ............................... 1.0 V(o-p) to 1.9 V(o-p)

      7.2.2  POWER SUPPLY

             Input voltage ....................... -36 V to -72 V
             Power consumption of the unit ....... LESS THAN OR EQUAL TO 12.5 W
</TABLE>

54                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                          SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------
<TABLE>
<S>         <C>                                   <C>
        7.3  V5.2 FRAME RELAY UNIT V52FR

             Input voltage ....................... -36 V to -72 V
             Power consumption of the unit ....... LESS THAN OR EQUAL TO 6.25 W

        7.4  CAS UNIT CASU

             Input voltage ....................... -36 V to -72 V
             Power consumption of the unit ....... LESS THAN OR EQUAL TO 6.25 W

        7.5  2-MBIT/S PORT UNITS PU2 AND PU2+

      7.5.1  F1 INTERFACES
             as per ITU-T G.703/6

             Impedance
               Balanced, floating
               and shielded connections .......... 120 Ohms
               Coaxial connections ............... 75 Ohms
             Bit rate ............................ 2048 kbit/s PLUS OR MINUS 50 ppm
             Coding .............................. HDB3
             Rated voltage
               Coaxial connections ............... 2.37 V
               Balanced connections .............. 3 V
             Rated value of the pulse width ...... 244 ns
             Frame structure
               V5-CMXII .......................... as per ITU-T G.704/5
               CAS-CMXII ......................... unframed or as per ITU-T G.704/5
             Jitter tolerance .................... as per ITU-T G.823, TBR-12
             Cable loss at F1in at 1024 kHz ...... LESS THAN OR EQUAL TO 6 dB
             Return loss
               51 Hz to 102 kHz .................. GREATER THAN OR EQUAL TO 12 dB
               102 kHz to 2048 kHz ............... GREATER THAN OR EQUAL TO 18 dB
               2048 kHz to 3072 kHz .............. GREATER THAN OR EQUAL TO 14 dB
             Unweighted noise voltage protection
               Differential mode ................. 20 V(AC)
               Common mode ....................... 100 V(DC)
             Lightning immunity .................. 1 kV for 10/700 (u)s
</TABLE>

A50010-A3-F102-2-7618                                                        55

<PAGE>

SSD:CMXII                                                           Information
                                                    Crossconnect Multiplexer II
-------------------------------------------------------------------------------
<TABLE>
<S>         <C>                                   <C>
      7.5.2  QSa INTERFACES

             There are no QSa interfaces on the PU2+ units.

             Configuration ....................... serial bus system as per EIA RS485
             Bus subscribers ..................... 1 master and up to 30 slaves
             Transmission lines .................. 4-wire, balanced
             Impedance ........................... high impedance
             Bus termination on the backplane .... 120 Ohms
             Sampling frequency .................. 4 kHz
             Transmission rate with 25%
             sampling distortion ................. 1 kbit/s
             Permissible length .................. up to 500 m

      7.5.3  POWER SUPPLY

             Operating voltage ................... +5.4 V
             Tolerance of the operating voltage .. PLUS OR MINUS 3%
             Power consumption ................... LESS THAN OR EQUAL TO 2.5 W
             Shorting protection ................. 1-A fuse

        7.6  SISA PORT UNIT PUSISA

             Operating voltage ................... +5.4 V
             Tolerance of the operating voltage .. PLUS OR MINUS 3%
             Power consumption ................... LESS THAN OR EQUAL TO 1.5 W
             Shorting protection ................. 1-A fuse

        7.7  SUPERVISION UNIT MCU

      7.7.1  F INTERFACE

             Configuration ....................... point-to-point as per ITU-T V.24/V.28
             Transmission lines .................. shielded, unbalanced
             Bit rate, configurable .............. 9.6 kbit/s or 19.2 kbit/s
             Transmission mode ................... asynchronous
             Line code ........................... NRZ
             Permissible length .................. 20 m
             Protocol
               Frame structure ................... IEC TC57
               Address and control byte .......... HDLC (NRM, polling)
               Initiator of the data connection .. primary (LCT)
               Address of the secondary .......... 1
</TABLE>

56                                                         A50010-A3-F102-2-7618

<PAGE>

Information                                                          SSD:CMXII
Crossconnect Multiplexer II
-------------------------------------------------------------------------------
<TABLE>
<S>         <C>                                   <C>

      7.7.2  QD2 INTERFACE

             Configuration ....................... serial bus system as per EIA RS 485
             Bus subscribers ..................... 1 master and up to 30 slaves
             Transmission lines .................. balanced, 4-wire
             Impedance of bus termination,
             selectable .......................... 120 Ohms or high impedance
             Bit rate (automatic detection) ...... 1.2 kbit/s, 9.6 kbit/s or 64 kbit/s
             Transmission mode ................... plesiochronous
             Line code ........................... NRZI
             Permissible length .................. 500 m
             Protocol                              HDLC (NRM, polling)
               Initiator of the data connection .. primary
               Addresses of the secondaries ...... 1 to 30
             Address setting, via backplane ...... 5 bit

      7.7.3  ALARM CONTACTS

             Maximum current load ................ 2 A

             The driver circuit is designed to be short-circuit-proof.

      7.7.4  POWER SUPPLY

             Input voltage ....................... -36 V to -72 V
             Power consumption of the unit ....... LESS THAN OR EQUAL TO 4.5 W

        7.8  POWER SUPPLY UNIT PSC

             Input voltage ....................... -36 V to -72 V
             Permissible overvoltage for
             max. 0.5 ms ......................... -90 V
             Efficiency with -48-V input voltage
             and 68-W output power ............... GREATER THAN OR EQUAL TO 75%
             Output voltage ...................... +5.4 V
             Tolerance of the output voltage
             with -48-V input voltage,
             +25 DEG. C ambient temperature,
             68-W output power ................... PLUS OR MINUS 2%
             Tolerance of the output voltage
             with -36-V to -72-V input
             voltage, +5 DEG. C to +40 DEG. C
             ambient temperature, power from
             no-load to full load ................ PLUS OR MINUS 4%
             Maximum output power ................ 68 W
             Shorting current .................... LESS THAN OR EQUAL TO 20 A
             Voltage increase .................... 100 ms

             The output voltage is shut dosn if the input voltage falls below a value
             in the range of -27 V to -33 V.
</TABLE>

A50010-A3-F102-2-7618                                                        57

<PAGE>

SSD:CMXII                                                           Information
                                                    Crossconnect Multiplexer II
-------------------------------------------------------------------------------

58                                                        A50010-A3-F102-2-7618

<PAGE>

--------------------------------------------------------------------------------
                                                                         GONCALU
--------------------------------------------------------------------------------

GONCALU

[CLIPART]MICROSOFT WORD - APPENDIX 3F
[CLIPART]06/07/00  21:47

                                   [GRAPHIC]
<PAGE>

--------------------------------------------------------------------------------
                              ACCESSINTEGRATOR V5.1
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
Issued by the
Siemens AG,
Information & Communication Networks Division
Hofmannstr. 51
D-81359 Munich

(C) Copyright Siemens AG 1999
All rights reserved.

This product description contains information supplied by Siemens
Aktiengesellschaft ("S") and all such information is supplied without liability
for errors or omissions. S reserves the right to alter the specifications and
description in this publication without prior notice. The material contained
herein is proprietary, privileged, and confidential. No disclosure thereof shall
be made to third parties without the express written permission of S. The
copyright and the foregoing restrictions on reproduction and use extend to all
media in which the information may be embodied.

No part of this publication - technical specifications and features - shall be
deemed to be part of any contract or warranty unless specifically incorporated
by reference into such contract or warranty or by other written permission by S.

<PAGE>

1  TABLE OF CONTENTS

1  TABLE OF CONTENTS ........................................................  2

2  INTRODUCTION .............................................................  6

2.1  ACCESS NETWORKS ........................................................  6

2.2  THE SIEMENS TMN CONCEPT ................................................ 10

2.3  THE ACCESSINTEGRATOR AS PART OF THE TMN SYSTEM ......................... 11

3  SYSTEM ARCHITECTURE ...................................................... 13

3.1  SOFTWARE PLATFORM ...................................................... 13

3.2  HARDWARE PLATFORM ...................................................... 13

3.3  INCORPORATION INTO OTHER PLATFORMS ..................................... 15

3.4  DATA COMMUNICATION NETWORK (DCN) ....................................... 16
  3.4.1  Communication between AccessIntegrator server and clients (LAN/WAN)  16
  3.4.2  Communication between AccessIntegrator server and the Network
         Elements (DCN) ..................................................... 16
      3.4.2.1  The QD2 based DCN ............................................ 16
      3.4.2.2  Managing SNMP based NEs ...................................... 20

4  INTEGRATION INTO EXTERNAL ENVIRONMENT .................................... 22

4.1  ON-LINE INTERFACES FOR REAL-TIME OPERATIONS ............................ 22
  4.1.1  SNMP based Interfaces .............................................. 23
  4.1.2  CORBA based interfaces ............................................. 24
  4.1.3  ASCII based Interfaces ............................................. 24
  4.1.4  Telner based Interfaces ............................................ 25

4.2  OFF-LINE INTERFACES .................................................... 25

4.3  INTEGRATION WITH EXTERNAL MEDIA ........................................ 26

5  GRAPHICAL USER INTERFACE ................................................. 27

ACCESSINTEGRATOR MAIN WINDOW ................................................ 27
  5.1.1  Context Sensitivity ................................................ 28
  5.1.2  Menu bar ........................................................... 29
  5.1.3  Tool Bar ........................................................... 29
  5.1.4  Status Bar ......................................................... 29
  5.1.5  Context menus ...................................................... 30

<PAGE>

  5.1.6  Dialog and Message boxes ........................................... 30
  5.1.7  Forms .............................................................. 30

5.2  HELP TEXT SYSTEM ....................................................... 30

5.3  BRANCH TO MAINTENANCE MANUAL ........................................... 31

5.4  GRAPHICAL VIEWS OF THE MANAGED NETWORK ................................. 32
  5.4.1  Port View .......................................................... 32
  5.4.2  DCN View ........................................................... 33
      5.4.2.1  QD2 DCN View ................................................. 33
      5.4.2.2  SNMP DCN View ................................................ 34
  5.4.3  Network Map View ................................................... 34
  5.4.4  Equipment View ..................................................... 35
      5.4.4.1  Equipment View for one NE .................................... 35
      5.4.4.2  Equipment View for the whole shelf ........................... 36
  5.4.5  Functional View .................................................... 37
  5.4.6  Common Features for all views ...................................... 38

5.5  NATIVE LANGUAGE SUPPORT ................................................ 41

6  MANAGEMENT FUNCTIONS ..................................................... 42

6.1  INTRODUCTION ........................................................... 42
  6.1.1  Management Layers .................................................. 42
  6.1.2  Functional Areas of Network Management ............................. 43

6.2  BASIC FUNCTIONALITY .................................................... 44
  6.2.1  QD2 Telegram Trace ................................................. 44
  6.2.2  Universal Scheduler ................................................ 45
  6.2.3  Date & Time Broadcast .............................................. 46

6.3  ELEMENT MANAGEMENT FUNCTIONS ........................................... 47
  6.3.1  Fault Management ................................................... 47
      6.3.1.1  Alarm Management ............................................. 47
      6.3.1.2  Event Log .................................................... 52
      6.3.1.3  Subscriber Line Text and Measurement ......................... 54
  6.3.2  Configuration Management ........................................... 57
      6.3.2.1  Network Element Configuration ................................ 57
      6.3.2.2  Resource Management .......................................... 59
      6.3.2.3  Parameter Download ........................................... 60
      6.3.2.4  File Upload for Diagnostics .................................. 60
      6.3.2.5  Upload and Download Configuration ............................ 60
      6.3.2.6  Inventory Management ......................................... 61
      6.3.2.7  Backup and Restore Features .................................. 65
      6.3.2.8  Software Management .......................................... 65
      6.3.2.9  Consistency Checks ........................................... 66
  6.3.3  Quality Management ................................................. 67
      6.3.3.1  Performance Management ....................................... 67
      6.3.3.2  Quality Measurement .......................................... 71
  6.3.4  Security Management ................................................ 72
  6.3.5  Generic SNMP Manager ............................................... 74

6.4  NETWORK MANAGEMENT LAYER ............................................... 75

<PAGE>

  6.4.1  Performance management ............................................. 75
      6.4.1.1  End-to-end Performance ....................................... 75
  6.4.2  Configuration Management ........................................... 75
      6.4.2.1  Network Editor ............................................... 75
      6.4.2.2  Automatic Detection of Changes in the Network ................ 79
      6.4.2.3  Extract Network Topology - List of ports and connections ..... 79
  6.4.3  Subscriber Management .............................................. 80
  6.4.4  Path and Service Management ........................................ 81
      6.4.4.1  Service Management ........................................... 81
      6.4.4.2  Path Management .............................................. 85
  6.4.5  Accounting Management .............................................. 87

6.5  MANAGEMENT OF NES BY 3RD PARTY SUBNETWORK MANAGER ...................... 88
  6.5.1  Management of WALKair .............................................. 89

7  SUPPORTING APPLICATIONS .................................................. 90

7.1  MASS PROVISIONING ...................................................... 90

8  LOCAL CRAFT TERMINAL (LCT) ............................................... 92

9  TECHNICAL DATA ........................................................... 93

9.1  PLANNING CHARACTERISTICS FOR ACCESSINTEGRATOR .......................... 93

9.2  MIGRATION TO ACCESSINTEGRATOR V5.1 ..................................... 93

9.3  STARTING ACCESSINTEGRATOR .............................................. 94

9.4  SOFTWARE PLATFORM ...................................................... 96
  9.4.1  Software Design .................................................... 96
  9.4.2  Processes .......................................................... 96
  9.4.3  Software Requirements .............................................. 98
  9.4.4  About VERSANT 5.0 Database Management System ....................... 98

9.5  HARDWARE PLATFORM ...................................................... 99
  9.5.1  Minimum Hardware Requirements ...................................... 99
  9.5.2  Power Consumption - UPS ............................................100
  9.5.3  Availability .......................................................100
  9.5.4  Fault Tolerance ....................................................101

10 COMMERCIAL DATA ..........................................................103

11 QUALITY STANDARDS ........................................................103

12 CUSTOMER INFORMATION REGARDING YEAR 2000 .................................104

13  MANAGEMENT STANDARDS AND PROTOCOLS ......................................105

13.1 MANAGEMENT PROTOCOLS ...................................................105

<PAGE>

13.2 TMN STANDARDS ..........................................................105

14 REFERENCE LIST ...........................................................107

15 LIST OF FIGURES AND TABLES ...............................................110

16 LIST OF ABBREVIATIONS ....................................................112

<PAGE>

2  INTRODUCTION

As non-voice services step-up alongside voice communication, network operators
need open systems that give them the flexibility they need to satisfy the
customers' changing requirements.

Network operators around the world are looking for new ways to generate
additional revenues from their network.

At the time, increasingly tougher competition acts as a driving force to reduce
costs and to find ways to efficiently integrate entirely new types of services
into existing infrastructures.

Emerging network operators are looking for cost-effective access to business and
residential subscribers to reap their own share of the lucrative telecom market.

Access Network products are Siemens' powerful, leading-edge solution for
cost-effective subscriber access and the best instrument for connecting people
to your network.

2.1  ACCESS NETWORKS

Few years ago the understanding of "access network" in the field of
telecommunications infrastructure was simply a copper star network. For
different services and technologies separate access networks have been
installed, e.g. separate networks for data and voice communications.

The investment of such an access network is between 60 - 80% of the total cost
of a network. Therefore, it can be clearly seen that reducing the costs in this
area has the highest impact on the total network cost.

In traditional telecommunication networks, the equipment, which is needed to
connect a subscriber to the switch, has to be provided by the switch supplier,
since only his line equipment works through proprietary interfaces with the
switch. Usually these switch suppliers support the 64 Kbit voice interfaces as
well as ISDN services. To give the telcos the possibility to offer new and value
added services and to develop the access networks for these new demands it was
necessary to change the philosophy by introducing more flexible access network
structures. One of the most important results thereof is to use only one access
network infrastructure for different types of services.

<PAGE>

This is only possible by installing the line equipment as close as possible to
the end-users' premises and multiplexing all different services and bandwidths
on one transport medium. At the network side, the different services have to be
separated to the different core networks. Since more and more users are
requiring more and more bandwidth the copper line technologies are not
sufficient anymore and fiber networks are being installed to bring higher
bandwidths to the end-users.

To be able to connect the access networks in a cost-effective way to the
switches and to reduce the costs for the operator the standard open V5.x
interfaces where defined. These interfaces, especially the V5.2 interface, allow
for cost-effective interconnection of different types of access technologies
from different vendors to the core network.

Therefore, new technologies have been developed to bring the subscribers to the
core network. These technologies can be divided into two categories, Wireless
Local Loop (WLL) systems and wireline systems (Fiber in the loop (FITL)).

o     WIRELINE SYSTEMS: Two major aspects can be seen by introducing wireline
      systems. The first is to bring the line equipment as close as possible to
      the end-customer and to use only one single access transport network, and
      secondly to become flexible with regard to bandwidth requirements by using
      optical fiber cables. To meet the different requirements of the operators
      S has developed two types of wireline systems:

      -     FastLink (including WideLink and FMXII), for services up to 2 Mbit/s
            and upgradable to broadband services

      -     Xpresslink D, for broadband services

o     WIRELESS LOCAL LOOP SYSTEMS: The benefits of WLL systems can be seen in
      the flexibility of WLL systems to fit in all topographical situations as
      well as in reduced installation time since there is no need for
      introducing a secondary copper network. As different operators have
      different reasons for the introduction of WLL systems DECTlink as well as
      WALKair are the fastest way to the dial tone for new constructions:

      -     DECTlink, a system based on the 32 Kbit/s DECT standard.

      -     WALKair, a point-to-multi-point radio system for 2Mbit/s services
            and feeder applications.

      -     SRA-L, a point-to-point radio system for 2Mbit/s services and feeder
            applications

<PAGE>

All these products were designed for different network scenarios to meet the
requirements of operators. In most cases, the isolated use of one technology
does not result in a reasonable solution for a complete access network. Only the
combination of the different technologies can provide a solution, which is
suitable for flexible and cost-effective access network applications. Therefore,
S has designed a modular product line allowing using FastLink as a common
platform for the flexible and efficient combination of all products. With this
family, called Access Network products, S provides access network solutions,
which are tailor-made for every operator providing all services, asked for in
modem networks. Access Network products are the flexible link between
subscribers and the core network.

In the following, a brief description of the different products can be found.

o     FastLink, S' fiber in the loop solution for services up to 2Mbit/s:

      As mentioned before, FastLink is used as the common platform for all
      different access solutions from S. FastLink addresses telephony networks,
      data networks, city networks as well as corporate networks. The main
      services that currently can be offered to the users are POTS/ISDN
      services, n[ILLEIGBLE]64k data services and 2Mbit/s connectivity services.

      FastLink is S' hybrid fiber-in-the-loop access network system which brings
      the optical fiber closest to the customers to create additional revenue
      streams. The modular system architecture allows the implementation of any
      network architecture and the utilization of existing copper infrastructure
      to reduce installation cost and time.

      All types of network architectures can be built using FastLink to meet any
      given requirement.

      Simply by changing the line interface card, FastLink can be used prepared
      for the efficient usage of existing copper networks employing HDSL
      technology or to build up new fiber based access networks. With its
      integrated SDH technology, FastLink is ideal to catch subscribers in a
      large area.

      A smooth evolution to broadband services is guaranteed with the
      introduction of future FastLink versions.

o     DECTlink, the flexible solution for WLL services:
<PAGE>

      According to the modular concept, FastLink can not only be used to serve
      wireline subscribers with a large variety of services, but also DECTlink
      can be integrated into the system. Following the ITU-T standard for the
      DECT air interface DECTlink is S' WLL solution to meet the services from
      POTS to ISDN as well as Cordless Terminal Mobility (CTM) with any GAP
      compliant DECT handheld. The connection to the local exchange is realized
      via the standard interfaces V5.x and VF.

      With a radio range of 5 km and more, DECTlink is ideal for medium to very
      high capacity cells. In addition to POTS and ISDN, other services like
      fax, modem data and Centrex can be offered to the customers.

o     WALKair, S' point-to-multi-point radio solution for business subscribers
      and feeder applications:

      To be as flexible as possible, S' WLL product WALKair is designed as a
      point-to-multipoint (PMP) system for 2 Mbit/s services. It can be used as
      a feeder system for the Access Network products family or other remote
      stations for GSM and access systems and/or as a direct connection to
      business subscribers.

      With its high bandwidth allocation, WALKair has a large service variety.
      Demanding business subscribers can be served with voice and data
      applications with dynamic net capacity of up to four Mbit/s per user.
      Besides voice, WALKair provides efficient access to ISDN, FR, ATM and
      leased lines. With a bit error rate (BER) of less than 10[ILLEGIBLE] p.a.
      a fiber equivalent quality can be provided with a true system transparency
      for all services.

o     SRA-L point-to-point radio solution for business subscribers and feeder
      applications:

      S' SRA-L offers flexible radio links within the access distribution
      network equipment and for the last-mile connection to medium and SOHO
      (Small Office Home Office) customers. It provides up to 16x2Mbit/s and is
      available for outdoor installations.

o     Xpresslink D opens the way for ATM to the customer

      By using FastLink as the platform of the Access Network products family,
      the smooth evolution to ATM based broadband services is guaranteed with
      the introduction of Xpresslink D. With broadband technology new revenue
      streams can be created with high speed interactive services like fast
      Internet. With the already available ADSL technology, Xpresslink D
      addresses 10-15% of the Internet market segment.

<PAGE>

      Most customers can be connected via xDSL employing the existing copper
      network with up to 8 Mbit/s downstream and 800 Kbit/s upstream using ADSL
      and up to 26 Mbit/s asymmetrical (13 Mbit/s symmetrical) using VDSL
      technology. Xpresslink D is also suitable for IP traffic and constant bit
      rate data streams (video, file transfer).

      Like the complete Access Network products family, Xpresslink D can work
      together with any existing telephone and broadband switch. Xpresslink D
      allows the simultaneous transmission of telephone traffic - even ISDN -
      parallel to ADSL and the use of ATM through to the end customer.

2.2   THE SIEMENS TMN CONCEPT

As it is clearly understandable, one of the most important issues with regard to
cost-effective and reliable management of a network is a powerful and
easy-to-use management system. S has a complete TMN (Telecommunications
Management Networks) portfolio in order to provide TMN solutions covering the
entire business process.

In times where the world telecom industry has to face general trends like
globalization, strategic alliances, deregulation and liberalization, there is a
shift towards customer-oriented features and integrated solutions. Customer
Care, enhanced billing, and integrated service/network management solution are
powerful differentiation factors for all telecommunication service providers.
Since it is impossible to provide one system that manages all operator tasks, S
provides a range of specialized modular systems that can flexibly be plugged
together to integrated TMN solutions meeting today's and future needs of an
operator.

At the element/subnetwork management layer, the TMN-products are driven either
by a specific technology (e.g. SDH, ATM) or from the operational usage (access
and mobile). At the network and the service management layer, the product
packages are driven from the requirements to support the business processes.

<PAGE>

2.3   THE ACCESSINTEGRATOR AS PART OF THE TMN SYSTEM

S has developed the management system AccessIntegrator (ACI), an operations
support system capable to manage the entire Access Network product family at the
element and network management layer. Designed to fit into the TMN philosophy of
S, the AccessIntegrator is modular expandable and has standardized interfaces to
higher level TMN-systems.

The main objectives of the AccessIntegrator are:

o     Efficient support of the main TMN processes (service provisioning, service
      assurance, place capacity) of a telecommunications operator in order to
      achieve the full benefits of TMN.

o     Provide a complete element and network management functionality according
      to ITU-T standards.

o     The complete coverage of all Siemens Access Network products with one
      system in order to unify the operational procedure across different access
      technologies.

o     Provide open, standard based interfaces for the integration into the
      established environment of operators

o     A high-performance solution which can grow from small networks to large
      ones.

o     A cost-effective solution also for small operators.

AccessIntegrator is connected to the network elements by the Data Communication
Network (DCN), which is responsible for transportation of Operation,
Administration and Maintenance information. The protocol used for this
communication is either SNMP or QD2, depending on the type of network elements
to be managed.

QD2 BASED PRODUCTS

o     FastLink (including FMXII, WideLink): fiber in the loop solution for
      services up to 2 Mbit/sec

o     DECTlink: a flexible solution for WLL services. DECTlink is only managed
      by AccessIntegrator V3.x

o     SRA-L: a point to point radio system providing up to 16 x 2Mbit/s.

SNMP BASED PRODUCTS:

o     WALKair: point-to-multipoint solution for business subscribers

<PAGE>

o     Xpresslink D: ATM based solution for broadband services. Xpresslink D is
      only managed by AccessIntegrator V4.x.

Other non-Siemens QD2/SNMP based products can also be integrated on request and
at extra cost.

                                    [GRAPHIC]

            FIGURE 1: ACCESS NETWORKS MANAGED BY THE ACCESSINTEGRATOR

 <PAGE>

3  SYSTEM ARCHITECTURE

3.1  SOFTWARE PLATFORM

The platform provides the following features:

o     Developed on the most advanced software techniques (e.g. C++),
      architecture, and communication principles guaranteeing a future proof
      system architecture and high performance

o     Running on Windows NT

o     Intuitive and easy-to-use graphical user interface (GUI) developed in
      accordance with the Microsoft User Interface Style Guide for Windows NT

o     Object oriented database;

      The database stores the Management Information Base (MIB). Management
      information like logs and path management information, user specific
      views, security data and element definitions. Since most of the MIB data
      structures are object oriented (e.g. inheritance, ...), employing an
      object oriented database (OODBMS) is much better suited than a relational
      database (RDBMS).

o     Database provides data persistency. This prevents from requesting all
      information from the network elements and enables quick start-up after an
      AccessIntegrator shut down.

o     Client-server architecture allowing the distribution of AccessIntegrator
      work places.

o     Multi-user, several users can work in parallel on the data.

The detailed structure of the software processes is shown in the chapter
"Processes".

3.2   HARDWARE PLATFORM

AccessIntegrator is capable of full operation, administration and management of
the Access Network in a centralized manner or from a remote site.

The HW platform consists of standard Intel-based personal computers (PCs)
resulting in the highest degree of modularity.

<PAGE>

By the use of technologically most advanced components, the chosen configuration
ensures high performance and provides great flexibility for setting up efficient
operating centers adapted to the operators organization.

                                    [GRAPHIC]

                 FIGURE 2: ACCESSINTEGRATOR SAMPLE CONFIGURATION

The following HW-components are used:

o     Server PC: The server hosts processes such as the MED-process, the
      database and the DCN-server. Depending on the size of the network, the
      server uses several processors and provides flexible disk storage
      capacities as well as different input/output devices. The possibility for
      distributed processing, e.g. different ACI-processes (e.g. Database,
      DCN-server) on different servers provides load sharing. Each server is
      connected to the access network elements via either a QD2-interface-card
      with 8 QD2 ports, or an Ethernet card (see Chapter Communication between
      AccessIntegrator server and the Network Elements ().

o     Client PC: The clients running the GUI process (WSAP-process) are OAM
      workplaces with ergonomical, high resolution 21 inch screens providing a
      comfortable place of work. The clients are interconnected with the servers
      via LAN/WAN, allowing for flexible configurations with operators working
      at local and remote sites.

<PAGE>

o     Peripheral equipment: For the realization of project specific requirements
      a broad range of peripheral equipment (e.g. printer, storage media,
      modems, streamer, UPS, GPS, etc.) can be integrated.

o     LCT: The LCT (Local Craft Terminal) is a portable, smaller variant of
      AccessIntegrator, used for operation in front of the network equipment.
      For more information, see chapter "Local Craft Terminal".

The following two basic workplace configurations cover the various scenarios
from small to large size networks:

o     Single workplace configuration: A single-user configuration running on the
      same workstation the ACI-client and ACI-server (no LAN is needed).

o     Multiple-workplace configuration consisting of different server and client
      workstations. Client and server workstations are hooked up via WAN/LAN. At
      start-up, each ACI-client has to select the ACI-server where to be
      connected. On each client-workstation, different ACI-clients can run in
      parallel each being connected to a different ACI-server. One ACI-server
      can of course serve many ACI-clients simultaneously.

3.3   INCORPORATION INTO OTHER PLATFORMS

Due to its standard software and hardware platform, AccessIntegrator can be
integrated into existing computer environment. In the case the heterogeneous
equipment of a network operator requires AccessIntegrator operation from e.g. a
Unix workstation workplace, a Citrix Metaframe based solution can be used.

That way, an AccessIntegrator client, running on a Windows NT PC or workstation,
can be displayed and accessed from the GUI on a HP UNIX WORKSTATION, or on a
WINDOWS 95/98 PC.

The display of the AccessIntegrator client, which is connected via TCP/IP, is
redirected to the Unix or Windows 9x workplace, where it is integrated into the
existing desktop environment.

<PAGE>

3.4  DATA COMMUNICATION NETWORK (DCN)

3.4.1  COMMUNICATION BETWEEN ACCESSINTEGRATOR SERVER AND CLIENTS (LAN / WAN)

Independent of the size of an ACI configuration the central LAN is used for the
interconnection of the HW-components. The distance covered by a LAN depends on
the LAN technology used:

o     10 Base T twisted pair cable:     up to 100 m

o     10 Base 5 coax:     up to 200 m

o     10 Base 2 Coax:     up to 1000 m

Over a Wide Area Network (WAN) it is possible to connect clients to a server
over a long distance via leased lines by means of routers/bridges. The
connection can also be realized via dial-in over X.25, ISDN, and telephone line
using the remote access service (RAS) of Windows NT.

3.4.2  COMMUNICATION BETWEEN ACCESSINTEGRATOR SERVER AND THE NETWORK ELEMENTS
       (DCN)

AccessIntegrator provides open interfaces towards the network elements, the SNMP
protocol and the German national standard protocol QD2.

The DCN represents the communication network, which is used to exchange
management information between the AccessIntegrator server and the connected
access resp. transport Network Elements (NE).

3.4.2.1  THE QD2 BASED DCN

The NEs can be managed and controlled via the QD2 interface. The SISA protocol
used for the QD2 interfaces of the managed NEs is a bit oriented protocol for
network management applications.

<PAGE>

The SISA-DCN system is responsible for the telegram transport and routing. To
provide the transport features in a telecommunication center a uniform basic
structure is used: a 64 Kbit/sec local serial QD2 bus with one master and up to
30 slaves. This basic structure can be cascaded to establish hierarchical
structures meeting specific requirements. Data is transported in both
directions.

                                    [GRAPHIC]

           FIGURE 3: CASCADED CONFIGURATION WITH MULTIPLE SISA-LAYERS.

The following types of telegrams are supported: command, acknowledgment,
request, response, event report. For each request, there is a response and
similarly for each command there is an acknowledgment. Event reports are sent
spontaneously by NEs when e.g. their internal state has changed. The sending of
such reports is initiated by the polling cycles of the superior SISA-node.

The upper most SISA-GK (SISA-GestellKonzentrator, SISA-rack concentrator)
provides the access point for the AccessIntegrator and the underlying SISA-GKs
build up the hierarchy and transport the telegrams to and from the NEs of the
sub tree below them.

<PAGE>

A SISA-GK has 3 kind of ports: master ports, slave ports and an F-interface
(RS232 connection) which is designed to connect a Local Craft Terminal (LCT) for
local configuration and fault detection. Both the master port and the slave
ports may be configured to operate via the QD2 interface (RS485 connection) or
the QD2* interface (G.703, V.11 async or V.11 sync./X.21 connection). The
SISA-GK polls via its master port the slave equipment on the QD2 bus or the
remote SISA-GK ( QD2* interface) via a point-to-point connection. Additionally
open-collector or relay contacts (SISA-ASA) may be shown as externally connected
alarms.

The following SISA-GKs are currently available (Table 1):

--------------------------------------------------------------------------------
          Interface Type   QD2 card    SISA-GK     SISA-GK    SISA-GK
                             with    V.11/X.24    V.11 async   G.703    SISA-GKE
Interface Feature        Hostess Box
--------------------------------------------------------------------------------
RS.485 (QD2 Bus) 64
Kbit/s: master/slave         8/-           1/1       1/2         1/2       1/2
--------------------------------------------------------------------------------
V.11 async Point-to-
Point: master/slave                        1/1*)
--------------------------------------------------------------------------------
V.11 async line:
master/slave                                         2/4*)
--------------------------------------------------------------------------------
V.11 /X24 synchron
(compatible with X.21)                     1/1*)
--------------------------------------------------------------------------------
supported bitrates V.11
async/sync: master/slave
--------------------------------------------------------------------------------
-1.2kbit/s                                 X/X
--------------------------------------------------------------------------------
-2.4kbit/s                                 X/X
--------------------------------------------------------------------------------
-4.8kbit/s                                 X/X
--------------------------------------------------------------------------------
-9.6kbit/s                                 X/X       X/X
--------------------------------------------------------------------------------
-19.2kbit/s                                X/X
--------------------------------------------------------------------------------
-64kbit/s                                  X/X       X/X
--------------------------------------------------------------------------------
G.703, 64kbit/s,
line: master/slave                                               2/4*)
--------------------------------------------------------------------------------
10BaseT, 10Mbit/s:
master/slave                                                               1/1*)
--------------------------------------------------------------------------------
RS232: 9.6kbit/s or
19.2 kbit/s                                 1         1           1         1
--------------------------------------------------------------------------------
bitrate adjustable
by LCT/auto-detection                      -/X       -/X         -/X       -/X
--------------------------------------------------------------------------------
*)Alternative RS485 or V.11   **)Either master or slave at Ethernet
--------------------------------------------------------------------------------

                           TABLE 1: SISA-GK FEATURES

The main goal of the SISA-DCN is to connect the ACI to the QD2-Network. In order
to improve the performance of the SISA-DCN a new concentrator SISA-GK/E -
completely manageable by ACI - is introduced, having the task to transport the
QD2 network data over TCP/IP or OSI-transport services by means of Ethernet.
Hereto, the QD2-protocol elements of VMP01 and AWP01 are embedded in the TCP/IP
or OSI-protocol and transparently transported. Typical operations modes as well
as SISA-GK/E configurations are shown in Figure 4.

<PAGE>

                                    [GRAPHIC]

                          FIGURE 4: DCN USING SISA-GK/E

The use of SISA-GK/E provides the following advantages:

o     By an effective transmission rate of 3-4 Mbit/sec, the transmission speed
      is 50-60 times higher than RS485 connections.

o     Up to 64 SISA-GK/E can be hooked up to an Ethernet connection (as compared
      to 30 SISA-GK using the classical QD2 bus (RS485 connection).

o     By embedding the QD2-protocol in a standard protocol (TCP/IP or OSI), it
      is possible to connect QD2-networks via router/bridges over
      LAN/WAN-connections.

Over an Ethernet connection it is possible to transport QD2-telegramms embedded
in the TCP/IP protocol as well as in OSI-protocol. Additionally, in parallel the
following communications participants can share this Ethernet connection: the
ACI client-server communication, the SNMP-commands to SNMP-based NEs managed by
the ACI, as well as other network participants.

Supported protocol stacks are listed in table 2. The level structure is in
accordance to the OSI layer model.

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------
OSI Layer Model          Stack 1               Stack 2               Stack 3               f-Interface
================================================================================================================
<S>                      <C>                   <C>                   <C>                   <C>
Local                    local, QD2            QD2*, remote          QD2*, remote          QD2f, remote
</TABLE>

<PAGE>

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------------
OSI Layer Model          Stack 1               Stack 2               Stack 3               f-Interface
================================================================================================================
<S>                      <C>                   <C>                   <C>                   <C>
Layer 7                  AWP01                 AWP01                 AWP01                 AWP01

(Application Functions)
----------------------------------------------------------------------------------------------------------------
Layer 4-6                not used              not used              not used              not used
----------------------------------------------------------------------------------------------------------------
Layer 3                  VMP01                 VMP01                 VMP01                 VMP01

(Network Control)
----------------------------------------------------------------------------------------------------------------
Layer 2                  ISO3309               ISO3309               ISO3309               IEC TC 57
                         ISO7809               ISO7809               ISO7809
(Link Control)           ISO4335               ISO4335               ISO4335
                         (HDLC)                (HDLC)                (HDLC)
----------------------------------------------------------------------------------------------------------------
Layer 1                  ISO8842               G.703 (syn.)          V.11 (asyn./sync)     RS232 (compatible
                         EIA RS                (64 Kbit/s)           (9.6/64 Kbit/s)       with V.24/V.28)
(Physical Interface)     485                                                               (9.6 Kbit/s)
                         (64 Kbit/s)
----------------------------------------------------------------------------------------------------------------
</TABLE>

                        TABLE 2: DCN SISA PROTOCOL STACK

The standard protocol used for the QD2 interface conforms to the ITU standard
for layers 1 (RS-485) and 2 (HDLC).

For the transmission of data between two telecommunications centers, SISA-GKs
have a direct access to the telecommunications network via a QD2* interface.

To communicate to the QD2 network three variants are provided:

o     Via RS485: By means of a separate QD2-card, which can be inserted in the
      server, 8 RS485 ports (64kbit/sec) are available.

o     Via RS232: For a very small number of QD2 network elements the RS232 can
      be used.

o     Via Ethernet: Using an Ethernet card the QD2-telegramms are embedded in
      the TCP/IP protocol providing means to connect the ACI directly to a
      maximum of 64 SISA-GK/E over a distributed LAN/WAN. The RS485/RS232
      interface and the Ethernet interface are supported in parallel.

3.4.2.2 MANAGING SNMP BASED NES

The Simple Network Management Protocol was developed to provide a basic,
universal to deploy network management protocol. It is by far the most popular
network management protocol.

<PAGE>

The SNMP management model is based on the notion of an SNMP-manager and the
SNMP-agents. The SNMP agents are loaded onto devices that are to be monitored.
The SNMP agents monitor behaviour and gather data, which is stored in the
management information database (MIB). An SNMP manager can access/modify that
information from any device loaded with an agent (request/response messages). In
addition, an agent can notify the manager when a particular event has occurred
(traps).

ACI currently supports the SNMP V1 providing the basic Get, Set, Get-Next, and
Trap operations.

For the communication to the SNMP network parts, an Ethernet (10BaseT) interface
is provided for the transport of SNMP messages over TCP/IP via a LAN/WAN. This
LAN/WAN can be shared by other ACI-interfaces as wells as by other Ethernet
based connections, like client-server communications.

<PAGE>

4  INTEGRATION INTO EXTERNAL ENVIRONMENT

Business process automation is for most operators of vital interest. Therefore,
an integration of ACI in the management environment is primordial. Hereto ACI
provides different kinds of interfaces for integration with External Management
Systems.

Both established and new-entrants operators require interfaces to their customer
care and operations support systems. To achieve an end-to-end automation as well
as an integrated flow-through provisioning different kinds of interfaces are
provided. These interfaces are not part of the basic AccessIntegrator
configuration and are at an extra cost.

The kind of interface is mainly defined by the kind of integration, interaction,
and function split with the other management systems. In principle an interface
on element management level, acting then as mediation for the management of NEs,
or on network management level, that abstracts the access network model from the
specific implementation of the network elements can be provided. Since ACI is a
high-end integrated OS with rich functionality supporting business automation,
the latter is assumed. The ACI then acts as a domain manager; tasks that are
specific to NEs (maintenance, SW-upgrade, NE-backup,..) are done via the ACI.
For the integration in the process flows interfaces supporting different tasks,
e.g. tasks for the coordination of several management domains, or for
coordination of processes with higher layers are provided. All these tasks may
have different requirements to the interface, and the interface may be split
into several parts, e.g. protocols for real-time tasks or batch procedures for
non time-critical operations.

Depending on the required functionality two kinds of interfaces are provided:

4.1  ON-LINE INTERFACES FOR REAL-TIME OPERATIONS

For real-time operations, protocol based interfaces based on SNMP and/or CORBA
are provided.

<PAGE>

4.1.1  SNMP BASED INTERFACE

This widely used interface allows an external system to communicate with the
AccessIntegrator via SNMP commands. The SNMP interface bases on SNMP V1. It is
easy to use as tools and developers are widely available on the market, and
minimal development effort is needed.

The SNMP interface is ideal for simple transactions of a few well-defined
scenarios (simple MIBs) and is best suited for pragmatic non-standard compliant
interfaces.

The following ACI-functionalities are currently opened to a external systems:

ALARM INTERFACE: Via an alarm interface the external system can

-     Transparently receive alarms as traps from all network elements, which are
      managed by the AccessIntegrator.

-     Set filter criteria to define the kind of alarms, which shall be
      forwarded.

-     Request the current alarm-state of the managed network. The list of all
      pending alarms (internal global alarm list) shall be forwarded to the
      external management system as a sequence of SNMP traps.

SUBSCRIBER LINE TEST: Via the subscriber line test interface (only for
FastLink), the connected external system has the possibility

-     To configure automatic tests of all subscriber lines (POTS/ISDN) of all
      AMX network elements, which are connected to a measurement unit

-     To set threshold values for the configuration of automatic tests.

-     To receive notifications about available test results.

-     To request the results of automatic testing.

-     To invoke the test of a single subscriber line.

VIA THE CONNECTION WATCHDOG the connection between the AccessIntegrator and the
external system can be surveyed. The external system can request the
AccessIntegrator to send periodically traps. The interval is configurable.

SERVICE PROVISIONING: Assuming a pre-configured FastLink V5 network (e.g.
V5.x-interfaces, V5.x-ports), a service can be activated, and an identifier
(e.g. directory number) can be associated to this service. AccessIntegrator then
monitors the service and the status and notifies the results via the interface.
The interface allows also the service deactivation.

<PAGE>

4.1.2  CORBA BASED INTERFACES

The focus of this kind of interfaces is to provide an open network- or service
management interface for the following typical kind of management functionality:

-     Alarm supervision of paths/services

-     Service activation resp. provisioning

-     V5.x-provisioning and configuration

As the latter is a more complex task, a more sophisticated CORBA interface
instead of SNMP is used for the exchange of information.

CORBA is a future proof protocol and is suitable for complex MIBs. Existing
standard modeling from ETSI, NMF and ITU-T (e.g. GDMO-models) can be (partially)
mapped into the CORBA Interface Description Language (IDL) providing some kind
of compliance to the standards. CORBA is relatively easy to use, tools as well
as developers are widely available on the market, and only a medium development
effort is needed. ACI currently supports a service oriented interface (modeled
circuit-like mainly for leased line management) with additional service
attributes. Its Object Model is based on ITU-T (along X.721 and M.3100) and NMF
(along NMF038) standards. The interface is based on Orbix V2.3 CORBA.

Using this interface, the following information is reported from the
AccessIntegrator:

-     Create/delete notifications of all network elements and their ports

-     create/delete notifications of a service;

-     state change notification of a service;

-     alarm notification if a service is affected;

-     global alarm counter indicating the number of alarms per severity (on
      demand and periodically)

4.1.3  ASCII BASED INTERFACES

The simplest way to communicate with the AccessIntegrator is via an
ASCII-interface over TCP/IP. It supports sending/receiving of ASCII-strings in a
pre-defined message format. Only a minimal development effort and no protocol
handling are needed by the managing systems. An ASCII-interface is ideally
suited for pragmatic - generally proprietary - interfaces. Currently only
alarming is supported:

-     Forward ACI-alarms

<PAGE>

-     Request of the global alarm list of the ACI. ACI responds with a sequence
      of all current ACI-alarms.

-     Sending of a heart-beat. The heart-beat interval can be set by the
      external system.

4.1.4  TELNET BASED INTERFACES

Operators may want to directly access the ACI-functionality by a command line.
This is typically the case for functionality that must be accessed by an
operator in case of customer complaints. Such a command line access can be
achieved by using a Telnet session over TCP/IP.

ASCII-commands according to a defined command-format are sent to the ACI. ACI
interpretes these commands, starts some activities, collects the test results,
and sends them back as ASCII-streams in a specific format to the operator.

Command line access is available for line tests. A test command for the faulty
number is send to the ACI. The ACI interpretes the test command, starts a line
test for the corresponding ports, and sends the results back to the operator.
The various test commands can be grouped as follows:

-     Subscriber circuit testing

-     Subscriber line testing

-     Subscriber terminal testing

4.2  OFF-LINE INTERFACES

For time uncritical operations, the AccessIntegrator GUI provides means to
export data (e.g. log-files) into ASCII files. Those files can be transferred -
time scheduling is possible via Windows NT functionality - via FTP to other
systems.

<PAGE>

4.3  INTEGRATION WITH EXTERNAL MEDIA

In some cases, the operator or maintenance personnel need to be alerted about
the occurrence of certain events in the AccessIntegrator without having direct
access to the AccessIntegrator. For this purpose, the AccessIntegrator provides
access to external media via its media interface. Currently implemented media
interfaces support sound and SMS (Short Message Service) to a pager or mobile
phone. In future, visual media such as fax and e-mail will be supported as well.

Currently, media events are definable for alarming purposes allowing for the
alarm severity and NE types for which an alarm event has to occur.

                                    [GRAPHIC]

                          FIGURE 5. MEDIA CONFIGURATION

<PAGE>

5  GRAPHICAL USER INTERFACE

AccessIntegrator provides a graphical user interface to access its features and
applications. AccessIntegrator uses the well established building blocks for
user interface design like menus, windows, forms, buttons, scrollable lists and
was developed in accordance with the Microsoft User Interface Style Guide for
Windows NT offering the same "Look and Feel". The network elements to be managed
are administrated in a graphical representation allowing for an object-oriented
approach. The operator first has to select an object or a group of objects on
which the operation has to be performed. The functions permitted for this object
are then displayed, and the user selects the desired function.

5.1

<PAGE>

ACCESSINTEGRATOR MAIN WINDOW

                                    [GRAPHIC]

                   FIGURE 6: THE ACCESSINTEGRATOR MAIN WINDOW

AccessIntegrator's main window is opened automatically at startup time and will
only be closed at log-out time. This main window is the central window always
provides menu-bar, toolbar, and status bar. Further windows with icons, various
views, dialog boxes, etc. are opened either via the menu or via double click on
an object on which these operations are defined.

5.1.1  CONTEXT SENSITIVITY

Access of the user to the functions on the interface is context-sensitive; i.e.
the user can only call those functions that are available under the current
context:

o     The system configuration.

o     The user class to which the user belongs.

o     The current view.

o     Number and type of selected objects.

<PAGE>

5.1.2.  MENU BAR

All features available in the system and in the current context may be accessed
via the menu-bar. The menu-bar is located at the upper border of the main
window. When an entry of the menu bar is activated, a submenu will drop down
containing those specific functions, which are applicable in the current
context. Functions that are not applicable are greyed out and may not be
selected.

The menu bar is valid for all windows, except for the network editor, which
features a special menu bar.

5.1.3  TOOL BAR

A tool bar is located just below the menu bar of the main window providing quick
access to the most frequently required functions. Buttons that cannot be
activated in the current context are greyed out.

The tool bar is valid for all windows, except for the network editor, which has
a special tool bar.

5.1.4  STATUS BAR

A status line is located at the bottom of the main window and therefore always
visible. Its purpose is to provide easy graphical indications about the network
status and activities to the user.

                                    [GRAPHIC]

     FIGURE 7: STATUS BAR WITH GRAPHICAL INDICATION ABOUT SYSTEM ACTIVITIES

The following indications are provided (from left to right):

o     The panel usually contains a description of the currently selected item
      (menu item or a network element. It is also used for textual indication of
      the progress of a lengthy computation or data transfer, etc.

o     The square box shows the color of the not yet acknowledged alarm with the
      highest severity currently observed in the system

o     The current date and time

o     The total number of currently disconnected network elements and modules

<PAGE>

5.1.5  CONTEXT MENUS

All objects (e.g. sub networks, network elements, etc.) which are displayed in
the views provide a context menu which offers the most important (not all)
functions available for this object. The context menus are accessed by clicking
the right mouse button. Functions that are not applicable are greyed out and can
not be selected.

5.1.6  DIALOG AND MESSAGE BOXES

Communication between the user and AccessIntegrator takes place by means of
dialog boxes. They are used for outputting all data requested by the system for
inputting and modifying data.

5.1.7  FORMS

Forms are special kinds of windows that are used for notification purposes, e.g.
an error notification form, or a confirmation form, or as input media to enter
textual and numerical data. Forms are realized as modal (the user has to close
the form before he may continue to work) or as non-modal (the form may remain
open).

5.2  HELP TEXT SYSTEM

The AccessIntegrator help text system offers detailed information on the
program. It is used to obtain instructions step-by-step, to look up information
related to particular subjects, to search using keywords, and to branch to
related topics. The help system can be accessed via the menu bar or context
related via help buttons in most windows.

<PAGE>

5.3  BRANCH TO MAINTENANCE MANUAL

AccessIntegrator provides operational guidance by the Help Text System. In
addition to this, direct and context sensitive access to online maintenance
manuals of the managed network elements is provided. From the entries in the
alarm list, it is possible to open automatically the FastLink Maintenance
Manual, already at the chapter associated with the Network Element and Fault
type. The Maintenance Manual is stored in HTML format on CD-ROM or hard disk. In
case of other Maintenance Manuals context sensitivity is restricted to the start
of the corresponding browser with the document, but no detailed pointer to the
required chapter.

5.4

<PAGE>

5.5  GRAPHICAL VIEWS OF THE MANAGED NETWORK

AccessIntegrator offers various views of the network elements to be managed.
Each view is displayed in a separate window, and all windows may be opened
simultaneously.

                                    [GRAPHIC]

                FIGURE 8: DIFFERENT VIEWS OF THE ACCESSINTEGRATOR

5.5.1  PORT VIEW

This view displays the eight ports of the QD2-card as well as the SNMP port by
means of which the ACI-server is connected to the access network. No alarms are
displayed in the port view. By selecting a port, the corresponding DCN-tree can
be opened. Each DCN-view is displayed in a separate DCN tree.

<PAGE>

                                    [GRAPHIC]

                               FIGURE 9. PORT VIEW

5.5.2  DCN VIEW

5.5.2.1  QD2 DCN VIEW

This view displays the network in a hierarchical structure (therefore it is also
called "DCN Tree") in accordance with the SISA addressing scheme, where the
leaves of the tree represent the QD2 network elements.

                                    [GRAPHIC]

                               FIGURE 10: DCN VIEW

<PAGE>

It is built automatically as soon as the AccessIntegrator is connected to the
SISA-DCN. Lower levels in the SISA hierarchy may be hidden in the display to
provide a better overview. They may be expanded on the operator's demand. Due to
the automatic detection of the NEs the DCN view does not need to be modified by
the operator at any time. If the QD2-network elements undergo a state
transition, this is signaled graphically to the user.

5.5.2.2  SNMP DCN VIEW

This view sequentially displays all SNMP network elements according to their IP
addresses. The corresponding SNMP network elements are have to be created by the
operator who also has to configure the type, name, and IP address of the NE, and
other SNMP-parameters. Once this information has been set-up, AccessIntegrator
detects these Network Elements automatically during the subsequent start-ups.

5.5.3  NETWORK MAP VIEW

This view displays the real network topology of all DCN trees without the SISA
network elements (e.g. SISA-GKs). It is constructed by the operator via the
network editor and may be modified easily and always. The symbols and the
connections between them may be arranged individually.

A network map can contain the following graphical elements:

o     QD2 and SNMP network elements: NE icons are copied from the DCN tree to
      the network map via drag-and-drop. They generally feature ports for
      interconnection.

o     External elements: special elements like alarm contacts.

o     Sub-networks and stations/network units: A network map may be distributed
      across several windows, thus allowing the network to be structured
      hierarchically. It is possible to generate an unlimited amount of windows
      with distinct relations. This is realized by special symbols, which
      represent sub networks or stations/network units. A double-click on these
      symbols opens the related map window.

o     Connections: a line represents connections between two NEs with a number
      indicating the number of connections between them. These connections are
      stored in the database and used by the AccessIntegrator for service and
      path management.

o     Network termination points: connections with endpoints located in
      different sub network windows.

<PAGE>

o     Labels: labels can be assigned to NEs for additional information, e.g.
      indicating to which local exchange the Access Network is connected to.

o     Note fields: a multi-line text element, which can be placed anywhere in
      the network map.

o     Background image, e.g. city maps or equipment photos

                                    [GRAPHIC]

Any changes to the network must be entered manually via the network editor.

                           FIGURE 11: NETWORK MAP VIEW

5.5.4  EQUIPMENT VIEW

5.5.4.1  EQUIPMENT VIEW FOR ONE NE

This view (also called genetic shelf view) displays the shelf of one network
element in a realistic way showing its module configuration (replaceable units).
Modules of other network elements in the same shelf are not shown in this view.
This is achieved by the equipment view for the whole shelf (see next chapter).
Each module (board) is displayed with the module name, slot number, mode and
alarm status/severity (color coded field). Tool tips contain information about
the concerned module, e.g. NE-name, module name.

AccessIntegrator automatically updates all detected changes in the module
configuration caused by the installation or removal of modules. Removed modules,
or a loss of connection to the module are indicated by a red cross while the NE
and higher objects containing that module in this case bear a violet cross.

<PAGE>

If the modules undergo a state transition (e.g. alarm states, sync states,
active and standby), this is signaled to the user graphically.

                                    [GRAPHIC]

                       FIGURE 12: EQUIPMENT VIEW OF A SMX1

5.5.4.2  EQUIPMENT VIEW FOR THE WHOLE SHELF

This view can be regarded as an extension to the equipment view for one Network
Element, showing the modules of all Network Elements in the chosen shelf (only
for QD2-NEs). For this purpose, an icon representing the shelf has to be
introduced into the network map which allows the opening of this equipment view
(see Chapter Network Editor).

                                    [GRAPHIC]

        FIGURE 13: SHELF VIEW OF THE SMXLS-SHELF WITH SMX1 AS SELECTED NE

In order to recognize the corresponding network element of a module tooltips are
used to display information about the concerned module, e.g. NE-name, module
name.

If a selected network element is contained in a shelf, the equipment view will
display the whole shelf with the selected equipment marked in blue.

<PAGE>

AccessIntegrator updates automatically in the shelf view detected changes in the
module configuration caused by the installation or removal of modules, insertion
and removal of NEs in the shelf subnetwork, deletion of the shelf subnetwork,
and changes in the title of the NEs. If the modules undergo a state transition
(e.g. alarm states, sync states, active and standby), this is signaled to the
user graphically.

5.5.5  FUNCTIONAL VIEW

This view displays a functional representation of a network element. Instead of
physical boards, it displays functional units such as ports, multiplexers, cross
connects, etc.

Compared to the equipment view, this view provides the operator an uniform
overview for network management purposes. While the equipment view is
continually changing, as boards are installed and removed, the functional view
remains constant. When representing a function graphically, it is immaterial
whether the function is implemented on a single module or distributed over
several modules. Thus, the operator can work with an uniform view, which
requires no new operational procedures for each new type of plug-in unit. This
makes the network management process more standardized and easier to handle for
the operator.

Changes to the functional view are detected by the AccessIntegrator and updated
accordingly in the view. State transitions are signaled to the user graphically.

                                    [GRAPHIC]

                       FIGURE 14: FUNCTIONAL VIEW OF FMXII

5.5.6

<PAGE>

5.5.7  COMMON FEATURES FOR ALL VIEWS

The following features are identical for all views:

o     zooming in and out

o     single and multiple selection

o     possibility to operate the system from the keyboard

o     view options can independently be set for the different views. These
      options can be saved and reloaded on demand. Typically for each view the
      following options can be specified: icon text (e.g. address, title,
      caption), zoom factor, icon font, other options.

                                    [GRAPHIC]

                             FIGURE 15: VIEW OPTIONS

o     navigation between views: For easier navigation between the different
      views, it is possible to switch between the different views: e.g.

      -     for a selected NE jump to the NE in the DCN- resp. Network Map view,

      -     jump to the parent or top network map

o     descriptions to objects: For objects like NEs, subnetworks, shelves,
      external elements, modules, labels, and notes a textual description
      field is associated. Depending on the object it consists of

      -     a unique name identifying the object

      -     captions used for additional identifying text

      -     object description: a multi-line description

      The text descriptions are shown in the DCN-view and/or in the Network Map
      view according to the view options that are in effect. The object
      description can only be read by a special dialog (Figure 16).

<PAGE>

                                    [GRAPHIC]

                      FIGURE 16: OBJECT DESCRIPTION FOR NE

o   In order to find a network element quickly a search function is provided.
    The goal of this function is to search NEs in the whole network and then to
    display the NEs in a result list. From this list it is possible to select an
    NE and jump to the different views (functional, equipment, DCN, network
    map). Several find dialogs can be opened. The input for a search can be

    - SISA-address, NE name/type,..

    - special state: maintenance, disconnected, ..

    - alarm state: critical, cleared,..
<PAGE>

                                    [GRAPHIC]

                               FIGURE 17: FIND NEs

o     Display of status information: If network elements or their components
      undergo a state transition, this is signaled in all views. Between the
      following states is distinguished:

      -     ALARM STATE: color-coding objects according to received alarms.
            Different colors are used for different alarm severities and
            different overlay symbols to distinguish between acknowledged and
            unacknowledged alarms. If several alarms are reported simultaneously
            for a network element or component, the alarm with the highest
            severity determines the color of the icon. The most critical alarm
            is propagated to the overlaying hierarchical level.

      -     MAINTENANCE STATE: All network elements in the 'In Maintenance'
            state are marked in every view with an overlay wrench symbol
            (overlay symbol). As long as this symbol is shown, the network
            element is excluded from the monitoring process and no alarms are
            sent.

      -     OPERATIONAL STATE: A red cross symbolizes the operational state
            'disabled', which signals the operator that this element or
            subnetwork is not accessible by the AccessIntegrator at the moment.
            A violet cross indicates that a object (e.g. a line card) within
            this element or subnetwork is 'disabled'.

      -     SYNCHRONIZATION STATE: The synchronization state of an NE is shown
            in the status bar, and provides information on the synchronization
            between the object in the database (MIB) and the physical NE in the
            network.

<PAGE>

5.6   NATIVE LANGUAGE SUPPORT

The prime language of AccessIntegrator is English, a German version can be
ordered. User Interfaces in other languages can be provided on request.

In order to enable an easy translation of AccessIntegrator into another
language, the following files are provided:

o     All text units of the user interface as well as all system messages are
      available in resource files.

o     The description of the network elements is also formally described in
      QD2-files.

o     The on-line-help is provided by means of Microsoft Help files.

<PAGE>

6     MANAGEMENT FUNCTIONS

6.1   INTRODUCTION

                         STRUCTURE OF THE TMN FUNCTIONS

                                    [GRAPHIC]

                 FIGURE 18: TMN STRUCTURE OF THE M.3010 STANDARD

AccessIntegrator has been developed according to the ITU-T Model for TMN
(Telecommunications Management Network) Functional Areas and Management Layers
(ITU-T Recommendations M.3010 and M.3400).

6.1.1 MANAGEMENT LAYERS

The TMN management layers have been used to define LOGICAL functional boundaries
and interfaces allowing for network management integration.

The layers are:

<PAGE>

o     Business Management Layer:

      Characterized by business planning and product definition finance
      management.

o     Service Management Layer:

      Provides contact with customers (subscribers) and with other service
      providers, provides a view of logical resources and subscriber services,
      identifies subscriber access, reports service usage for billing and
      maintains and reports on service quality.

o     Network Management Layer:

      -     Provides comprehensive information about the network as a whole:
            availability, network topology/connectivity, performance, usage and
            outages.

      -     Supports control and coordination of the network by providing a
            global view of the NEs in the Element Layer. The Network Management
            Layer may also facilitate configuring and monitoring network
            equipment and transmission facilities, and managing network
            activation and restoration activities.

o     Network Element Management Layer:

      Controls and co-ordinates a subset of network elements on an individual
      function basis and on a collective basis, provides a gateway to NEs for
      the Network Management Layer and higher layers, maintains statistics and
      history pertaining to the individual NEs or groups of NEs as a Subnetwork.
      Generally the Element Managers are implemented for specific technologies
      e.g. ATM EMs, FITL EMs, Radio EMs.

The layers provide a hierarchy where the functions in the higher layers
themselves utilize facilities in the lower layers i.e. functions in the service
management layer are supported by functions in the network management layer and
in turn, the network element management layer. The relationship between the
layers can be thought of as client/server or manager/agent.

Business management has been determined out of the scope of this document
because it does not directly relate to the selection of network or management
capabilities to provide services on the network.

6.1.2 Functional Areas of Network Management

Network management can be broken into five functional areas. Each area defines a
discrete domain of management with specific needs.

The following functional areas are defined:

o     Configuration Management:

      -     Deals with updating, changing, modifying resources within a network:
            e.g. Installation: Supports the placement of equipment in the
            telecommunications network, including the extension or reduction of
            resources, loading software, and coordinating of resource changes.

      -     Provisioning: Is used to bring equipment into service. This includes
            design and connection of resources to provide service, loading of
            software logic, setting of service features, and all activities
            associated with the delivery of service to a customer.

<PAGE>

      -     Status and Control: Provides the capability to monitor and control
            certain aspects of the network on demand.

o     Performance Management:

      Deals with the analysis and evaluation of system and network performance:
      e.g.

      -     Performance Monitoring: the non-intrusive collection, analysis, and
            reporting of performance data.

      -     Performance Management Control: The group of functions that control
            the operation of the network: e.g. traffic control that affect the
            routing of traffic and processing of calls, the setting of
            thresholds and other variables

      -     Performance Analysis: Performance Analysis processes performance
            data into reports, forecasts, and recommendations

o     Fault Management

      Fault Management involves the collection, storage, reporting, analysis,
      summary, and archiving of network element generated events. It assists in
      the isolation of faults, diagnosing of faults, and the repair of failed
      components. This includes performing tests, such as connectivity tests,
      integrity tests, response time tests, diagnostic tests, etc.

o     Accounting Management

      Accounting Management is concerned with the allocation of resources within
      a network and charging for their services. It Includes the collection of
      usage information from networked components and the creation of accurate
      billing information.

o     Security Management

      Security Management provides the protection of resources within a system
      or network. Security becomes more important within increased connectivity.
      It is closely related to fault and configuration since configuration of
      important devices must be secure. Security management can be divided into
      two areas:

      -     management of the security of a network: controls the access to the
            OS and determine the rights and privileges of the different users.
            Furthermore it supervises the Management System security and reports
            security violations and maintains security audit logs.

      -     management using secure protocols: making sure that the management
            of NEs is performed using protocols that prevent unauthenticated
            access.

6.2   BASIC FUNCTIONALITY

6.2.1 QD2 TELEGRAM TRACE

In case of misbehavior, AccessIntegrator provides the possibility to log all
QD2-telegrams sent and received into a log file. Each time stamped record
contains the direction of the QD2 telegram and the QD2 telegram content.

<PAGE>

6.2.2 UNIVERSAL SCHEDULER

In AccessIntegrator a universal scheduler is implemented that can be used for
any kind of job that is completely determined before the activity is really
started. The jobs are to be invoked by the AccessIntegrator (not by the NE, such
as user port testing) at a given point in time in the future. At present, the
following operations are supported by the AccessIntegrator universal time
scheduler:

-     SW Download.

-     NE Backup

-     Retrieval of performance data,

-     Export of alarm, event, and, subscriber line test logs

-     Time distribution in the access network.

In order to see the result of time scheduled operations, AccessIntegrator
maintains a log, logging both the start and completion times of the
time-scheduled operations.

The scheduler provides different scheduling options for periodic and
non-periodic jobs, as well as functions for the creation of a scheduled job, the
supervision of all pending jobs, the invocation of the AccessIntegrator
functionality that is associated with a scheduled job, and the display of the
log-file.

<PAGE>

                                    [GRAPHIC]

                     FIGURE 19: UNIVERSAL PERIODIC SCHEDULER

6.2.3 DATA & TIME BROADCAST

To synchronize the different network elements with the ACI server - which is
itself time synchronized to an external "timer source" e.g. GPS-system, - the
following options are provided to set the absolute time in the NEs:

o     An on demand time broadcast to the selected NEs or to the entire network,

o     A scheduled time broadcast to the entire network.

                                    [GRAPHIC]

                         FIGURE 20: DATE & TIME SETTING

<PAGE>

6.3   ELEMENT MANAGEMENT FUNCTIONS

6.3.1 FAULT MANAGEMENT

6.3.1.1 ALARM MANAGEMENT

The AccessIntegrator alarm management performs the following main tasks:

o     monitoring of alarm states of all network elements

o     managing the visual signaling in the views

o     logging the alarms

o     configuration of alarms

AccessIntegrator automatically surveys all state transitions in the NEs, which
are reported as spontaneous notifications by the network elements, and which are
reported to the operator in form of alarms. Each network element and its
components have a predefined set of different alarms. Alarms are presented to
the operator in various ways:

1.    The color of the icons of the (sub)-networks, stations/network units,
      network elements, functional units, and modules changes accordingly to the
      severity of the alarms, the alarm with the highest severity determining
      the color of an icon. The assignment between alarm severity and color can
      be modified by the system administrator.

                                    [GRAPHIC]

                         FIGURE 21: ALARM COLOUR SETTING

2.    In the status bar of the desktop, a colored square signals the alarm with
      the highest severity in the entire network which is not yet acknowledged.

3.    The current list of alarms (alarm status) of an object (sub network, NE,
      module, or functional unit) can be displayed.

<PAGE>

                                    [GRAPHIC]

  FIGURE 22: VISUAL ALARM SIGNALING IN DIFFERENT VIEWS AND ALARM CONFIGURATION

4.    Each alarm received by AccessIntegrator is entered in an alarm list, which
      is updated automatically when a new alarm message is received.

      Each alarm entry generally consists of the following information

      o     date and time of arrival into the ACI

      o     alarm state ("on", "off", "acknowledged");

      o     severity ("critical", "major, "minor", "warning")

      o     description of alarm

      o     type of alarm

      o     network element and functional object in which the alarm occurred

      o     hardware module as well as slot number in which the alarm occurred

      The different fields to be shown in an alarm list can be defined by an
      operator.

<PAGE>

If an alarm with state "0FF" is received, the associated alarm with state "ON"
is deleted from the list. When active alarms are acknowledged by the operator,
their state changes to "ACK" and remains in the list. The alarm list thus always
indicates the current state of all alarms in the network. The global alarm list
holds all alarms of the entire network. Alarm lists can be restricted to display
only alarms of a specific object e.g. sub-networks, NEs, modules, functional
units. They can be filtered, printed, and exported into an ASCII-file suitable
for export into other tools.

                                    [GRAPHIC]

              FIGURE 23: GLOBAL ALARM LIST OF THE ACCESSINTEGRATOR

Each alarm may be acknowledged. The acknowledgment changes the state of the
individual entry in the alarm list - which gets a tag in the corresponding alarm
color - and marks also the respective object (NE, functional unit, and module)
with this color. This can be done individually for each alarm in the alarm list
or for all outstanding alarms of an object by means of the alarm status
functionality.

AccessIntegrator provides a fast access to detailed information about an alarm
from an alarm list allowing to branch directly to the corresponding page in the
online maintenance manual, where descriptions of the probable cause and the
fault correction procedure are given.

For a rapid localisation of an alarm, a direct link from the selected alarm of
an alarm list to the corresponding equipment view, functional view or the
network map containing the NE is provided.

<PAGE>

S

5.    AccessIntegrator provides a log administration tool, which allows you to
      log alarms (alarm history). As soon as a log is created, time-stamped
      alarms (same entries as for alarm lists) are entered in the log file.
      Unlike the alarm list, the log file also records alarms with state "off".
      This makes it possible to determine how long an alarm has been active in
      the network. A log file is helpful for troubleshooting and for statistical
      purposes. Alarms can be logged for the entire network, subnetworks,
      stations/network units, NEs, modules or functional units. The alarm log
      administration allows for easy creation, stopping, viewing, printing,
      exporting and deleting of alarms logs. Various filter and sorting criteria
      may be applied. AsscessIntegrator can be configured to provide a default
      global alarm log for the whole network, which is created automatically at
      server start-up. For a rapid localisation of an alarm, a direct link from
      the selected alarm of an alarm log to the corresponding equipment view,
      functional view or the network map containing the NE is provided.

                               [GRAPHIC OMITTED]

                 Figure 24: Alarm Log Creation and View Window

      Alarm logs can be exported as ASCII files allowing for import into
      MS-Access or MS-Excel, either

      o     automatically as a scheduled service; After a suceessful scheduled
            export the alarm log is cleared but continues logging.

<PAGE>

      manually on user demand (an entire log, a filtered portion of a log). No
      clearing of the logs shall be performed.

6.    Media interfaces (e.g. sound, SMS) alarms and NEs can be configured.

7.    In case an SNMP alarm interface is used (available on customer request and
      at extra cost), an alarm message shall be sent to the external system at
      the occurrence of an alarm.

8.    For each object (NE, functional unit, module) the current status of the
      alarms (alarm state, severity, priority) is displayed.

9.    For a quick overview about the current alarm and event situation,
      Accessintegrator provides a global alarm counter showing the number of
      active alarms per severity.

For QD2 network elements, the following alarm parameter can be configured:

o     Alarm priority (high, low, disabled): this parameter determines if an
      alarm is sent with a higher priority or lower priority through the
      SISA-DCN, or not sent at all.

o     Stabilizing period: Used to control the sending of the alarms.

o     A/B-type (for NEs of type BW7R)

o     ZA-type (for NEs of type BW7R)

                                   [GRAPHIC]

<PAGE>

                         FIGURE 25: ALARM CONFIGURATION

6.3.1.2 EVENT LOG

Events are internal messages, which are generated under certain circumstances,
e.g. changes in the network topology (e.g. new NE) or state changes of a network
element (e.g. changes of the Operational State). Accessintegrator distinguishes
between the following event types:

--------------------------------------------------------------------------------
Event type            Description
--------------------------------------------------------------------------------
Reset                 Generated when a NE sends the report 'Reset'
--------------------------------------------------------------------------------
System Configuration  Signals changes in the system configuration of a NE:
                      o  MODULE INSERTED/REMOVED
                      o  FUNCTIONAL UNIT ADDED/REMOVED
--------------------------------------------------------------------------------
Poll List             Generated when an NE is added or removed from the network
--------------------------------------------------------------------------------
Operational State     Generated when the operator changes the state of a NE:
                      from OPERATIONAL to IN MAINTENANCE and vice versa
--------------------------------------------------------------------------------
Alarm Priority        Generated when the operator changes the parameter
                      'priority' in the dialog window 'Alarm status...'
--------------------------------------------------------------------------------
Communication         Signals an interface problem between the DCN and the OS:
                      o  LOSS OF CONTACT WITH THE DCN SERVER PROCESS
                      o  ESTABLISHMENT OF CONTACT WITH THE DCN SERVER PROCESS
--------------------------------------------------------------------------------
Cross connect         Generated when the operator creates, disconnects, and
                      deletes a crossconnect
--------------------------------------------------------------------------------
Protection switching  Generated by the following NEs: CMXII, OTRU36, FMX2 with
                      AUTOMATIC/MANUAL/FORCED SWITCH FROM THE WORKING LINE TO
                      THE PROTECTION LINE AND VICE VERSA.
--------------------------------------------------------------------------------

                   TABLE 3: EVENTS RECORDED IN THE EVENT LOG

<PAGE>

Events are not signaled by color-coding the objects involved, and not entered
into the alarm lists. However, events which are of interest for network
monitoring, can be logged using the AccessIntegrator Log administration tool.
When creating the log file, the user can determine which events are to be
logged. Events can be logged for the entire network, subnetworks,
stations/network units, NEs or functional units. AccessIntegrator can be
configured to automatically create a global event log at start-up.

Event logs can be exported as ASCII files suitable for import into MS-Access or
MS-Excel, either

-     automatically as a scheduled service: After a successful scheduled export
      the event log is cleared but continues logging.

-     manually on user demand (an entire log, a filtered portion of a log) No
      clearing of the logs shall be performed.

                                   [GRAPHIC]

                              FIGURE 26: EVENT LOG

<PAGE>

                                   [GRAPHIC]

                           FIGURE 27: EVENT LOG VIEW

6.3.1.3 SUBSCRIBER LINE TEST AND MEASUREMENT

The execution of subscriber line tests for preventive maintenance is an
important feature for network operators. FastLink as a modern access network
solution provides an Integrated Line Test Function (ILTF) for POTS and ISDN line
cards of the Access Multiplexer. The ILTF enables the operator to carry out all
necessary measurements and to verify the quality of the connected subscriber
lines as well as the subscriber interfaces.

The test program checks a series of measurement points depending on the line
type (POTS/ISDN): line parameters of a subscriber line, including specific
parameters of subscriber terminal equipment, and the subscriber interface
functions. Each measured value has a specific value range and for each
measurement point thresholds can be specified. Two kind of tests are provided:

o     AUTOMATIC TEST, PROVIDING THE POSSIBILITY TO CONSTANTLY MONITOR THE LINE
      QUALITY: In this case, the automatic test program is started at defined
      intervals. The response on the signal is evaluated by the ILTF micro
      controller, which can detect abnormal behavior of the line. In case that
      thresholds are exceeded, the controller generates an alarm message and
      starts the complete measuring program, which gives a detailed overview on
      the line status. The following errors are notified:

      o     results are not within the defined range; measured values outside
            the tolerance range are buffered and can be requested during service
            operations.

<PAGE>

      o     a line could not be tested

                                   [GRAPHIC]

                        FIGURE 28: SETTING OF THRESHOLDS

      To monitor a particular line over a longer period, it is recommended to
      log the test results.

      The Log Administration Tool provides the test log.

      Like any other log, subscriber line test logs can be exported as ASCII
      file allowing for import into MS-Access or MS-Excel, either automatically
      as a scheduled service, or manually on user demand (a selected log).

o     MANUAL TEST, PERMITTING TO PERFORM AN ON DEMAND TEST ON INDIVIDUAL LINES:
      The measurement variables are set by the operator. The measured values are
      displayed in a window immediately after completion of the test. The
      possibility to start the line test directly from the service management
      window contributes to a high Quality of Service.

<PAGE>

                                   [GRAPHIC]

               FIGURE 29: TEST RESULT OF MANUAL USER PORT TESTING

      The subscriber line test function, either automatic or manual, can also be
      accessed via an external SNMP based interface. This interface is an
      additional feature at extra cost.

      6.3.2

<PAGE>

      6.3.3 CONFIGURATION MANAGEMENT

6.3.3.1 NETWORK ELEMENT CONFIGURATION

Configuration management comprises features to get and display the current
configuration from a network element and to change its settings.

The AccessIntegrator provides the following GUI-supported configuration
facilities:

o     General NE-configuration (if supported by NE)

      -     Time and date: set time and date of the workstation, for selected
            network elements, or for all network elements of the managed network
            (see chapter Date & Time Broadcast)

      -     set/reset of service identification

      -     Set/reset in maintenance mode: Setting in maintenance mode will
            inhibit alarm events from being sent.

      -     NE-reset

      -     alarm/performance configuration at the network element

      -     network elements and termination point can be associated with a
            number of user files in which the operator can write user specific
            information, e.g. location, street name, customer, etc.

o     Specific configuration for certain types of network elements such as the

      -     setting of cross connections

      -     configuration of V5.1/V5.2 interface parameters and routing tables

      -     blocking/unblocking of subscriber ports

      -     display of configuration parameter of RNT, e.g. POC, ACC1-2-3

o     Configuration for internal testing purposes such as

      -     setting of switches

      -     setting of control registers

      -     setting of loops

<PAGE>

                                   [GRAPHIC]

                        FIGURE 30: CONFIGURATION OF V5.1

In order to configure NEs, two kinds of GUI approaches, depending on the kind of
selected object, are implemented:

o     Generic configuration (for a functional unit, NE, etc.), which is not
      oriented towards the hardware view, is basically oriented towards QD2 and
      mainly used for simple parameter settings.

o     Custom configuration (for modules), which is oriented towards the hardware
      view and therefore more intuitive for the operator.

                                   [GRAPHIC]

                     FIGURE 31: CUSTOM CONFIGURATION WINDOW

<PAGE>

The establishing of Cross Connections is improved by some features which make
the handling more comfortable:

o     Multiple Operations: By one operator action an operation (e.g. (dis-)
      connect, delete, create, switch, ..) can be performed on
      n-cross-connections. If the NE supports group connections the operation is
      performed at the same time for all group members and consistency is
      guaranteed. Otherwise, the operation is executed as a sequence of n single
      operations, and consistency may not be guaranteed.

o     Filtering the Display of Cross-Connections: The goal is to reduce the
      amount of data handled when executing an operation for display, i.e.
      focussing on the connections to be handled, by means of scoping and
      filtering

o     If the operator configures a n *64 Kbit/s port using the custom
      configuration window, AccessIntegrator switches all related cross
      connections automatically, inclusive conferences, and checks, whether this
      port is connected in a way that makes a transmission possible. This
      facility is of use for the FMX2 set up and works for POTS, ISDN and data
      services.

6.3.3.2 RESOURCE MANAGEMENT

For resource planning and in order to achieve a concise overview on the level of
usage and status of cross connect ports and timeslots (CMXII), the following
functionality is provided:

o     Graphical display of the 2 Mbps port usage on the NE. A matrix shows all
      available 2Mbps ports for each port unit, indicating by three different
      colors how many of their timeslots are used (Figure 32). In addition, for
      each port the number of timeslots with connected, created and planned
      cross connects is shown in form of a tooltip.

o     Graphical 64kbps cross connection overview displaying a matrix of the
      64kbps-timeslots for each port of the selected NE. For each time slot a
      legend indicates the state of the crossconnect (connected, not connected,
      created, planned, logical).

o     For a selected subset of ports detailed information about all the cross
      connections existing to all the timeslots on them may be displayed.

o     For a selected subset of timeslots detailed information about all the
      cross connections existing on them may be displayed.

<PAGE>

                                   [GRAPHIC]

             FIGURE 32: GRAPHICAL PRESENTATION OF 2MBPS PORT USAGE

6.3.3.3 PARAMETER DOWNLOAD

For faster configuration of NEs which require many parameters (e.g. for country
specific adaptations) AccessIntegrator features parameter download: the
parameter set is contained in a file and can be downloaded to the respective NE
via a file transfer. Those files are stored in the directory structure of the
server. If an invalid set of parameters is loaded, the NE indicates an alarm.
The name of the downloaded parameter file is loaded in the ACI-database as well
as the loaded version can be retrieved from the NE.

The following functionality is provided:

o     download a parameter set to a number of NEs of the same type

o     insert and remove parameter files in the directory structure of the
      server.

6.3.3.4 FILE UPLOAD FOR DIAGNOSTICS

Some NEs provide data for diagnostics purposes, which can be uploaded via a file
transfer from the NEs and exported in form of ASCII-files:

o     SW error logs for the collection of indicators for SW errors or sporadic
      HW errors documenting erroneous behavior

o     memory dumps

o     trace files containing debug information

6.3.3.5 UPLOAD AND DOWNLOAD CONFIGURATION

In order to perform a fast and consistent configuration of network elements of
the same type the following facility is provided:

<PAGE>

-     Upload the configuration of a NE: a selection of the data to be uploaded
      can be specified. Among others, the following data can be selected:
      configuration information (cross connects, V5.x, etc.), alarm
      disabling/priority, switching information, performance counter values,
      etc.

-     Download a previously uploaded configuration to selected NEs of the same
      type, or to all NEs of the same type within a defined scope.

                                   [GRAPHIC]

                        FIGURE 33: UPLOAD CONFIGURATION

6.3.3.6 INVENTORY MANAGEMENT

The configuration of a network is constantly changing, as network elements
and/or modules are replaced or added, and network elements are loaded with new
SW-versions. From time to time, therefore, the network provider may need to
retrieve current network data, such as NE-type, module configuration, serial
number, etc.

NE data can be retrieved as follows:

o     Manually: The equipment data sheet may be displayed after selecting an
      object (NE, module). The equipment data sheet has five pages: inventory
      data (equipment name, location, SW-versions), label data (module
      nameplates and detailed information on the HW-status), modification
      information (current data, edit data) and reference list. The first two
      pages are available for every NE. Label data is only supported for modules
      and the modification information is restricted to certain modules.

<PAGE>

                                   [GRAPHIC]

<PAGE>

                                   [GRAPHIC]

 FIGURE 34: INVENTORY DATA OF A NE, LABEL DATA, SUB-MODULES AND REFERENCE LIST
                                  FOR A MODULE

o     Automatically: AccessIntegrator provides a function for collection of
      inventory data of network elements and modules, for a selected set of
      network elements or for the whole network. Modules or functional units
      cannot be selected, as they are always polled for each NE during automatic
      data retrieval. During automatic inventory retrieval, AccessIntegrator
      sequentially requests data from each NE and saves the responses in an
      ASCII file on the ACI-server, which can be post processed using external
      tools. An automatic retrieval process can only be active once and can be
      canceled at any time.

                                    [GRAPHIC]

    FIGURE 35: SELECT INVENTORY FILE AND INVENTORY DATA RETRIEVING PROGRESS

<PAGE>

      The inventory file consists of the inventory data of the selected NEs and
their modules.

                                   [GRAPHIC]

                    FIGURE 36: EXAMPLE OF AN INVENTORY FILE

6.3.3.7

<PAGE>

      6.3.3.8 BACKUP AND RESTORE FEATURES

Facilities to backup data to external media and to restore the configuration
from those media are included in AccessIntegrator. AccessIntegrator provides a
series of different backup and restore mechanisms for different types of data:

o     Backup and Restore of the database: The system administrator uses
      functionality of the Versant database to save/restore the database data
      on/from a file. By using the Windows NT backup application these files can
      be exported/imported to/from an external backup medium such as tape.

o     Scheduled backup and restore of network element data: This operation
      provides the ability to store all data of the selected network elements,
      to which the AccessIntegrator has both read and write access, on hard disk
      and to reconfigure a network element using stored data. These actions are
      performed by using single QD2-telegrams or by the QD2-"file transfer"
      function. During this process, a directory structure according to the
      SISA-tree is created which can be backed-up/restored on/from an external
      medium.

o     Backup and restore of ACI-software and certain ACI-data such as
      configuration files, initialization files, etc. by means of the Windows NT
      Backup application.

6.3.3.9 SOFTWARE MANAGEMENT

AccessIntegrator provides the possibility of a software download on demand or as
a scheduled job to the whole Access Network or parts of it (e.g. network
elements). Software downloads may be necessary under the following possible
scenarios: first installation, repair, checksum error in FEPROM, SW upgrade,
fallback to an older SW version, following network extension, module/NE
replacement, etc.

The NE-software is delivered by means of "application program software" (APS)
packages covering all module-specific software for a particular version of an
Access Network. The ACI-server disk contains all the load files of one or more
APS versions. Each APS contains a stock list describing the load file
corresponding to each module type as well as its reset behavior. This guarantees
that each module shall get the correct SW.

<PAGE>

Software management supports the operator in the following areas:

o     APS management: display of all available APS-versions, display of running
      APS-versions of the scope of selection, running load files in one selected
      NE/module, and inserting and deleting APS versions on the hard disk. APS
      versions can only be removed from the hard disk if they are no longer
      active in the Access Network.

o     Checking the SW-versions loaded in the Access Network in order to
      determine which NEs in the Access Network have an APS-version other than
      the current one.

o     SW downloads for individual NEs, sub-networks or the entire network. SW
      download can be performed in single mode (downloading via QD2-commands
      several modules one after the other like a batch job) or in broadcast mode
      for different modules of the same type (the same QD2-command is sent to
      several modules of the same type in parallel). For the newer NEs, the
      SW-download shall be performed by the QD2 file transfer command. A manual
      SW-download of an individual module as well as an automatic download of
      all needed files of APS-version to an Access Network is possible. In case
      of a failure in the network element during software download or a faulty
      downloaded SW (e.g. short power down and then unsuccessful attempt to auto
      reset), a critical alarm will be sent from the network element indicating
      the corresponding module.

6.3.3.10 CONSISTENCY CHECKS

During normal operation, AccessIntegrator and the Access Network can get out of
synchronization due to network faults: interruption in the SISA-DCN or loss of
connection between AccessIntegrator and the Access Network and a resumption of
the connection. This disconnection-reconnection is notified to AccessIntegrator,
and a time stamped event is entered in the event log as well as the status of
the respective objects (network element, module) is changed. Upon receipt,
AccessIntegrator starts an exploration of the sub tree:

o     In case of reconnection, the SISA-topology is verified and the NE/Network
      status updated.

o     In case of newly detected sub trees, a complete exploration takes place:
      upload of module/system configuration, references lists, NE/Network status
      update etc.

Update of the NE/network status consists of NE-alarm information (status,
priority), NE-configuration (test loops, cross connects), update of parameters
(e.g. loaded APS-versions) of the APS management, update of the loaded parameter
file from the RNTs, update of the traffic measurement points, etc.

<PAGE>

Information about the network elements in AccessIntegrator is adjustable on
operator request at any time. Such an operation can be required if for example a
NE is by one of a different type.

6.3.4 QUALITY MANAGEMENT

6.3.4.1 PERFORMANCE MANAGEMENT

Performance data are used for statistical analysis and saved as evidence of the
service quality and as input for service level agreements. Various network
elements support the measurement of performance data of termination ports (e.g.
2 Mb, 8Mb, 34 Mb, SMT1, STM4, VC-4, VC-3, VC-12) in accordance to ITU-T G.821 or
G.826. Performance data are measured at specified measurement points in the NEs
and stored in the NEs. Some NEs have a single measurement point, while others
have several measurement points. Each measurement point has a number of
performance counters, such as

--------------------------------------------------------------------------------
TMP                                 total measurement period
--------------------------------------------------------------------------------
EFS                                 error free seconds
--------------------------------------------------------------------------------
BBE                                 background block error
--------------------------------------------------------------------------------
ES                                  errored seconds
--------------------------------------------------------------------------------
SES                                 severely errored seconds
--------------------------------------------------------------------------------
UT                                  unavailable time
--------------------------------------------------------------------------------
EC                                  Error counter 1: Number of alignment of code
                                    errors
--------------------------------------------------------------------------------
CRC/EC2                             Error counter 2: Number of CRC errors
--------------------------------------------------------------------------------
LOF                                 loss of frame
--------------------------------------------------------------------------------
AIS                                 alarm indication signal
--------------------------------------------------------------------------------
LOS                                 loss of signal
--------------------------------------------------------------------------------

                   TABLE 4: PERFORMANCE MEASUREMENT COUNTERS

<PAGE>

There are two types of performance counters:

o     15-minute counter which collects data for a 15 minute period

o     24-hour counter which collects data for a 24 hour period

Performance Management provides the following performance monitoring facilities.

o     Configuration and monitoring of current performance data from the network
      elements. Each measurement point can be activated or deactivated as
      desired by configuring the size of the wrap-around-buffer in the NE:
      generally up to 100 15-minute counters and 30 24-hour counter. The current
      as well as the historical counters of a measurement point can be
      displayed.

                                   [GRAPHIC]

                    FIGURE 37: CONFIGURING PERFORMANCE DATA

                                   [GRAPHIC]

                     FIGURE 38: DISPLAYING PERFORMANCE DATA

<PAGE>

o     Periodic retrieval of performance data and storage of the data in logs:
      Logging is an automatic periodic background task by which performance
      records from a particular measurement point are retrieved and stored in a
      log. To optimise the DCN throughput, this retrieval can be scheduled. The
      operator can define a separate schedule for each log as well as for the 15
      minute / 24 hours counters. If the operator does not schedule the
      retrieval for a particular log, the default retrieval schedules will be
      applied which can be configured by the operator. The initial values of
      these default schedules will be 'every 15 minutes' and 'every 24 hours'
      respectively.

      All performance logs are presented in a performance-log-administration
      tool that is used to configure, start, stop or view logs.

                                   [GRAPHIC]

                FIGURE 39: LOG CREATION AND OPEN PERFORMANCE LOG

<PAGE>

                                   [GRAPHIC]

                        FIGURE 40: PERFORMANCE LOG VIEW

All performance data, which have been retrieved into logs, can be exported as
ASCII file allowing for import into MS-Access or MS-Excel:

-     automatically as a scheduled service: The operator can choose to define a
      scheduled performance-data export task, which is executed on all available
      logs at the specified time. After a successful export the logs are
      cleared, but logging is continued

-     manually on user request: The operator can invoke a function to export all
      available performance logs or a set of selected performance logs.

                                    [GRAPHIC]

                     FIGURE 41: PERFORMANCE LOG SCHEDULING

<PAGE>

6.3.4.2 QUALITY MEASUREMENT

Some of the network elements in Access Networks have specified test-points that
are dedicated to measure certain physical characteristics such as temperature of
a component, laser bias current, etc. Each FU/module that supports such
measurements can have one or more test-points. Each test-point is identified by
a test-point number and measures a different value. For most of such
test-points, thresholds are specified in the network element. For some of the
test-points, the thresholds are configurable. Whenever the measured value
exceeds/falls below the specified threshold, an event report is generated.

The AccessIntegrator quality measurement feature provides configuration of the
thresholds for selected test-points, logs events which indicate that thresholds
have been violated in the database and allows for continuous logging in the
database of the measured value and measured value thresholds for specified
test-points. The measured values and the thresholds of the measured values for a
specified test-point are presented in a tabular form. All quality measurement
logs are presented in a quality measurement log administration tool that is used
to configure, start, stop or view logs.

                                    [GRAPHIC]

                       FIGURE 42: QUALITY MEASUREMENT LOG
<PAGE>

                                    [GRAPHIC]

                       FIGURE 43: QUALITY MEASUREMENT DATA

6.3.5 SECURITY MANAGEMENT

The security management of AccessIntegrator allows the system administrator for
flexible definition and control of:

o     access to the workstation

o     user-classes, also called permission classes

Authorization to the workstation is controlled by means of the Windows NT
authorization mechanism (NT login name and password). If the login procedure is
successful, access is granted to the login name and the user can start the
ACI-client.

User rights (i.e. the functions that can be accessed by a user) of individual
users are controlled by means of ACI user-classes. Up to 6 different ACI
user-classes can be defined with regard to ACI functionality and have to be
assigned to global NT user groups (defined by the system administrator). A user
belonging to a certain global NT user group is granted the ACI functionality of
the corresponding user-class

                                    [GRAPHIC]

             FIGURE 44: ASSIGNMENT PERMISSION CLASS TO GLOBAL GROUPS
<PAGE>

The system administrator can enable and disable individual functions for each
particular user class. For that purpose the enabled and diabled functionalities
are represented in function permission table in form of a tree structure which
allows for easy navigation from main function groups, e.g. 'Fault', down to very
specific tasks.

                                    [GRAPHIC]

                      FIGURE 45: FUNCTION PERMISSION TABLE

AccessIntegrator provides at installation time six default user classes:

o     Subscriber management: generate, modify, or delete subscriber data

o     Subscriber Line Test: permission to access measuring equipment and
      functions used to test the line.

o     Operation and Maintenance: functions to operate the loop manager, and to
      configure and maintain NEs and boards.

o     System Administration, all AccessIntegrator functions

o     Intelligence Features: permitted to test telephone lines.

o     Super user: all ACI functions

The AccessIntegrator user-class table does not affect the super user
permissions.

                                    [GRAPHIC]

                    FIGURE 46: DEFINE PERMISSION CLASS ENTRY
<PAGE>

Windows NT provides security logs for all security-related events, allowing to
monitor changes to the security system and possible violations.

6.3.6 GENERIC SNMP MANAGER

The generic SNMP manager provides the basis for fast integration of the element
management functionality for relatively simple NEs, e.g. bridges and routers,
into the AccessIntegrator via SNMP.

Since the network element is modeled in a minimal way, only the basic
AccessIntegrator functionality is supported: No data of the network element are
kept in the database of the AccessIntegrator, and all access to NE-data is
routed directly to the NE. Therefore only the following Element Management
functionality is provided:

o     Integration in the AccessIntegrator GUI: SNMP NEs are integrated into the
      GUI like any other network element: e.g. Port/DCN/transmission view,
      context sensitive menu appears which shows the available functionality

o     NE Configuration is supported by means of custom configuration windows
      tailored to the the specific NE. The values of the corresponding SNMP-MIB
      variables are read directly from the NE. The operator can change those
      values and apply them on the NE.

o     SW-download/upgrade is realized via (t)-ftp. The operator is allowed to
      enter in the name of the load as far as provided by the NE.

o     Alarm surveillance: All alarms are completely integrated in the alarm
      functionality: lists, logs, object coloring, interfaces, etc,.

o     Connection surveillance: Since all access to the NE is directly routed to
      the NE, no consistency checks are needed, and thus only the
      synchronization states on/off-line are supported.

<PAGE>

6.4 NETWORK MANAGEMENT LAYER

6.4.1 PERFORMANCE MANAGEMENT

6.4.11 END-TO-END PERFORMANCE

End to end performance management (SES, UT,...) between two points is only
possible for structured 2Mbit/sec electrical leased lines (G.703, G.704),
connected to interfaces providing the CRC4-frame, and which is transparently
transmitted in the transmission network between the two end-points. For those
interfaces, performance logs can be created.

Since one can assume that there are almost no losses in the network termination
equipment with an electrical structured 2 Mbit/sec interface (e.g. FMXII), the
end-to-end performance data (SES, UT,...) of the 2 Mbit/s line interface can be
extrapolated to a respective n*64kbit/s port.

6.4.2 CONFIGURATION MANAGEMENT

6.4.2.1 NETWORK EDITOR

To facilitate the handling of large networks, the network editor provides
support for the creation of the network map.

When AccessIntegrator is started the first time on a network, no icons are
displayed in the network map, but a counter indicates the number of transmission
network elements in the DCN-View not yet transported into the network map. The
DCN-View is built up automatically and all transmission network elements are
marked with an asterisk (not transferred to network map yet). The nodes in the
DCN hierarchy are selectable (individual NEs or entire branches by selecting the
corresponding SISA-controller) and can be copied by "drag and drop" to the
network map. If a SISA node is copied to the network map, the whole sub tree
below is copied as well, except the SISA-controllers and already transferred
network elements. New NEs are detected during polling and are automatically
displayed in the DCN view (marked with an asterisk). In order to avoid conflicts
only one network editor can be active at a time.

The network editor features special menu and tool bar and provides all functions
for fast creation and modification of transmission network maps.
<PAGE>

A transmission map is created during a network editor session by issuing special
menu commands and by drawing the graphical elements using the mouse.

o     Create/delete subnetworks and stations/networks units

o     Create a shelf icon representing a shelf. This special subnetwork has all
      the features of ordinary subnetworks with the following additional ones:

      -     If the shelf subnetwork contains at least one NE, it is possible to
            open the shelf view.

      -     If an NE is added to the shelf subnetwork it is checked if It fits

o     Position network elements in subnetworks or stations resp. remove network
      elements

o     Create/delete connections between network elements even between different
      sub networks. Connections provide a better overview of the real network,
      and are required for the path and service management. AccessIntegrator
      cannot verity the existence of an actual physical connection, i.e. it is
      assumed the connections exist in the Access Network.

o     Insert note fields to display information to the operator

                                    [GRAPHIC]

             FIGURE 47: NETWORK EDITOR WITH OPENED NOTE FIELD DIALOG
<PAGE>

                                    [GRAPHIC]

      FIGURE 48: EXAMPLE FOR THE DEFINITION OF A ONU250FTTC SHELF INSERTION

o     Insert/delete bitmap files as background images, e.g. city maps or station
      photos

o     make optional extensions such as external elements (icons representing
      alarm contacts) and labels (to assign additional information to the NEs)

o     add descriptions to objects, e.g. name, kind of shelf, possible NEs which
      may be contained in the shelf, used alarm bit, etc. Most text fields can
      be filled when creating the object or later by means of the network editor
      (please refer to chapter
<PAGE>

5.5.7 Common Features for all views)

All objects elements created in the network map are immediately added to the
database.

                                    [GRAPHIC]

                         FIGURE 49: NETWORK EDITOR VIEW

In order to accelerate the set-up of a network map, network templates can be
used. These describe configurations of QD2 Network elements which appear more
than once in the whole network, e.g. a certain FastLink ONU with all its NEs. A
template is created by a "copy" of an existing configuration (subnetwork
structure, QD2-elements, external elements, connections, background map, etc.).
It may then be applied to an identical set of other QD2-network elements in
order to define an equivalent network configuration.

The AccessIntegrator provides template administration which allows to list,
rename and delete existing templates.

                                    [GRAPHIC]

                              FIGURE 50: TEMPLATES

6.4.2.2
<PAGE>

6.4.2.3 AUTOMATIC DETECTION OF CHANGES IN THE NETWORK

AccessIntegrator permanently polls the Access Network and is automatically
informed about network changes. The following list gives a short overview of the
actions taken by AccessIntegrator on different network events:

o     New NE/sub-tree: automatic network exploration of the NE and potential
      subordinates. The type of the detected network elements is displayed if
      the NE is supported by AccessIntegrator. Other, unknown types of network
      elements are also detected and displayed as a network element of unknown
      type.

o     new FU/module: a new module/FU is created

o     NE replaced by an NE of another type; AccessIntegrator gets informed about
      this, and a consistency check must explicitly be started

o     removed sub tree/NE/FU/module: state of NE/FU/module is set to off-line

o     value change of attributes: attributes are set to new value

o     new/deleted managed objects (e.g. cross connect)

6.4.2.4 EXTRACT NETWORK TOPOLOGY - LIST OF PORTS AND CONNECTIONS

Once the network topology has been defined by the operator, the AccessIntegrator
provides an offline tool to extract it in form of a file. This file can be
imported by other tools, e.g. for planning purposes. This tool can be started
from the AccessIntegrator menu or "outside" the AccessIntegrator in the MS
Windows NT environment. It produces a readable ASCII file with a format that can
be imported for instance by MS Excel. Per connection, there is one entry
specifying source and destination port by sub-network name, NE name, NE, type,
NE-address, and port name.

6.4.3
<PAGE>

6.4.4 SUBSCRIBER MANAGEMENT

Subscriber management is responsible for the management of the different
subscribers and their respective subscriber data. To each subscriber several
services can be assigned, e.g. one leased line and several ISDN services.

The subscriber management supports the following tasks:

o     Create, modify and delete subscriber

o     Browse (filtered) and display the different subscribers with their
      subscriber data

o     Relate resp. Unrelate services to subscribers

o     Show related services

o     Export of the subscriber grid data (all or subset matching a filter) into
      an ASCII-file readable by Microsoft Office applications.

                                    [GRAPHIC]

                          FIGURE 51: CREATE SUBSCRIBER

                                    [GRAPHIC]

             FIGURE 52: SUBSCRIBER LIST AND SERVICES OF A SUBSCRIBER
<PAGE>

                                    [GRAPHIC]

                   FIGURE 53: RELATE A SERVICE TO A SUBSCRIBER

6.4.5 PATH AND SERVICE MANAGEMENT

The Access Network provides subscribers with access to various services. Path
and Service Management allow for creation and monitoring of those services. In
case of problems, it enables the operator to react proactively, locate the
affected subscribers, and to initiate the necessary corrective measures.

Path management is concerned with the physical connection between two points;
e.g., subscriber access point and service access point, which is defined by the
network resources involved (e.g., V5 ports at a local exchange, cross
connections). A service (e.g. ISDN) generally comprises one or more paths and
all resources (e.g. signaling) to make a path operational.

6.4.5.1 SERVICE MANAGEMENT

Service management is responsible for the service data.

AccessIntegrator supports the following services:

o     PSTN

o     ISDN    64kB (IB+D), 2*64kB (2B+D)

o     LL      64kB, n*64kB, 2Mb

o     Conferences

The service management supports the following tasks:

o     Displaying service related data like service title, address
<PAGE>

o     Configuration of services

o     Extending/reducing services with new paths

o     Deleting services

o     Modifying services

o     Requesting path information.

o     Relate resp. Unrelate a service to subscriber

o     Show corresponding subscriber to a service

o     Export of the service data (all or subset matching a filter) into an
      ASCII-file readable by Microsoft Office applications.

Within Service management, a service is created and deleted in two phases:

1.    First, a service is planned (route path between the two end-points, ask
      for missing configurations, set reservations on the resources). The
      selection of timeslots can be done either automatically,
      semi-automatically or manually.

2.    Then the service is activated by activating the resources in the network
      state management. This concept permits to plan services without
      interrupting the network operation. All reservations are entered in the
      database, and checked for completeness and correctness. The configuration
      is loaded into the NEs at activation time (immediately or at a later point
      in time).

                                    [GRAPHIC]

                    FIGURE 54: SERVICE MANAGEMENT MAIN WINDOW
<PAGE>

                                    [GRAPHIC]

             FIGURE 55: OPTIONS FOR CONFIGURATION OF SERVICE ACTIONS

The mode of service actions (create, delete, display) can be selected in the
option view.

                                    [GRAPHIC]

                       FIGURE 56: SERVICE CREATION WINDOW
<PAGE>

                                    [GRAPHIC]

                     FIGURE 57: SHOW SUBSCRIBER OF A SERVICE

The service deletion performs the reverse procedure: deactivate service
(deactivate the resources in the network), then delete the service (shut down
state management, delete service). This two-phase process ensures that the NEs
do not contain any undesired data. Each service has an overall service state
(state management), which consists of the overall state of all paths involved in
a service. The path management is responsible for monitoring the states of the
network resources of the individual paths.

                                    [GRAPHIC]

                            FIGURE 58: DELETE SERVICE
<PAGE>

6.4.5.2 PATH MANAGEMENT

The path management provides an integrated interface to configure paths and the
associated resources (e.g. V5 interfaces).

The following path types are supported:

o     64 Kbps

o     2 Mbps

o     34 Mbps

                                    [GRAPHIC]

                     FIGURE 59: PATH MANAGEMENT MAIN WINDOW

A path through the network can be created either manually or automatically. It
always uses the network map as the basis for information on the route of a path.
Path management always starts from a subscriber access point towards a service
access point, based on the connections/cross connections in the network map and
the resources not yet reserved by another service. With automatic path
selection, the path router tries to find a path between the selected end-points
by automatically selecting the cross connections. With semi-automatic/manual
path selection, the operator has to select - in case of different alternatives -
the cross connect manually.

Each path has an overall path state consisting of the following states:

o     operational state: indicates whether a path is operational

o     administrative state: indicates whether a network resource has been locked
      by means of a user command

o     alarm state

o     loop state
<PAGE>

o     protection state

                                    [GRAPHIC]

                             FIGURE 60: PATH STATES

Each of these path states itself represents an overall state, which is derived
from the current states of all network resources involved: V5, cross connect,
termination points.

The path management supports the following tasks:

o     path browser

o     activate, modify, delete, analyse a path

o     display state information

o     request service information

o     perform a manual subscriber line test

o     export of the path data (all or subset matching a filter) extended with
      inventory data into an ASCII-file readable by Microsoft Office
      applications.

                                    [GRAPHIC]

                        FIGURE 61: SHOW SERVICE OF A PATH
<PAGE>

All Network Elements and Modules the building a path are listed in the path
detail window. If an alarm occurred for one of these Network Elements, it is
also shown in this window. This makes it easy for the operator to check the
status of a path.

                                    [GRAPHIC]

                             FIGURE 62: PATH DETAILS

6.4.6 ACCOUNTING MANAGEMENT

AccessIntegrator currently provides no accounting data. For voice services,
accounting data are available in the Local Exchange (LE). However to support
accounting, in ACI V6.1 the following data will be logged for all supported
services

o     date and time of creation

o     date and time of deletion

o     date and time of state changes for the following states

      - operational state

      - administrative state

      - loop state

      - alarm state

      - protection state

The log records are displayed using existing ACI capabilities. Additionally the
log can be accessed via an ODBC interface e.g. for an external reporting tool.

6.5
<PAGE>

      6.6 MANAGEMENT OF NES BY 3 RD PARTY SUBNETWORK MANAGER

In access networks one often finds embedded subnetworks, e.g. complex
SDH-structures, as well as networks elements of other providers, which are an
integral part of the access domain. Usually those subnetworks build a server
layer providing transport capacity for the different access services. For those
embedded subnetworks, specialized subnetwork management systems are available.
To provide a common management of such access networks a kind of integration of
the ACI and those management systems is provided. The integration of subnetwork
manager into the AccessIntegrator is based on the following philosophy:

o     The subnetwork manager is responsible for the management of the
      subnetwork; e.g. element management, subnetwork management. It acts as a
      server manager for the ACI.

o     The AccessIntegrator is responsible for the overall management of the
      access network. It is connected to the subnetwork manager via "interfaces"
      allowing it to appear to the operator as a single TMN system. Each
      subnetwork or subnetwork manager is according to the available
      "interfaces" and kind of integration modeled in the AccessIntegrator and
      represented by an icon. It is integrated into the ACI-GUI like any other
      network element: e.g. Port/DCN/transmission view, context sensitive menu
      according to the available functionality, etc..

o     Depending on the kind of integration the following
      "interface"-functionality is provided:

      -     Context sensitive windowing provides the ability to launch from the
            ACI other management systems and depending on the selected
            functionality, NE and the degree of integration to open a specific
            window.

      -     Since management systems generally have an own security handling,
            security information like user name, password, user profile shall be
            exchanged between the ACI end the subnetwork manager in order to
            provide a common security management.

      -     All alarms of the subnetwork are forwarded to the ACI, providing an
            integrated alarm management.

In order to provide an integrated end-to-end management the underlying
subnetwork manager reports the ACI specific resources providing an abstract view
of the subnetwork: e.g. ports, NEs, services, service/port status, etc..
<PAGE>

6.6.1 MANAGEMENT OF WALKAIR

In order to provide a common management of access networks embedding WALKair
network elements, the element manager WALKnet is integrated into
AccessIntegrator. WALKnet is an SNMP-based management system and provides the
operator with the capability to manage the WALKair NEs.

In the first step as realized in AccessIntegrator V5.1, only an integration on
element management level is provided; an integration on network level will be
provided in future releases. Since WALKair has an SNMP interface, the
integration of WALKnet is based on the generic SNMP manager concept (please
refer to chapter Generic SNMP Manager).

In the following the main integration issues are described:

o     Each WALKair NE - having an IP-address - is represented by an icon.
      WALKair icons can be created/deleted in the DCN view and in the network
      view as described chapters SNMP DCN View and Network Map View.

o     The complete configuration and performance management of the WALKair NEs
      is provided by the WALKnet application. Access to this functionality from
      the AccessIntegrator is provided via context sensitive windowing according
      to the selected WALKnet icon and requested functionality.

o     Common fault management of WALKair together with other access network
      products, e.g. FastLink, is provided as all WALKair alarms are sent as
      traps directly to the AccessIntegrator. These alarms are completely
      integrated in the ACI alarm functionality (please refer to chapter Alarm
      Management). For any further alarm handling like identification of the
      alarming unit, repair actions, .., a context sensitive access to WALKnet
      has to be invoked.

o     Connection monitoring: support of the synchronisation states on/off-line

o     Common Security with one user login as well as common user classes

<PAGE>

7 SUPPORTING APPLICATIONS

7.1 MASS PROVISIONING

The S Access Network products enable carriers to provide customers with access
to telecommunication services in a flexible and cost-effective manner.

Generally, subscribers are first created in the switch and then in the Access
Network. in order to support the time-consuming subscriber administration and to
keep the open V5.x interface between the EWSD and an Access Network consistent,
the tool MassProvi has been developed. It supports the automatic creation of a
large number of subscribers in the Access Network.

As input for MassProvi Subscriber and V5.x data from EWSD (in form of
MML-Commands) and the planning data (SISA-Network) of the Access Network are
needed. These data are used in MassProvi to:

1.    create a configuration file which serves to configure the network elements
      as well as the AccessIntegrator database,

2.    create a detailed documentation of the Access Network (subscriber and V5
      information) to support administration and fault management.

3.    to perform plausibility checks to secure data consistency between local
      exchange and access network.

The MassProvi is intended only for the S service department and its
corresponding Local Companies for installation-/network planning.
<PAGE>

                                   [GRAPHIC]

                     FIGURE 63: MASS PROVISIONING OVERVIEW

MassProvi supports the following features:

o     Multiple checks of input data to check for errors and to correct them

o     Graphical User Interface supporting a smooth handling process

o     Generation of the data for AccessIntegrator concerning V5/subscriber -
      data

o     Documentation of Access Network database parts

o     Data consistency between Local Exchange (EWSD) and Access Network,
      concerning V5/subscriber data

o     Stepwise mass provisioning

o     Extension of existing access network(s)

o     Updates and SW-service

o     Editor functions

o     Portable tool, with regard to time and place of the processes of network
      planning

<PAGE>

8 LOCAL CRAFT TERMINAL (LCT)

The LCT supports both local and remote management of NEs. It is used for
operation and management of the NEs in the following cases:

o     Installation of network elements

o     Local operation by customers and service

o     When operation via AccessIntegrator is not possible, e.g. SISA-DCN is
      down.

The LCT provides the basic TMN element management functionality. The Graphical
User Interface of the LCT has the same look-and-feel as AccessIntegrator,
offering the advantage that the user is already familiar with the operation. The
LCT is easy in use and has a fast bring-up. The LCT is hooked-up to the NEs via
the F-interface (RS232).

Due to the field of operation of the LCT, Its functionality is - compared with
AccessIntegrator

-     restricted:

-     no RS48S-interface

-     no network map, network editor, templates

-     only one kind of operator "super user"

-     no Interfaces to higher level management systems (SNMP- ,CORBA-,
      ASCII-interfaces), no Mass Provisioning

-     no Subscriber, Path- and Service management

-     multiple selection and best effort command execution on more than one NE
      excluded

-     APS management not available

-     broadcast mode not available; only manual SW-download possible

-     no global alarm list

-     inventory data restricted to the selected NE

-     log management functions excluded or restricted to the period of permanent
      connection to the NE.

<PAGE>

9 TECHNICAL DATA

9.1 PLANNING CHARACTERISTICS FOR ACCESSINTEGRATOR

AccessIntegrator features a modular design and can be tailored and extended
according to customer needs and network growth. A single-workplace system is
sufficient for up to 10,000 subscribers. For more subscribers a client-server
configuration is recommended. One ACI-server is capable of managing up to
approximately 50,000 wireline services (FastLink, WideLink, and FMXII) and
serving a maximum number of 20 clients. One client workplace is recommended per
8,000 subscribers in order to guarantee an adequate processing by the operator.
For bigger networks, multi-server configurations are provided as described in
chapter 3.2. In a future version of the AccessIntegrator the multi-server
concept will be enhanced to allow each ACI-client to simultaneously be connected
to several ACI-servers.

9.2 MIGRATION TO ACCESSINTEGRATOR V5.1

AccessIntegrator provides migration procedures in order to upgrade an already
installed system to a newer version, incorporating the already existing
information base. This comprises - among others - the whole network information
and data from path and subscriber management.

An overview about available migration procedures is given by the following
picture:

<PAGE>

                                   [GRAPHIC]

           FIGURE 64: AVAILABLE MIGRATION STEPS FOR ACCESSINTEGRATOR

As far as possible, these steps are supported by automated procedures reducing
the necessary operator interaction.

9.3 STARTING ACCESSINTEGRATOR

Users are granted access to AccessIntegrator functions through Windows NT
authorization and the assignment of an ACI user class. The ACI user class
determines the functions that can be executed by the user. AccessIntegrator has
six default user classes, which can be modified by the system administrator with
regard to the permitted functionality. Starting the three main processes in the
correct sequence starts the AccessIntegrator: DCN-Server, ACI-server, and
ACI-client.

As soon as the connection to the Access Network is established by the
DCN-server, the ACI-server determines the network configuration by issuing QD2
telegrams and analyzing the responses.

For QD2 network elements, the start-up is performed in the following phases:

1.    Read-in of QD2-files, describing the manageable network elements.

2.    Analysis of the SISA-hierarchy reap. NEs and creation of corresponding
      objects in the database.

3.    Determination of internal structure of each NE (module/system
      configuration, reference lists) and creation of objects in the database
      for the modules, functional units, and termination points.

4.    Determination of all attributes (e.g. alarms, status, priority, etc.) for
      each object (time consuming).

<PAGE>

At initial start-up, all phases have to be passed through; the server starts to
accept ACI-client requests during phases 3 and 4. During all phases, all data
are kept persistent in the database so that all phases can be interrupted and
restarted.

At restart, the information in the database will be used so that only the
network topology (SISA-hierarchy, type of NE) has to be verified. The internal
structure and attributes have to be collected only for new NEs. Finally, the
alarm information of all known network elements is polled. Using the information
in the database, requests from the ACI-clients are accepted during phases 2 to 4
in this case.

A start-up window allows to follow the progress of the start-up phases, to view
error messages and start- and end- times of the phases allowing to calculate the
time required to learn the network.

                                   [GRAPHIC]

                        FIGURE 65: START-UP INFORMATION

<PAGE>

9.4 SOFTWARE PLATFORM

9.4.1 SOFTWARE DESIGN

The design of AccessIntegrator subsystems follows the object-oriented approach
for its user interface as well as for its internal structure. At the user
interface, the user always selects an object or a set of objects and will be
offered only those functions that are applicable to the set of selected objects.
The Microsoft Foundation Classes (MFC) are used as the basis for development of
the user interface.

9.4.2 PROCESSES

The process structure of the AccessIntegrator system is shown in the following
picture.

<PAGE>

                                   [GRAPHIC]

                FIGURE 66: PROCESS STRUCTURE OF ACCESSINTEGRATOR

The processes have the following purpose:

o WORKSTATION APPLICATION (WSAP)

This client process provides the graphical user interface. It is based on the
Microsoft Foundation Classes (MFC), from which the AccessIntegrator classes were
derived.

o MEDIATION APPLICATION (MED)

This is the server process, responsible for internal communication and
administration of the database. It controls all communication between the WSAP
and the Access Network.

o SNMP API APPLICATION

The 'Application Programmer's Interface' forms the connection to other TMN
systems via an SNMP interface. The API process, which is operated the same as a
WSAP process, is a special client for the MED process.

o SNIF API APPLICATION

This 'Application Programmer's Interface' forms the connection to other TMN
systems via a CORBA

<PAGE>

interface. The API process, which is operated the same as a WSAP process, is a
special client for the MED process

o DATABASE

The object-oriented database stores network data (network model), the Network
Map data, subscriber data, Network configuration management data and logs.

o DCN SERVER

The DCN server forms the connection to the Access Network (QD2 interface) and is
responsible for data communications in both directions.

The ACI Toolset provides various tools, such as the tool for evaluating traffic
data (PDPT).

9.4.3 SOFTWARE REQUIREMENTS

--------------------------------------------------------------------------------
SOFTWARE                     SINGLE-     MULTI-     WORKPLACE   LCT
                             WORKPLACE   (SERVER)   (CLIENT)
================================================================================
Windows NT 4.0 Workstation                          1           1
--------------------------------------------------------------------------------
Windows NT 4.0 Server        1           1
--------------------------------------------------------------------------------

                   TABLE 6: SOFTWARE SERVER, CLIENT, AND LCT

9.4.4 ABOUT VERSANT 6.0 DATABASE MANAGEMENT SYSTEM

VERSANT - the database management system used by AccessIntegrator - is an object
oriented system for multi-user and distributed applications.

o     It offers on-line recovery, on-line schema evolution and disk space
      management.

o     It provides transparent failover and high reliability for full 24 x 7
      availability is guaranteed by the VERSANT Fault Tolerant Server, an add-on
      product.

o     Supports dual-caching, server-based queries, event management and
      multi-threading.

o     To support workgroup-computing, features like personal databases,
      check-in/check-out, long transactions, and object versioning are offered.

o     Navigational or path queries, support for queries on collections of
      objects, Boolean functions and pattern matching are provided

o     The DBMS provides object locking and features including group and class
      operations. Locks may be applied on classes, instances or versioned
      objects. Short and persistent locks (needed for long transactions) are
      supported. The lock requests are queued by the DBMS. Deadlocks are
      automatically prevented

<PAGE>

o     Transparent distributed two-phase commit guarantees the atomicity of
      transactions. Additional partial cache commit, checkpoints and save-points
      are supported. Logical transactions are used to perform an automatic
      rollback and release of the locks in failure of a database transaction.
      The DBMS provides nested transactions and shared sessions

o     Support for national languages, TCP/IP and binary coded decimal data types
      are provided

o     The VERSANT DBMS complies to the OMG standard

9.5 HARDWARE PLATFORM

9.5.1 MINIMUM HARDWARE REQUIREMENTS

--------------------------------------------------------------------------------
HARDWARE           SINGLE-     MULTI-      SINGLE USER  USER          LCT
                   USER        (SERVER)    (SMALL)      (CLIENT)
================================================================================
Intel Pentium      233 MHz     233 MHz     233 MHz      233 MHz       200 MHz
                   PII         Dual - P II P II         P II          MMX
--------------------------------------------------------------------------------
RAM                256 MB      268 MB      128 MB       128 MB        128 MB
--------------------------------------------------------------------------------
Ethernet board     1           1           1            1             PC-card
--------------------------------------------------------------------------------
Fast SCSI          1           1
controller
--------------------------------------------------------------------------------
HD                 4 GB        4 GB        4 GB         4 GB          2.1   GB
                   (SCSI-UW)   (SCSI-UW)   (Ultra DMA)  (Ultra DMA)   (Fast-IDE)
--------------------------------------------------------------------------------
floppy drive 3.5"  1           1           1            1             1
1.44MB
--------------------------------------------------------------------------------
streamer DAT 4GB   1           1           1
SCSI-2
--------------------------------------------------------------------------------
CD-R0M             32 x spin   32 x spin   32 x spin    32 x spin     20 x spin
                   (SCSI)      (SCSI)      (IDE)        (IDE)
--------------------------------------------------------------------------------
mouse              PS/2        PS/2        PS/2         PS/2
--------------------------------------------------------------------------------
graphic board      4MB VRAM    4MB         4MB VRAM     4MB VRAM      4     MB
                   SVGA        VRAM        SVGA         SVGA          VRAM
                               SVGA                                   SVGA
--------------------------------------------------------------------------------

<PAGE>

--------------------------------------------------------------------------------
HARDWARE           SINGLE-     MULTI-      SINGLE USER  USER          LCT
                   USER        (SERVER)    (SMALL)      (CLIENT)
================================================================================
monitor            21"         17"         17"          21"           13.3"
                                                                      XGA
--------------------------------------------------------------------------------
keyboard           1           1           1            1
--------------------------------------------------------------------------------
mirror disk                    optional
--------------------------------------------------------------------------------
printer            optional    optional
--------------------------------------------------------------------------------
Doubled power                  optional
--------------------------------------------------------------------------------
supply
--------------------------------------------------------------------------------
UPS                optional    optional
--------------------------------------------------------------------------------

           TABLE 8: HARDWARE REQUIREMENTS FOR SERVER, CLIENT AND LCT

9.5.2 POWER CONSUMPTION - UPS

In case a customer wants to install an uninterruptable power supply (UPS), the
following power consumption values have to be considered:

--------------------------------------------------------------------------------
   EQUIPMENT                SIEMENS                  POWER CONSUMPTION
                                                            [W]
================================================================================
      Server PC           PRIMERGY 470                   350 (MAX.)
   Single User PC
--------------------------------------------------------------------------------
      Client PC            SCENIC 850                    200 (MAX.)
--------------------------------------------------------------------------------
Single User PC (small      SCENIC 860                    200 (MAX.)
      networks)
--------------------------------------------------------------------------------
   Monitor 17 inch          MCM 17P1                        130
--------------------------------------------------------------------------------
   Monitor 2l inch          MCM 21P1                        145
--------------------------------------------------------------------------------
 HP LaserJet 4050                                During printing 330, standby
                                                 18, power save 18
--------------------------------------------------------------------------------

            TABLE 7: POWER CONSUMPTION OF ACCESSINTEGRATOR HARDWARE

9.5.3 AVAILABILITY

o     The MTBF (Mean Time Between Faults) of the Siemens PCs for a 24 hour
      operation per day is 11,600 hours (about 1.5 years).

<PAGE>

o     The MTBF of the QD2 interface card is 10.3 years.

o     The usage of a mirror disk will decrease the MTBF parameters, but the
      availability of the system will increase.

9.5.4 FAULT TOLERANCE

In the standard configuration, there is no redundancy concept. As an option at
extra cost, the fault tolerance of the AccessIntegrator can BE Improved by the
following:

HARDWARE PLATFORM:

o     Use of mirror disks and RAID-systems

o     Use of exchangeable hard-disks

ACI-SOFTWARE:

o     Cold-standby: A first step towards fault tolerance can be achieved by
      deploying a standby-server and regularly making a backup of the active
      database. After a crash of the active server, the standby database is
      filled with a historical backup of the active database. Generally, a
      consistency check between the Access Network and the standby-database has
      to be executed in order to update the database. In this case, there is no
      automatic synchronization between the primary and the backup server
      (database) and all changes (configuration, alarms, etc) between a backup
      and a crash of the active server are lost.

o     Warm-standby: Warm-standby is provided by a replication server. The
      Versant OODB provides a method for a synchronous database replication
      (every store access is automatically written in the active and a standby
      database) such that the two databases have always the same contents (EM:
      network elements, connections, alarms, etc; NM: subscriber, paths,
      services etc.).

      Whenever a notification from the network comes up, a SISA concentrator
      duplicates the messages. The standby server ignores the notification,
      because the AccessIntegrator software is not running. If the server
      hardware crashes, the user has to start the standby AccessIntegrator
      manually, which will proceed operation with the standby database. Since
      the standby AccessIntegrator server starts with a filled database, there
      is only a warm startup. If the server is up, the user can start the client
      and connect to the server. The standby database stores all changes into a
      log file, polls the active database and if the active server is up again,
      it synchronous the databases by writing the log contents to the active
      database.

<PAGE>

                                   [GRAPHIC]

o     Hot-standby (only on element management level): A hot standby on element
      management level can be achieved in the following way. The operating and
      the standby-server, both with running AccessIntegrator, are connected to a
      SISA-Concentrator duplicating all notifications from the Network elements.
      Hence every alarm, NE-configuration change, etc., is automatically updated
      in both databases and both databases are synchronized at Element
      Management level.

      If the active server hardware crashes, the user can instantaneously
      continue to supervise the Access Network on the standby-server. If the
      server is up again a resynchronization to the Access Network is generally
      needed.

<PAGE>

10 COMMERCIAL DATA

The basic AccessIntegrator consists of all features described in this system
description except the ones mentioned below which are at an extra cost:

o     Interfaces: SNMP interfaces, CORBA-interface, media interface, MassProvi
      Interface,..

o     Mass provisioning tool

o     Warm-standby (replication server)

11 QUALITY STANDARDS

AccessIntegrator was developed to meet the highest quality standards. The
following list gives an overview about the currently approved certifications of
the companies involved in the AccessIntegrator development or suppliers:

o     The Business Unit WireLine Networks, belonging to the
      Information&Communication Networks Group of S is certified according to
      DIN EN ISO 9001 and 14001.

o     The Siemens Business Unit Personal Computer supplying the AccessIntegrator
      hardware is certified according to DIN ISO 9001.

o     Versant Object Technology, the supplier of the VERSANT database has been
      approved to the standards BS EN ISO 9001, ANSI/ASQC Q9001 and AS/NZS 9001.

o     The Microsoft Windows NT operating system is developed according to
      internal quality standards of Microsoft Corporation.

<PAGE>

12 CUSTOMER INFORMATION REGARDING YEAR 2000

We are aware that the transition to the next millennium is a challenge for our
products. Therefore, we have tested the various versions of AccessIntegrator on
their "year 2000 compliance".

o     All deliveries of AccessIntegrator software (delivery without OEM
      products, e.g. Windows NT) from Version 2.6 on are "year 2000 compliant".

o     All previous deliveries of AccessIntegrator software can be made "year
      2000 compliant" by upgrading to versions 2.6 or higher.

o     The hardware and software platform which AccessIntegrator is running on
      can handle the year 2000 as well, provided it is conform to the
      recommended standard configuration required for a particular release

We hereby point out that according to the state of the art it is not possible to
guarantee that products, specifically software programs, work entirely error
free. In particular, the combination with other products, especially products
from third parties, might lead to deficiencies in the functionality of products
or systems. Therefore, we recommend you to test the particular configuration of
your network with respect to its overall "year 2000 compliance". TESTED BEHAVIOR

o     Year of operating system time set in range of 1980 until 2099.

o     Network element time in range of 1982 until 2045.

o     29/02/2000 (leap year) does exist.

o     Application run from 31/12/1999 23:55 to 01/01/2000 00:05 (millennium
      change).

o     All dates are displayed and logged in the OS with century and year.

<PAGE>

13 MANAGEMENT STANDARDS AND PROTOCOLS

Standards play a critical role in the management of systems and networks. They
allow heterogeneous systems to be managed using a single technology and
different management systems to communicate with each other.

13.1 MANAGEMENT PROTOCOLS

SNMP:

o     compliant to the following RFCs: 1155, 1156, 1157, 1212, 1213

QD2:

--------------------------------------------------------------------------------
ITU-T RECOMMENDATIONS         COMPLIED    COMMENTS
================================================================================
G,773: Protocol suites for    Partially   QD2 protocol is compliant
Q-Interfaces for Management               with Layer 1 and 2 of short
of Transmission Systems                   stack protocol suite A1
--------------------------------------------------------------------------------

13.2 TMN STANDARDS

--------------------------------------------------------------------------------
ITU-T RECOMMENDATIONS         COMPLIED    COMMENTS
================================================================================
M.10 Scope and application    yes
of Recommendations for
maintenance of
telecommunication networks
and services
--------------------------------------------------------------------------------
M.3010: Principles for a      yes
Telecommunication
Management Network
--------------------------------------------------------------------------------
M.3020: TMN interface         yes
specification methodology
--------------------------------------------------------------------------------
M.3400. TMN management        yes
functions
--------------------------------------------------------------------------------
X.711: Common Management      no          German national Standard QD2
Information Protocol
Specification for CCITT
Applications
--------------------------------------------------------------------------------
<PAGE>

--------------------------------------------------------------------------------
ITU-T RECOMMENDATIONS         COMPLIED    COMMENTS
================================================================================
X.720: Information           No           German national Standard QD2
Technology - Open Systems
Interconnection - Structure
of management information:
management information
model
--------------------------------------------------------------------------------
X.721: Information           No           German national Standard QD2
Technology - Open Systems
Interconnection - Structure
of management information:
management information
--------------------------------------------------------------------------------
X.733: Information           Partially    Not supported are Event Classes and
Technology - Open Systems                 Probable Cause.
Interconnection - Systems
Management Alarm reporting
function
--------------------------------------------------------------------------------
X.903: Information            Yes
Technology - Open
Distributed Processing -
Reference Model:
Architecture
--------------------------------------------------------------------------------
G.771: Graphical and object  Yes
oriented user interface
--------------------------------------------------------------------------------
G.784: SDH Management        Partially    The connection between management
                                          system and network element is based on
                                          QD2
--------------------------------------------------------------------------------
G.821 and G.826:             Yes          The collection of performance data is
Performance Management                    in accordance with the definitions in
                                          G.821 and G.826
--------------------------------------------------------------------------------

<PAGE>

14 REFERENCE LIST

AccessIntegrator is a field proven system with worldwide installations. The
following list gives an overview:

--------------------------------------------------------------------------------
COUNTRY                       OPERATOR
================================================================================
Algeria                       PTT
--------------------------------------------------------------------------------
Argentina                     Coop. Centario, Telecom
--------------------------------------------------------------------------------
Austria                       EVA, TIWAG, PTA
--------------------------------------------------------------------------------
Belgium                       COLT
--------------------------------------------------------------------------------
Bolivia                       Cotel
--------------------------------------------------------------------------------
Bulgaria                      BTC Varna/Sofia
--------------------------------------------------------------------------------
Brazil                        CTBC, COTEL, Telebras, Telerj, Telems
--------------------------------------------------------------------------------
Brunei                        SAE Brunei
--------------------------------------------------------------------------------
Chile                         Entelphone, CNT
--------------------------------------------------------------------------------
China                         BTA, GPT Shanghai, div. PTAs, PTB
--------------------------------------------------------------------------------
Colombia                      Telecom, Transtel, Capitel, Caribitel, Norte de
                              Santander, ISA
--------------------------------------------------------------------------------
Cyprus                        Northern Cyprus
--------------------------------------------------------------------------------
Czech Republic                SPT Telecom
--------------------------------------------------------------------------------
Denmark                       Tele Danmark, SEAS KomSys
--------------------------------------------------------------------------------
Egypt                         Arento, Telecom Egypt
--------------------------------------------------------------------------------
Finland                       HTV, HTO
--------------------------------------------------------------------------------
France                        Dauphin Telecom
--------------------------------------------------------------------------------
Germany                       Deutsche Telekom, Arcor, Viag Interkom, MNET,
                              ISIS, ComTel, COLT, EWE Tel, NEFCOM, Telnet,
                              WuKom, AugustaKom, HTN, Autobahn Sudbayern,
                              Thyssen Telekom, Citycom Munster, Citynetz
                              Nurnberg, Berliner Feuerwehr, VEWTelNet,
                              Stadtwerke Leipzig, LKOM, Stadtwerke Schwerin,
                              3H Halle
--------------------------------------------------------------------------------

<PAGE>

--------------------------------------------------------------------------------
COUNTRY                       OPERATOR
================================================================================
Greece                        OTE
--------------------------------------------------------------------------------
Hungary                       Digital 2002, HTCC, MAV GIR
--------------------------------------------------------------------------------
India                         DoT (TEC), Barthi Telenet
--------------------------------------------------------------------------------
Indonesia                     PT Telekom, PT Aria West, PT Bukaka, PT Daya Mitra
                              Malino, Bukaka Singtel BSI, C&WM, MGTI, PIN,
                              Pramindo Ikat, Utara
--------------------------------------------------------------------------------
Iran                          TCI
--------------------------------------------------------------------------------
Ireland                       Telecom Eireann
--------------------------------------------------------------------------------
Island                        Island PTT
--------------------------------------------------------------------------------
Italy                         Telecom Italia, WIND
--------------------------------------------------------------------------------
Jordan                        PTT
--------------------------------------------------------------------------------
Kirghizia                     Areopag, Kirgiztelekom
--------------------------------------------------------------------------------
Latvia (Lettland)             Latvenergo, SS Broceni
--------------------------------------------------------------------------------
Lithuania                     Lituvos Telecom
--------------------------------------------------------------------------------
Luxembourg                    P&T
--------------------------------------------------------------------------------
Malaysia                      Binariang, Celcom Petronet, Telcom
--------------------------------------------------------------------------------
Maroc                         ONPT
--------------------------------------------------------------------------------
Mexico                        Telinor (LOI)
--------------------------------------------------------------------------------
Namibia                       Telecom Windhoek, Telecom Namibia
--------------------------------------------------------------------------------
Netherlands                   Telfort, Enertel
--------------------------------------------------------------------------------
Norway                        Telenor, OSLO FTD
--------------------------------------------------------------------------------
Westjordanland & Gaza         PalTel
--------------------------------------------------------------------------------
Pakistan                      PTCL
--------------------------------------------------------------------------------
Paraguay                      ANTELCO
--------------------------------------------------------------------------------
Philippines                   PLDT, Islacom
--------------------------------------------------------------------------------
Poland                        TPSA, Tele Debicka, ZWUT
--------------------------------------------------------------------------------
Rumania                       EMCOM4
--------------------------------------------------------------------------------
Russia                        Fapsi Moscow, Samara Koss, Sverdlovsk
--------------------------------------------------------------------------------
Singapore                     SingTel
--------------------------------------------------------------------------------
Slovakia                      Slovak Telecom
--------------------------------------------------------------------------------

<PAGE>

--------------------------------------------------------------------------------
COUNTRY                       OPERATOR
================================================================================
Slovenia                      Telecom Slovenia
--------------------------------------------------------------------------------
South Africa                  Telkom
--------------------------------------------------------------------------------
Spain                         Airtel, Telefonica, CTC
--------------------------------------------------------------------------------
Sudan                         Moglad Basin Oil
--------------------------------------------------------------------------------
Swaziland                     SPTC
--------------------------------------------------------------------------------
Switzerland                   Swisscom, Multilink
--------------------------------------------------------------------------------
Taiwan                        CHT-TL
--------------------------------------------------------------------------------
Thailand                      Telecom Asia
--------------------------------------------------------------------------------
Tunisia                       Tunisia Telcom
--------------------------------------------------------------------------------
Turkey                        TCS
--------------------------------------------------------------------------------
USA                           Long Island Telephone Company
--------------------------------------------------------------------------------
Vietnam                       Viete1, Hanoi P&T
--------------------------------------------------------------------------------

                            TABLE 8: REFERENCE LIST

<PAGE>

15 LIST OF FIGURES AND TABLES

FIGURE 1: ACCESS NETWORKS MANAGED BY THE ACCESSINTEGRATOR ....................12
FIGURE 2: PROCESS STRUCTURE OF ACCESSINTEGRATOR V5 ...........................97
FIGURE 3. ACCESSINTEGRATOR SAMPLE CONFIGURATION ..............................14
FIGURE 4: CASCADED CONFIGURATION WITH MULTIPLE SISA-LAYERS ...................17
FIGURE 5: DCN USING SISA-GK/E ................................................19
FIGURE 6: MEDIA CONFIGURATION ................................................26
FIGURE 7: START-UP INFORMATION ...............................................95
FIGURE 8: THE ACCESSINTEGRATOR MAIN WINDOW ...................................28
FIGURE 9: STATUS BAR WITH GRAPHICAL INDICATION ABOUT SYSTEM
          ACTIVITIES .........................................................29
FIGURE 10: DIFFERENT VIEWS OF THE ACCESSINTEGRATOR ...........................32
FIGURE 11: PORT VIEW .........................................................33
FIGURE 12: DCN TREE ..........................................................33
FIGURE 13: NETWORK MAP VIEW ..................................................35
FIGURE 14: EQUIPMENT VIEW OF A SMX1 ..........................................36
FIGURE 15: SHELF VIEW OF THE SMXLS-SHELF WITH SMX1 AS SELECTED NE ............36
FIGURE 16: FUNCTIONAL VIEW OF FMX11 ..........................................37
FIGURE 17: VIEW OPTIONS ......................................................38
FIGURE 18: OBJECT DESCRIPTION FOR NE .........................................39
FIGURE 19: FIND NES ..........................................................40
FIGURE 20: TMN STRUCTURE OF THE M.3010 STANDARD ..............................42
FIGURE 21: UNIVERSAL PERIODIC SCHEDULER ......................................46
FIGURE 22: DATE & TIME SETTING ...............................................46
FIGURE 23: ALARM COLOUR SETTING ..............................................47
FIGURE 24: VISUAL ALARM SIGNALING IN DIFFERENT VIEWS AND ALARM
           CONFIGURATION .....................................................48
FIGURE 25: GLOBAL ALARM LIST OF THE ACCESSINTEGRATOR .........................49
FIGURE 26: ALARM LOG CREATION AND VIEW WINDOW ................................50
FIGURE 27: ALARM CONFIGURATION ...............................................52
FIGURE 28: EVENT LOG .........................................................53
FIGURE 29: EVENT LOG VIEW ....................................................54
FIGURE 30: SETTING OF THRESHOLDS .............................................55
FIGURE 31: TEST RESULT OF MANUAL USER PORT TESTING ...........................56
FIGURE 32: CONFIGURATION OF V5.1 .............................................58
FIGURE 33: CUSTOM CONFIGURATION WINDOW .......................................58
FIGURE 34: GRAPHICAL PRESENTATION OF 2MBPS PORT USAGE ........................60
FIGURE 35: UPLOAD CONFIGURATION ..............................................61
FIGURE 36: INVENTORY DATA OF A NE, LABEL DATA AND REFERENCE LIST
           FOR A MODULE ......................................................63
FIGURE 37: SELECT INVENTORY FILE AND INVENTORY DATA RETRIEVING
           PROGRESS ..........................................................63
FIGURE 38: EXAMPLE OF AN INVENTORY FILE ......................................64
FIGURE 39: CONFIGURING PERFORMANCE DATA ......................................68
FIGURE 40: DISPLAYING PERFORMANCE DATA .......................................68
FIGURE 41: LOG CREATION AND OPEN PERFORMANCE LOG .............................69
FIGURE 42: PERFORMANCE LOG VIEW ..............................................70
FIGURE 43: PERFORMANCE LOG SCHEDULING ........................................70
FIGURE 44: QUALITY MEASUREMENT LOG ...........................................71
FIGURE 46: ASSIGNMENT PERMISSION CLASS TO GLOBAL GROUPS ......................72
FIGURE 47: FUNCTION PERMISSION TABLE .........................................73
FIGURE 48: DEFINE PERMISSION CLASS ENTRY .....................................73
<PAGE>

FIGURE 49: NETWORK EDITOR WITH OPENED NOTE FIELD EDITOR ......................76
FIGURE 50: EXAMPLE FOR THE DEFINITION OF A ONU250FTTC; UMX2S SHELF
           INSERTION .........................................................78
FIGURE 51: NETWORK EDITOR VIEW ...............................................78
FIGURE 52: TEMPLATES .........................................................78
FIGURE 53: CREATE SUBSCRIBER .................................................80
FIGURE 54: SUBSCRIBER LIST AND SERVICES OF A SUBSCRIBER ......................80
FIGURE 55: RELATE A SERVICE TO A SUBSCRIBER ..................................81
FIGURE 56: SERVICE MANAGEMENT MAIN WINDOW ....................................82
FIGURE 57: OPTIONS FOR CONFIGURATION OF SERVICE ACTIONS ......................83
FIGURE 58: SERVICE CREATION WINDOWS ..........................................83
FIGURE 59: SHOW SUBSCRIBER OF A SERVICE ......................................84
FIGURE 60: DELETE SERVICE ....................................................84
FIGURE 61: PATH MANAGEMENT MAIN WINDOW .......................................85
FIGURE 62: PATH STATES .......................................................86
FIGURE 63: SHOW SERVICE OF A PATH ............................................86
FIGURE 64: PATH DETAILS ......................................................87
FIGURE 65: MASS PROVISIONING OVERVIEW ........................................91
FIGURE 66: MIGRATION STEPS V2.6 > V3.3 .......................................94

TABLE 1: SISA-GK FEATURES ....................................................18
TABLE 2: DCN SISA PROTOCOL STACK .............................................20
TABLE 3: EVENTS RECORDED IN THE EVENT LOG ....................................52
TABLE 4: PERFORMANCE MEASUREMENT COUNTERS ....................................67
TABLE 5: SOFTWARE SERVER, CLIENT, AND LCT ....................................98
TABLE 6: HARDWARE REQUIREMENTS FOR SERVER, CLIENT AND LCT ...................100
TABLE 7: POWER CONSUMPTION OF ACCESSINTEGRATOR HARDWARE .....................100
TABLE 8: REFERENCE LIST .....................................................109

<PAGE>

16 LIST OF ABBREVIATIONS

A

AC                Access Code

ADM               Add Drop Multiplexer

ADMIN             Administration

ADSL              Asymmetrical Digital Subscriber Line

AIS               Alarm Indication Signal

AMX               Access Multiplexer

AN                Access Network

API               Application Programmer's Interface

ATM               Asynchronous Transfer Mode

B

BOOTP             Bootstrap Protocol

C

CAS               Channel Associated Signaling

CMU               Control and Multiplexer Unit

CMXII             Cross connect Multiplexer for V5.1/V5.2

COT               Central Office Terminal

CTM               Cordless Terminal Mobility

CUA               Control Unit Access

CUD               Control Unit Drop / Insert

D

DB                Database

DCN               Data Communication Network

DECT              Digital Enhanced Cordless Telecommunications

DN                Directory Number

ETSI              European Telecommunications Standard Institute

EWSD              Digital Electronic Switching System

EWSXpress         self-connecting ATM-switch
<PAGE>

F

FEPROM            Flash EPROM

FG                Functional Group

FTP               File Transfer Protocol

FU                Functional Unit

G

GAIN              Global Advanced Intelligent Network

GAP               Generic Access Profiles

GUI               Graphical User Interface

H

HDLC              High Level Data Link Control

HDSL              High-bit rate Digital Subscriber Line

HH                Handheld

HW                Hardware

I

IEEE              Institute of Electrical and Electronic Engineers

IP                Internet Protocol

IPUI              International Portable User Identification

ISDN              Integrated Service Digital Network

ISDN-BA           ISDN Basic Access

ITU               International Telecommunication Union

ITU-T             Telecommunication Standardization Sector of ITU

K

L

LAN               Local Area Network

LCT               Local Craft Terminal

LE                Local Exchange

LED               Light Emitting Diode

LL                Leased Line

LT                Line Terminator

M

MED               Mediation Application
<PAGE>

MEU               Measurement Unit

MFC               Microsoft Foundation Classes

MIB               Management Information Base

MSUE              Measurement and Supervision Unit with Embedded Control Channel

MTBF              Meantime between Faults

N

NE                Network Element

NMF               Network Management Forum

NT                Network Termination

O

O.N.M.S.          Optimized Network Management System

OAM               Operation, Administration and Maintenance

OMC               Operation and Maintenance Center

ONU               Optical Network Unit

OS                Operations System

OSI               Open System Interconnection

P

PARK              Portable Access Right Key

PLI               PARK Length Indicator

POTS              Pain Old Telephone Service

PSTN              Public Switched Telephone Network

Q

QD2               Q Interface German Standard No.2 (Deutsche Telekom specific
                  TMN interface)

Q3                Interface according to ITU-T M.3010

R

RAS               Remote Access Service

RID               Remote Inventory Data

RS 232            ANSI Standard RS 232

RS 485            ANSI Standard RS 405

S

SDH               Synchronous Digital Hierarchy
<PAGE>

SeAP              Service Access Point

SISA              Supervision and information System for Local and Remote Areas

SISA-ASA          SISA alarm collector (Alarmsammler)

SISA-GK           Physical SISA-DCN node (GestellKonzentrator)

SISA-V            Logical SISA-DCN node (Virtual Konzentrator)

SNMP              Simple Network Management Protocol

STM               Synchronous Transfer Mode

STM-l             Synchronous Transport Module Level 1 (155.52 Mbit/s)

SeAP              Service Access Point

SuAP              Subscriber Access Point

SW                Software

T

TCP/IP            Transport Control Protocol/Internet Protocol

TMN               Telecommunication Management Network

U

UDP               User Datagram Protocol

V

VS.1/V5.2         2Mbit/s Interface Standard

VADSL             Very high bit rate Asymmetrical Digital Subscriber Line

VDSL              Very-high bit rate Digital Subscriber Line

VHDSL             Very-High bit rate Digital Subscriber Line

VPI               Virtual Path Identifier

VPL               Virtual Path Link

W

WAN               Wide Area Network

WSAP              Workstation Application

WLL               Wireless Local Loop

X

X.25              ITU Standard X.25

XLD               Xpresslink D

<PAGE>
[OBJECT OMITTED]                                             [OBJECT OMITTED]

INFORMATION FOR DCN CONCEPT WITH CMX II / ONU 30

The CMXII is designed principally for the following applications:
-    Concentrating crossconnect multiplexer for 2-Mbit/s signals with V5
     protocol,
     -    concentrating V5C interface on the subscriber side and / or
     -    concentrating V5.2 interface or V5.1 interface on the exchange side
-    Crossconnect multiplexer for 2-Mbit/s signals with V5.1 protocol
-    Crossconnect multiplexer for channel-associated signaling (CAS).

All ports of the CMXII allow equipment to be connected that has 2-Mbit/s
interfaces per ITU-T G.703/6. The 2-Mbit/s signals are connected at time slot
level (64 kbit/s).

For V5 processing CMXII is equipped as follows:
-    One or two crossconnect units CCU
-    Up to 46 Port Units 2 Mbit/s PU2+ (provides inband transmission of TMN data
     via an ECC channel including ECC extraction)
-    A SISA interface unit PUSISA (Port Unit SISA) one of which can be
     optionally provided in the CMXII in place of a PU2/PU2+ unit on the LE side
-    One or two V5.2 frame relay units V52FR (V5.2 Frame Relay Unit)
-    One management control unit MCU
-    Two to four power supply units PSC.

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<PAGE>

PORT UNIT PUSISA

The SISA information for remote devices is fed in via the QD2 slave port or the
F interface of the MCU and transferred to the PUSISA via a supervision bus.
There the information is embedded in a PCI link, transferred via the CCU
connection matrix to the PU2 on the AN side and mapped onto the ECC slot in the
2-Mbit/s frame structure. In the remote device which disassembles the 2-Mbit/s
frame the relevant ECC is mapped out and applied transparently to an ECC port
that corresponds to a QD2 master port. The number of ECCs to be served by the
PUSISA is identical to the number of devices to be monitored. Using a PUSISA
unit reduces the number of 2-Mbit/s ports available for leased lines on the LE
side by 4. (Provision of up to 128 ECC channels (inband 64 kbit/s) in entire CMX
II for remote control and monitoring of remote network elements)

The PUSISA is used for implementing the inband transmission of TMN data between
the OLT and remote ONUs. By way of a transmission medium, for each ONU an ECC is
used which seizes one of the 30 traffic channels of a 2-Mbit/s link framed
according to ITU-T Recommendation G.704. The transmission rate in an ECC is 64
kbit/s. The PUSISA unit can be used once in the CMXII instead of a PU2 unit in
the CMXII-2S shelf on the LE side.

The PUSISA unit performs the following functions:

-    Reception from the MCU of the data for all ECCs to be controlled
-    Generation of four SISA-V (Each SISA-V operates up to 32 ECCs.)
-    PCI framing and transmission of the PCI links (The TMN information is
     transmitted in a PCI link to the CCU, mapped into position in a 2-Mbit/s
     signal as per ITU-T G.704 in the CCU-crossconnect matrix and transmitted to
     the remote equipment.)
-    Frame synchronization of the PCI receive signal
-    Recovery of the ECC data

                        MECHANICAL DESIGN OF CMX II

The mechanical design of the CMXII is based on 19-inch shelves with associated
terminal panel. The maximum number of 2-Mbit/s interfaces can be adapted to the
network configuration using different shelf variants:

- Three shelves for up to 184 2-Mbit/s interfaces, one CMXII-CS shelf and two
CMXII-2S shelves

- Two shelves for up to 140 2-Mbit/s interfaces, one CMXII-LS shelf and one
CMXII-2S shelf, or one CMXII-CS shelf and one CMXII-2S shelf

- One shelf for up 48 2-Mbit/s interfaces, one CMXII-LS shelf. The shelves
themselves are designed such that they can be accommodated in 19-inch or ETSI
standardized racks. All units are in the form of double Eurocards. A backplane
PCB interconnects all the units within a shelf and implements the connections to
the terminal panel.

See figure 5.1

INTERFACES / UPGRADE

A single shelf CMX II supports up to 44 ports 2-Mbit/s (11 cards PU2+ with 4
interfaces on each), the 12th interface slot is occupied by PUSISA. If more
2-Mbit/s interfaces are required, a shelf update is possible by adding one ore
two more shelves. With the 2 - shelf solution 136 2-Mbit/s interfaces are
possible, with a 3 - shelf CMX II then 180 2-Mbit/s interfaces. A single CMX II
(1-, 2-, 3- shelf) supports max. 128 ECC, if more ECC (ore more then 180
2-Mbit/s interfaces) are needed, an additional CMX II is nessecary.

<PAGE>

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[HTML]

[HTML]

MECHANICAL DESIGN OF AMXMS

AMXMS is central multiplexer shelf of ONU30. The AMXMS accommodates the
following double Eurocard units without front panel:
-    One central unit CUA
-    One supervision unit MSUE
-    Up to three line cards LC
-    One line terminating unit LTC, LTCP (HDSL) or LTO (optical)
Fig. 5.8 shows the equipment fitted when deploying the AMXMS in copper networks
and optical networks. The backplane inerconnects the units via external and
internal interfaces.

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<PAGE>

QD2 ACCESS TO AMXMS

The AMX including the various line cards forms a SISA network element. The
addressing of the network element is assigned by backplane coding with five bits
for the card that provides the access to the network element. Access via a OS or
a LCT is provided to this network element via the CUA or the MSU/MSUE. The
interfaces are:
-    QD2 interface of the CUA with 1.2 kbit/s, 9.6 kbit/s and 64 kbit/s
-    QD2 interface of the MSU/MSUE with 1.2 kbit/s, 9.6 kbit/s and 64 kbit/s
-    ECC interface of the MSUE with 64 kbit/s.
Automatic interface and bit rate detection is provided by the operating program
of the relevant card. The MSU/MSUE can be accessed, for example, via a
transparent overhead channel of the line termination or, in case of the MSUE,
via an ECC included in the PCM signal. Fig. 4.3 shows an example of OS access.
Local operator control of the AMX is effected via the F interface of the
MSU/MSUE.

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<PAGE>

                                European Agreement
                                   Appendix 4
                                     Content

OBJECT OF CONTRACT

The rights and duties of Purchaser and Contractor with respect to planning
services for sites will later be agreed separately between Purchaser and
Contractor.

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

                         APPENDIX 4a+b - RF PLANNING

DOCUMENT

DOCUMENT NAME   Appendix 4a+b - RF Planning
BACKGROUND      Description of RF Planning Services of the European
                Agreement between FirstMark Europe SA and Siemens AG

Appendix 4ab - RF planning, final version 000427                  Page 1 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

TABLE OF CONTENTS

Table of contents

1     Definitions
2     Initial Planning
3     Detailed planning

Appendix 4ab - RF planning, final version 000427                  Page 2 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

1      DEFINITIONS

INTRODUCTION

This version of the appendix applies for the Federal Republic of Germany. The
parties reserve the right to agree an extension of the area of application of
this appendix taking into consideration the country-specific particularities.

SUPPLY AREA

The supply area of a PMP license region which is determined by the RegTP and
defined by drawing up to 32 vertices of a polygon around it.

PLANNING REGION

A contiguous region which is described by means of a closed polygon defined
by Purchaser and defined in the course of radio-network planning. It can
extend over several supply areas or parts thereof.

CALL-OFF AREA

The call-off area describes the potential marketing region which is located
among the search districts cleared by Purchaser. It serves for radio-network
planning for orientation in the detailed planning of sites. The call-off area
is defined by drawing one or more closed polygons.

TRAFFIC POINTS

Geographically-coded potential customer sites which are defined by
co-ordinates and differentiated traffic profiles.

COVERAGE FOOTPRINT

A coverage footprint is a graphical representation of the field-intensity
distribution in the region supplied by the individual base station.

MINIMUM COVERAGE

The minimum coverage describes the customer coverage of a planning region as
a percentage.

BS

PMP base station

Appendix 4ab - RF planning, final version 000427                  Page 3 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

BSBU
Base station base unit

2      INITIAL PLANNING

2.1    DUTIES OF THE CONTRACTOR

The initial planning is the first step of radio planning for a planning
region. The result of the initial planning is a radio-network concept on whose
basis the detailed planning and the set-up of individual sites is performed.
In addition, the initial planning supplies important inputs for the order and
forecast process and forms the basis for marketing/sales activities.

The initial planning performed by the contractor includes at least the
following tasks:

    -  Analysis of the planning region
    -  Determining the number of required base stations in accordance with
       coverage and capacity points of view
    -  Determining the necessary BS configurations in accordance with
       geography, topography, traffic density and other factors affecting the
       planning region
    -  Determining a network design

2.2    PLANNING SPECIFICATIONS

Necessary specifications for the performance of the initial planning by
Purchaser are in particular:

    -  Purchaser planning strategy
    -  Determining the planning region
    -  Provision of traffic forecast data in the form of traffic points and
       purchaser market shares
    -  Provision of the license specifications in accordance with license
       certificate
    -  Site specifications by Purchaser
       -  Proposals of sites offered to Purchaser in the course of his
          business activities or which are available to him
       -  Specification of fixed or potential subscriber sites acquired by
          Purchaser in the course of his sales/marketing activities
    -  Quality-assurance specifications in accordance with Appendix 3 System
       Specification

The planning specifications must be available or be made available at the
time of placement of the order. If the planning specifications are
incomplete, Purchaser shall be notified of this immediately so that the
missing information can be made available at short notice.

Appendix 4ab - RF planning, final version 000427                  Page 4 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

2.3    BASIC CONDITIONS

The initial planning shall be performed with the aid of tools using a PMP
planning tool provided by the contractor as well as supportive resources.

The following geo-data in particular are required for the planning:

    -  Elevation data of grid 25m for all of Germany
    -  3D building-height data of grid 5m for major-city regions
    -  Clutter data of 25m grid with default heights for all of Germany
    -  Digital maps (grid data/vector data) for visual orientation
    -  Topographical maps of scale 1:25000 where required

This shall be made available by Purchaser. If 3D data are only available to a
limited extent for a planning region, alternative solutions for the planning
are to be examined in mutual agreement between Purchaser and contractor and
documented. The reliability of the results in such a case can be limited.

2.4    SCOPE OF PLANNING

The initial planning includes in particular the three focal points planning
preparation, coverage planning and capacity analysis.

PLANNING PREPARATION

Planning preparation includes the compilation and preparation of all planning
data and an analysis of the planning region. This also involves the
radio-network planning locally becoming familiar with the particularities of
the planning region on site.

COVERAGE PLANNING

During coverage planning, base stations are placed. The objective is to
realise a maximum customer coverage with a minimum of base stations. The
minimum coverage shall be specified and updated by Purchaser. The current
specification for the minimum coverage is 75% of all traffic points of the
relevant planning region. When the choice of base stations is made, the
radio-network planner should be largely oriented towards existing potential
BS sites which were already localised in the preliminary stages by means of
on-site inspection.

CAPACITY ANALYSIS

Capacity analysis includes a capacity evaluation on the basis of the base
stations defined by coverage planning. This includes determining the degree
of potential traffic among the coverage regions of the individual base
stations, determining the number of required BSBUs and checking how well the
frequency can be planned. Deriving from this, additional network adjustments
shall be performed by changing the configurations or setting additional base
stations.

Appendix 4ab - RF planning, final version 000427                  Page 5 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

2.5    RESULT

The result of the initial planning is a planning document containing at least
the following information:

    -  Summary of the planning specifications
    -  Summary of the planning strategy
    -  Summary of the network/configuration data
         -  number of base stations
         -  number of sectors
         -  number of BSBUs
         -  percentage customer coverage
         -  average base-station spacing
    -  Remarks and comments
    -  Base-station specifications with
         -  Object identification Code
         -  Base-station name
         -  Co-ordinates in the agreed format
         -  Antenna heights above ground
         -  Sector specifications
            *Antennas type
            *Orientation
            *Forecast traffic value
            *Number of BSBUs
    -  Coverage plot for each base station
    -  Coverage plot for each planning region

The planning document shall be made available in both hardcopy and electronic
form.

2.6    PLANNING PERIOD

The period for the initial planning of a supply area is 10 working days from
the time of placement of the order as defined in Appendix 4g as long as the
above-mentioned basic conditions are fulfilled. In the case of larger or more
complex supply areas, both parties can agree an extension of this period by 5
working days. Each calendar week, the contractor shall accept an order of two
supply areas for each region. Any additional orders shall be processed by
mutual agreement.

Appendix 4ab - RF planning, final version 000427                  Page 6 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

3      DETAILED PLANNING

The detailed planning shall be performed by the contractor in the region
cleared by Purchaser for detailed planning and shall be performed on the
basis of the initial planning results. Real site candidates and their area
and capacity coverage shall be evaluated and configured on the basis of their
integration potential.

3.1    OBJECTIVES OF DETAILED PLANNING

-  Analysis of the site candidates
-  Determining the BS configuration on the basis of the coverage and capacity
   requirements

3.2    SPECIFICATIONS

Necessary specifications for the performance of the detailed planning by
Purchaser are in particular:

    -  Purchaser planning strategy
    -  Provision of traffic forecast data in the form of traffic points and
       purchaser market shares
    -  Provision of license specifications in accordance with license
       certificate
    -  Results of the initial planning
    -  Determining of the call-off area with the search districts contained
       and cleared therein
    -  Site specifications by Purchaser
         -  Proposals of sites offered to Purchaser in the course of his
            business activities or available to him.
         -  Specification of fixed or potential subscriber sites acquired by
            Purchaser in the course of his sales/marketing activities.
    -  Quality specifications in accordance with Appendix 3 System
       Specification

The planning specifications must be available or be made available at the
time of placement of the order. If the planning specifications are
incomplete, the purchaser shall be notified of this immediately so that the
missing information can be made available at short notice.

Appendix 4ab - RF planning, final version 000427                  Page 7 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

3.3    BASIC CONDITIONS

The detailed planning shall be performed with the aid of tools using a PMP
planning tool provided by the contractor as well as supportive resources.

The following geo-data in particular are required for the planning:

    -  Elevation data of grid 25m for all of Germany
    -  3D building-height data of grid 5m for major-city regions
    -  Clutter data of 25m grid with default heights for all of Germany
    -  Digital maps (grid data/vector data) for visual orientation
    -  Topographical maps of scale 1:25000 where required

This shall be made available by Purchaser. If 3D data are only available to a
limited extent for a planning region, alternative solutions for the planning
are to be examined in mutual agreement between Purchaser and contractor and
documented. The reliability of the results in such a case can be limited.

3.4    SCOPE OF PLANNING

PLANNING PREPARATION

The planning preparation includes the compilation and preparation of all
planning data.

ISSUE OF SEARCH DISTRICTS

By means of radio-network planning by the Contractor, a search order in
accordance with the agreed form shall be created on the basis of the search
districts from the initial planning as cleared by Purchaser and this search
order shall be passed on to Purchaser's project co-ordinator as a basis for
the authorisation of the acquisition.

EVALUATION OF THE SITE CANDIDATES

The site candidates registered by the acquisition shall be evaluated by
Contractor with respect to radio technology. For this purpose, a coverage and
capacity analysis shall be performed with the aid of tools. The result is a
ranking of the site candidates with the favourite being indicated as Rank 1
Candidate.

All site candidates shall be entered by Contractor in the purchaser site
database.

SITE REVIEW

A site review must be performed for shortlisted site candidates. The site
review includes a test of the radio-technical and constructional
circumstances on site. This includes the location of possible antenna sites
and the testing of the circumstances relating to space for the system
equipment. The results of the site review must be documented.

Appendix 4ab - RF planning, final version 000427                  Page 8 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

The appointment for the site review must be communicated to Purchaser in good
time so as to enable his participation.

CLEARANCE FOR SITE CONTRACTUAL NEGOTIATIONS

Contractual negotiations shall commence following clearance of a site
candidate by Purchaser. In addition to the site data contained in the site
database, at least the following information is required in electronic form
for the site candidate intended for clearance:

    -  Photographic documentation
         -  building views
         -  roof photos
         -  panorama photos
         -  photos of operating room
    -  Capacity and traffic estimate
    -  Preliminary site configuration
    -  Coverage footprint
    -  Information on available space for system equipment.

The timeframe for the clearance of the site candidates is 5 working days.

TECHNICAL REVIEW (TR)

The TR is an on-site meeting at which agreement is reached on how the
technical (constructional) realisation of the site configuration determined
by the radio and feeder-network planning is to take place.

The contractor (radio-network planning) shall supply the TR with the
following data specific to the PMP base station:

    -  Co-ordinates in the defined format
    -  Height over NN
    -  Antenna height above ground/above roof
    -  Antenna type
    -  Antenna orientation
    -  Elevation
    -  Desired antenna positions
    -  Final construction for antennas and system equipment

Purchaser shall supply the TR with the following data specific to the PMP
base station:

    -  Initial construction for antennas and system equipment

Purchaser (feeder-network planning) shall supply the TR with the following
data for station connection:

    -  Antenna height above ground/above roof
    -  Antenna type
    -  Antenna orientation
    -  Elevation
    -  Desired antenna positions
    -  Initial/final construction for antennas and system equipment

Appendix 4ab - RF planning, final version 000427                  Page 9 of 10

<PAGE>

                              European Agreement
                                Appendix 4a+b
                              Section RF Planning

The result of the TR shall be documented in the TR protocol and shall form
the basis of the infrastructure planning.  The specifications for the PMP
station and/or for the connection of the station shall be documented in the
agreed forms which shall become a component of the TR protocol.

The invitation of Purchase to the Technical Review shall take place at least
10 days before the TR date. At this time at the latest, all necessary data
must be available to Purchaser.

THE FOLLOWING ACTIVITIES

After the TR, Purchaser shall call the system technology from the contractor
in accordance with the call form.

Following completion of the building plans, they must be checked by the
contractor (radio-network planning) with respect to the
radio-network-planning specifications.

In preparation for commissioning of the base station, the frequency
applications, EMVU applications and BIMSCH notification shall take place in
keeping with the application time limits of the authorities. These shall be
submitted to Purchaser for signing.

3.5    OTHER MATTERS

All results of the detailed planning for the site to be realised shall be
entered by the contractor in the purchaser site database in accordance with
Appendix 4i (Project Management).

The latest up-to-date version of the radio network planning guide shall serve
as a basis for planning. (The current version PMP Planning Guide).

Appendix 4ab - RF planning, final version 000427                  Page 10 of 10

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

                           Appendix 4 c- Site Acquisition

<TABLE>

DOCUMENT
<S>                        <C>
--------------------------------------------------------------------------
DOCUMENT NAME              Appendix 4 c- Site Acquisition
--------------------------------------------------------------------------
BACKGROUND                 Appendix 4 c to the European Agreement between
                           FirstMark Europe SA and Siemens AG
--------------------------------------------------------------------------
                           Description of site acquisition Services
--------------------------------------------------------------------------
</TABLE>

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

                                APPENDIX 4c, PART 1
                             TO THE EUROPEAN AGREEMENT

                                     SECTION 1

                                OBJECT OF CONTRACT

The Client intends to use locations in the Federal Republic of Germany for
operating a digital radio network by means of erecting, operating and
maintaining fixed radio stations with connections to the supply system as well
as by means of housing the corresponding supply units.

The Contractor is ordered to carry out with his vicarious agents the
acquisition that is required for operating such a digital radio network.

                                     SECTION 2

                                 SCOPE OF SERVICE

The Contractor undertakes to provide the following services:

(1)  SEARCH FOR LOCATIONS

     On the basis of an agreement with the Client the Contractor will define
     search districts for his vicarious agents. Within these search districts
     the vicarious agents will identify 3 to 5 locations that seem to be
     suitable for Point-to-Multi-Point-Base stations or radio-relay repeater
     stations provided that any suitable locations exist in the respective
     search district. Photos will be taken of the location from the site
     itself and these photos will be documented as indicated by the Client in
     the following way:

     Photos will be taken of the location on road level and initially only of
     one of the locations from the roof at 360DEG. Of the other locations the
     photos at 360DEG. will be taken on request of the radio network planner
     to be nominated by the Client.

     The following data will be identified for the corresponding location:

       -  information on ownership

       -  addresses of owners and tenants

       -  contact persons (also at the locations itself)

       -  address of the location

       -  heights of the building/the structures on the surface

       -  sketch of the location, sketch of the roof with rough dimensions

       -  coordinates (Gauss-Kruger)

       -  section of topographic map scale 1:25000

       -  information on possibility for fixing antennas and housing
          technical equipment

       -  description of access and approach

       -  information in parallel utilization by other radio network operators

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

     Both the photos and the data will be provided for the Client in the form
     required by the Client - also on data carrier or by entering them into
     corresponding software of the Client - within 10 working days after the
     search districts were allocated. After the period has expired the Client
     will be entitled to withdraw the allocation of the search district
     without remuneration.

     The period and the right to withdrawal of the search district do not
     apply for contracts on acquisitions which have been concluded with
     subcontractors before this appendix became valid.

(2)  CONTRACT NEGOTIATIONS

     The contract negotiations will be carried out between the Client and the
     corresponding lesser of the Client until a rental contract has been
     concluded and they comprise:

       -  establishing contact with the owners or lessers of the locations
          maximum of three) which are assessed as being suitable by the radio
          network planners which were appointed by the Client, parallel
          negotiation of the conditions and terms of contract

       -  documentation of requirements with respect to construction and legal
          conditions raised by the owners

       -  negotiating and processing the contracts until they are signed in
          coordination with the group for contract issues of the Client

       -  participating in meetings (e.g.) meetings of the community counsil,
          meetings related to the law on housing property and permanent
          dwelling right, citizens' initiatives)

       -  acquiring the signature of the lesser for the tenancy contract

       -  acquiring the signature of the owner for the application for
          connection to the public energy supply system (below:
          EVU-application)

       -  acquiring the authority of the owner for reviewing the land register

       -  acquiring the authority of the owner for acquiring the as-built
          drawings of structure (drawings of the building, elevation and
          statistics calculations of the sections of the building that will
          be utilized)

       -  acquiring the declaration of the owners of the property according
          to Section 10 TKV

       -  agreeing rights of way together with notarially certified award of
          entry by the owner for a limited personal easement provided that the
          access to the location of the antenna is only possible by crossing
          other properties

       -  agreement on permit together with a notarially certified award of
          entry by the owner for a limited personal easement provided that
          ducts have to be laid for connection to the power supply system and
          to the telecommunication system

       -  agreement on permit together with notarially certified award of
          entry by the owner for limited personal easements for erecting or
          utilization of unused land; unused land in the above sense is any
          area that is not built up and with bushes of a maximum height of
          20 cm

       -  answering questions related to the conclusion of the contract

<PAGE>

(3) OTHER ACTIVITIES

    The Contractor undertakes to provide the following services:

       -  acquiring the appendices to the contract as mentioned in
          Section 2 (4)

       -  acquiring information whether the respective building is protected
          as a monument

       -  assessing the possibility for executing the construction on the
          basis of the current form (Site assessment form Appendix 1)
          provided by the Client

       -  describing the location of the energy meter and of the nearest
          connection point for energy supply outside the building

       -  participating in meetings on acquisition with the Client

       -  acquiring contract addresses for approvals and permits (e.g.
          authorities, VU-applications), organizing and participating in
          site inspections together with the owner or lesser, other radio
          operators and the Client after the contract has been concluded,
          technical building inspection

       -  acquiring the as-built drawings available at the owner or lesser
          (drawings of the building, elevation and statics calculations of
          the sections of the building that will be used)

       -  presenting the construction plan to the owner, acquiring the
          agreement on construction at the owner provided that this has been
          agreed for the individual case between the Client and the owner

       -  support for acquiring the building permit by means of nominating
          contact persons

       -  acquiring the keys from the lesser and handing them over to the
          site engineer who was appointed by the Client

       -  support for developing the location until a contract has been
          signed by the lesser or owner (maintaining contact with the owner
          or lesser in case of disputes)

(4) APPENDICES TO THE CONTRACT

    When the contract is presented to the Client for being signed the
    following appendices must be attached

       -  one uncertified excerpt from the land register for the respective
          property, divisions I to III (division III may be excluded if the
          land register refuses it in the individual case)

       -  proof of the authority of the person signing by company register,
          register of associations, powers of attorney, company agreement,
          decision according to the law on housing property and permanent
          dwelling, decision of the community council, consent of co-owners,
          partners, etc.

       -  if required consent of neighbors (provided that the respective
          project requires a building permit)

       -  attachment "Deviations from the sample contract" or automatic
          comparison of versions by e-mail

    Excerpts from the land register and other registers must be acquired
    directly from the relevant authority and at the moment when the contract
    is signed they must not be older than three months.

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

                                     SECTION 3

                               METHOD OF COOPERATION

(1)  For efficient collaboration the parties will nominate skilled responsible
     staff who are able to provide the information and take the decisions
     which are required for executing this contract or have them provided or
     taken. In case the contact persons for one of the contracting parties
     changes the other party will be informed immediately in writing:

     for the Client:
     Project management: Harald Schemionek, FMCD, Leiter Liegenschaften, Kleine
     Brudergasse 3, 01067 Dresden, tele.: 0172/9448823
     technical design and planning: Alfred Poppe, see above,
     tel.: 0177/2597033

     for the Contractor: Gunther Schmidt, Siemens AG, Account Manager Carrier
     Sales, Volklinger Strasse 1, 40219 Dusseldorf, tel.: 0177/8992250
     project management Dieter Rudeck, see above, tele.: 01272/55 84 732
     technical design and planning

(2)  If necessary, any activities as described in section 2 must be carried
     out in coordination with the Client.

(3)  The Contractor must not begin the negotiations on the contract before the
     Client has accepted the location.

(4)  In their contact with the owner and lesser the Contractor and his
     vicarious agents will present themselves as acting "by order of FirstMark
     Communications Deutschland". The Client will issue to the Contractor a
     written confirmation according to the sample (Appendix 3) that can be
     used for authorization towards the owner or lesser.

(5)  The Contractor must use exclusively the current contracts and sample
     clauses that were released by the Client. In case the Client releases a
     clause in an individual case this does not constitute a general release
     for other cases.

(6)  Stipulations in the rental contract, the contract or other agreements of
     the Client with third Parties on the ownership of the property to be
     contributed or contributed by the Client in connection with the rental
     contract must be drafted or amended only with previous written consent of
     the legal department of the Siemens AG, Hofmannstrasse 51, 81359 Munchen.
     Client in the sense of the paragraph is the Client in the sense of
     Section 14 (1) of this appendix or the companies that are related to it
     in the sense of Section 15 Company Law or Section 15 Company Law analog
     or FirstMark Communications Europe S.A. or companies that are related to
     it (affiliates in the sense of appendix 5).

(7)  In case the owner or lesser does not accept the current sample
     contract the Contractor must contact the Client. The negotiations on the
     contract must be continued until the Client accepts the draft.

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

(8)  The Contractor will inform the Client on a weekly basis on the status of
     the acquisition activities in the form that has been agreed by the
     parties. The report must contain all activities with respect to all the
     locations within the search district that has been allocated by the
     Client.

(9)  The client intends to sign framework contracts with significant partners
     for making acquisition easier.

(10) The Contractor is not entitled to claim an order for carrying out
     acquisition in all or in certain search districts. As soon as a search
     district has been allocated by the Client he must not order a third
     party to carry out acquisition.

(11) The Client undertakes to issue orders to the Contractor for the years
     2000 until 2002 for acquisition within 80% (in 2000), 70% (in 2001) and
     60% (in 2002) of the search districts for point-to-multi-point-base
     stations that are released by the radio network planning department of
     the Contractor in coordination with the Client.

                                  SECTION 4

                                  EFFICIENCY

(1)  The Contractor will exclude that the vicarious agents employed by him
     will be active simultaneously for other wireless local loop operators in
     the same supply area (in correspondence with the allocation by the
     RegTP). This limitation does not apply for those contracts on acquisition
     purposes which have already been signed with subcontractors. Clause 1 of
     the paragraph will apply only for five years after this European
     Agreement became valid.

(2)  The staff employed by the Contractor must be skilled and experienced in
     acquisition. A valid certificate on fitness for working at heights (G 41)
     for each agent must be presented to the Client upon written request.

(3)  On written request the Contractor will inform the Client upon the
     subcontractors he employed. Before a contract is concluded with a
     subcontractor the Client is entitled to refuse individual subcontractors
     provided that any indications of lack of suitability exist.

(4)  The Contractor must make sure that the persons employed for fulfilling
     the contract receive all the necessary and suitable equipment.

                                  SECTION 5

                             DUTIES OF THE CLIENT

(1)  The Client has in particular the following duties:
         1.  instruction and legal training for the vicarious agents
         2.  legal assistance, support in difficult negotiations by contract
             managers or lawyers
         3.  supply of information brochures, manuals, standard letters

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

         4.  all other forms of support that are necessary for executing the
             contract according to Section 2

(2)  The Client will guaranty that all vicarious agents participate in
     coordination and further education meetings held by the Client provided
     they are not hindered by important reasons (e.g. disease). These meetings
     are held once per quarter and on special occasions. They last for a
     maximum of 2 days.

(3)  Except traveling expenses and accommodation expenses these meetings will
     not incur any costs for the Contractor. Usually the meetings will be held
     decentralized for each region.

                                     SECTION 6

                     REMUNERATION AND REIMBURSEMENT OF EXPENSES

(1)  The remuneration for each location for which the Client concludes a
     contract consists of the basic amount, the allowances and the deductions.

(2)  The basic amount for a concluded contract on a point-to-multi-point-base
     station or for a radio relay repeater is *** per contract.

(3)  For each rental contract that coincides literally with the current rental
     contract or that contains only standard clauses that were accepted as
     being "harmless" the Contractor will receive an allowance amounting to

                                 ****

(4) For each rental Contract with an annual rent that is below the standard
    rent of
                                 ****

    the Contractor will receive an allowance that is the same as the
    difference between the annual rent and the standard rent for one year. The
    parties will agree on adapting the standard rent if necessary, e.g. for
    individual regions, as soon as some empirical values on average rent per
    region are available.
    The annual rent will be calculated on the basis of all services that may
    be provided for the lesser in addition to or instead of the rent.

(5) For each rental contract that is being signed by both parties within four
    weeks after a location was accepted for contract negotiations the
    Contractor will receive an allowance amounting to

                                 ****

    In case a sample rental contract or - in the case of a deviation from the
    sample rental contract - a sample rental contract that has been approved
    by the Client and signed by the lesser is received by the Client within
    four weeks after the location was accepted for contract negotiations and
    the Client signs this rental contract without any modification after the
    above mentioned period of four weeks has expired this rental

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

    contract shall be considered to have been signed by both parties within
    four weeks after the location has been accepted for contract negotiation.

(6)  For each rental contract that is concluded although it does not coincide
     with the sample that was provided and that was neither released by the
     Client after previous review the remuneration will be cut by

                                 ****

(7)  For acquiring the consent of neighbors in case of projects that are
     subject to building permit procedures the Contractor will receive an
     additional payment of

                                 ****

(8)  For contracts which were concluded on the basis of framework contracts
     provided by the Client (Section 3, paragraph 9 of this appendix) the
     Contractor will receive *** of the basic amount.

(9)  This remuneration covers all ancillary costs and expenses except expenses
     for official fees and notary costs provided that this contract does not
     contain any deviating stipulation. The mentioned fees and notary costs
     will be reimbursed by the Client.

(10) All amounts are indicated as net amounts. The currently valid legal VAT
     will be paid additionally.

                                  SECTION 7

                          ABANDONING SEARCH DISTRICTS

Per search district that is abandoned by the Client for reasons that do not
lie with the Contractor or in case the contract between the Client and
Contractor is terminated the Contractor will receive the following
remuneration:

     1.  If the complete documentation for at least three suitable locations
         is submitted:

                          *** of the basic amount

     2.  After at least one location was released by the Client:

                          *** of the basic amount

     3.  Upon presentation of a contract that was agreed with the Client and
         signed by the owner or lesser provided that the location is abandoned
         only after the contract was signed by the owner or lesser

                   *** of the basic amount plus applicable allowances.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

                                     SECTION 8

                           CONTINUATION OF SEARCH DISTRICTS

In case a Contractor is allocated search districts where another agent
carried out acquisition before him the following staggering will apply for
remuneration:

     1.  provided that the complete documentation for at least three suitable
         locations is taken over the Contractor will receive

            *** of the basic amount and all applicable allowances.

     2.  After a location was accepted for beginning contract negotiations he
         will receive

            *** of the basic amount and all applicable allowances.

                                    SECTION 9

               NEGOTIATIONS FOR CONTRACT RECTIFICATION, NEW NEGOTIATIONS

(1)  In case negotiations for rectifying contracts on a location become
     necessary after a contract was concluded because the conditions changed
     an additional hourly remuneration amounting to **** plus VAT up
     to maximum *** plus VAT will be paid.

(2)  In case new negotiations on the same location must be entered into the
     Contractor will receive *** of the remuneration defined in Section 6.

                                   SECTION 10

                              CONDITIONS OF PAYMENT

(1)  The invoice may be submitted

        -  after the rental contract was concluded,

        -  when the appendices in the sense of Section 2 (4) were submitted

        -  upon presentation of the performance record signed by the Client
           (sample appendix 4) and

(2)  The remuneration is due four weeks after the invoice was submitted.

                                   SECTION 11

                                    LIABILITY

The parties are mutually liable in relation to this appendix for personal
injury without limitation, for damage to property up to DM 100,000.00 per
case. The amount of total liability of the parties is limited to DM
500,000.00 per calendar year and to DM 1,000,000.00 for the total duration of
the contract. Any further liability claims of the Client that those expressly

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

defined in this appendix, no matter for which legal reason, in particular
claims due to loss of information and data, loss of production or
interruption of operation, loss of profit, interests as well as consequential
harm caused by defects are excluded.

                                   SECTION 12

                                    SECRECY

(1)  Both parties will use the documents and information which they will
     receive in connection to this appendix only for the purposes of this
     appendix and will keep them secret to third parties with the same care
     as if they were this party's own documents and information provided
     that the other party indicates that these documents and information are
     confidential or is obviously interested in keeping them secret. This
     obligation begins with the first reception of the documents or
     information and ends 24 months after the end of this agreement.

(2)  This obligation does not apply for documents and information that are
     generally known or that were known to the other party when it received
     them without this party having being obliged to keep them secret at that
     time or which are conveyed by a third party that is entitled to pass them
     on or if they are developed by the receiving party without using secret
     documents or information of the other party.

                                   SECTION 13

                             OWNERSHIP AND COPYRIGHT

(1)  All documents and instruments which are provided for the Contractor in
     connection with this appendix remain property of the party that provides
     them and upon termination of the contract they must either be returned
     immediately to the Client or they must be destroyed. The right to
     destruction does not apply if the property can obviously be used again
     by the Client (e.g. acquisition manual, software, computer hardware).

(2)  All results achieved by the Contractor in the course of executing the
     works that are related to this contract become upon their production
     unlimited property of the Client with right to exclusive use and
     utilization (also in copyright sense).

                                    SECTION 14

                                DEFINITION OF TERMS

(1)  CLIENT means FirstMark Communications Deutschland GmbH, Uhlandstrasse
     179/180, 10623 Berlin.

(2)  CONTRACTOR means Siemens AG (Hofmannstrasse 51, 81359 Munchen).

(3)  PARTIES means Client and Contractor.

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

(4)  ACQUISITION means the search for, collection of data on and conclusion
     of contracts on location by means of executing the services to be
     provided by the Contractor according to Section 2.

(5)  CONTRACT comprises the rental contract between the lesser and Client
     according to the current sample as provided by the Client (sample
     appendix 5: issue 13th April, 2000) as well as the contracts and
     declarations that are required for legal purposes, i.e. agreements on
     rights of way, agreements on permits, notarially certified awards of
     entries of the owner for a limited personal easement provided that the
     conditions as described in Section 2 (2) prevail.

(6)  RENTAL CONTRACT comprises beside the current rental contract (sample
     appendix 5 a, issue: 13th April, 2000, version 3) also current
     reservation and rental contract (sample appendix 5b, issue: 13th April,
     2000, version 3).

(7)  FRAMEWORK CONTRACT is any contract that was concluded between the Client
     and a lesser that will be used as basis for renting an unidentified
     number of locations irrespective of the point whether it is an approved
     sample contract or a set of contracts consisting of a framework contract
     and samples for individual locations.

(8)  NEGOTIATIONS FOR RECTIFYING CONTRACTS are negotiations on a location for
     which a contract has been concluded already with the purpose of a minor
     extension of the scope of utilization (up to 30% more area and antennas)
     or for amending stipulations in the contract.

(9)  NEW NEGOTIATIONS are negotiations on a location for which a contract has
     already been concluded for the purpose of significantly extending the
     scope of utilization (more than 30% more area and antennas).

(10) CURRENT means the version of a document that is valid at the moment when
     the Client accepts a search district Section 3 (3)) and on which the
     Contractor is informed.

(11) POINT-TO-MULTI-POINT BASE STATION is a fixed radio station as described
     in the sample rental contract (appendix 5) in Section 2.1 and
     Section 10.

(12) RADIO RELAY REPEATER is a pure point-to-point radio relay station which
     serves only for connecting point-to-multi-point base stations mutually
     or for connecting these to the cable network. For radio relay repeaters
     only parabolic antennas will be used.

                                    SECTION 15

                                   MISCELLANEOUS

This appendix applies for the territory of the Federal Republic of Germany.
The parties reserve for themselves the right to agree in writing an extension
of the scope of this appendix taking into consideration the specific
situation in each country.

<PAGE>

                                European Agreement
                                   Appendix 4 c
                                 Site Acquisition

                                    SECTION 16

                                    APPENDICES

(1)  The appendices as mentioned below are part and parcel of this appendix:

     1.   sample location assessment form
     2.   checklist appendices to the contract
     3.   proof of the authorization of the Contractor versus the lesser or
          owner
     4.   sample service report
     5.a) current sample rental contract
     5.b) current reservation and rental contract

(2)  In case any contradictions occur between the stipulations of this
     appendix and the above appendices only the stipulations that are
     contained in this appendix shall prevail.

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

                  APPENDIX 4c, PART 2 OF THE EUROPEAN AGREEMENT

                                    AGREEMENT
                            ON THE USE OF PROPERTIES

between

SIEMENS AKTIENGESELLSCHAFT

80286 Munchen

                                                       - called Siemens below -

and

FIRSTMARK COMMUNICATIONS DEUTSCHLAND GMBH

Kleine Brudergasse 3
01067 Dresden

                                                     - called FirstMark below -

                                    PREAMBLE

FirstMark intends to use property of the Siemens AG and Siemens Immobilien
Management OHG (called SIM OHG) for operating a digital radio network by
means of erecting and operating fixed radio stations.

For this purpose Siemens and FirstMark agree the following:

                                    SECTION 1

                                   FUNDAMENTALS

(1)    Siemens and the SIM OHG will provide their properties for operating fixed
       radio stations within the legal and technical possibilities and within
       the following agreement and provided that an agreement can be reached
       concerning the rent and the other details in the rental contract that are
       specific for the location (energy, rental object) provided that
       point-to-multi-point systems supplied by Siemens (System Walkair) are
       used for the purpose. For connections to the cable system or for
       point-to-point radio relay (feeder network) may be used equipment from
       other suppliers.

(2)    Provided that SIEMENS is owner of the property which FirstMark wants to
       use Siemens may agree that FirstMark concludes a rental contract with the
       SIM OHG on the basis of the attached sample rental contract.

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

                                    SECTION 2

                                      RENT

For the first *** after the European Agreement was signed FirstMark may
use the corresponding property ***. For another ***
FirstMark has to pay *** of the agreed rent. The use ***** and the
reduction of the rent will apply only provided that Siemens has the status of a
"Preferred supplier" according to the European Agreement. Siemens will agree
directly with SIM OHG on how to balance for the total loss of rent for the first
*** and for the reduction of the rent by *** for the subsequent ***.

                                    SECTION 3

                                     METHOD

(1)    When planning the radio network Siemens will take into consideration
       suitable properties of the Siemens AG and of affiliated companies.

(2)    As soon as a suitable property has been found Siemens and FirstMark will
       negotiate the amount of rent together with the relevant subsidiary of SIM
       OHG.

(3)    In case the three parties cannot reach an agreement on the amount of rent
       FirstMark may rent an alternative location from another lesser with the
       consent of Siemens. For this alternative location Siemens will pay to
       FirstMark a rent allowance in correspondence with the stipulations that
       apply in case locations are rented from SIM OHG. This means that Siemens
       will pay the entire rent for the initial *** after the European
       Agreement was concluded and *** of the rent for the subsequent ***.

(4)    Firstmark will not incur any costs for the initiation of the contract
       with SIM OHG or with the owner of the alternative location.
       In both cases Siemens will provide acquisition services by own personnel
       or subcontractors at the expense of Siemens as described in appendix 4
       of the European Agreement (business management contract for acquisition
       services).

                                    SECTION 4

                                    DURATION

(1)    The duration of this agreement is not limited.

(2)    It may be cancelled ordinarily by either party with 6 months notice,
       however, at the earliest after 4 years have passed from the signing of
       the contract.

(3)    Siemens may cancel this contract without notice provided that the
       European Agreement is terminated, no matter for which reason.
       The same applies provided that point-to-multi-point systems of other
       suppliers are used during the duration of the contract in violation of
       Section 1 paragraph 1.

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

(4)    The termination of this agreement does not affect the continuation of the
       individual rental contracts that were concluded between FirstMark and SIM
       OHG or Siemens, however, from this moment on FirstMark will have to pay
       the rent itself.

(5)    The cancellation must be expressed in writing.

                                    SECTION 5

                                OTHER AGREEMENTS

(1)    There are no other agreements beside those in this contract. Amendments
       or complementations of this contract must be made in writing.

(2)    In case one or several of the clauses in this contract are invalid this
       does not affect the validity of the remaining contract. The parties
       undertake to agree in such a case a new stipulation that is getting as
       close as possible to the economic purpose of the invalid stipulation.

(3)    The stipulations in the European Agreement between FirstMark
       Communications Europe S.A. of ______________________ Section 1;2.10 -
       2.12.8 and 9 apply correspondingly.

                                    SECTION 6

                               DEFINITION OF TERMS

AFFILIATED COMPANIES are companies to which the relevant party is related in
correspondence with or analog to Section 15 and following Company Law.

THEIR PROPERTIES are all the land owned by Siemens including the buildings
erected on this land.

The term of FIXED RADIO STATION includes the supply unit, the antenna system
with an output up to 5 Watt, the antenna carriers, the connecting units, and
the connections to the supply system as described in detail in Section 1
(Terms) of the sample rental contract (appendix).

APPENDIX 1: sample rental contract

Munchen, dated ____________________     Dresden, dated ________________________

___________________________________     _______________________________________
(signature Siemens)                     (signature FirstMark)

___________________________________     _______________________________________
(name in print)                         (name in print)

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

                      APPENDIX 1 TO THE FRAMEWORK CONTRACT

                             SAMPLE RENTAL CONTRACT

between

Siemens Immobilien Management GmbH & Co. OHG or respectively the owner/lesser
(Address:   AM 6
            Postfach 801760
            81617 Munchen)

                                                       - called "lesser" below -

and

FIRSTMARK COMMUNICATIONS DEUTSCHLAND GMBH

Kleine Brudergasse 3
01067 Dresden

                                                       - called "tenant" below -

PREAMBLE:

The tenant intends to erect a fixed radio station in the building defined in
Section 2 and on the property defined in Section 2 (called "property" below) for
connection to the public supply network for operating a digital radio network
and to rent rooms for housing the corresponding supply unit.

For this purpose both tenant and lesser (called "contracting parties" below)
agree the following and conclude the following rental contract:

                                 SECTION 1 TERMS

(1)    Fixed radio station is the installation for distributing, transmitting
       and receiving radio signals. By means of this radio station is
       established a direct contact with many transmitter and receiver stations
       which serve the purposes of both receiving and transmitting information
       and data.

       The fixed radio station comprises the necessary technical equipment for
       transmitting these signals either directly via cable or indirectly from
       the fixed radio station by directional radio links to telecommunication
       facilities.

       A fixed radio station consists in particular of the supply unit, the
       antenna unit, the antenna carriers, the connection units and connections
       to the supply system (...)

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

(2)    The supply unit consists of the transmission and receiver unit, the power
       supply (consisting of the connection to the power supply network, the
       emergency power supply batteries, the air-conditioning unit and perhaps
       the emergency power generator) and the interface for antenna input.

       The supply unit may be established both at the open air and in a room.

(3)    The antenna unit consists of a configuration of antennas which will be
       installed as plane antennas and/or directional radio antennas.

(4)    The antenna carrier consists of a structure for carrying the antennas
       that is adapted to the building.

(5)    The access is the connection between the public road network and the
       fixed radio station (___).

(6)    The connection to the supply system is the entirety of all lines, in
       particular power supply, telephone and telecommunication lines which are
       necessary for connecting the fixed radio station to the supply network.

(7)    Connection units is the term used for cables connecting the antennas to
       the supply unit as well as for the connection to the supply network.

                              SECTION 2 UTILIZATION

(1)    The lesser permits the tenant to erect, operate and maintain a fixed
       radio station in the sense of Section 1 on the property defined below:

BUILDING

       town                 ___________________________________
       street               ___________________________________
       rented rooms         ___________________________________

       (precise denomination for: basement, residential, store room, garage)
       total area           approx. ___________________ sqm

       The precise location of the rooms is marked in color on the location plan
       that is attached as attachment 1.

       The access way and the connections to the public supply network are
       marked in color on the location plan that is attached as attachment 2.

PROPERTY

       local court of       ___________________________________
       land register of     ___________________________________
       volume               ___________________________________
       sheet                ___________________________________
       area                 ___________________________________
       field                ___________________________________
       parcel               ___________________________________

OWNER

       ___________________________________

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

The scope is mainly: (Note: the scope is to be defined for each individual case
since it influences the amount of rent, e.g.:)

-      up to 8 antenna carriers on the roof for

       -      up to 8 plane antennas

       -      with one antenna amplifier of a size of 26 cm x 24 cm x 15 cm and

       -      up to three parabolic antennas with a maximum diameter of 1.2 m,

-      the supply unit in a container with a size of approx. 4.8 m x 2.5 m x 3 m
       (lxwxh) or: in a room in the building with a size of approx. 4.8 x 2.5 x
       2.5 m (lxwxh)

-      cable connections from the supply unit to the antennas and across the
       property if possible along two separate alignments to the nearest
       connection point

-      recooler for the air-conditioning unit with a maximum area of 4 m(2) on
       the roof or on another suitable area

-      access and car park for trucks.

       The precise location of the facilities on the roof is marked in color on
       the location plan attached as attachment 3. The alignment of the cables
       across the property is shown in the plan attached as attachment 4.

(2)    The tenant is aware of the fact that radio units are already operated on
       the property. The tenant therefore undertakes to abstain from any action
       that might disturb the utilization of the other radio facilities.
       The lesser is entitled to permit third parties also in future to use the
       property for erecting and operating radio facilities. The transmission
       and reception of the fixed radio station of the tenant must not be
       impaired or disturbed by this additional utilization.

       The tenant is obliged to fulfill all requirements raised by
       authorities with respect to the operation of the fixed radio station
       and to apply for and execute all provisions and documents in his own
       responsibility and at his own expense. The tenant must erect, operate
       and maintain the technical facilities and structures with adherence to
       the legal regulations and the state of technology. This includes
       lightning protection for the fixed radio station as well. The tenant
       undertakes to establish facilities on the roof for reaching his
       facilities provided that this is necessary and technically feasible.
       Further, the fixed radio station and the other facilities to be
       established on the roof must be erected in such a way that any
       building activity related to the building or the roof can be carried
       out without disturbing the operation of the radio station. In case the
       operation of the radio station causes additional costs for building
       activities the tenant undertakes already now to pay these additional
       costs. This shall apply only in case the tenant was informed of these
       additional costs before the building works were started and in case
       the tenant did not offer to stop the operation of the radio station
       within 1 week after he received the calculation for the additional
       costs. This does not affect the regulation in Section 5(2)c).

(3)    The tenant will provide for the lesser a copy of the clearance
       certificate issued by the regulation authority for telecommunications and
       post. Before erecting the facility the tenant assures that persons cannot
       stay for a prolonged time within the safety distance from the units as it
       is defined in the clearance certificate or that safety distances are
       sufficiently marked.

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

       In correspondence with the requirements raised by the legal regulations
       the tenant guaranties reliably and lastingly that outside the required
       safety distances no risks for persons exist.

       The tenant guaranties that the facilities that were installed by him
       fulfill the requirements of the law on electromagnetic compatibility of
       devices (EMVG). Electrical and electronic devices which do comply with
       the above mentioned regulations, too, will not be disturbed by the
       operation of the facilities of the tenant. Further, the tenant guaranties
       that his facilities comply with the requirements and limit values of the
       law on radiation protection. The facilities may be erected only if the
       permitted limits will not be exceeded when its radiation is added.

(4)    The tenant does not raise any claims versus the lesser with respect to
       the violation of the duty to guaranty traffic safety in case of snow, ice
       and slipperiness.

       The tenant releases the lesser in this respect from any legal claims that
       are raised by persons who access the property on initiative of the
       tenant.

       Disturbances of other tenants and users of the property by erecting,
       operating and maintaining the facilities must be avoided. In case
       business is disturbed the lesser will be entitled to cancel the contract
       prematurely provided that the tenant does not stop the disturbance within
       a reasonable period despite written request.

(5)    The tenant is entitled to update the technical equipment of the radio
       station permanently and to alter it entirely or partially provided that
       this does not extend the scope of utilization of the property and the
       impairment of the lesser provided that the operation of other radio
       facilities and the other users of the building are not disturbed by these
       activities and their consequences. Essential alterations require the
       consent of the lesser.

(6)    For the purpose of erecting the fixed radio station and the connection
       units the tenant may access the property by car and trucks. Any damage
       that is caused in relation to this by the tenant or parties acting by his
       order must be repaired by the tenant even if he is not responsible for
       it.

(7)    In case third party companies will carry out maintenance the tenant must
       inform the lesser in advance on the name of these companies.

       The lesser reserves for himself the right to refuse access to the
       property for certain companies for important reasons.

(8)    The tenant accepts the rooms in the known state. The lesser does not
       warrant the size, quality, composition and suitability of these rooms for
       the intended purpose.

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

(9)    The tenant is not entitled to permit third parties to share the location
       of the radio station.

(10)   All facilities and equipment that are connected with the building/the
       rented rooms by the tenant by exercising his rights as they result from
       this rental contract remain property of the tenant and do not become
       property of the lesser.

(11)   The installation of the technical facilities will be carried out by the
       tenant or by companies working on his order. The execution of
       installation must be coordinated with the lesser. The tenant must
       guaranty that the lesser is able to observe the installation works.

(12)   The lesser must guaranty that access to the facilities is provided for 24
       hours per day and 365 days per year. In case special measures must be
       taken for providing the required access (e.g. installation of key box)
       the tenant will bear the related costs.

                 SECTION 3 MAINTENANCE, LIABILITY, INSURANCE

(1)    The tenant will maintain the fixed radio station, the facilities that
       belong to it as well as the connection units and the rented rooms
       permanently in safe state. The costs for repairs, renewals, co-called
       repairs for interior decoration in the rented rooms etc. will be paid by
       the tenant.

(2)    The tenant is liable within the framework of the legal stipulations
       provided that no deviating agreements are made below. Further, the tenant
       releases the lesser from any claims for damages that are raised by third
       parties against the lesser due to the erection, operation or maintenance
       of the fixed radio station. The tenant further releases the lesser
       entirely from any legal liability in his capacity as owner of the
       property resulting from the operation of the fixed radio station provided
       that the lesser is owner of the rented object. The above obligations of
       release do not apply provided that the claims were caused by negligent
       conduct of the lesser, his employees or persons acting on his order. In
       case the lesser suffers any damage that was caused by the technical
       facilities and connection units that were installed within the framework
       of this rental contract it will be up to the tenant to prove that he is
       not responsible for the relevant damage according to the legal
       regulations.

(3)    The tenant has to prepare the rooms for his purposes at his own expense.
       It is up to the tenant to insure sufficiently at his own expense any risk
       that is related to the rooms, in particular also the property installed
       by him. This does not include the insurance on buildings.

(4)    The lesser is liable towards the tenant only for damages which are caused
       for the tenant by intent or gross negligence of the lesser or by an
       employee of the lesser as well as by a vicarious agent of the lesser
       (e.g. administrator, craftsman who carries out a repair) upon executing
       works. In case essential duties or essential contractual duties are
       violated the lesser will be liable also for minor

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

                  APPENDIX 4c, PART 2 OF THE EUROPEAN AGREEMENT

       negligence of the mentioned persons, however, only for compensating the
       typical damage that can be expected.

(5)    In case the supply of electricity, gas or water or the disposal of sewage
       is interrupted due to a circumstance that was not caused intentionally or
       by gross negligence by the lesser or in case they are altered to the
       disadvantage of the tenant (supply disturbances) or disturbances of
       supply occur due to force majeure, flood and other catastrophes the
       tenant will not be entitled to raise any claims against the lesser that
       are related to these disturbances.

                                 SECTION 4 RENT

(1)    The rent for the rooms includes the right to install the antenna unit and
       the connection units (Section 1).

       As from the beginning of the building works the rent amounts to the
       annual total of

<TABLE>
<S>                                                            <C>
              net:                                             EUR
                                                                   ------------

              plus currently valid legal VAT, at present 16%   EUR
                                                                   ------------

              gross:
                                                                   ------------

              (in words: EURO                               ).
</TABLE>

       The lesser declares that he submits the rent he receives from the tenant
       to VAT at the standard tax rate (Section 12, 1 VAT tax law). Towards the
       tax office he waives a possible exemption from VAT and--provided it would
       be applicable--the application of the regulation for small entrepreneurs.
       Therefore, the tenant is obliged to pay the monthly rent plus currently
       valid legal VAT.

       The rent is to be paid annually once in advance in one sum by the 5th
       January of each year to the account of the lesser at the

       bank:
       account no.:
       sorting code:
       holder of the account:
       purpose: "****

       The tenant may use the rented object **** until **** and for the
       period from **** until **** he has to pay only **** of the agreed rent.

(2)    The non-payment of rent and the reduction of the rent will apply provided
       that the Siemens AG has the status of a preferred supplier according to
       the European Agreement and that the European Agreement was not cancelled.
       At the first day of the month when Siemens loses the status of a
       "preferred

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

       supplier" or when the cancellation of the European Agreement arrives the
       waiver of the rent or the reduction of the rent are cancelled and
       FirstMark has to pay the rent as agreed in paragraph 1 (1) above taking
       into consideration possible rent increases according to paragraph (3).

(2)    In case the price index for the cost of living of all private households
       in Germany as it is published by the Federal Office for Statistics (1995
       = 100) is increased or reduced by more than 5 points in comparison with
       the index that was applicable at the moment when the duration of the
       rental contract began the agreed rent is altered correspondingly.

       In case the rent was altered on the basis of the above regulation the
       clause will be applied once more in case the index for the cost of living
       has increased or dropped once more by more than 5 points in comparison
       with the previous adaptation.

       In case the Federal Office for Statistics alters the basis for
       calculating the price index and discontinues the use of the present
       price index the index on the new basis will replace the old one.

(5)    The amount defined in Section (1) covers all ancillary and operating
       costs--except costs for energy consumption--for the rented object
       (rented rooms including common facilities. Separate invoices will not
       be issued.

(6)    ALTERNATIVE 1:

       The tenant will arrange that energy consumption is accounted and invoiced
       directly by the relevant supply company. For this purpose the tenant
       entitles the lesser to apply for "connection to the low voltage grid" at
       the relevant energy supply company.

       ALTERNATIVE 2:

       The lesser will have a meter installed at the expense of the tenant for
       measuring the electricity consumption and on each 30th September he will
       charge the cost for the consumed electricity The costs for installing the
       meter have to be paid by the tenant also in case he is using the right to
       cancellation of the rental contract according to Section 5 (2).

       The lesser guaranties that the price he will charge the tenant for energy
       will not exceed the working price for tariff clients of the local energy
       supplier.

       The lesser will inform the tenant of planned interruptions of energy
       supply by the lesser which affect also the energy supply of the radio
       station in time, i.e. if possible one week in advance.

                  SECTION 5 DURATION OF CONTRACT, CANCELLATION

(1)    The duration of the rental contract beings on ___ and ends on ___ (10
       years).

       The tenant is entitled to prolong the rental relationship beyond the
       _____ (date of the end of the rental relationship) twice by a period of 5
       years at the conditions

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

       of this rental contract by unilateral written declaration which must have
       reached the lesser at least 6 months before the end of a rental
       relationship (option).

       Further, the contract is prolonged by one year each in case neither of
       the parties cancels the contract with a period of six months to the end
       of the duration of contract. This applies also in case the right to the
       option is not used.

(2)    The lesser is entitled to extraordinary cancellation of this contract in
       particular

       a)     with immediate effect if

              aa)    the payment of rent by the tenant is more than 4 weeks late
                     despite written reminder.

              bb)    an insolvency procedure or settlement procedure was opened
                     against the assets of the tenant,

              cc)    the tenant continues to use the object in a way that
                     constitutes a violation of the contract despite written
                     protest,

              dd)    the tenant uses in violation of Section 1(1) of the
                     framework contract facilities that were not acquired from
                     Siemens or for which Siemens did not give its consent.

       b)     at the latest possible moment after an order to pull down the
              building was issued in case the tenant is obliged to pull down the
              used building due to requirements raised by authorities that
              cannot be anticipated now.

       The lesser undertakes to support the tenant in conversations the tenant
       may have with the authorities for preserving the building.

       c)     with a period of 6 months to the end of a month in case the radio
              station must be removed because building measures must be carried
              out at the building where the radio station was installed and the
              radio station must be removed for this purpose despite the above
              regulation in Section 2 (2) or because the building will be
              removed. The lesser will inform the tenant early if this occurs.

       d)     with effect to the end of each month in case the fixed radio
              station causes repeatedly damages and disturbances despite the
              stipulations in Section 2 nos. 3 and 4 and the tenant does not
              eliminate these within a reasonable period despite written
              protest.

       In cases of extraordinary cancellation according to the above letters b)
       and c) the lesser will provide for the tenant another suitable location
       on the same property if possible. However, he will not warrant that the
       alternative location has the same technical suitability. The costs that
       are related to the removal of the fixed radio station to the alternative
       location will be paid by the tenant.

(3)    The cancellation must be made in writing.

(4)    The tenant is entitled to cancel this contract with effect to the end of
       a calendar year for instance in case the property is or becomes
       unsuitable for erecting or operating the fixed radio station as
       transmitter and receiver, in case it is not

<PAGE>

                               European Agreement
                                   Appendix 4c
                                Site Acquisition

       possible to link the station to the radio network, its further operation
       in the radio network is impaired or necessary permits are not awarded or
       not prolonged.

                             SECTION 6 TERMINATION

In case the contractual relationship ends the tenant is obliged to remove the
fixed radio station, the connection units and all related facilities and
installations at his own expense. The tenant must reestablish the original state
or a state that is technically and in terms of value comparable to the original
state provided that the lesser requires this. The removal must be completed at
the end of the contractual relationship.

                     SECTION 7 PROHIBITION OF ADVERTISEMENT

(1)    The tenant warrants that his suppliers do not use the location were they
       make supplies for purposes of advertisement and/or publications.

(2)    The tenant warrants that antennas and other elements that are visible
       from outside are neutral, i.e. that they bear no company logo, company
       marks etc.

                          SECTION 8 REDUCTION OF RENT

The amount of rent may be reduced only in case of severe reductions of the use
value. A change of transmission or reception quality does not entitle to a
reduction of rent.

                          SECTION 9 FINAL STIPULATIONS

(1)    In case the lesser has sold the rented object or the property and the
       purchaser does not fulfill his obligations the lesser will not be liable
       like a guarantor for the damage to be compensated by the purchaser in
       contrast to the regulation in Section 571 paragraph 2 Civil Code.

(3)    Other agreements than those contained in this contract do not exist.
       Amendments and complementations of this contract must be made in writing.

(4)    In case the contract contains any gaps or any of its stipulations is
       invalid this does not affect the validity of the remaining stipulations.
       For this case the contracting parties undertake to agree a valid
       regulation that is economically as close as possible to the invalid or
       incomplete regulation.

(5)    The time schedule of all construction activities must be agreed with the
       subsidiaries of SIM.

(6)    Necessary installations up to the fixed radio station which are required
       for operating the fixed radio station will be executed by the tenant
       after having been coordinated with the lesser.

(7)    The following attachments are parts of this contract:

       ATTACHMENT 1                location plan rooms

<PAGE>

                               European Agreement
                                  Appendix 4c
                                Site Acquisition

       ATTACHMENT 2                location plan access/connection with the
                                   public supply system

       ATTACHMENT 3                location plan roof areas

       ATTACHMENT 4                location plan cable alignment across the
                                   property

_______________dated________________             Dresden, dated_________________

____________________________________             _______________________________
Siemens Immobilien Management GmbH               FirstMark Communications
                                                 Deutschland GmbH

<PAGE>

                               EUROPEAN AGREEMENT
                                  APPENDIX 4 C
                               SITE ACQUISITION

                                  ENCLOSURE 1

                         SITE-EVALUATION QUESTIONNAIRE

SITE-EVALUATION QUESTIONNAIRE

Site name                                   ID:

                                WLL radio-technical suitability

very good                          good                limited in area
                                                       ---------------

                                              RF suitability

very good                          good                limited in area
                                                       ---------------

Technical room                     available           not available

<TABLE>
<S>         <C>                      <C>                                    <C>
Size:       LESS THAN 15 m(2)        LESS THAN 20 m(2)  LESS THAN 12m(2)    GREATER THAN 12 m(2)
Height:     LESS THAN 2.50 m         LESS THAN 2.30 m   LESS THAN 2.30m
Location:   directly under the roof

</TABLE>

Container                          necessary                  possible

at the lowest point of the building
on the roof

Permission necessary:

<TABLE>
<S>                               <C>                                              <C>
because of antenna height         change in utilisation of technical room          because building is under
                                                                                   monument protection

air-traffic-control authority     container

Joint users on the building        yes                                             no

                                   sufficient space without agreement              agreement necessary with..
                                                                                   joint users

                                                  Estimate of construction costs

normal                             above average                                    high

</TABLE>

Appendix 4c -- Site Acquisition Appendices GBV 000510               Page 1 of 20

<PAGE>

                               EUROPEAN AGREEMENT
                                  APPENDIX 4 C
                               SITE ACQUISITION

<TABLE>

<S>                                <C>                                             <C>
Lease agreement probable           Standard                                        with acceptable modifications

Particularities

                                             Rent level probable

       ***                                           ***                                  ***

greater than DM...............

Installation:

</TABLE>

Date                               Agent

Clearance FirstMark Communication Network

Date:                              Property name:

Version 1

Site-evaluation questionnaire
Compiled: 5 March, 2000 Harald Schemionek

Appendix 4c -- Site Acquisition Appendices GBV 000510               Page 2 of 20

-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

<PAGE>

                               EUROPEAN AGREEMENT
                                  APPENDIX 4 C
                               SITE ACQUISITION

                                  ENCLOSURE 2

                     CHECKLIST OF ANNEXES TO THE AGREEMENT

--  Site sketch
--  Roof sketch with approximate measurements
--  Co-ordinates (Gauss-Krueger projection)
--  Telecommunications map cutting 1:25,000
--  Supplementary sheet "Deviations from the sample agreement"
--  A non-authenticated abstract of title for the site in question
--  Complete documentary proof of the authority of proxy of the signatory by
    means of trade register, register of associations, powers of attorney,
    article of association etc.

--  Energy-distribution company application
--  Declaration of site owner in accordance with Section 10 TKV (German
    telecommunications customer-protection ordinance)
--  Power of attorney for access to the land register and existing documents
    from the construction supervisory authority.

This list is only intended as an aid. The legally binding basis is the scope
of services stipulated in Section 2 of the agreement and the corresponding
instructions of the orderer.

Appendix 4c -- Site Acquisition Appendices GBV 000510               Page 3 of 20

<PAGE>

                              EUROPEAN AGREEMENT
                                  APPENDIX 4 C
                               SITE ACQUISITION

                                  ENCLOSURE 3

                        CERTIFICATION FOR AUTHORISATION

To:

Building owner and administrator of properties

Land registries

Building authorities

CERTIFICATION

We hereby certify that Mr. / Mrs. / Miss ................ is authorised by us
in the acquisition of sites and properties for telecommunications facilities.

In addition, he/she shall collect information by our order from the land
registry and view construction projection documents and accept mimeographed
excerpts.

FirstMark Communications
Deutschland GmbH

Harald Schemionek                 Ingo Brand
Properties manager                Properties syndic

Tel. +49 351 / 8631-138           Tele. +49 351 / 8631-129

Appendix 4c -- Site Acquisition Appendices GBV 000510               Page 4 of 20

<PAGE>

                               EUROPEAN AGREEMENT
                                  APPENDIX 4 C
                               SITE ACQUISITION

                                  ENCLOSURE 4

                               SERVICE STATEMENT

For site no ..........
in the region East, West, North, South,

the agent ..................
rendered all requested services.

The bonus for submission of the signed agreement within four weeks following
clearance for negotiation of the agreement is not payable

The annual rent negotiated by him is ..................
The payable difference between this and the standard value is thus: ...........

The agreement complies / does not comply with the current sample lease
agreement of the orderer without discrepancies.

A deduction for modifications to the agreement which have not been agreed
does not have to be made.

Total amount bonuses:

Dresden, ...........              Dresden, .................

 ............................      ...............................
(Signature)                       (Signature)

Appendix 4c -- Site Acquisition Appendices GBV 000510               Page 5 of 20

<PAGE>

                               EUROPEAN AGREEMENT
                                  APPENDIX 4 C
                               SITE ACQUISITION

                                  ENCLOSURE 5 a

            SAMPLE LEASE AGREEMENT BUILDING AND RESERVATION AGREEMENT

                                 LEASE AGREEMENT
                     (VERSION 3 BUILDING, VERSION 13 APRIL, 2000)

between

                                   -hereinafter referred to as "THE LESSOR "-

and

FirstMark Communications Deutschland GmbH
Kleine Bruedergasse 3
D-01067 Dresden
Germany

                                   -hereinafter refereed to as "THE LESSEE"-

                          SECTION 1 SUBJECT MATTER OF THE AGREEMENT

The lessor shall lease parts of his site to the lessee for the operation of a
radio fixed station. The radio fixed station is a part of the WLL network of
the lessee.

The leasing shall take place of the roof areas necessary for the realisation
of the scope of  utilisation, one technical room in the ......... floor having
an area of ........... m(2) and the required cable paths in and on the

BUILDING:

Type of constructional plant:
Street:
Postal code / place:
Local sub-district:
Cadastral district:
Lot:
Registered at district council:
In the (heritable-building) land registry of:
Volume:
Sheet:
Running number in the property register:

THE FOLLOWING IS / ARE ENTERED IN THE FIRST SECTION OF THE LAND REGISTER:
Name:
Date of birth:
Address:

Appendix 4c -- Site Acquisition Appendices GBV 000510               Page 6 of 20

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

THE FOLLOWING IS/ARE ENTERED IN THE FIRST SECTION OF THE HERITABLE-BUILDING
LAND REGISTRY:

Name:
Date of birth:
Address:
Heritable-building land-register sheet and volume:

The lessor ensures that the building complies with the public-law regulations
and, in particular, is in a state approved under construction law.
The lessor further ensures that the leased technical room has never been used
as a dwelling area (prohibition of inappropriate utilisation).

                         SECTION 2 SCOPE OF UTILISATION

2.1   The lessee shall install all system parts (see Section 10) belonging to
      a radio fixed station.
      Essentially, the scope includes:
      - up to 8 antenna holders on the roof for
        - up to 8 flat-top antennas of the size 40 cm x 20 cm x 5 cm
        - each having one antenna booster of size 26 cm x 24 cm x 15 cm and
        - up to three parabolic antennas with a maximum diameter of 1.2 m,
      - the power-supply unit in a container having dimensions c. 4.8 m x 2.5 m
        x 3 m (LxWxH) or: in one room of the building of size c. 4.8 x 2.5 x
        2.5 m (LxWxH).
      - cable connections from the power-supply unit to the antennas and over
        the site via two separate paths to the next connection point
      - heat exchangers for the air-conditioning system with a maximum area
        of 2m(2) on the roof
      - access path and storage space for lorries.

2.2   The precise location of the system components can only be finalised
      shortly before commencement of construction in the course of a
      construction-technical inspection. The lessor shall be invited to
      participate in this inspection. If he does not appear or if he does not
      raise any objections, this shall be regarded as tacit consent to the
      planned realisation of the scope of utilisation.

2.3   The scope of utilisation can also be realised in steps.

2.4   The lessee can modify the radio fixed station at any time and upgrade
      it to state-of-the-art technology as long as the area requirement is
      not significantly increased in the process.

2.5   The lessee is entitled to lay all necessary cables and install
      distributors in order to connect the other lessees in the building to
      his radio fixed station.

2.6   The lessee can enter the site un-impeded at any time. In this context,
      "at any time" means 24 hours a day and 365 days a year. When entering
      the site, he shall show consideration for the other lessees.

      To enable access at all times, the lessee shall receive two sets of
      all necessary keys. One set of keys shall be deposited in a key safe
      which the lessee shall mount at his own expense on the house entrance.
      The lessee is liable in the case of loss of the keys.

                                                                 Page 7 of 20
Appendix 4c -- Site Acquisition Appendices GBV 000510
<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

2.7   If the lessee notifies the lessor which particular areas he requires
      for installation / construction, the lessor shall keep clear these areas
      and rule out utilisation for other purposes.

                                  SECTION 3 RENT

3.1   The annual rent for utilisation is:

                                                           DM
      In words                                             German marks
      *VAT (sales tax) currently 16%                       DM
      *The annual rent including VAT is                    DM
      (*omit as appropriate if no sales tax is payable).

      Payment of the rent is due on the first day of the month in which
      construction of the radio fixed stations commences. The date which applies
      for the commencement of construction is the date on which notification of
      the commencement of construction is sent to the lessor.

3.2   The first rent payment is payable within a period of 6 weeks following
      commencement of construction. Thereafter, the rent is payable annually in
      advance in each case at or before 15 January.

      The rent is payable to the following account:

      Account holder:
      Account number:
      BLZ (German bank code):
      Bank:
      Remitter's message:

3.3   The rent covers all incidental and operative costs for the utilisation
      of the property with the exception of the energy costs. The energy costs
      shall be paid by the lessee directly to the relevant energy-supply
      company.

3.4   If the consumer price index established by the German Federal Office of
      Statistics for the cost of living of all private households in Germany
      (1995 = 100) increases or decreases overall by more than 10% compared with
      the level for the month of January of the year following the signing of
      the agreement, the agreed rent shall be modified accordingly.
      The rent shall be adjusted again as soon as the consumer price index
      has increased or decreased by more than 10% compared with its level at the
      time of the previous adjustment.

                                  SECTION 4 CONSTRUCTION

4.1   Where necessary, the OWNER shall declare his agreement to the necessary
      constructional measures vis-a-vis third parties and in particular
      authorities and public departments.

4.2   During the constructional phase, the lessee can temporarily place his
      vehicles (transporters, lorries and crane) on the lessor's property
      within the limits allowed by the legal and practical possibilities.

                                                                 Page 8 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

      He can store building materials on the site until the conclusion of the
      construction work.

4.3   The lessee shall exercise particular caution when inspecting the roof,
      if necessary, he shall install a protective mechanism for inspections to
      reduce the strain on the exterior of the roof to a reasonable degree.

4.4   If, in the course of construction, damage occurs to the lessor's
      property, the lessee shall eliminate this damage immediately.

4.5   During the constructional phase, the lessor shall allow the lessee to
      utilise all supply lines (e.g. electricity and telephone lines) in return
      for payment of the running costs for these.

                                SECTION 5 OPERATION

5.1   The lessee shall operate his station in accordance with the rules of
      technology and the legal regulations.

5.2   He shall ensure the maintenance of the lightning conductors all the way
      to the connection to the lightning-protection system of the building.

5.3   The lessor shall not utilise the property in any manner which
      adversely affects the operation and safety of the lessee's technical
      systems. The radio links must not be subjected to interference caused by
      obstacles in front of the antennas in the direction of radiation. Even if
      the antenna is briefly covered, this causes the link to be broken. The
      antennas shall be mounted at a sufficient height so that accidental
      interference by persons is very unlikely. The lessor must ensure that all
      persons operating in the area of the antennas by his order or with his
      consent refrain from even briefly covering the antennas.
      Entry into the technical room shall only be possible with the prior
      consent of the lessee.

5.4   When entering, the lessor must pay attention to complying with the
      required safety distances specified in the site certification of the
      regulation authority for post and telecommunications. The certification
      shall be made available by the lessee.

5.5   The lessor is not prevented from letting to additional network
      providers as long as he rules out adverse effects to the radio fixed
      station of the lessee and obliges the other network provider to switch off
      immediately if adverse effects occur.
      If adverse effects occur nevertheless, the lessor must ensure that
      these adverse effects be eliminated - in accordance with their severity -
      immediately, even if this necessitates the systems of the other lessee to
      be switched off immediately. If he intends concluding a lease agreement
      with another network provider, the lessor shall notify the lessee of this
      in good time prior to the conclusion of the contract.

5.6   The lessee shall ensure that his radio fixed station does not interfere
      with the stations of other network providers on the same site, as long as
      these stations comply with the currently applicable laws and technical
      norms and observe any required minimum distances to the system components
      of the lessee.

                                                                 Page 9 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

                             SECTION 6 DISASSEMBLY

6.1   For disassembly, the lessee can again park lorries and utilise the
      supply lines of the lessor as described under Section 4.

6.2   The lessee shall dismantle all systems set up by him and re-establish
      a state which is economically comparable with the original state.
      This also applies for the systems permanently connected with the
      property because the link is only temporary (Section 95 BGB (German
      Civil Code)). Consequently, ownership of the introduced systems is not
      transferred to the lessor.

                                SECTION 7 TERM

7.1   The lease agreement is concluded for the term of 10 years.

7.2   The lessee is granted the option to twice extend the term of the
      agreement in each case by five years. The lessee can exercise the option
      by means of a unilateral written declaration at or before six months at
      the latest prior to the expiry of the term of the agreement.

7.3   The agreement shall be extended by one further year if neither of the
      parties terminates it with a period of notice of six months prior to
      expiry of the term of the agreement. The also applies if an option is not
      exercised.

7.4   Prior to the commencement of construction, the lessee is entitled to
      terminate this agreement at any time effective at the end of a month.
      This right of termination only exists in the first year after the signing
      of the agreement.

7.5   Following the commencement of construction or expiry of the first year
      of the agreement, the lessee can terminate the agreement at any time with
      a period of notice of 6 months if
      - the suitability of the site for the operation of the radio fixed
        station worsens considerably because e.g. the radio fixed station
        cannot be connected into the remaining network or an important
        customer cannot be connected or
      - it becomes clear that the constructional realisation would be too
        costly or
      - necessary permission or licences are not granted or extended.

7.6   The lessor has all rights of termination arising from the German Civil
      Code.

7.7   The termination of the agreement must be effected in writing.

7.8   Any rent payments made in advance must be refunded on a pro-rata basis.

                                 SECTION 8 LIABILITY

The liability of the parties with respect to each other is defined by the
legal regulations.

                                                                 Page 10 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

                              SECTION 9 MISCELLANEOUS

9.1   The lessee can pass on all rights arising from this agreement to his
      employees or other parties commissioned by him (construction companies,
      maintenance companies etc.).

9.2   If the lessor sells the site, he shall notify the buyer of the
      agreement at hand and inform the lessee of the sale.

9.3   The lessee has the right to transfer at any time his rights and
      obligations arising from this agreement to a different company which
      offers a sufficient warranty for its ability to meet financial
      obligations and for its reliability. He shall inform the owner regarding
      the new party to the agreement.

9.4   The lessor authorises the lessee to obtain the necessary information from
      authorities and other offices / departments, to view the land register
      and obtain excerpts where necessary, to apply for necessary permission
      and to duplicate the documents required for this at the offices of the
      authorities responsible.

9.5   Arrangements other than those specified in this agreement do not exist.
      Changes and amendments to this agreement must be made in writing.

9.6   If one or several provisions of this agreement are legally
      ineffective, this shall not affect the effectiveness of the remaining
      agreement. In such a case, the parties undertake to make a new provision
      which comes closest to the economic purpose of the invalid provision.

9.7   The parties to the agreement agree to the storage of the data contained
      in this agreement within the scope of the legal regulations.

9.8   The place of jurisdiction is Dresden, Germany.

9.9   This agreement shall be drawn up in triplicate. The lessor shall
      receive one and the lessee two copies.

                        SECTION 10 TERMINOLOGICAL PROVISIONS

10.1  A WLL NETWORK is a telecommunications network where the connection at
      the end customer's end takes place not via cable but instead by wireless
      means (wireless local loop). A radio-link antenna is located on the
      customer's site and this establishes the link to the next radio-link
      collecting station of the lessee. This function (radio-link collecting
      station) is performed by the radio fixed station which is the subject of
      this agreement.

10.2  The SUITABILITY of the site for the operation of the radio fixed
      station depends on the permanently undisturbed reachability of as many
      end customers as possible in a direct line of sight without obstacles
      adversely affecting the radio link or interference from radio waves.

10.3  RADIO FIXED STATION is the collective term for all equipment for
      transmitting and receiving radio signals on a single site. Via a radio
      fixed station, the direct contact is established to several other immobile
      radio stations.

                                                                 Page 11 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

      The radio fixed station includes the necessary technical equipment for
      transmitting these signals directly via cable or indirectly via radio-link
      to other telecommunications facilities.
      In particular, a radio fixed station consists of the supply unit, the
      antenna system, the antenna holders, the link equipment, the connections
      to the supply network and the access path.

10.4  The SUPPLY UNIT consists of the transmission and reception equipment,
      the power supply (comprising the connection to the electricity mains, the
      emergency-power batteries and, where applicable, the emergency-power
      unit), the air-conditioning system and the interchange point for the
      feeding of the antenna.

10.5  The ANTENNA SYSTEM consists of a configuration of flat-top and
      parabolic antennas.

10.6  The ANTENNA HOLDER comprises a construction adapted to the site for the
      holding the antennas, generally a steel tube with a flange.

10.10 The term LINK EQUIPMENT describes the cable connections from the
      antennas to the supply unit as well as the links from the supply unit to
      the supply network via cable or radio link.

10.11 The CONNECTION TO THE SUPPLY NETWORK is the entirety of all lines (in
      particular electricity and communications lines) and parabolic antennas
      which are required for connecting the radio fixed station to the public
      electricity mains and telecommunications network.

10.12 The ACCESS PATH is the connection between the public street network and
      the radio fixed station. The access path must be placed and secured so
      that the supply of the radio fixed station, in particular in an emergency
      necessitating the replacement of the emergency-power batteries, is
      possible with the aid of lorries.

              Date:
------------,      --------------            Berlin, Date:
                                                          -----------------

------------------                           -----------------------
(Signature lessor)                           (Signature lessee)

------------------                           -----------------------
(Name in block letters)                      (Name in block letters)

------------------                           -----------------------
(Stamp, where applicable)                    (Stamp)

                                                                 Page 12 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

                                 Enclosure 5 b

          SAMPLE LEASE AGREEMENT BUILDING AND RESERVATION AGREEMENT
                                 SAMPLE FOR
         RESERVATION AND LEASE AGREEMENT (VERSION 3, DATE 13 APRIL, 2000)

Between

                        - hereinafter referred to as "THE LESSOR".

and

FIRSTMARK COMMUNICATIONS DEUTSCHLAND GmbH
Kleine Bruedergasse 3
D-01067 Dresden
Germany

                        - hereinafter referred to as "THE LESSEE".

                      SECTION 1 SUBJECT MATTER OF THE AGREEMENT

The lessor shall reserve parts of his site for the lessee for the operation
of a radio fixed station. The radio fixed station is a part of the WLL
network of the lessee.

The reservation includes the roof areas necessary for the realisation of the
scope of utilisation, a technical room in the _____ floor having a size of
______m(2) and the required cable paths in and on the

BUILDING:

Type of constructional plant:
Street:
Postal code / place:
Local sub-district:
Cadastral district:
Lot:
Registered at district council:
In the (heritable-building) land registry of:
Volume:
Sheet:
Running number in the property register:

THE FOLLOWING IS/ARE ENTERED IN THE FIRST SECTION OF THE LAND REGISTER:
Name:
Date of birth:
Address:

                                                                 Page 13 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

THE FOLLOWING IS/ARE ENTERED IN THE FIRST SECTION OF THE HERITABLE-BUILDING
LAND REGISTRY:
Name:
Date of birth:
Address:
Heritable-building land-register sheet and volume:

The lessor ensures that the building complies with the public-law regulations
and, in particular, is in the state approved under construction law.
The lessor further ensures that the leased technical room has never been used
as a dwelling area (prohibition of inappropriate utilisation).

                           SECTION 3 SCOPE OF RESERVATION

2.1   The lessee plans to construct a radio fixed station having the scope
      defined in Section 6.1. Consequently, areas must be kept clear for:
      -  one to 8 antenna holders on the roof
      -  the supply unit in a container with the dimensions
         c. 4.8 m x 2.5 m x 3 m (LxWxH) or; in a room in the building having
         dimensions c. 4.8 x 2.5 x 2.5 m (LxWxH)
      -  heat exchanger for the air-conditioning system with an area of
         max. 2 m(2) on the roof

2.2   The possible location of the system components and thus the reserved
      areas shall be decided in the course of a constructional inspection.
      The lessor shall be invited to participate in this inspection. The result
      shall be recorded in a simple drawing which shall form the basis for the
      keeping clear of the designated areas.
      During the period of reservation, the lessor shall make these areas
      available to third parties.

2.3   The lessee can enter the site at any time. In this context, "at any
      time" means 24 hours a day and 365 days a year. When entering the site,
      he shall show consideration for the other lessees.

                           SECTION 3 PERIOD OF RESERVATION

3.1   The reservation is initially valid for one year.

3.2   The lessee can extend once the reservation by one year by means of a
      declaration in writing.

3.3   If for this period of two years the lessee does not exercise his right
      of conversion to a lease agreement, then all rights arising from this
      agreement shall expire.

3.4   If the OWNER sells the property during the period of reservation, he
      shall oblige the buyer to become a party to this agreement.

                                                                 Page 14 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

                     SECTION 4 REMUNERATION OF RESERVATION

For each year of the reservation, the lessor shall receive a remuneration of

<TABLE>
<CAPTION>
                                                    DM
<S>                                               <C>
In words                                            German marks
* VAT (sales tax) currently 16%                     DM
* The annual rent including VAT is                  DM
(*omit as appropriate if no sales tax is payable).

</TABLE>

The remuneration for reservation for the first year of the agreement is
payable within 6 weeks following the signing of the agreement.
For the second year of the agreement, it is payable at the beginning of the
year.

If the agreement is converted to a lease agreement, any remuneration for
reservation which was paid in advance shall be deducted on a pro-rata basis
from the first rent payable.

                    SECTION 5 CONVERSION TO A LEASE AGREEMENT

By sending a communication on the planned commencement of construction
(notification of the commencement of construction), the lessee can convert
this agreement for reservation to a lease agreement.

                          SECTION 6 SCOPE OF UTILISATION

6.1   The lessor permits the lessee to install all system components belonging
      to a radio fixed station (see Section 13) on and in the building
      specified in SECTION 1. This essentially includes:

      -  up to 8 antenna holders on the roof for
         -  up to 8 flat-top antennas of six 40 cm x 20 cm x 5 cm
         -  each having one antenna booster of size 26 cm x 24 cm x 15 cm and
         -  up to three parabolic antennas with a maximum diameter of 1.2m,
      -  the supply unit in a container of dimensions c. 4.8 m x 2.5 m x 3 m
         (LxWxH) or: in a room of the building having dimensions 4.8 x 2.5 x
         2.6m (LxWxH).
      -  cable connections from the supply unit to the antennas and over the
         site via two separate paths all the way to the next connection point
      -  heat exchangers for the air-conditioning system with an area of max.
         2 m(2) on the roof
      -  access path and parking area for lorries.

      The scope of utilisation can also be realised in steps.

6.2   The lessee can modify the radio fixed station at any time and upgrade
      it to state-of-the-art technology as long as this does not significantly
      increase the area requirements.

6.3   The lessee has the right to lay all necessary cables and install
      distributors so as to connect the other lessees in the building to his
      radio fixed station.

      To enable access at any time, the lessee shall receive two sets of all
      required keys. One set of keys shall be stored in a key deposit box which
      the lessee shall have mounted on the house entrance. The lessee is liable
      for the loss of the keys.

                                                                 Page 15 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

                                SECTION 7 RENT

7.1   The annual agreed rent for utilisation is:

<TABLE>
<CAPTION>
                                                    DM
     <S>                                               <C>
     In words                                            German marks
     * VAT (sales tax) currently 16%                     DM
     * The annual rent including VAT is                  DM
     (*omit as appropriate if no sales tax is payable).

</TABLE>

      Payment of the rent is due on the first day of the month in which
      construction of the radio fixed stations commences. The date which
      applies for the commencement of construction is the data on which
      notification of the commencement of construction is sent to the lessor.

7.2   The first rent payment is payable within a period of 6 weeks following
      commencement of construction. Thereafter, the rent is payable annually in
      advance in each case at or before 15 January.

      The rent is payable to the following account:

      Account holder:
      Account number:
      BLZ (German bank code):
      Bank:
      Remitter's message:

7.3   The rent covers all incidental and operative costs for the utilisation
      of the property with the exception of the energy costs. The energy costs
      shall be paid by the lessee directly to the relevant energy-supply
      company.

7.4   If the consumer price index established by the German Federal Office of
      Statistics for the cost of living of all private households in Germany
      (1995 = 100) increases or decreases by more than 10% overall compared
      with the level for the month of January of the year following the
      signing of the agreement, the agreed rent shall be adjusted
      accordingly.

      The rent shall be adjusted again as soon as the consumer price index has
      increased or decreased by more than 10% compared to its level at the time
      of the previous adjustment.

                              SECTION 8 CONSTRUCTION

8.1   Where necessary, the OWNER shall declare his agreement to the necessary
      constructional measures vis-a-vis third parties and in particular
      authorities and public departments.

8.2   During the constructional phase, the lessee can temporarily place his
      vehicles (transporters, lorries and crane) on the property of the lessor
      within the limits allowed by the legal and practical possibilities.

      He can store building materials on the site until the conclusion of the
      construction work.

                                                                 Page 16 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

8.3   The lessee shall exercise particular caution when inspecting the roof.
      If necessary, he shall install a protective mechanism for inspections to
      reduce the strain on the exterior of the roof to a reasonable degree.

8.4   If, in the course of construction, damage occurs to the lessor's
      property, the lessee shall eliminate this damage immediately.

8.5   During the constructional phase, the lessor shall allow the lessee to
      utilise all supply lines (e.g. electricity and telephone lines) in return
      for payment of the running costs for these.

                                SECTION 5 OPERATION

8.1   The lessee shall operate his station in accordance with the rules of
      technology and the legal regulations.

8.2   He shall ensure the maintenance of the lightning conductors all the way
      to the connection to the lightning-protection system of the building.

8.3   The lessor shall not utilise the property in any manner which adversely
      affects the operation and safety of the lessee's technical systems. The
      radio links must not be subjected to interference due to obstacles in
      front of the antennas in the direction of radiation. Even if the
      antenna is briefly covered, this causes the link to be broken. The
      antennas shall be mounted at a sufficient height so that unintentional
      interference by persons is very unlikely. The lessor must ensure that all
      persons operating in the area of the antennas by his order or with his
      consent refrain from even briefly covering the antennas.
      Entry into the technical room shall only be possible with the prior
      consent of the lessee.

8.4   When entering, the lessor shall pay attention to complying with the
      required safety distances specified in the site certification of the
      regulation authority for post and telecommunications. The certification
      shall be made available by the lessee.

8.5   The lessor is not prevented from letting to additional network
      providers as long as he rules out adverse effects to the radio fixed
      station of the lessee and obliges the other network provider to switch
      off immediately if adverse effects occur.
      If adverse effects occur nevertheless, the lessor must ensure that
      these adverse effects are eliminated -- in accordance with their
      severity -- immediately, even if this requires that the systems of the
      other lessee be switched off immediately.
      If he intends concluding a lease agreement with another network
      provider, the lessor shall notify the lessee of this in good time prior
      to the conclusion of the contract.

8.6   The lessee shall ensure that his radio fixed station does not interfere
      with the stations of other network providers on the same site, as long as
      these stations comply with the currently applicable laws and technical
      norms and observe any required minimum distances to the system components
      of the lessee.

                                                                 Page 17 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

                             SECTION 9 DISASSEMBLY

9.1   For disassembly, the lessee can again park lorries and utilise the
      supply lines of the lessor as described under Section 4.

9.2   The lessee shall dismantle all systems set up by him and re-establish a
      state which is economically comparable with the original state.
      This also applies for the systems permanently connected with the
      property because the link is only temporary (SS 95 BGB (German Civil
      Code)). Consequently, ownership of the introduced systems is not
      transferred to the lessor.

                                SECTION 10 TERM

10.1  The lease shall commence on receipt of notification of the commencement
      of construction and is concluded for a term of 10 years.

10.2  The lessee is granted the option to twice extend the term of the
      agreement in each case by five years. The lessee can exercise the option
      by means of a unilateral written declaration at or before six months at
      the latest prior to the expiry of the term of the agreement.

10.3  The agreement shall be extended by one further year if neither of the
      parties terminates it with a period of notice of six months prior to the
      expiry of the term of the agreement. The also applies if an option is not
      exercised.

10.4  The lessee can terminate the agreement at any time with a period of
      notice of 6 months if
      -  the suitability of the site for the operation of the radio fixed
         station worsens considerably because e.g. the radio fixed station
         cannot be connected to the remaining network or an important customer
         cannot be connected or
      -  it becomes clear that the constructional realisation would be too
         costly or
      -  necessary permission or licences are not granted or extended.

10.5  The lessor has all rights of termination arising from the German Civil
      Code.

10.6  The termination of the agreement must be effected in writing.

10.7  Any rent payments made in advance must be refunded on a pro-rata basis.

                             SECTION 11 LIABILITY

The liability of the parties with respect to each other is defined by the
legal regulations.

                            SECTION 12 MISCELLANEOUS

12.1  The lessee can pass on all rights arising from this agreement to his
      employees or other parties commissioned by him (construction companies,
      maintenance companies etc.).

                                                                 Page 18 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

12.2  If the lessor sells the site, he shall notify the buyer regarding this
      agreement and inform the lessee of the sale.

12.3  The lessee has the right to transfer at any time his rights and
      obligations arising from this agreement to a different company which
      offers a sufficient warranty for its ability to meet financial obligations
      and its reliability. He shall inform the owner regarding the new party to
      the agreement.

12.4  The lessor authorises the lessee to obtain the necessary information
      from authorities and other offices / departments, to view the land
      register and obtain excerpts where necessary, to apply for necessary
      permission and to duplicate the documents required for this at the offices
      of the authorities responsible.

12.5  Arrangements other than those specified in this agreement do not exist
      - with the exception of the drawing mentioned in Section 2.2. Changes and
      amendments to this agreement must be made in writing.

12.6  If one or several provisions of this agreement are legally ineffective,
      this shall not affect the effectiveness of the remaining agreement. In
      such a case, the parties undertake to make a new provision which comes
      closest to the economic purpose of the invalid provision.

12.7  The parties to the agreement to the storage of the data contained in
      this agreement within the scope of the legal regulations.

12.8  The place of jurisdiction is Dresden, Germany.

12.9   This agreement shall be drawn up in triplicate. The lessor shall
       receive one and the lessee two copies.

                       SECTION 13 TERMINOLOGICAL PROVISIONS

13.1  A WLL NETWORK is a telecommunications network where the connection at
      the end customer's end takes place not via cable but instead by wireless
      means (wireless local loop). A radio-link antenna is located on the
      customer's site and this establishes the link to the next radio-link
      collection station of the lessee. This function (radio-link collecting
      station) is performed by the radio fixed station which is the subject of
      the agreement.

13.2  The SUITABILITY of the site for the operation of the radio fixed station
      depends on the permanently undisturbed reachability of as many end
      customers as possible in a direct line of site without obstacles adversely
      affecting the radio link or interference from radio waves.

13.3  RADIO FIXED STATION is the collective term for all equipment for
      transmitting and receiving radio signals on a single site. Via a radio
      fixed station, the direct contact is established to several other immobile
      radio stations.
      The radio fixed station includes the required technical equipment for
      transmitting these signals directly via cable or indirectly via radio-link
      to other telecommunications facilities.
      In particular, a radio fixed station consists of the supply unit, the
      antenna system, the antenna holders, the link equipment, the connections
      to the supply network and the access path.

                                                                 Page 19 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                              European Agreement
                                 Appendix 4 c
                               Site Acquisition

13.4  The SUPPLY UNIT consists of the transmission and reception equipment,
      the power supply (comprising the connection to the electricity mains,
      the emergency-power batteries and, where applicable, the emergency-power
      unit), the air-conditioning system and the interchange point for the
      feeding of the antenna.

13.5  The ANTENNA SYSTEM consists of a configuration of flat-top and
      parabolic antennas.

13.6  An ANTENNA  HOLDER comprises a construction adapted to the site for the
      holding of the antennas, generally a steel tube with a flange.

13.10 The term LINK EQUIPMENT describes the cable connections from the
      antennas for the supply unit as well as the links from the supply unit
      to the supply network via cable or radio link.

13.11 The CONNECTION TO THE SUPPLY NETWORK is the entirety of all lines (in
      particular electricity and communications lines) and parabolic antennas
      which are required for connecting the radio fixed station to the public
      electricity mains and telecommunications network.

13.12 The ACCESS PATH is the connection between the public street network and
      the radio fixed station. The access path must be placed and secured so
      that the supply of the radio fixed station, in particular in an
      emergency necessitating the replacement of the emergency-power batteries,
      is possible with the aid of lorries.

              Date:
------------,      --------------            Berlin, Date:
                                                          -----------------

------------------                           -----------------------
(Signature lessor)                           (Signature lessee)

------------------                           -----------------------
(Name in block letters)                      (Name in block letters)

------------------                           -----------------------
(Stamp, where applicable)                    (Stamp)

                                                                 Page 20 of 20

Appendix 4c -- Site Acquisition Appendices GBV 000510

<PAGE>

                               European Agreement
                                  Appendix 4d
                           Site Design and Civil Works

                   APPENDIX 4D - SITE DESIGN AND CIVIL WORKS

DOCUMENT

<TABLE>

<S>                 <C>
-------------------------------------------------------------------------------
DOCUMENT NAME       Appendix 4d - Site Design and Civil Works
-------------------------------------------------------------------------------
BACKGROUND          Description of Site Design and Civil Works, European
                    Agreement between FirstMark Europe SA and Siemens AG
-------------------------------------------------------------------------------
</TABLE>

<PAGE>

                               European Agreement
                                  Appendix 4d
                           Site Design and Civil Works

OBJECT OF CONTRACT

The rights and duties of Purchaser and Contractor with respect to planning
services for sites will later be agreed separately between Purchaser and
Contractor.

<PAGE>

                               European Agreement
                                   Appendix 4e
                    Installation / Commissioning / Acceptance

                    INSTALLATION / COMMISSIONING / ACCEPTANCE

                                   APPENDIX 4e

                               TECHNICAL SERVICES

<PAGE>

                               European Agreement
                                   Appendix 4e
                    Installation / Commissioning / Acceptance

TABLE OF CONTENTS

<TABLE>
<S>                                                                                         <C>
1       DEFINITIONS AND ABBREVIATIONS....................................................   3

1.1     DEFINITIONS......................................................................   3

2       INSTALLATION.....................................................................   3

3       COMMISSIONING AND IMPLEMENTATION.................................................   3

4       NETWORK INTEGRATION AND NETWORK INTERCONNECT.....................................   4

4.1     TYPE ACCEPTANCE TESTING AND VERIFICATION / NEW HARDWARE - OR SOFTWARE-VERSIONS...   5

5       FIELD ACCEPTANCE TESTING.........................................................   6

5.1     GENERAL..........................................................................   6

5.2     FIELD ACCEPTANCE DOCUMENTATION...................................................   7

5.3     FIELD ACCEPTANCE.................................................................   7

5.4     PRIORITY OF FAULTS: TYPICAL CASES / EXAMPLES.....................................   8

</TABLE>

<PAGE>

                               European Agreement
                                   Appendix 4e
                    Installation / Commissioning / Acceptance

1     DEFINITIONS AND ABBREVIATIONS

1.1   DEFINITIONS

Installation                       Installation shall mean materials, labour,
                                   testing and anything else necessary to be
                                   provided or to be undertaken by Contractor
                                   under the Contract to enable the System to be
                                   installed Ready for Acceptance.

Ready for Type Acceptance          Ready for Type Acceptance shall mean the date
                                   at which all tasks have been finalised to
                                   start Type Acceptance Testing in test floor.

Regression Testing                 Regression Testing shall mean testing of the
                                   correct functionality of a selected range of
                                   the features of a previous Type included in
                                   the new Type.

2     INSTALLATION

      Prerequisite for System Installation is the successful completion of the
      civil works; and the site must be in a shape to enable the System
      Installation, which shall be subject to the acceptance Civil Works.

      The Installation shall be performed by the Contractor in accordance with
      the Installation instructions, which will be agreed between the Parties.

      All required materials, labour, testing and anything else necessary for
      Installation of the System shall be provided or undertaken by the
      Contractor.

      The Installation work is subject to the Field Acceptance test. Contractor
      shall deliver full installation documentation including cabling plan and
      floor plan for each Site.

      Contractor shall list all equipment, tools and other items necessary for
      Site installation that Contractor recommends to use in the appropriate
      installation manuals.

3     COMMISSIONING AND IMPLEMENTATION

      During commissioning and implementation the Contractor shall prepare the
      System to allow the agreed Field Acceptance Tests.

      Testing, commissioning and final assessment shall be performed by
      Contractors commissioning engineers.

      Each System and equipment shall have a checklist according to Contractors
      regulations to ensure that the correct procedures are followed during
      installation and commissioning. Included in the procedure shall be
      sign-off sheets and test record sheets which shall form a permanent record
      in the test report. All transmission and radio equipment shall incorporate

<PAGE>

                               European Agreement
                                   Appendix 4e
                    Installation / Commissioning / Acceptance

     end to end testing, where the contracted Bit Error Rate Threshold shall be
     proved to system performance levels as specified.

     The integration team shall ensure that all functionality is completely
     operational. External interfaces for synchronisation, remote diagnostics,
     network management and leased lines to other operators shall be validated
     at the Field Acceptance test. Tests could be simulated where third party
     networks are not available.

     Testing shall commence in accordance with the project plan and shall
     require a team of commissioning engineers to complete section stability.

     Contractor shall list all tools and test equipment in all appropriate
     commissioning specifications. Contractor shall be responsible for the
     supply of tools and test equipment necessary for Contractors use during the
     commissioning phase.

     As part of the Commissioning activities the Contractor shall integrate all
     the Systems and Network Management systems after the Field Acceptance
     Test, in accordance with the Field Acceptance procedure

     Contractor will not unreasonably refuse to test and integrate Third Party
     equipment within the network, subject to a separate offer of the scope of
     such work and price.

4    NETWORK INTEGRATION AND NETWORK INTERCONNECT

-    NETWORK INTEGRATION
The role of the Network Integration is to provide assistance in the delivery of
a complex network involving multiple elements/products. In the case of new
technology networks, the Network Integration role is seen as being vital to the
development of a system that is composed of leading-edge equipment from several
vendors.

All related costs will be subject to a separate offer.

-    INTERCONNECT TESTING
Contractor shall provide assistance to Purchaser for the following aspects of
interworking testing on behalf of the customer and with the agreement of the
interconnecting partner.

-    Assist in defining and agreeing interconnect process with interconnect
     partner.
-    Audit information and documentation provided by the interconnect partner
     and capture and verify information required by them to perform
     interconnect.
-    Define Interconnect project plan, test schedule and success criteria and
     agree with interconnect partner.
-    Supply relevant testing equipment and protocol analysers if required.
-    Conduct interconnect testing on behalf of the customer
-    Ownership and management to resolution of issues arising from interconnect
     testing for items related to products.
-    Completion of test schedule

<PAGE>

                               European Agreement
                                   Appendix 4e
                    Installation / Commissioning / Acceptance

All related costs will be subject to a separate offer.

     V5.1 / V5.2
     The Contractor is willing to support V5.1/V5.2 related integration TESTS
     (WITH SWITCHES OF SHORTLISTED TENDERERS FOR FMC'S CORE NETWORK PROJECT)
     of the WALKair equipment with technical on site support during the test
     period. For functions in the interoperability between the tested switch and
     WALKair, which are maybe not covered from WALKair's SW, the Contractor
     will perform the necessary adaptations to ensure the functionalities which
     are described in the V5.2/V5.1 standard.

     Above mentioned efforts the Contractor is providing once free of charge for
     one switch SW version, provided that the Purchaser will ensure, that the
     switch supplier will participate and perform for his part in the relevant
     interoperability test.

     The Contractor's V5.1/V5.2 SW is based on the tdsoft product and has
     already interoperability certifications for a large amount of switch
     suppliers as well as national specifications. The Contractor will provide a
     list of certificated switches and national specifications.

     The Contractors technicians will support these V5.1/V5.2 interoperability
     tests which should take place at the switch suppliers sites/location.

4.1  TYPE ACCEPTANCE TESTING AND VERIFICATION / NEW HARDWARE - OR
     SOFTWARE-VERSIONS

4.1.1 AIM

-    The purpose of the Type acceptance test is to certify the function of the
     new Hardware or Software versions, according to its specification. The Type
     acceptance test shall be performed in the Contractors diagnostic centre
     (central or regional). All costs and expenses incurred by the Parties in
     connection with the Type Acceptance Test shall be borne by the Parties
     incurring the same. The Type Acceptance, tests and procedure shall be
     agreed between the Parties.

-    Successful completion of the System acceptance test is confirmed with the
     issue of an Type acceptance certificate. With the Type acceptance
     certificate the system version is released for operation by the Purchaser
     and valid for all following units of the same system version.

-    In case of system-upgrade, the new or changed features have to be tested in
     conjunction with the operation of the Systems and network.

4.1.1.1       PREREQUISITES

     Contractor has established the HW-configuration .
-    Contractor shall provide  the new software system version.
-    The Parties have agreed the procedures and tests to be performed and
     documented in the Acceptance test manual (ATMN)
-    Contractor shall provide all necessary test equipment

<PAGE>

                               European Agreement
                                   Appendix 4e
                    Installation / Commissioning / Acceptance

4.1.1.2 SCOPE OF TYPE ACCEPTANCE TESTS

      The Type acceptance tests consists of:

-    VERIFICATION OF MAINTAINABILITY

     -    Functionality of automatic routine tests
     -    Automatic hardware error detection
     -    Alarm indication and localisation of faulty equipment
     -    Removal of faulty equipment from service
     -    Safeguarding against HW- and SW-faults

-    VERIFICATION OF OPERABILITY

     -    Functionality of the operational features for administration of
          e.g.        system equipment
                      traffic-/performance-measurement
                      call charge registration

-    VERIFICATION OF FEATURES

     -    inter working of the signalling system
     -    types of traffic
     -    supplementary services

-    All steps of the Type acceptance test are documented in the acceptance test
     manual (ATMN) and will be performed by the Purchasers personnel with
     assistance of the Contractor

-    Every test-step has to be recorded and this test protocol should be signed
     by both Parties.

4.1.1.3 FIRST OFFICE APPLICATION (FOA)

-    It is agreed that not every software system version or software correction
     can be fully tested in the central or regional test system. In some cases
     the Purchaser may request to observe the system in the network environment
     of the Purchaser.

-    The new System software or the modification will be incorporated into
     selected network elements as planned. After the system is connected to
     traffic, normal operation is carried out during a defined observation
     phase.

5    FIELD ACCEPTANCE TESTING

5.1  GENERAL

1.   The Contractor provide support for preparation of and shall accompany the
     Field Acceptance test to show that the integration into Purchaser's network
     has been conducted according to mutual agreed specifications and
     requirements.

<PAGE>

                               European Agreement
                                   Appendix 4e
                    Installation / Commissioning / Acceptance

2.   The Field Acceptance shall be carried out for each single System

     -    The date of Field Acceptance Test shall be mutual coordinated.

5.2 FIELD ACCEPTANCE DOCUMENTATION

5.2.1 FIELD ACCEPTANCE PROTOCOL

1.
     The following Field Acceptance procedures and tests have been agreed,
     including an agreed Field Acceptance Certificate , the detailed test
     procedures and the Field Acceptance Test Protocol.

     [OBJECT OMITTED]

     [OBJECT OMITTED]

2.   The Field acceptance protocols shall be compiled in electronic format and
     allow storage in a central database structure. (format shall be mutual
     agreed both Parties)

5.3  FIELD ACCEPTANCE

     -    If the Field Acceptance fails then the Contractor forthwith implements
          alterations or modifications to the system as it is necessary to
          repeat the final acceptance test within seven calendar days from the
          date of the unsuccessful Field Acceptance Test. In the case of failure
          Contractor will immediately present a step by step solution plan.

     -    Field Acceptance Test is successful in case no errors exist or just
          minor faults existing.
     -    The System is only partially Field accepted (Partial Field Acceptance)
          in case of major fault existing. Uncompleted site specific
          documentation is considered as a major fault.
     -    Field Acceptance is rejected in case of one critical fault existing
          and/or in case of three (3) or more major faults existing.

<PAGE>

                               European Agreement
                                  Appendix 4e
                                Technical Support

5.4           PRIORITY OF FAULTS: TYPICAL CASES / EXAMPLES

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------
PRIORITY          DEFINITION                                      EXAMPLE
--------------------------------------------------------------------------------------------------------------
<S>              <C>                                              <C>
                  CRITICAL FAULT                                  -   a fault report that is related
1                 -   An urgent software or hardware                  to an already neutralized emergency
                      problem that has escalated to produce       -   a problem that threatens to
                      considerable operational restrictions. As       escalate to an emergency
                      a result, the fault may cause system        -   an important key function of the
                      availability to be significantly reduced.       system is unusable
--------------------------------------------------------------------------------------------------------------
                  MAJOR FAULT                                     -   uncritical features are
2                 -   An software or hardware problem                 inoperative
                      that has escalated to produce               -   a fault report that is related
                      unconsiderable operational restrictions.        to an urgent problem which could be
                                                                      neutralized by a workaround
                                                                  -   site specific documentation is
                                                                      uncomplete
--------------------------------------------------------------------------------------------------------------
                  MINOR FAULT                                     -   scratches on surfaces, fastening
3                 -   The System is working error                     of cables, labeling
                      free; but ther are minor restrictions,
                      without any degrations
--------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

S

                    INSTRUCTION FOR WALKAIR FIELD ACCEPTANCE

                            FIRSTMARK COMMUNICATIONS

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications

1.       INSTALLATION ASPECTS

The correctness should be verified during Field Acceptance. The installation of
WALKair units must be performed according to the instructions in the
Installation Manual IMN.

1.1      INSTALLATION CHECK

- CONNECTORS AT RFU'S:              Check if N type connectors at RFU side are
                                    mounted according to suppliers
                                    specification.

                                    Check if connectors are sealed.

- CONNECTORS AT IF- MUX'S:          Check if N type connectors at IF- Mux side
                                    are mounted according to suppliers
                                    specification.

- EARTHING OF BS/BU'S:              Check if ground connections of BS/BU's are
                                    made properly

- EARTHING OF IF- MUX'S:            Check if ground connections of IF- Mux's are
                                    made properly

- EARTHING OF RFU'S:                Check if ground connections of RFU`s are
                                    made properly

- EARTHING OF CABLES:               Check if all IF cables are grounded properly

- EMP PROTECTORS:                   Check if EMP protectors are installed
                                    according to suppliers specification (if
                                    used in this project)

- COAX CABLE MOUNTING:              Check if all IF cables are mounted and
                                    fastened properly

- E1- CABLE LABELING:               Check if all E1- Interface- Cables are
                                    labeled at equipment side and distribution
                                    frame side

1.2 POWER SUPPLY CHECK              NECESSARY EQUIPMENT:  VOLTMETER

The Base Station components are supplied with 48 VDC power. Every unit is fused
up separately. Check if the power supply is in a range between 45 VDC and 75
VDC.

1.3 BASE STATION SYSTEM CLOCK       NECESSARY EQUIPMENT:  LCI, FREQUENCY COUNTER

The BS/BU can be set to different synchronisation sources. The setting should be
the same for all BS/BU's in one Base Station.

The different settings are:  - internal    to use the internal clock of the
                                           BS/BU
                             - port # 1    to use the clock from the incoming
                                           signal at port # 1
                             - port # 2    to use the clock from the incoming
                                           signal at port # 2
                             - port # 3    to use the clock from the incoming
                                           signal at port # 3
                             - automatic   to use the clock from the first
                                           connected port
                                           (if this port becomes faulty, clock
                                           from next one is taken)
                             - external    to use the clock from an external
                                           2.048 MHz generator

If an external synchronisation source is used, its performance should be
verified by the help of a frequency counter.

Note down the measured clock.

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications

2. HARDWARE DATA

The serial numbers of all components (indoor- and outdoor units) should be noted
down in the Field Acceptance Protocol. There is a sticker on each component
which contains serial number and information about equipment type. The serial
number information of BS/BU's can also be seen at the management system WALKnet
or at the Local Craft Interface.

2.1 BASE STATION SERIAL NUMBERS

The serial numbers of all different units should be noted down for each Base
Station Sector accordingly. The Type of the Sector Antenna and Polarisation
should be noted down as well.

3. RADIO LINK DATA

During the commissioning phase, all different BS/BU's are set to a specific
carrier frequency. This carrier frequency must be according to the project
frequency planning. The settings should be noted down in the Field Acceptance
Protocol.
Further more, the modem of each BS/BU must be set to a specific power
level for transmitting and receiving. The recommended default values are
displayed when setting the modem working point. Note down the actual settings
for this project.

3.1 BASE STATION CARRIER FREQUENCIES     NECESSARY EQUIPMENT:      LCI

Note down the FREQUENCY INDEX of each BS/BU in the corresponding sector.
There is a frequency index table in the Operation and Maintenance Manual
OPAM.
From the Main Menu, choose ,,Configuration Menu"
From the Configuration Menu, choose ,,Radio Link Parameters"
From the Radio Link Parameters, choose ,,Get Frequency Index"
Note down the value
Repeat for all BS/BU`s

3.2 BASE STATION POWER LEVELS            NECESSARY EQUIPMENT:      LCI

Note down the modem working point of each BS/BU in the corresponding sector.
From the Main Menu, choose ,,Configuration Menu"
From the Configuration Menu, choose ,,Radio Link Parameters"
From the Radio Link Parameters, choose ,,Get Modem Working Point"
Note down the values
Repeat for all BS/BU's

4. BASE STATION SOFTWARE DATA            NECESSARY EQUIPMENT:      LCI

Each BS/BU has two software sections, an active and a standby section. The
active and backup version of WALKair should be noted down in the protocol.

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications

5. BASE STATION NETWORK PARAMETERS

Each BS/BU serves as a SNMP agent to the Network Management System.

Every single BS/BU must be set to a specific IP- Address according to the DCN
Project planning. This is done during the commissioning phase. The correctness
of all network parameters is checked and noted down in the protocol.

5.1 BASE STATION IP- ADDRESS             NECESSARY EQUIPMENT:      LCI, WALKNET

The Network Mask and Default Gateway must be the same in every BS/BU of the Base
Station. The IP- Address is set according to the project documentation.

The address can be seen by the help of LCI and WALKnet. It is recommended to use
the WALKnet application in order to verify, that the Ethernet connection to all
BS/BU's is working properly as well.

Connect the WALKnet to the Network- Hub and check the functionality of getting
access to all BS/BU's.

Please consider, that the IP- Address of the WALKnet machine must be registered
as a Manager Station in all BS/BU's. If a BS/BU is set to a Manager Station with
IP- Address 255.255.255.255 ,it allows configuration to any machine. But it also
means, that there is no security against misuse. So it is recommended to use it
only for testing purpose.

WITH WALKNET

Go to the detailed view of each BS/BU and note down the values

5.2 AUTHORIZED MANAGER STATIONS          NECESSARY EQUIPMENT:      LCI

Each BS/BU may have several authorized manager stations which have the ability
to change parameters in the system. The settings should be the same for all
BS/BU's. The values can be seen by the help of LCI.

From the Main Menu, choose ,,Configuration Menu"
From the Configuration Menu, choose ,,Administrative Parameters"
From Administrative Parameters, choose ,,BS Parameters"
From BS Parameters, choose ,,Get Authorized Manager Stations"
Note down the value into the protocol
Check if they are identical in all BS/BU's

To avoid alarm messages on the OMC during the acceptance phase, set the
IP-address at the end of the tests or disconnect the Ethernet connector until
test 6.4 is carried out.

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications

6. FUNCTIONALITY TESTING

During Field Acceptance, some functionality tests are performed. It has to be
checked, that the system is free of alarms on all units.

The cabeling between the telecom interfaces at the BS/BU and the distribution
frame should be checked as well.
It is suggested to register the mobile Terminal Station at each BS/BU with a
different Customer ID before leaving the BS Site.

By changing the Customer ID of the mobile Terminal Station according to the
previous set ID's at the Base Station, a link can be created to each BS/BU
without reconfiguring the Base Station. Therefore it is not necessary that
somebody stays at the Base Station for configuration while the measurements at
the Terminal Station are done.

6.1 ALARM INDICATION CHECK

Check that there is no fault in the system and no alarm visible.
LED indicators of:        - Internal Alarm at BS/BU`s
                          - External Alarm at BS/BU's
                          - Ethernet Alarm at BS/BU's
                          - Telecom Interface Alarms at BS/BU's
                          - IF- Mux Alarms

are set to status ,,GREEN".

6.2 BS- INTERFACE- CABELING TEST

The cabeling between the telecom interfaces of all BS/BU's and the distribution
frame must be checked. Connect a cable loop at the side of the distribution
frame to the tested telecom interface ( Rx - Tx ) and verify, that the status
LED of the corresponding interface on the BS/BU changes from RED to GREEN.

Repeat for all BS/BU's in one Sector and note down the result.
Repeat for all Base Station Sectors.

6.3 TESTING OF 64 QAM MODULATION      NECESSARY EQUIPMENT:  LCI, CONST. ANALYZER

This measurement should be done for every BS/BU. A constellation analyzer is
necessary to measure the downlink constellation. It has to be protected by DC-
Blocks.
Create a link between a BS/BU and the Terminal Station and verify the
constellation displayed. It has to be within the limits.

Note down the result.

Repeat the procedure for all other BS/BU's too.

* See optional measurement 6.3.1

6.3.1 BER TEST                     NECESSARY EQUIPMENT:   LCI, 2MBIT BER TESTER

This measurement is carried out for every BS/BU as long as a constellation
measurement is not possible (item 6.3).

Create a link between a BS/BU and the Terminal Station and verify the BER Tester
for 5 minutes. A service (e.g 31x64kBit; channel 1-31) must have been created on
the base station including a 2Mbit Software loop (local loopback).

Note down the result.

Repeat the procedure for all other BS/BU's too.

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications

SERVICE- CONFIGURATION OF WALKAIR:

BETWEEN THE BASE STATION AND THE TERMINAL STATION A SERVICE OF 31 X 64 KBIT/S
WILL BE CREATED. THE CONFIGURATION AT THE WALKAIR BS/BU IS THE FOLLOWING:

BS/BU:

SERVICE # 00
SERVICE BANDWIDTH (NX64KBIT/S):    31
INTERFACE #:                       0
START TIMESLOT #:                  1
CUSTOMER #:                        "CUSTOMER ID OF THE MOBILE TERMINAL STATION"
INTERFACE #:                       0
START TIMESLOT:                    1

E1- INTERFACES/ PHYSICAL CONFIGURATION:

LINE CODING (TRANSMIT & RECEIVE)   HDB3
FRAMING FORMAT:                    MFF_CRC4
ALARM MODE:                        ETSI

E1- INTERFACES/ OTHER PARAMETERS:

E1 MODE (TRANSPARENT/ UNFRAMED):   TRANSPARENT (TIME SLOT 16 USED FOR TRAFFIC)
TRANSMIT JITTER ATTENUATOR:        ENABLE

CONFIGURATION OF E1- TESTER

MODE:              RX / TX
INTERFACE:         G.703             RX SLOTS:        1-31
LINE CODE:         HDB3              TX SLOTS:        AS RX
FRAMING:           PCM31C
TERMINATION:       75 / 120 (OMEGA)
TX CLOCK SOURCE:   INTERNAL
BERT PATTERN:      2 TO THE POWER OF 15-1

6.4 WALKNET CONNECTIVITY TEST      NECESSARY EQUIPMENT:  WALKNET, OMC CONNECTION

If a WALKnet connection is already established verify that the BS/BU can be seen
on the OMC. The corresponding BS/BU must be added on the OMC. Create an
interface alarm (remove the E1 input signal) on the BS/BU and check if the alarm
appears on the OMC.

Repeat the procedure for all other BS/BU's in one Sector. Note down the result.

Repeat for all other Sectors.

<PAGE>

[OBJECT OMITTED]

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications

7. TERMINAL STATION DATA                 NECESSARY EQUIPMENT:      LCI

This section is meant to note down the data of already available Terminal
Stations.

Please note down the address where the TS is located, the Terminal Station
Customer ID which was given to this customer, the BS/BU number which provides
the service as well as the service bandwidth which was set. Repeat for each
available TS and make a copy for each Base Station Sector.

8. FINAL RESULT

After performing all steps from the Field Acceptance Protocol, both parties have
to state the final result.

If the Base Station is working error free and the installation is done according
to specifications, choose: BASE STATION IS ACCEPTED WITHOUT ANY RESTRICTION

-----

If the Base Station is working error free but there are minor restrictions (e.g.
scratches on surfaces; fastening of cables), choose:
BASE STATION IS ACCEPTED WITH MINOR RESTRICTION

Please define a date for the improvement and note down what has to be improved.

-----
If all Base Station Sectors (IF-Mux's, RFU's, Antennas) are working error free,
but single units failed, choose:

BASE STATION IS ACCEPTED WITH MAJOR RESTRICTION (PARTIAL ACCEPTANCE)
Please define a date for repair and note down which unit has to be changed.

-----
If one or more Base Station Sectors failed during the Acceptance, choose:
BASE STATION IS NOT ACCEPTED

Please define a date for repair and note down which units have to be changed.
Define also a new date for Acceptance together with the customer.

AFTER THE FIELD ACCEPTANCE IS FINISHED, PLEASE MAKE SURE THAT THE CUSTOMER ID'S
OF THE MOBILE TERMINAL STATION AS WELL AS THE CREATED SERVICES AND SOFTWARE
LOOPS (WHICH WERE NECESSARY FOR THE FUNCTIONALITY TESTS) ARE DELETED AGAIN.

<PAGE>

<TABLE>
<S>                                              <C>
------------------------------------------------------------------------------------------------------------

                      FIELD ACCEPTANCE PROTOCOL FOR WALKAIR

                            FIRSTMARK COMMUNICATIONS

------------------------------------------------------------------------------------------------------------
    Country       :

------------------------------------------------------------------------------------------------------------

    Customer      :

------------------------------------------------------------------------------------------------------------

    Site     :

------------------------------------------------------------------------------------------------------------

    Date     :                                                Line up Engineer :

------------------------------------------------------------------------------------------------------------

    For the Customer                                          For Siemens AG

    Print Name: __________________________                    Print Name: __________________________

    Signature:  __________________________                    Signature:  __________________________

------------------------------------------------------------------------------------------------------------
    Test Instruments:
    -  Bit Error Tester 2Mbit/s *                PC for PROCOMM PLUS
    -  Voltmeter                                 CPU 486 or higher,16MB RAM;
    -  Frequency Counter                         200MB HD or higher; VGA Display,
    -  Constellation Analyzer 64 QAM *           Serial Port RS232,
    -  Personal Computer                         Floppy Disk and/or CD ROM drive
    -  PROCOMM PLUS SW                           Windows-C-95 or Windows NT
    * optional to each other                     Adapter RJ45 to D-type 9 pin
                                                 RS232 Connection Cable (pin to pin)
------------------------------------------------------------------------------------------------------------
    Frequency Band:                                           Remarks:

     / /   3,5 GHz     Subband ______

     / /   26 GHz      Subband ______

     /X/ Select

------------------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<S>                                        <C>                       <C>
----------------------------------------------------------------------------------
                SIEMENS AG                 Author:                   Released:
  Information and Communication Networks   Manetinsky Stoklasek      Hafner
                                           ICN TR S R4               ICN TR S R4
                                           Last updated: 14.03.2000  14.03.2000
----------------------------------------------------------------------------------
</TABLE>

<PAGE>

                              FIELD ACCEPTANCE PROTOCOL
--------------------------------------------------------------------------------

1. INSTALLATION ASPECTS

1.1 INSTALLATION CHECK

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------
              ITEM                     INSTALLATION O.K. ?                        REMARKS
-------------------------------------------------------------------------------------------------------------
<S>                                    <C>                              <C>
Connectors at RFU's                     / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
Connectors at IF- Mux's                 / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
Earthing of BS/BU's                     / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
Earthing of IF- Mux's                   / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
Earthing of RFU's                       / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
Earthing of Cables                      / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
EMP Protectors                          / /  Yes    / /  No             if installed in this project
-------------------------------------------------------------------------------------------------------------
Coax Cable Mounting                     / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
E1- Cable Labeling                      / /  Yes    / /  No
-------------------------------------------------------------------------------------------------------------
</TABLE>

/X/ Select

1.2 POWER SUPPLY CHECK (FOR THE WHOLE BASE STATION)

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------
              ITEM                       VOLTAGE O.K. ?                           REMARKS
-------------------------------------------------------------------------------------------------------------
<S>                                     <C>                     <C>
DC Power Supply at BS                   / /  Yes    / /  No     DC Voltage in a range between 45 and 75 VDC
-------------------------------------------------------------------------------------------------------------
</TABLE>

1.3 BASE STATION SYSTEM CLOCK (FOR THE WHOLE BASE STATION)

Should be identical for all BS/BU's

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------
    INTERNAL        PORT # 1       PORT # 2        PORT # 3      AUTOMATIC       EXTERNAL
----------------------------------------------------------------------------------------------
<S>                 <C>            <C>             <C>           <C>             <C>
      / /             / /             / /            / /            / /             / /
----------------------------------------------------------------------------------------------
</TABLE>

/X/ Select

IF EXTERNAL CLOCK SYNCHRONISATION IS USED, PLEASE VERIFY CLOCK WITH FREQUENCY
COUNTER

MEASURED CLOCK:            2.04 _ _ _ _ MHZ

<TABLE>
<S>                   <C>                  <C>                                   <C>
------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                       Sig. / Date Siemens AG
  Information and Communication Networks                      WALKAIR
-------------------------------------------                                      ---------------------------
Author:               Released:                                                  Sig. / Date Customer
Stoklasek             Hafner               SITE:   _________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                              FIELD ACCEPTANCE PROTOCOL
--------------------------------------------------------------------------------

2. HARDWARE DATA

2.1 BASE STATION SERIAL NUMBERS

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------
SECTOR NUMBER           SER.NR. OF IF-MUX       SER.NR. OF RFU          ANTENNA TYPE/ POL.
--------------------------------------------------------------------------------------------------
<S>                     <C>                     <C>                     <C>
           1
--------------------------------------------------------------------------------------------------
           2
--------------------------------------------------------------------------------------------------
           3
--------------------------------------------------------------------------------------------------
           4
--------------------------------------------------------------------------------------------------
           5
--------------------------------------------------------------------------------------------------
           6
--------------------------------------------------------------------------------------------------
           7
--------------------------------------------------------------------------------------------------
           8
--------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>
             ----------------------------------------------------------------------------------------------
                                        SERIAL NUMBERS OF BS/BU'S IN EACH SECTOR
-----------------------------------------------------------------------------------------------------------
   BS/BU      Sector 1    Sector 2    Sector 3   Sector 4    Sector 5    Sector 6    Sector 7   Sector 8
-----------------------------------------------------------------------------------------------------------
<S>           <C>         <C>         <C>        <C>         <C>         <C>         <C>        <C>
     1
-----------------------------------------------------------------------------------------------------------
     2
-----------------------------------------------------------------------------------------------------------
     3
-----------------------------------------------------------------------------------------------------------
     4
-----------------------------------------------------------------------------------------------------------
     5
-----------------------------------------------------------------------------------------------------------
     6
-----------------------------------------------------------------------------------------------------------
     7
-----------------------------------------------------------------------------------------------------------
     8
-----------------------------------------------------------------------------------------------------------
     9
-----------------------------------------------------------------------------------------------------------
     10
-----------------------------------------------------------------------------------------------------------
     11
-----------------------------------------------------------------------------------------------------------
     12
-----------------------------------------------------------------------------------------------------------
     13
-----------------------------------------------------------------------------------------------------------
     14
-----------------------------------------------------------------------------------------------------------
     15
-----------------------------------------------------------------------------------------------------------
     16
-----------------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<S>                   <C>                  <C>                                   <C>
------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                       Sig. / Date Siemens AG
  Information and Communication Networks                      WALKAIR
-------------------------------------------                                      ---------------------------
Author:               Released:                                                  Sig. / Date Customer
Stoklasek             Hafner               SITE:   _________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                              FIELD ACCEPTANCE PROTOCOL
--------------------------------------------------------------------------------

3. RADIO LINK DATA

3.1 BASE STATION CARRIER FREQUENCIES

<TABLE>
<CAPTION>
             ----------------------------------------------------------------------------------------------
                         FREQUENCY INDEX FOR EACH BS/BU IN CORRESPONDING SECTOR
-----------------------------------------------------------------------------------------------------------
   BS/BU      Sector 1    Sector 2    Sector 3   Sector 4    Sector 5    Sector 6    Sector 7   Sector 8
-----------------------------------------------------------------------------------------------------------
<S>           <C>         <C>         <C>        <C>         <C>         <C>         <C>        <C>
     1
-----------------------------------------------------------------------------------------------------------
     2
-----------------------------------------------------------------------------------------------------------
     3
-----------------------------------------------------------------------------------------------------------
     4
-----------------------------------------------------------------------------------------------------------
     5
-----------------------------------------------------------------------------------------------------------
     6
-----------------------------------------------------------------------------------------------------------
     7
-----------------------------------------------------------------------------------------------------------
     8
-----------------------------------------------------------------------------------------------------------
     9
-----------------------------------------------------------------------------------------------------------
     10
-----------------------------------------------------------------------------------------------------------
     11
-----------------------------------------------------------------------------------------------------------
     12
-----------------------------------------------------------------------------------------------------------
     13
-----------------------------------------------------------------------------------------------------------
     14
-----------------------------------------------------------------------------------------------------------
     15
-----------------------------------------------------------------------------------------------------------
     16
-----------------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<S>                   <C>                  <C>                                   <C>
------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                       Sig. / Date Siemens AG
  Information and Communication Networks                      WALKAIR
-------------------------------------------                                      ---------------------------
Author:               Released:                                                  Sig. / Date Customer
Stoklasek             Hafner               SITE:   _________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                              FIELD ACCEPTANCE PROTOCOL
--------------------------------------------------------------------------------

3.2 BASE STATION POWER LEVELS

<TABLE>
<CAPTION>
             ----------------------------------------------------------------------------------------------
                                MODEM WORKING POINT (TRANSMIT / RECEIVE) IN DBM
-----------------------------------------------------------------------------------------------------------
   BS/BU      Sector 1    Sector 2    Sector 3   Sector 4    Sector 5    Sector 6    Sector 7   Sector 8
-----------------------------------------------------------------------------------------------------------
<S>           <C>         <C>         <C>        <C>         <C>         <C>         <C>        <C>
     1
-----------------------------------------------------------------------------------------------------------
     2
-----------------------------------------------------------------------------------------------------------
     3
-----------------------------------------------------------------------------------------------------------
     4
-----------------------------------------------------------------------------------------------------------
     5
-----------------------------------------------------------------------------------------------------------
     6
-----------------------------------------------------------------------------------------------------------
     7
-----------------------------------------------------------------------------------------------------------
     8
-----------------------------------------------------------------------------------------------------------
     9
-----------------------------------------------------------------------------------------------------------
     10
-----------------------------------------------------------------------------------------------------------
     11
-----------------------------------------------------------------------------------------------------------
     12
-----------------------------------------------------------------------------------------------------------
     13
-----------------------------------------------------------------------------------------------------------
     14
-----------------------------------------------------------------------------------------------------------
     15
-----------------------------------------------------------------------------------------------------------
     16
-----------------------------------------------------------------------------------------------------------
</TABLE>

4. BASE STATION SOFTWARE DATA

<TABLE>
<CAPTION>
--------------------------------------------------------------------------
ACTIVE SW VERSION                    BACKUP SW VERSION
--------------------------------------------------------------------------
<S>                                  <C>
--------------------------------------------------------------------------
</TABLE>

<TABLE>
<S>                   <C>                  <C>                                   <C>
------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                       Sig. / Date Siemens AG
  Information and Communication Networks                      WALKAIR
-------------------------------------------                                      ---------------------------
Author:               Released:                                                  Sig. / Date Customer
Stoklasek             Hafner               SITE:   _________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
------------------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<S>                   <C>                  <C>                                   <C>
------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                       Sig. / Date Siemens AG
  Information and Communication Networks                      WALKAIR
-------------------------------------------                                      ---------------------------
Author:               Released:                                                  Sig. / Date Customer
Stoklasek             Hafner               SITE:   _________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
------------------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>

                                           FIELD ACCEPTANCE PROTOCOL

5. BASE STATION NETWORK PARAMETERS

5.1 BASE STATION IP- ADDRESS                          NETWORK MASK:    _________
                                                      DEFAULT GATEWAY: _________

<TABLE>
<CAPTION>
                -----------------------------------------------------------------------------------------------------
                        BS/BU IP- ADDRESS IN EACH SECTOR
---------------------------------------------------------------------------------------------------------------------
     BS/BU              SECTOR 1                 SECTOR 2                 SECTOR 3                  SECTOR 4
---------------------------------------------------------------------------------------------------------------------
     <S>                <C>                      <C>                      <C>                       <C>
       1                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       2                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       3                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       4                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       5                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       6                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       7                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       8                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       9                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      10                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      11                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      12                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      13                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      14                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      15                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      16                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>
                -----------------------------------------------------------------------------------------------------
                        BS/BU IP- ADDRESS IN EACH SECTOR
---------------------------------------------------------------------------------------------------------------------
     BS/BU              SECTOR 5                 SECTOR 6                 SECTOR 7                  SECTOR 8
---------------------------------------------------------------------------------------------------------------------
     <S>                <C>                      <C>                      <C>                       <C>
       1                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       2                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       3                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       4                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       5                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       6                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       7                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       8                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
       9                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      10                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      11                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      12                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      13                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      14                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      15                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
      16                 . . .                    . . .                     . . .                    . . .
---------------------------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                              Sig. / Date Siemens AG
  Information and Communication Networks                    WALKAIR
-------------------------------------------                                             ---------------------------
<S>                   <C>                  <C>                                          <C>
Author:               Released:                                                         Sig. / Date Customer
Stoklasek             Hafner               SITE:   _______________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
-------------------------------------------------------------------------------------------------------------------
Document:  Appendix 4e -  Install Comm Acc Stand 000410 FTP_WALKair_FMC2.doc  Edition 1            Page 6/12
                                           All rights reserved
</TABLE>

<PAGE>

                                           FIELD ACCEPTANCE PROTOCOL

5.2. AUTHORIZED MANAGER STATIONS (FOR THE WHOLE BASE STATION)

Should be equal for all BS/BU's

<TABLE>
<S>                                                 <C>                <C>
-----------------------------------------------------------------------------------------
Manager Station IP- Address # 1                       . . .
-----------------------------------------------------------------------------------------
Manager Station IP- Address # 2                       . . .              if available
-----------------------------------------------------------------------------------------
Manager Station IP- Address # 3                       . . .              if available
-----------------------------------------------------------------------------------------
Manager Station IP- Address # 4                       . . .              if available
-----------------------------------------------------------------------------------------
Manager Station IP- Address # 5                       . . .              if available
-----------------------------------------------------------------------------------------
</TABLE>

6. FUNCTIONALITY TESTING

6.1 ALARM INDICATION CHECK

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------
                ALARM TYPE                       ALARM VISIBLE ?                        REMARKS
------------------------------------------------------------------------------------------------------------------
<S>                                              <C>                                    <C>
Internal Alarms at BS/BU's                       |_|  No    |_|  Yes
------------------------------------------------------------------------------------------------------------------
External Alarms at BS/BU's                       |_|  No    |_|  Yes
------------------------------------------------------------------------------------------------------------------
Ethernet Alarms at BS/BU's                       |_|  No    |_|  Yes
------------------------------------------------------------------------------------------------------------------
Telecom Interface Alarms                         |_|  No    |_|  Yes
------------------------------------------------------------------------------------------------------------------
IF - Mux Alarms                                  |_|  No    |_|  Yes
------------------------------------------------------------------------------------------------------------------
 ...                                              |_|  No    |_|  Yes
------------------------------------------------------------------------------------------------------------------
 ...                                              |_|  No    |_|  Yes
------------------------------------------------------------------------------------------------------------------
</TABLE>

|X| Select

6.2. BS- INTERFACE- CABELING TEST            Check the interface cabeling to the
                                             distribution frame for every BS/BU

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------
        TESTED BS SECTOR          CABELING FOR EVERY BS/BU                       REMARKS
                                         O.K. ?
------------------------------------------------------------------------------------------------------------------
<S>                               <C>                                            <C>
Base Station Sector # 1                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 2                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 3                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 4                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 5                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 6                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 7                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 8                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
</TABLE>

|X| Select

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                              Sig. / Date Siemens AG
  Information and Communication Networks                    WALKAIR
-------------------------------------------                                             ---------------------------
<S>                   <C>                  <C>                                          <C>
Author:               Released:                                                         Sig. / Date Customer
Stoklasek             Hafner               SITE:   _______________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
-------------------------------------------------------------------------------------------------------------------
Document:  Appendix 4e -  Install Comm Acc Stand 000410 FTP_WALKair_FMC2.doc  Edition 1            Page 7/12
                                           All rights reserved
</TABLE>

<PAGE>

                                           FIELD ACCEPTANCE PROTOCOL

6.3 SINGLE BS/BU FUNCTIONALITY TEST         Measurement should be done for every
                                            BS/BU in each Base Station Sector

SECTOR NR. 1

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
    <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

SECTOR NR. 2

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
      <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

SECTOR NR. 3

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
      <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                              Sig. / Date Siemens AG
  Information and Communication Networks                    WALKAIR
-------------------------------------------                                             ---------------------------
<S>                   <C>                  <C>                                          <C>
Author:               Released:                                                         Sig. / Date Customer
Stoklasek             Hafner               SITE:   _______________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
-------------------------------------------------------------------------------------------------------------------
Document:  Appendix 4e -  Install Comm Acc Stand 000410 FTP_WALKair_FMC2.doc  Edition 1            Page 8/12
                                           All rights reserved
</TABLE>

<PAGE>

                                           FIELD ACCEPTANCE PROTOCOL

SECTOR NR. 4

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
      <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

SECTOR NR. 5

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
      <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

SECTOR NR. 6

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
      <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                              Sig. / Date Siemens AG
  Information and Communication Networks                    WALKAIR
-------------------------------------------                                             ---------------------------
<S>                   <C>                  <C>                                          <C>
Author:               Released:                                                         Sig. / Date Customer
Stoklasek             Hafner               SITE:   _______________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
-------------------------------------------------------------------------------------------------------------------
Document:  Appendix 4e -  Install Comm Acc Stand 000410 FTP_WALKair_FMC2.doc  Edition 1            Page 9/12
                                           All rights reserved
</TABLE>

<PAGE>

                                           FIELD ACCEPTANCE PROTOCOL

SECTOR NR. 7

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
      <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

SECTOR NR. 8

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------
    MEASURED BS/BU      BER OR 64QAM O.K.?       MEASURED BS/BU      BER OR 64QAM O.K.?
------------------------------------------------------------------------------------------
      <S>                 <C>                      <C>                 <C>
      BS/BU # 1           |_| Yes |_| No           BS/BU # 9           |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 2           |_| Yes |_| No           BS/BU # 10          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 3           |_| Yes |_| No           BS/BU # 11          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 4           |_| Yes |_| No           BS/BU # 12          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 5           |_| Yes |_| No           BS/BU # 13          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 6           |_| Yes |_| No           BS/BU # 14          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 7           |_| Yes |_| No           BS/BU # 15          |_| Yes |_| No
------------------------------------------------------------------------------------------
      BS/BU # 8           |_| Yes |_| No           BS/BU # 16          |_| Yes |_| No
------------------------------------------------------------------------------------------
</TABLE>

6.4. WALKNET CONNECTIVITY TEST                 Check the connectivity to the OMC
                                               for every BS/BU

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------
        TESTED BS SECTOR            OMC SUPERVISION FOR EVERY                        REMARKS
                                           BS/BU O.K. ?
------------------------------------------------------------------------------------------------------------------
<S>                                 <C>                                              <C>
Base Station Sector # 1                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 2                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 3                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 4                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 5                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 6                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 7                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
Base Station Sector # 8                   |_| Yes |_| No
------------------------------------------------------------------------------------------------------------------
</TABLE>

|X| Select

<TABLE>
<CAPTION>
-------------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                              Sig. / Date Siemens AG
  Information and Communication Networks                    WALKAIR
-------------------------------------------                                             ---------------------------
<S>                   <C>                  <C>                                          <C>
Author:               Released:                                                         Sig. / Date Customer
Stoklasek             Hafner               SITE:   _______________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
-------------------------------------------------------------------------------------------------------------------
Document:  Appendix 4e -  Install Comm Acc Stand 000410 FTP_WALKair_FMC2.doc  Edition 1            Page 10/12
                                           All rights reserved
</TABLE>

<PAGE>

                                           FIELD ACCEPTANCE PROTOCOL

7. TERMINAL STATION DATA IN SECTOR NR.       (copy for each Base Station Sector)

<TABLE>
<CAPTION>
        -------------------------------------------------------------------------------------------------
                    TS ADDRESS                      TS CUSTOMER ID         BS/BU NR.      N X 64 KBIT/S
---------------------------------------------------------------------------------------------------------
   <S>                                              <C>                    <C>            <C>
   1
---------------------------------------------------------------------------------------------------------
   2
---------------------------------------------------------------------------------------------------------
   3
---------------------------------------------------------------------------------------------------------
   4
---------------------------------------------------------------------------------------------------------
   5
---------------------------------------------------------------------------------------------------------
   6
---------------------------------------------------------------------------------------------------------
   7
---------------------------------------------------------------------------------------------------------
   8
---------------------------------------------------------------------------------------------------------
   9
---------------------------------------------------------------------------------------------------------
  10
---------------------------------------------------------------------------------------------------------
  11
---------------------------------------------------------------------------------------------------------
  12
---------------------------------------------------------------------------------------------------------
  13
---------------------------------------------------------------------------------------------------------
  14
---------------------------------------------------------------------------------------------------------
  15
---------------------------------------------------------------------------------------------------------
  16
---------------------------------------------------------------------------------------------------------
  17
---------------------------------------------------------------------------------------------------------
  18
---------------------------------------------------------------------------------------------------------
  19
---------------------------------------------------------------------------------------------------------
  20
---------------------------------------------------------------------------------------------------------
  21
---------------------------------------------------------------------------------------------------------
  22
---------------------------------------------------------------------------------------------------------
  23
---------------------------------------------------------------------------------------------------------
  24
---------------------------------------------------------------------------------------------------------
  25
---------------------------------------------------------------------------------------------------------
  26
---------------------------------------------------------------------------------------------------------
  27
---------------------------------------------------------------------------------------------------------
  28
---------------------------------------------------------------------------------------------------------
  29
---------------------------------------------------------------------------------------------------------
  30
---------------------------------------------------------------------------------------------------------
  31
---------------------------------------------------------------------------------------------------------
  32
---------------------------------------------------------------------------------------------------------
  33
---------------------------------------------------------------------------------------------------------
  34
---------------------------------------------------------------------------------------------------------
  35
---------------------------------------------------------------------------------------------------------
  36
---------------------------------------------------------------------------------------------------------
  37
---------------------------------------------------------------------------------------------------------
  38
---------------------------------------------------------------------------------------------------------
  39
---------------------------------------------------------------------------------------------------------
  40
---------------------------------------------------------------------------------------------------------
</TABLE>

<TABLE>
<CAPTION>
                SIEMENS AG                                                              Sig. / Date Siemens AG
  Information and Communication Networks                    WALKAIR
-------------------------------------------                                             ---------------------------
<S>                   <C>                  <C>                                          <C>
Author:               Released:                                                         Sig. / Date Customer
Stoklasek             Hafner               SITE:   _______________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
-------------------------------------------------------------------------------------------------------------------
Document:  Appendix 4e -  Install Comm Acc Stand 000410 FTP_WALKair_FMC2.doc  Edition 1            Page 11/12
                                           All rights reserved
</TABLE>

<PAGE>

                                           FIELD ACCEPTANCE PROTOCOL

8. FINAL RESULT                             SITE:

                 |_|      BASE STATION IS ACCEPTED WITHOUT ANY RESTRICTION

                 |_|      BASE STATION IS ACCEPTED WITH MINOR RESTRICTION
                          ( PLEASE DEFINE DATE FOR IMPROVEMENT )

                          REMARKS:

                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------

                 |_|      BASE STATION IS ACCEPTED WITH MAJOR RESTRICTION
                          (PARTIAL ACCEPTANCE; PLEASE DEFINE DATE FOR REPAIR )

                          REMARKS:

                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------

                 |_|      BASE STATION IS NOT ACCEPTED

                          REMARKS:

                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------
                          ----------------------------------------------------

|X| Select

                  --------------------------         ---------------------------
                  Signature for Customer             Signature for SIEMENS AG

<TABLE>
-------------------------------------------------------------------------------------------------------------------
                SIEMENS AG                                                              Sig. / Date Siemens AG
  Information and Communication Networks                    WALKAIR
-------------------------------------------                                             ---------------------------
<S>                   <C>                  <C>                                          <C>    <C>    <C>    <C>
Author:               Released:                                                         Sig. / Date Customer
Stoklasek             Hafner               SITE:   _______________________________
ICN TR S R4           ICN TR S R4
14.03.2000            14.03.2000           PAGE: _____ / ____
-------------------------------------------------------------------------------------------------------------------
Document:  Appendix 4e -  Install Comm Acc Stand 000410 FTP_WALKair_FMC2.doc  Edition 1            Page 12/12
                                           All rights reserved
</TABLE>

<PAGE>

        INSTRUCTION FOR WALKAIR FIELD ACCEPTANCE AT TERMINAL STATION SIDE

                            FIRSTMARK COMMUNICATIONS

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications
--------------------------------------------------------------------------------

7. TERMINAL STATION     NECESSARY EQUIPMENT: LCI, BER TESTER, WALKNET, VOLTMETER

This section covers the most relevant parts of Walkair Terminal Stations.

In the case that the Terminal Stations are integrated at the same time as the
Base Sation this pages used for each Terminal Station are finally added to the
WALKair Field Acceptance protocol and replace chapter 7 there.

If Terminal Integration is done later this protocol can be used Stand Alone
including the cover page.

ITEM 7.5 "NETWORK INTEGRATION" IS NOT PART OF THE TERMINAL ACCEPTANCE TESTS.
NETWORK INTEGRATION WILL BE DONE ON CUSTOMER EXPENSE IF INTEGRATION DATA
(SERVICE PARAMETER OR OMC CONNECTION) IS NOT AVAILABLE DURING TERMINAL
ACCEPTANCE.

7.1 HARDWARE DATA

Please note down the address where the TS is located, the Terminal Station
Customer ID which was given to this customer, the Sector and BS/BU number which
provides the service. Additional the serial numbers of all components (indoor-
and outdoor units) should be noted. There is a sticker on each component which
contains serial number and information about equipment type. Finally note down
the loaded Software version in Active and Backup. The serial number information
of TS/BU's can also be seen at the management system WALKnet or at the Local
Craft Interface.

7.2 INSTALLATION ASPECTS / CHECK

The correctness should be verified during Field Acceptance. The installation of
WALKair units must be performed according to the instructions in the
Installation Manual IMN.

- CONNECTOR AT RFU'S:              Check if N type connectors at RFU side are
                                   mounted according to suppliers
                                   specification.
                                   Check if connectors are sealed.

- EARTHING OF TS/BU'S:             Check if ground connection of TS/BU's are
                                   made properly

- EARTHING OF RFU'S:               Check if ground connections of RFU`s are made
                                   properly

- EARTHING OF CABLES:              Check if all IF cables are grounded properly

- EMP PROTECTORS:                  Check if EMP protectors are installed
                                   according to suppliers specification
                                   (if used in this project)

- COAX CABLE MOUNTING:             Check if all IF cables are mounted and
                                   fastened properly

- E1- CABLE LABELING:              Check if all E1- Interface- Cables are
                                   labeled at equipment side and
                                   distribution frame side

- POWER SUPPLY VOLTAGE:            Check if the AC or DC voltage is in tolerance

7.3 RADIO LINK DATA

During the commissioning phase, all different BS/BU's are set to a specific
carrier frequency. This carrier frequency must be according to the project
frequency planning. The modem of each TS/BU must be set to a specific power
level for transmitting and receiving. The recommended default values are
displayed when setting the modem working point. Note down the actual settings
for this project as well as the receive level after antenna alignment.

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications
--------------------------------------------------------------------------------

From the Main LCI TS Menu, choose ,,Configuration Menu"
From the Configuration Menu, choose ,,Radio Link Parameters"
From the Radio Link Parameters, choose ,,Get RFU Head Information"
From the Radio Link Parameters, choose ,,Get Modem Working Point"
From the Radio Link Parameters, choose ,,Get Cable Length"
From the Radio Link Parameters, choose ,,Get Cable Type"

From the Main LCI TS Menu, choose ,,Maintenance"
From the Maintenance Menu, choose ,,Air Performance"
From the Air Performance Menu, choose ,,Report Local Measurements"
After enabling note down TX and RX levels displayed and disable monitoring
afterwards.

7.4 FUNCTIONALITY TESTING

During Field Acceptance, some functionality tests are performed. It has to be
checked, that the system is free of alarms on all units.

It is not necessary that somebody stays at the Base Station for configuration
while the measurements at the Terminal Station can be done.

ALARM INDICATION CHECK

Check that there is no fault in the system and no alarm visible.
LED indicators of:        - Internal Alarm at TS/BU`s
                          - External Alarm at TS/BU's
                          - Telecom Interface Alarms at TS/BU's

are set to status ,,GREEN".

BER TEST                   NECESSARY EQUIPMENT:      LCI, 2MBIT BER TESTER

This measurement is carried out for every TS/BU. The target is to show the TS-BS
functionality with an external BER tester (A) or with the feature "Air
Performance Monitoring" (B). Which method will be used has to be decided case by
case for each Terminal station.

A) MEASUREMENT WITH BER TESTER

Measurements with external BER test equippment can only be done if the terminal
station does not carry traffic or has one free E1 interface. Additionaly on the
BS/BU side a software loop on one E1 interface must be possible. This insists
one free E1 interface or TRAFFIC INTERRUPTION for the whole testperiode if a
free E1 port is not available at the BU/BS side.

Connect the BER tester on the TS side and verify the measurement for 30 minutes.
A service (e.g 31x64kBit; channel 1-31) must be created on the base station
including a 2Mbit Software loop (local loopback) on the BS/BU.

Note down the result.

B) MEASUREMENT WITH AIR PERFORMANCE MONITORING

If traffic interruption is not possible or one free E1 interface for a software
loop on BS/BU is not available it is recommended to use the inbuilt "Air
Performance Monitoring". With this feature the Up and Downlink performance can
be verified without any interruption. Enable the performance monitoring with the
LCI (RX,CRC,FER,SNR values) or WALKnet (G826 values) and note down the result
after 30 minutes.

<PAGE>

Instruction for WALKair Field Acceptance                FirstMark Communications
--------------------------------------------------------------------------------

7.5 NETWORK INTEGRATION

WALKNET CONNECTIVITY TEST          NECESSARY EQUIPMENT:  WALKNET, OMC CONNECTION

If a WALKnet connection is already established verify that the TS/BU can be seen
on the OMC. The corresponding TS/BU must be added on the OMC.

In case that a OMC connection is not available during the test the item will be
skipped from the acceptance test and does not restrict the acceptance. Note down
the result.

CUSTOMER SPECIFIC SERVICE SETTING ON BS/BU

This chapter shows the customer specific service and interface setting. E1, V35
or V5 settings are possible. Because of different types and the huge number of
settings a printout of the Telecom Port and Telecom Service Configuration should
be added to the protocol.

In case that service setting information is not available during Terminal
acceptance the item will be skipped from the acceptance tests completely.

7.6  FINAL RESULT

After performing all steps from the Field Acceptance Protocol, both parties have
to state the final result.

If Terminal Stations are working error free and the installation is done
according to specifications, choose:
TERMINAL STATION IS ACCEPTED WITHOUT ANY RESTRICTION

If Terminal Stations are working error free but there are minor restrictions
(e.g. scratches on surfaces; fastening of cables), choose:
TERMINAL STATION IS ACCEPTED WITH MINOR RESTRICTION
Please define a date for the improvement and note down what has to be improved.

If Terminal Stations (RFU's, Antennas) are working error free, but single units
failed, choose:
TERMINAL STATION IS ACCEPTED WITH MAJOR RESTRICTION (PARTIAL ACCEPTANCE)
Please define a date for repair and note down which unit has to be changed.

If Terminal Stations failed during the Acceptance, choose:
TERMINAL STATION IS NOT ACCEPTED
Please define a date for repair and note down which units have to be changed.
Define also a new date for Acceptance together with the customer.

AFTER THE TERMINAL STATION ACCEPTANCE IS FINISHED, PLEASE MAKE SURE THAT THE
CREATED SERVICES AND SOFTWARE LOOPS (WHICH WERE NECESSARY FOR THE FUNCTIONALITY
TESTS) ARE DELETED AGAIN.

<PAGE>
-------------------------------------------------------------------------------

                    Field Acceptance Protocol for WALKair

                            Terminal Station (CPE)

                           FirstMark Communications

-------------------------------------------------------------------------------

Country:

-------------------------------------------------------------------------------

Customer:

-------------------------------------------------------------------------------

Site:

-------------------------------------------------------------------------------

Date:                                   Line up Engineer:

-------------------------------------------------------------------------------

For the Customer                        For Siemens AG

Print Name: _____________________       Print Name: ___________________________

Signature: ______________________       Signature: ____________________________

-------------------------------------------------------------------------------

Test Instruments:

- Bit Error Tester 2Mbits/s            PC for PROCOMM PLUS
- Voltmeter                            CPU 486 or higher, 16mb RAM;
- Personal Computer                    200 MB HD or higher, VGA Display,
- PROCOMM PLUS SW                     Serial Port RS232,
- Antenna Alignment Unit*              Floppy Disk and CD ROM drive
                                       Windows-C- 95 or Windows NT
                                       Adapter RJ45 to D-type 9 pin
                                       RS232 Connection Cable (pin to pin)
* optional

-------------------------------------------------------------------------------

Frequency Band:                        Remarks:

/ / 3,5 GHz Subband _______

/ / 26 GHz Subband _______

-------------------------------------------------------------------------------

-------------------------------------------------------------------------------

SIEMENS AG                               Author:                   Released:
Information and Communication Networks   Stoklasek                 Tichopad
                                         ICN TR S R4               ICN TR S R4
                                         Last Update: 06.04.2000   08.05.2000

-------------------------------------------------------------------------------

<PAGE>

                         FIELD ACCEPTANCE PROTOCOL
-------------------------------------------------------------------------------

7. TERMINAL STATION                    (copy chapter for each Terminal Station)

7.1 HARDWARE DATA

<TABLE>
<CAPTION>
                        TS          TS/BU       TS/RFU      Software   Connected
TS Location          Customer       Part -      Part -      version    to Sector -
                        ID           and         and        Active -   BS-BU No.
                                  Serial No.   Serial No.    Backup
----------------------------------------------------------------------------------
<S>                  <C>          <C>          <C>          <C>        <C>

                                  ------------------------------------------------

                                  ------------------------------------------------

----------------------------------------------------------------------------------
</TABLE>

7.2 INSTALLATION ASPECTS/CHECK

<TABLE>
<CAPTION>

       Item                     Installation o.k.?                            Remarks
-----------------------------------------------------------------------------------------------
<S>                             <C>                                <C>

Connector at RFU                / / Yes   / / No
-----------------------------------------------------------------------------------------------
Earthing of TS/BU               / / Yes   / / No
-----------------------------------------------------------------------------------------------
Earthing of RFU                 / / Yes   / / No
-----------------------------------------------------------------------------------------------
Earthing of Cables              / / Yes   / / No
-----------------------------------------------------------------------------------------------
EMP Protectors                  / / Yes   / / No                  If installed in this project
-----------------------------------------------------------------------------------------------
Coax Cable Mounting             / / Yes   / / No                  Cable type _________________
-----------------------------------------------------------------------------------------------
E-1 Cable Labeling              / / Yes   / / No
-----------------------------------------------------------------------------------------------
/x/ Select

</TABLE>

<TABLE>
<CAPTION>

-----------------------------------------------------------------------------------------------
     Item                       Voltage o.k.?                                Remarks
-----------------------------------------------------------------------------------------------
<S>                             <C>                              <C>

Power Supply Voltage           / / Yes   / / No                 Tolerance: DC version 45-75 V;
                                                                 AC version 110/230 V + 10-20%

-----------------------------------------------------------------------------------------------
</TABLE>

7.3 RADIO LINK DATA

<TABLE>
<CAPTION>

-----------------------------------------------------------------------------------------------
RFU Head         Coax Cable     Receive level      TX level      Modem Working Point
  type           Length [m]         [dBm]           [dBm]        (transmit/receive) [dBm]
-----------------------------------------------------------------------------------------------
<S>              <C>            <C>                <C>           <C>

-----------------------------------------------------------------------------------------------
</TABLE>

<TABLE>

<S>                                             <C>                                                  <C>
---------------------------------------------------------------------------------------------------------------------------
            SIEMENS AG                                         WALKair                               Sig./Date SIEMENS AG
Information and Communication Networks
-----------------------------------------                                                            ----------------------
Author:             Released:
Stoklasek           Tichopad                    Site: ____________________________________________   Sig./Date Customer
ICN TR S R4         ICN TR SR4
06.04.2000          08.05.2000                  Page: _____ / _____

---------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                         FIELD ACCEPTANCE PROTOCOL
-------------------------------------------------------------------------------

7.4. FUNCTIONALITY TESTING

ALARM INDICATION CHECK

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------
    Alarm Type                     Alarm visible?                Remarks
-----------------------------------------------------------------------------------------------
<S>                             <C>                                <C>

Internal Alarm at TS/BU         / / No    / / Yes
-----------------------------------------------------------------------------------------------
External Alarms at TS/BU        / / No    / / Yes
-----------------------------------------------------------------------------------------------
Telecom Interface Alarms        / / No    / / Yes
-----------------------------------------------------------------------------------------------
</TABLE>

/x/ Select

SINGLE TERMINAL STATION BIT ERROR TEST

<TABLE>
<CAPTION>

-----------------------------------------------------------------------------------------------
     Test Type                      BER o.k.?                                Remarks
-----------------------------------------------------------------------------------------------
<S>                             <C>                              <C>

With External BER Tester *     / / No    / / Yes
-----------------------------------------------------------------------------------------------
Air Performance Monitoring     / / No    / / Yes
-----------------------------------------------------------------------------------------------
</TABLE>

/x/ Select                   * External BER tests cause traffic interruption

7.5. NETWORK INTEGRATION

WALKNET CONNECTIVITY TEST

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------
<S>                                   <C>                              <C>
Check the availability of the        OMC supervision o.k.?               Remarks
Terminal Station on WALKnet           / / No    / / Yes
-----------------------------------------------------------------------------------------------
</TABLE>

/x/ Select                       *Only if customer specific Service Database
                                  is know during Acceptance Test

/ / Connectivity Test not part of this Acceptance Test

CUSTOMER SERVICE SETTING ON BS/BU*

<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------
<S>                                   <C>                              <C>
Total number of                       Printout of configured               Remarks
configured services                     Services attached?
                                        / / No*   / / Yes
-----------------------------------------------------------------------------------------------
</TABLE>

/x/ Select                       *Only if customer specific Service Database
                                  is know during Acceptance Test

/ / Service setting not part of this Acceptance Test

<TABLE>

<S>                                             <C>                                                  <C>
---------------------------------------------------------------------------------------------------------------------------
            SIEMENS AG                                         WALKair                               Sig./Date SIEMENS AG
Information and Communication Networks
-----------------------------------------                                                            ----------------------
Author:             Released:
Stoklasek           Tichopad                    Site: ____________________________________________   Sig./Date Customer
ICN TR S R4         ICN TR SR4
06.04.2000          08.05.2000                  Page: _____ / _____

---------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

7.6. FINAL RESULT

TERMINAL STATION:_____________________________________________________________

           / /   TERMINAL STATION IS ACCEPTED WITHOUT ANY RESTRICTION

           / /   TERMINAL STATION IS ACCEPTED WITH MINOR RESTRICTION
                 (PLEASE DEFINE DATE FOR IMPROVEMENT)

                 REMARKS:
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________

           / /   TERMINAL STATION IS ACCEPTED WITH MAJOR RESTRICTION
                 (PARTIAL ACCEPTANCE; PLEASE DEFINE DATE FOR REPAIR)

                 REMARKS:

                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________

           / /   TERMINAL STATION IS NOT ACCEPTED

                 REMARKS:

                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________
                 _____________________________________________________________

/x/ Select

                 ____________________________   ______________________________
                 Signature for Customer         Signature for SIEMENS AG

<TABLE>

<S>                                             <C>                                                  <C>
---------------------------------------------------------------------------------------------------------------------------
            SIEMENS AG                                         WALKair                               Sig./Date SIEMENS AG
Information and Communication Networks
-----------------------------------------                                                            ----------------------
Author:             Released:
Stoklasek           Tichopad                    Site: ____________________________________________   Sig./Date Customer
ICN TR S R4         ICN TR SR4
06.04.2000          08.05.2000                  Page: _____ / _____

---------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                               European Agreement
                                  Appendix 4 f
                                Technical Support

                        APPENDIX 4 f - TECHNICAL SUPPORT

DOKUMENT

              ---------------------------------------------------------------
              DOKUMENT NAME           Appendix 4 f - Technical Supports
              ---------------------------------------------------------------
              BACKGROUND              Appendix 4 f - Technical Support to the
                                      European Agreement between FirstMark
                                      Europe SA and Siemens AG - description
                                      of the technical support services
              ---------------------------------------------------------------

1

<PAGE>

                               European Agreement
                                  Appendix 4 f
                                Technical Support

2      INTRODUCTION

       This Appendix 4 f describes the technical Services with respect to the
       technical support Services, which the Contractor provides at no
       additional costs to the Purchaser during the warranty period.

3      EMERGENCY SERVICE

       The emergency service is a time-to-site service in Germany during Working
       Days(8a.m.-5p.m.) with a maximum time to site within 24 hours. The
       response time to the Purchaser call by the Contractor is less than or
       equal to 30 minutes.

       The emergency service also includes the Contractor's emergency call
       service.

       It is the responsibility of the Purchaser to ensure site access to base
       station and terminal station without any restrictions and time delays.
       Delays because of such circumstances will extend the time-to-site.

       Diagnostics and collecting error symptoms will be done either by the
       Purchaser's network operation centre (NOC) and/or by the Contractor's
       engineers on site.

4      FAULT AND FAULT REPORT PROCESSING

       Following fault report service shall be provided:

       3.1    Provision of first commentary with the fault priority within the
              following response times beginning with the notification by the
              Purchaser For classification of the priorities see Section 6 of
              this appendx 4f.

                     - fault priority 1          less than or equal to 2 weeks
                                                 for 90% of errors per year
                     - fault priority 2          less than or equal to 1 month
                                                 for 90% of errors per year
              - fault priority 3        less than or equal to 3 months for 90%
                                        of errors per year

              Provision of the final commentary and delivery of a
              workaround-solution within the following maximum times

                     - fault priority 1          less than or equal to 1 month
                                                 for 90% of errors per year
                     - fault priority 2          less than or equal to 2 months
                                                 for 90% of errors per year
              - fault priority 3        less than or equal to months for 90% of
                                        errors per year

              With delivery of this final commentary the times defined in
              Section15.4.2 of Appendix 1(50 Working Days for Hardware, 30
              Working Days for Software) will start.

       3.2    SW-fault correction

              According with Section15.4.2 of Appendix 1.

<PAGE>

                               European Agreement
                                  Appendix 4 f
                                Technical Support

5      SOFTWARE AND HARDWARE UPDATE

       Delivery and implementation of software and hardware update packages if
       available and mutually agreed between Purchaser and Contractor.

6      SPARES AND FIELD SERVICE

       According to Appendix 1 Section 16.

6      CLASSIFICATION OF FAULT PRIORITIES

       FAULT REPORT PROCESSING service processes the incoming fault reports
       according to their urgency. For this, each fault report is given one of
       the following priorities.

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------
PRIORITY          DEFINITION                                      EXAMPLE
---------------------------------------------------------------------------------------------------------------
<S>               <C>                                             <C>
                  CRITICAL FAULT                                  -   a fault report that is related
1                 -   An urgent software or hardware                  to an already neutralized emergency
                      problem that has escalated to produce       -   a problem that threatens to
                      considerable operational restrictions. As       escalate to an emergency
                      a result, the fault may cause system        -   an important key function of the
                      availability to be significantly reduced.       system is unusable
---------------------------------------------------------------------------------------------------------------
                  MAJOR FAULT                                     -   particular features are
2                 -   A software or hardware problem                  inoperative
                      that produces operational and service       -   a fault report that is related
                      restrictions, but does not affect the main      to an urgent problem which could be
                      functions of the system.                        neutralized by a workaround
---------------------------------------------------------------------------------------------------------------
                  MINOR FAULT                                     -   errors in documents
3                 -   a minor software or hardware                -   failure of automatic procedures
                      problem that, while an inconvenience, does      which can be avoided manually (e.g. auto
                      not affect system functionality                 back-up)
---------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

           APPENDIX 4G - FORECASTING, ORDERING AND CALL-OFF PROCEDURE

DOCUMENT

              ------------------------------------------------------------------
              DOCUMENT NAME              Appendix 4g-Forecasting, Ordering and
                                         Call-Off Procedure
              ------------------------------------------------------------------
              CONTENT                    Appendix 4g, Technical Services of the
                                         European Agreement between FirstMark
                                         Europe SA and Siemens AG

                                         Description of the forecasting,
                                         ordering and call-off procedure
              ------------------------------------------------------------------

                                                                     Page 1 of 9

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

CONTENT

<TABLE>
<S>                                                                           <C>
     Document...............................................................  1
1.   Preamble...............................................................  3
2.   Base Station - BS......................................................  3

   2.1    Long Term Forecast................................................  3
     2.1.1     Definition...................................................  3
     2.1.2     Long term forecast structure and frequency of process........  3
     2.1.3     BS long term forecast - input................................  4

   2.2 BS - Ordering and Call-Off Procedure.................................  4
     2.2.1     Introduction.................................................  4
     2.2.2     First Market Deployment Order for a certain Market -- Initial
                  radio frequency planning..................................  5
     2.2.3     Second Market Deployment Order for a certain Market..........  5
     2.2.3     Non-Market Deployment Order..................................  5
     2.2.4     BS System Call-Off...........................................  5

3.   Customer Premises Equipment - CPE......................................  5
   3.1    CPE - Long Term Forecast..........................................  5
   3.2    CPE - Short Term Forecast and Ordering............................  6

     3.2.4     Warehousing..................................................  7
     3.2.5     CPE payment terms............................................  7

4.   Lead times.............................................................  7
   4.1    BS lead times.....................................................  7
   4.2    CPE lead times....................................................  8
</TABLE>

                                                                     Page 2 of 9

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

1.       PREAMBLE

This Appendix 4g details the Contractors requirements for the Purchaser with
regard to the forecasting, Ordering and call-off procedure of the System and
Services.

2.       BASE STATION - BS

2.1       LONG TERM FORECAST

2.1.1    DEFINITION

Every quarter Purchaser shall make a good faith, non-binding estimate as to
Purchasers likely roll out for the nine month period which begins from the 7th
(seventh) month from the date of the long term forecast as specified in 2.1.2
and 2.1.3 of this Appendix 4g.

                                   [GRAPHIC]

2.1.2    LONG TERM FORECAST STRUCTURE AND FREQUENCY OF PROCESS

The Purchaser will provide the Contractor with a rolling 9 (nine) months
non-binding long term forecast for the 7th (seventh) to the 15th (fifteenth)
month from the date of forecasting, with a first identification of the
deployment areas in the forecasted quarters. This long term forecast includes
also the delivery of Services as well as the delivery of the Systems and any
other equipment agreed to be delivered to a BS site.

The rolling long term forecast will be updated by the Purchaser once per quarter
and will be issued to the Contractor on the first Working Day of a quarter.

                                                                     Page 3 of 9

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

2.1.3    BS LONG TERM FORECAST - INPUT

The Purchaser will provide the following information in the long term forecast:

          -    PMP-licence areas to be deployed with priorities

          -    List of licence area with the awarded frequency band (to be
               issued once upon each change)

          -    rollout plan/curve on a regional basis including estimated number
               of BS sites

          -    assumption on initial BS configuration in respect of capacity and
               amount of sectors

2.2 BS - ORDERING AND CALL-OFF PROCEDURE

2.2.1    INTRODUCTION

For the completion dates set out in a Contract only the lead times as specified
in Section 4 of this Appendix 4g shall apply unless otherwise expressly stated.

                                   [GRAPHIC]

                                                                     Page 4 of 9

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

2.2.2    ORDER - INITIAL RADIO FREQUENCY PLANNING

The Order for initial radio frequency (RF) planning shall be in accordance with
Section 2.6 of Appendix 4 a+b.

2.2.3    MARKET DEPLOYMENT ORDER

Upon receipt of the initial RF planning result the Purchaser may place a Market
Deployment Order (MDO) for the Systems and related installation, commissioning
and acceptance Services for the search areas within the planned Market the
Purchaser requires to be rolled out.

2.2.3    OTHER ORDERS

Upon receipt of the initial RF planning result the Purchaser may place a
separate Order for the site acquisition Services.

Site design may be ordered separately upon the technical review meeting
according to Section 3.4 of Appendix 4 a+b.

Civil works may be ordered upon issuance of site specific quotation by the
Contractor.

2.2.4    BS SYSTEM CALL-OFF

At the technical review according to Section 3.4 of Appendix 4a+b the
configuration of the System of a Site of Installation ordered in the MDO, which
was based on the result of the initial RF planning result shall be checked and
the Purchaser shall either confirm this configuration or amend the configuration
of the System as verified on the Site of Installation with a System call-off in
writing.

In case the configuration verified at the technical review is different than
that configuration ordered in the MDO based on the initial RF planning result,
the MDO shall be amended subsequently in accordance with the System call-off
made. Delivery times as set out in Section 4 of this Appendix 4g for changed or
additional items of the MDO shall apply accordingly.

3. CUSTOMER PREMISES EQUIPMENT - CPE

3.1      CPE - LONG TERM FORECAST

In conjunction with the long term forecast of BS equipment as described in
Section 2.1. of Appendix 4g the Purchaser shall issue on the respective first
Working Day of a quarter a non-binding rolling quarterly based long term
forecast indicating the estimated amount of CPE Systems per region. Section
2.1.1 and 2.1.2 of this Appendix 4g shall apply accordingly.

INPUT

Purchaser shall include the following data in this forecast:

          -    estimated number of CPEs and related frequencies and service per
               region

                                                                     Page 5 of 9

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

3.2       CPE - SHORT TERM FORECAST AND ORDERING

3.2.1    INPUT

In addition to the long term forecast the Purchaser shall indicate in a rolling
non-binding short term forecast on a regional basis for the following 6 (six)
months in relation to the BS rollout.

The following data shall be forecasted:

/X/      the estimated number of required CPE in relation to the BS rollout
/X/      the services the CPE shall be capable of serving

To enable the timely issuance of the CPE short term forecast the Contractor
shall issue mid of each months for the respective 6 (six) months of the CPE
short term forecast on a monthly basis the number of BS per region, where the
Site will be Site Ready for Installation in the respective month.

The Purchaser shall issue the CPE short term forecast to the Contractor on the
first Working Day of a month, provided that the Contractor has issued the
aforesaid information.

3.2.2    ORDERING OF CPE

Purchaser shall place 2 (two) months prior to the required delivery date an
Order for the required CPE. This Order shall include the following information
e.g.:

          -    Number of CPE
          -    Configuration of CPE e.g. service
          -    Frequency and subband

To enable the timely Ordering of the correct number and configuration of the CPE
Systems the Contractor shall issue mid of each months the number of BS per
region where the BS Site will be Site Ready for Installation in 2 (two) months
from the actual date.

3.2.3    CALL OFF OF CPE

The Purchaser shall call off the CPE to Site of Installation latest 10 (ten)
calendar days prior to the required date of the CPE Site Ready for Field
Acceptance. Prerequisite is, that the Site is Site-Ready-for-Installation
minimum of 10 calendar days prior to the required date of the CPE Site Ready for
Field Acceptance.

In case Purchaser has ordered civil works for CPE from Contractor the Purchaser
shall call off the CPE to site latest 5 (five) calendar days prior to the
required date of the CPE Site Ready for Field Acceptance

                                                                     Page 6 of 9

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

3.2.4    WAREHOUSING

In case the ordered CPE Systems are not called off to site at the required
delivery date specified in the Order the Contractor shall store the ordered CPE
Systems at no additional costs to the Purchaser until the CPE Systems are called
off to site by the Purchaser but in any case the Contractor shall store each CPE
System no longer than 2 years at no additional costs.

The Contractor will also bear the warehousing costs for de-installed CPE,
provided that the churn rate does not exceed 20% but in any case the Contractor
shall store each de-installed CPE no longer than 2 years at no additional costs.

3.2.5    CPE PAYMENT TERMS

100% (hundred percent) of the Price of the CPE System shall be paid within 60
(sixty) days from receipt by the Purchaser of the respective and correct
invoice, such invoice to be issued upon delivery of the CPE to the warehouse.

100% (hundred percent) of the Price of the CPE System shall be paid within 30
(thirty) days from receipt by the Purchaser of the respective and correct
invoice, such invoice to be issued upon Field Acceptance of the CPE if delivered
directly to the Site of Installation.

4.       LEAD TIMES

4.1       BS LEAD TIMES

The following lead times shall apply to BS Services:

     -   INITIAL PLANNING

         The lead time of the initial RF planning is 10 (ten) Working Days from
         receipt of the Order pursuant to Section 2.2.2 of this Appendix . This
         lead time can be prolonged in accordance with Section 2.6 of Appendix
         4a+b.

     -   SITE ACQUISITION

         The standard lead time for site acquisition is 60 (sixty) Working Days
         from receipt of the respective Order.

         Delinquency charges for delays shall not be compensated.

     -   DETAILED RF PLANNING

         The lead time of the detailed RF planning is 5 (five) Working Days from
         the date the site candidate is released by the Purchaser for
         negotiation of the lease agreement.

     -   SITE DESIGN (CW PLANNING)

         The lead time of the blue prints (Grundwerkplan) shall be 5 (five)
         Working Days following the technical review meeting. The lead time of
         the detailed site design is 10 (ten) Working Days from the date the
         Purchaser released the site for detailed civil works planning.
         Applicable liquidated damages in case of delays are set out in Section
         5 of Appendix 4d.

                                                                     Page 7 of 9

<PAGE>

                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

     -   CIVIL WORKS

         The lead time of civil works shall be 20 (twenty) Working Days from the
         date the Purchaser release the site for civil works. Applicable
         liquidated damages in case of delays are set out in Section 5 of
         Appendix 4d.

     -   DELIVERY TIME BS SYSTEM

         The lead time of delivery to the Site of Installation of the BS System
         is 2 (two) months from the receipt of the respective Order.

     -   INSTALLATION, COMMISSIONING

         The lead time of installation and commissioning services of BS Systems
         to achieve Site Ready for Service as specified in Appendix 4e is 10
         (ten) Working Days from the date the Purchaser approved in writing the
         Site Ready for Installation.

4.2       CPE LEAD TIMES

The following lead times shall apply to CPE Services and Systems:

     -   LEAD TIME OF CPE SYSTEM DELIVERY

         The delivery time of CPE System either directly to the Site of
         Installation or to the warehouse is 2 (two) months from receipt of the
         respective Order.

     -   INSTALLATION, COMMISSIONING AND ACCEPTANCE SERVICE

         The lead time for installation, commissioning and acceptance of CPE
         Systems to be understood as the time from call off the CPE System to
         the Site of Installation until the CPE System is Field Accepted. The
         lead time of the installation, commissioning, integration and
         acceptance of CPE Systems is 10 (ten) or 5 (five) calendar days
         pursuant to section 3.2.3 of this Appendix 4g.

5.       ROLL OUT PLAN 2000

The Contractor commits to achieve the attached rollout plan for the year 2000
(annex 1), provided that the following lead times are met:

-        site acquisition                        45 Working Days
-        site design                             20 Working Days
-        civil works                             20 Working Days

The Contractor will use its best effort to ensure to meet such lead times for
site acquisition, site design and civil works.

                                                                     Page 8 of 9

<PAGE>
                               European Agreement
                                   Appendix 4g
                    Forecasting, Ordering, Call Off Procedure

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------

                                                 OVERALL ROLL OUT PLAN 2000

------------------------------------------------------------------------------------------------------------------------------

------------------------------------------------------------------------------------------------------------------------------
                                                      CUMULATIVE STATUS
------------------------------------------------------------------------------------------------------------------------------

                                                                                  QUARTER I YEAR 2000

                                                  DURATION             JANUAR          FEBRUAR             MARCH         STATUS
<S>                                               <C>                  <C>             <C>                 <C>           <C>
        299 Ready for acquisition                      **                                                                  **
        400 Contracts signed                           **                                                                   *
        660 Infrastructure complete                    **                                                                   *
        730 Systems installed/commissioned             **                                                                   *
==============================================================================================================================
CW                                                                                                                         **

Gesamtdurchlaufzeit                                   ***

------------------------------------------------------------------------------------------------------------------------------
                                                        WEEKLY STATUS
------------------------------------------------------------------------------------------------------------------------------

        299
        400
        660
        730
==============================================================================================================================
CW
------------------------------------------------------------------------------------------------------------------------------

<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
                                                      CUMULATIVE STATUS
------------------------------------------------------------------------------------------------------------------------------

                                                                               QUARTER II YEAR 2000

                                                              APRIL                  MAY                       JUNE
<S>                                                   <C>   <C>  <C>   <C>   <C>  <C>   <C>   <C>    <C>  <C>   <C>   <C>  <C>
        299 Ready for acquisition                     **    **   **    **    **   **    **    **     **   **    **    ***  ***
        400 Contracts signed                           *     *    *    **    **   **    **    **     **   **    **     **   **
        660 Infrastructure complete                    *     *    *    **    **   **    **    **     **   **    **     **   **
        730 Systems installed/commissioned             *     *    *     *     *   **    **    **     **   **    **     **   **
===============================================================================================================================
CW                                                    **    **   **    **    **   **    **    **     **   **    **     **   **

Gesamtdurchlaufzeit

-------------------------------------------------------------------------------------------------------------------------------
                                                        WEEKLY STATUS
-------------------------------------------------------------------------------------------------------------------------------

        ***                                            *     *    *     *     *    *     *     *      *    *     *      *    *
        ***                                            *     *    *     *     *    *     *     *      *    *     *      *    *
        ***                                                  *    *     *     *    *     *     *      *    *     *      *    *
        ***                                                  *                     *     *     *      *    *     *      *    *
===============================================================================================================================
CW                                                    **    **   **    **    **   **    **    **     **   **    **     **   **
-------------------------------------------------------------------------------------------------------------------------------

<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
                                                      CUMULATIVE STATUS
------------------------------------------------------------------------------------------------------------------------------

                                                                                QUARTER III YEAR 2000

                                                                                    VACATION PERIOD

                                                                JULY                     AUGUST                 SEPTEMBER
<S>                                                   <C>    <C>   <C>   <C>  <C>   <C>   <C>  <C>   <C>   <C>   <C>   <C>   <C>
        299 Ready for acquisition                     ***    ***   ***   ***  ***   ***   ***  ***   ***   ***   ***   ***   ***
        400 Contracts signed                           **     **    **    **  ***   ***   ***  ***   ***   ***   ***   ***   ***
        660 Infrastructure complete                    **     **    **    **   **    **    **   **   ***   ***   ***   ***   ***
        730 Systems installed/commissioned             **     **    **    **   **    **    **   **    **    **    **   ***   ***
=================================================================================================================================
CW                                                     **     **    **    **   **    **    **   **    **    **    **    **    **

Gesamtdurchlaufzeit

---------------------------------------------------------------------------------------------------------------------------------
                                                        WEEKLY STATUS
---------------------------------------------------------------------------------------------------------------------------------

        ***                                             *      *     *     *    *     *     *    *     *     *     *     *     *
        ***                                             *      *     *     *    *     *     *    *     *     *     *     *     *
        ***                                             *      *     *     *    *     *     *    *     *     *     *     *     *
        ***                                             *      *     *     *    *     *     *    *     *     *     *     *     *
=================================================================================================================================
CW                                                     **     **    **    **   **    **    **   **    **    **    **     **    **
---------------------------------------------------------------------------------------------------------------------------------

<CAPTION>
------------------------------------------------------------------------------------------------------------------------------
                                                      CUMULATIVE STATUS
------------------------------------------------------------------------------------------------------------------------------

                              QUARTER IV YEAR 2000
                                                                                                                           DITO

                                                             OCTOBER                  NOVEMBER                    DECEMBER
<S>                                                  <C>   <C>    <C>  <C>   <C>   <C>  <C>    <C>   <C>   <C>   <C>    <C>    <C>
        299 Ready for acquisition                    ***   ***    ***  ***   ***   ***  ***   ***    ***   ***   ***    ***    ***
        400 Contracts signed                         ***   ***    ***  ***   ***   ***  ***   ***    ***   ***   ***    ***    ***
        660 Infrastructure complete                  ***   ***    ***  ***   ***   ***  ***   ***    ***   ***   ***    ***    ***
        730 Systems installed/commissioned           ***   ***    ***  ***   ***   ***  ***   ***    ***   ***   ***    ***    ***
==================================================================================================================================
CW                                                    **    **     **   **    **    **   **    **     **    **    **     **     **

Gesamtdurchlaufzeit

-----------------------------------------------------------------------------------------------------------------------------------
                                                        WEEKLY STATUS
-----------------------------------------------------------------------------------------------------------------------------------

        ***                                            *     *      *    *     *     *    *      *     *     *     *
        ***                                            *     *      *    *     *     *    *      *     *     *     *
        ***                                            *     *      *    *     *     *    *      *     *     *     *
        ***                                            *     *      *    *     *     *    *      *     *     *     *
===================================================================================================================================
CW                                                    **    **     **   **    **    **   **     **    **    **    **     **     **
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>
-----------------------
* Omitted and filed separately with the Securities and Exchange Commission
  pursuant to a request for confidential treatment.

                                                                     Page 9 of 9

<PAGE>

                               European Agreement
                                  Appendix 4 h
                                    Training

                             APPENDIX 4H - TRAINING

DOCUMENT

          ----------------------------------------------------------------------
          DOCUMENT NAME      Appendix 4 - Training
          ----------------------------------------------------------------------
          BACKGROUND         Description of Training services and conditions of
                             Appendix 4, Technical Services, of the European
                             Agreement between FirstMark Europe SA and Siemens
                             AG
          ----------------------------------------------------------------------

<PAGE>
                               European Agreement
                                  Appendix 4 h
                                    Training

Content

<TABLE>
<S>                                                                        <C>
1     OBJECTIVES............................................................3
2     TRAINING PROGRAM......................................................3
3     SCOPE OF TRAINING.....................................................3
4     TRAINING LOCATION.....................................................4
5     TRAINING DOCUMENTATION AND LANGUAGE...................................5
6     QUALITY...............................................................5
7     OPEN COURSES..........................................................6
8     DEDICATED COURSES.....................................................6
9     TRAINING SCHEDULE.....................................................6
10       ORDERING OF TRAINING...............................................6
11       CANCELLATION AND POSTPONEMENT......................................7
12       TRAINING PRICES....................................................7
13       DATA PROTECTION AND EXPORT CONTROL PROVISIONS......................8
</TABLE>

1

<PAGE>

                               European Agreement
                                  Appendix 4 h
                                    Training

2      OBJECTIVES

       This section of Appendix 4 relates to the Training of the Purchaser's
       personnel and Third Party personnel if requested by Purchaser
       (hereinafter referred to as "Personnel").

       In this document, training shall cover Contractor's activities pursuant
       to Section 3 of this Appendix 4h involved in the transmission of
       knowledge and skills, i.e. training courses, on-site training, guidance,
       computer-based training (CBT) and instruction (hereinafter referred to as
       "Training").

3      TRAINING PROGRAM

       The Contractor shall offer details of courses regarding Training (in the
       following referred to as "Courses") available to the Purchaser. The
       Purchaser will decide on the Training required from the options offered.

       The Contractor shall tailor a Training program providing Courses and
       related Course path for the different categories of the Purchaser's
       personnel, which needs to be approved by the Purchaser. The Training
       program will be reviewed by both Parties at least twice a year.

       The Contractor will continuously inform the Purchaser of relevant
       Courses, their availability and content and shall assist the Purchaser in
       identifying suitable Courses for the different categories of the
       Personnel to be trained.

       The Contractor shall work together with the Purchaser to adapt the
       Training program to match the Purchaser's requirements.

4      SCOPE OF TRAINING

       During the period of the Agreement if ordered and beyond if ordered and
       confirmed by Contractor, the Personnel will be trained by the Contractor
       in all aspects associated with the implementation and operation of the
       network i.e. the radio network planning and optimisation, installation,
       commissioning, integration, operation, administration, maintenance,
       upgrade, and supervision of the System and network including all
       functions and any related support systems.

       The Personnel shall be trained to a standard agreed with the Purchaser.

       The Training will be applicable to the different categories of the
       Purchaser's personnel. Exact Training requirements (including development
       of new Courses) such as Training content, objectives and duration will be
       defined and agreed by the Parties.

       The Contractor shall prepare new Courses for afore said aspects and to
       offer and conduct such Courses for the Purchaser if required by the
       Purchaser. Upon mutual agreement the Contractor shall prepare new
       dedicated Courses, change Courses and their content as well as change
       Course flows. The Course content, Course documentation, price and other
       factors relating to the new Courses shall correspond to the other Courses
       agreed under the European Agreement, and the terms and conditions of new
       Courses shall also correspond with those stipulated in the European
       Agreement.

<PAGE>

                               European Agreement
                                  Appendix 4 h
                                    Training

       The Contractor shall emphasis that Training, which will consider System
       enhancements, especially the introduction of new products or features of
       the System shall be available no later than 4 (four) weeks prior to the
       agreed availability or delivery of the new product or feature to the
       Purchaser but in any case such Training shall be available prior to the
       delivery or upgrade of aforesaid new products or features to the
       Purchaser's network.

       The Contractor shall also offer Training-on-the-Job to the Purchaser upon
       request.

       The Contractor shall supply and organise Training for third party
       Hardware and Software delivered under this Contract.

       The Contractor shall update the Course according to Section 5.

       Training will be provided and shall be remain available according the
       time period mentioned in Sect. 16.1 of Appendix 1.As part of the Training
       program according to Section 3 the Contractor shall provide detailed
       Training descriptions for each Course covering as a minimum:

              Scope and recommended category of Personnel to attend
              Course medium (e.g. computer based Training, presentation etc.)
              Required equipment
              Participant's pre-requisite
              Training objectives and subjects
              Training location
              Training duration
              Recommended minimum and maximum number of participants
              Available Training languages the Training can be conducted

       The Contractor shall be responsible to update these Training descriptions
       continuously.

5      TRAINING LOCATION

       Training is performed either at the Contractor's customer Training
       centres in Germany or at the Purchaser's premises.

       Participants undertake to comply with the safety rules and order
       regulations ("Hausordnung") applying to the training location.

       The Contractor's customer Training centres in Dusseldorf and Munich have
       a fully equipped WALKair Training model. The Contractor shall provide
       Training models in its Training centres, which will correspond to the
       Purchaser's network and Systems with respect to the current Hardware and
       Software versions. The Contractor shall also provide Training Courses to
       be delivered at the Purchaser's premises. The Contractor shall clarify in
       advance all necessary pre-requisites such as required Training equipment
       and outline these in the respective Training description.

<PAGE>

                               European Agreement
                                  Appendix 4 h
                                    Training

       The Contractor shall deliver Training also elsewhere if the Purchaser
       provides a suitable classroom or other appropriate environment and all
       necessary Training facilities.

6      TRAINING DOCUMENTATION AND LANGUAGE

       Accompanying material left in the possession of training participants is
       intended for their individual use only. No part of the training
       documentation may be duplicated, electronically processed, disseminated
       or passed on to others externally. In this context, training
       documentation also includes any electronic knowledge products or learning
       systems made available to training participants on data media or on the
       Intranet.

       Software made available by the Contractor for training purposes must not
       be removed, nor may it be copied either wholly or in part or rendered
       useable in any other form for which consent has not been obtained. The
       Contractor will not accept liability for any damage that may result from
       possible viruses on copied file diskettes. Diskettes brought in by
       participants must not be used on the Contractor's computers.

       The Contractor shall supply the Training documentation as standard in
       English language. The edition of the Training documentation shall be
       updated to cover the latest status of the Hardware and Software versions
       in the Purchaser's network. The Purchaser shall be entitled to translate
       the Training documentation at its own cost. The Contractor will provide
       an offer for translated version of the documentation upon request by the
       Purchaser.

       Trainees may keep the individual Course material handed out during the
       Training.

       Courses will be conducted as standard in German language. The Contractor
       shall indicate in each Training description the languages the Course can
       be conducted.

7      QUALITY

       Upon mutual agreement the Purchaser shall be entitled to attend Training
       courses for quality assessment purposes free of charge to ensure that the
       Contractor's Training meets the agreed quality level. At the end of each
       Training the trainees shall evaluate the Course by filling in an
       evaluation template, which needs to be agreed between the Parties. These
       evaluation templates filled in by the trainees shall be forwarded by the
       Contractor to the Purchaser.

       The Purchaser and the Contractor shall agree on a measurement scheme for
       the Purchaser's evaluation of the Courses.

       In case the result of a Course does not reach the agreed quality the
       Contractor is obliged to offer possibilities to assure that the Personnel
       attending the Training Course receives the necessary knowledge, by a
       repetition of the Course free of charge to the Purchaser or if a
       repetition cannot be arranged within the following three (3) months the
       Contractor shall reimburse the payment for the Training Course wholly or
       partly as agreed to the Purchaser.

<PAGE>

                               European Agreement
                                  Appendix 4 h
                                    Training

       The Purchaser and the Contractor shall at least once per year review the
       quality of the delivered Training. If necessary according to the agreed
       measurement scheme the Contractor is obliged to improve the quality of
       Training.

8      OPEN COURSES

       Open Courses are Courses, which are not exclusively scheduled for and
       offered to the Purchaser. Latest at the beginning of the Training Course
       the Purchaser or its Personnel attending the Training shall be informed
       if any of the Purchaser's competitors will or is attending the same open
       Training Course.

       The Personnel shall have the possibility to attend the Contractor's open
       Training Courses which shall be considered in the Training schedule
       pursuant to section 10 of this section of Appendix 4 to enable the
       Purchaser to plan the participation of its personnel.

9      DEDICATED COURSES

       Dedicated Courses are Courses exclusively scheduled for and offered to
       the Purchaser without any attendants from any other company.

       The Contractor shall provide dedicated Courses to the Purchaser and shall
       include these dedicated Courses into a Training schedule pursuant to
       section 10 of this section of the Appendix 4.

       The number of minimum participants for all dedicated Courses is mentioned
       in the Training schedule. In case the number of minimum participants will
       not participate in the training, the total price for training of the
       minimum participants will be charged to the Purchaser. This only applies
       in case that in the respective Quarter no corresponding open Courses are
       available to the Purchaser and Purchaser will order in year 2000 a
       minimum of 100 student days.

10     TRAINING SCHEDULE

       The Contractor shall offer Training in a 6 (six) months Training schedule
       to the Purchaser. This Training schedule shall indicate the Course name,
       date, place and language of Training. The Contractor shall be obliged to
       keep this Training schedule up-to-date after each amendment.

       In addition the Contractor's general schedule for open Training Courses
       for the fiscal year of the Contractor addressing also Training for other
       equipment not delivered to the Purchaser and other Courses is available
       on the internet page http://www.siemens.de/ic/training.

11     ORDERING OF TRAINING

       In accordance with the agreed Training schedule the Purchaser is entitled
       to issue orders for the available number of Training places in case of
       open Courses respectively for each scheduled Course in case of dedicated
       Courses. Orders for the Training shall be issued LATEST

                  i. 14 (fourteen) calendar days prior to the scheduled start
                     of the Training in case of places of open Trainings and

<PAGE>

                               European Agreement
                                  Appendix 4 h
                                    Training

                 ii. 4 (four) weeks prior to the scheduled start of the
                     Training in case of dedicated Trainings independent if the
                     dedicated Training is to be delivered at the Contractor's
                     Training centres or at the Purchaser's premises.

12     CANCELLATION AND POSTPONEMENT

       The Purchaser shall be entitled to cancel or postpone ordered places of
       open Courses 14 (fourteen) calendar days prior to the start of the
       respective open Course at no cost.

       In case the Purchaser cancels or postpones ordered and confirmed places
       of open Courses with a period of

                  i. less than 14 (fourteen) calendar days prior to the start
                     of the respective open Course, the Contractor shall be
                     entitled to invoice 100 % (fifty percent) of the related
                     Training price

       if the Contractor is not able to replace the cancelled or postponed place
       with a participant of any other customer or internally.

       For the avoidance of doubt, places of open Courses ordered by the
       Purchaser are not allocated to a specific person of the Purchaser's
       personnel.

       The Purchaser shall have the right to cancel or postpone dedicated
       Courses previously ordered in accordance with section 11 of this section
       of Appendix 4 from the Contractor with a notice period of 4 (four) weeks
       prior to the start of the respective dedicated Course at no cost.

       In case the Purchaser cancels or postpones ordered and confirmed
       dedicated Courses with a period of

                  i. less than 4 (four) weeks prior to the start of the
                     respective dedicated Course, the Contractor shall be
                     entitled to invoice 50 % (fifty percent) of the related
                     Training price

                 ii. less than 2 (two) weeks prior to the start of the
                     respective dedicated Course, the Contractor shall be
                     entitled to invoice 100 % (hundred percent) of the related
                     Training price

       if the Contractor is not able to replace the cancelled or postponed
       Course with the participation of any other customer or internally.

       In case the Contractor cancels or postpones an ordered and confirmed
       Training on short notice the Contractor shall reimburse the Purchaser any
       incurred costs caused due to the cancellation such as cancellation fees
       of flights, hotels etc.

13     TRAINING PRICES

       Prices for Training are set out in Appendix 2 of this Contract. In case
       of development of new training in the future the parties shall mutually
       agree the price level.

<PAGE>

                               European Agreement
                                  Appendix 4 h
                                    Training

       Training prices as set forth in Appendix 2 of this Contract include
       participants Training documentation and if applicable material costs such
       as hand outs for participants and usage of the Contractor's Training
       centre facilities including training equipment. Training prices do not
       include participants or trainers travel expenses, daily allowances and
       accommodation.

       In case Training is conducted at the Purchaser's premises and the
       Purchaser provides the classroom and all necessary Training equipment
       Training is charged on a per trainer per day basis as set out in Appendix
       2.

14     DATA PROTECTION AND EXPORT CONTROL PROVISIONS

       Participants agree to allow their booking data only to be processed to
       the extent necessary for the purposes of the Training.

       All goods and services provided by the Contractor are subject to the
       necessary export permits being granted and to there being no other
       obstacles arising from German or other relevant export regulations.
<PAGE>

                               European Agreement
                                  Appendix 4 i
                               Project Management

                   APPENDIX 4 i - PROJECT MANAGEMENT SERVICES

DOCUMENT
<TABLE>
<CAPTION>
           ------------------------------------------------------------------------------
           DOCUMENT NAME     Appendix 4 i - Project Management
           ------------------------------------------------------------------------------
           <S>               <C>
           BACKGROUND        Description  of Project  Management  Services of Appendix 4,
                             Technical  Services,  of the European  Agreement  between
                             FirstMark Europe SA and Siemens AG
           ------------------------------------------------------------------------------
</TABLE>

                                                                     Page 1 of 8
<PAGE>
                               European Agreement
                                  Appendix 4 i
                               Project Management

<TABLE>
<CAPTION>
CONTENT

<S>                                                                          <C>
1     Introduction........................................................   3
2     Project Groups, Working Groups And Escalation.......................   3
3     Meetings............................................................   4
4     Reports.............................................................   5
5     Milestones And Related Database Management System...................   6
6     Documentation.......................................................   6
7     Contractor's Subcontractor..........................................   7

</TABLE>

                                                                     Page 2 of 8
<PAGE>

                               European Agreement
                                  Appendix 4 i
                               Project Management

1 INTRODUCTION

           This section of Appendix 4 details the Purchaser's requirements from
           the Contractor with regard to the project management services.

           The Contractor shall be responsible for the project management of the
           network rollout activities incorporating but not limited to the radio
           network planning, site search and acquisition, site design, site
           construction work packages, delivery of the Systems and its
           installation, commissioning, integrating and acceptance, network
           operation and technical support. All these activities, if ordered by
           the Purchaser, shall be managed and controlled by the Contractor in
           accordance with this Agreement in order to meet the contractual
           obligations provided that the Purchaser pays all agreed prices in
           accordance with this agreement.

           The Contractor shall undertake the task of project planning in
           conjunction with the Purchaser's project management team.

           The Contractor shall be responsible for updating the project plan
           during the project to reflect the status of the project and any
           improvements in processes and procedures.

2        PROJECT GROUPS, WORKING GROUPS AND ESCALATION

           For the continuous supervision of the Parties' performance under the
           Agreement the Parties shall form joint project groups and other
           reference working groups dependent on the subject to be discussed.
           The project groups and other reference working groups shall meet when
           decided upon by the Parties at regular intervals. Each Party shall
           bear all costs for its own representative of each Party authorised to
           this effect. When considered necessary by a Party, representatives of
           sub-contractors and experts of the Parties shall attend the meetings.
           It is incumbent upon the Contractor to see to it that representatives
           of the Contractor's sub-contractors attend, if so required and
           mutually agreed by the Parties.

           The technical project and reference working groups are authorised to
           make decisions within the technical scope of the project only. The
           Contractor shall propose a final solution for any technical change or
           addition requested by the Purchaser as soon as possible but, where
           possible not later than four (4) weeks from the date of the request.
           Decisions on proposed technical changes or additions shall be taken
           and implemented as soon as possible but, where possible not later
           than four (4) weeks after the proposal has been submitted. A proposed
           technical change or addition, which may affect prices, condition or
           any contractual date of delivery or otherwise influence on any
           commercial decisions shall be informed in writing to the Parties who
           may agree a change or addition to this Agreement. A decision binding
           on all Parties shall be deemed to have been made only if it is of
           technical nature and all the representatives of both Parties agree
           and the decision is contained in duly signed minutes and/or confirmed
           in writing. It is understood that the technical project groups and
           other reference working groups shall not be authorised to make
           decisions that will affect prices or the contractual date of delivery
           or otherwise decisions resulting in modifications of this Agreement.
           In the event that any of the representatives deems a question to fall
           outside

                                                                     Page 3 of 8
<PAGE>

                               European Agreement
                                  Appendix 4 i
                               Project Management

           the authority or competence of the project group or reference
           working group the question shall be referred to the Parties.

           The Parties shall establish a commercial project group - meeting
           regularly - handling all commercial issues and preparing Agreement
           modifications. A decision binding on all Parties shall be deemed to
           have been made only if it is of a commercial nature and all the
           representatives of both Parties agree and the decision is contained
           in duly signed minutes and/or confirmed in writing.

           In case consent cannot be reached within the specific project group
           or reference working group the issue shall be escalated in accordance
           with the escalation procedure.

           The Contractor will appoint a project director, who will have overall
           responsibility and authority to achieve all cost, programme,
           contractual and technical objectives. The Project Director will also
           be responsible for scheduling the work, the project reporting and
           will have full ownership of the project plan.

3        MEETINGS

           The Parties will define the schedule for regularly meetings of the
           various project and working groups. In addition to the regularly
           meetings, the Purchaser may request further meetings. Frequency of
           meetings may be varied by the Purchaser to reflect, for example,
           various stages of the network rollout.

           The Contractor shall ensure that formal minutes are produced at the
           meetings along with specific lists of actions. If not otherwise
           stated such notes shall be made available in general within three (3)
           working days of the meeting.

           The Purchaser shall be entitled to deploy upon mutual agreement any
           members of its network rollout team into any of the Contractor
           project teams to assist with any of the activities undertaken by the
           Contractor on behalf of the Purchaser. The Contractor shall support
           the operations and activities of any members of the Purchaser network
           rollout team deployed into the Contractor organisation.

           On a regular basis to be defined by the Purchaser project status
           meetings shall be conducted at the Purchaser's in-country premises or
           if agreed at any other premise with the project status report being
           the basis of the agenda. Formal minutes shall be produced by the
           Contractor, which shall be made available within one (3) working days
           of the meeting. The Purchaser shall define the general scope of the
           project status meeting. In addition the Purchaser may request further
           meetings. Normally the Contractor's project director, project manager
           and relevant members of the team shall attend and discuss contractual
           issues, the project progress and any issues and risks that need
           resolution. It is in the decision of the Contractor to appoint the
           relevant members of the Contractors team. Accordingly the project
           status report, which shall include coverage plots on request shall be
           issued with up-to-date information at least one (1) working day prior
           to the project status meeting.

                                                                     Page 4 of 8

<PAGE>
                               European Agreement
                                  Appendix 4 i
                               Project Management

4        REPORTS

           The Contractor shall be responsible for the production of reports to
           the Purchaser. The structure, content, schedule and detail of reports
           shall be defined by the Purchaser and shall be generated by using a
           data format, which is compatible for import and export purposes to
           the most common applications on the market (hereinafter referred to
           as "Data Format"). These reports will only include project specific
           information. A rollout plan and all activities that are required for
           the implementation of the Purchaser's network shall be generated in a
           data format, which is compatible for import and export purposes to
           the most common applications on the market. The development of the
           respective report generators shall be the Purchaser's responsibility.

           The Contractor shall operate a formal project management process
           supported by planning tools supporting aforesaid Data Format. Formal
           baseline plans will be specified by the Purchaser and used by both
           Parties as an ongoing reference against progress. Progress reports
           against these baselines will form part of the progress meetings with
           the Purchaser.

           The Contractor will ensure that their management reporting structure
           is lined up with the Purchaser's structure to achieve free flow of
           communications and correct level of responsibilities. The
           organization shall be flexible enough to take into consideration all
           required changes as the project progresses.

           Project reporting will be achieved through a number of working
           levels. These will be adapted to the particular requirements of the
           Purchaser.

           The Contractor shall submit on a reasonable regular basis to be
           defined by the Purchaser a management progress report to the
           Purchaser. The management progress report shall contain, as a minimum
           a report of all activities related to the project that have taken
           place since the last issued report as well as information regarding
           future activities and the progress of the Contractor's scope of work,
           standard of work, the problem areas encountered during the said
           period and foreseen for the future, and corrective actions taken or
           anticipated to be taken in order to overcome such problems, a
           schedule of issued documents, a technical progress report and when
           appropriate cost plans in a format to be agreed with the Purchaser to
           summarise payments to date and projected timings of future payments
           in order to facilitate cash flow analysis and evaluation of financing
           requirements. The Contractor shall be required to complete a detailed
           risk analysis for the network rollout project and include the
           analysis as part of the progress report submitted to the Purchaser.

           The Contractor shall submit a weekly project status report including
           coverage plots on request, which shall be the basis of discussion of
           the project status meetings as set forth in section 3. In addition
           extraordinary events that might jeopardise the rollout progress with
           respect to time and cost shall be reported immediately without any
           delay to the Purchaser.

                                                                     Page 5 of 8
<PAGE>

                               European Agreement
                                  Appendix 4 i
                               Project Management

5        MILESTONES AND RELATED DATABASE MANAGEMENT SYSTEM

           The Purchaser shall define the project milestones (hereinafter
           referred to as "Milestones") to be achieved throughout the network
           rollout. The Purchaser shall be responsible to keep the Milestone
           definitions up to date and to inform the Contractor.

           The Milestones are not subject to any claims of damages as long as
           these Milestones are not contractually agreed.

           The Contractor shall be responsible for the real-time data update of
           the Purchaser's core database management system (hereinafter referred
           to as "RDMS") for the identified site information such as but not
           limited to site access details, serial number of equipment delivered,
           the status milestone in order to provide online information on the
           work progress and to have "real time" visibility of all levels of the
           project activities on line. All data storage shall be based on RDMS
           to ensure data continuity and accuracy. The Contractor shall provide
           weekly reports to the Purchaser's rollout management department using
           aforesaid RDMS. The Contractor shall be obliged to ensure consistence
           between the data entered into RDMS and the information and status
           reported.

           The Purchaser shall provide access and all technical support for RDMS
           to the Contractor free of any license fees or charges.

           In case of remote login the Contractor is responsible to follow the
           Purchaser's remote login procedures.

           The Contractor's database system shall, if required by the Purchaser,
           be able to interface with RDMS.

           All project data or information that is entered into RDMS or any
           other tool shall be the sole property of the Purchaser. Contractor
           may use its own data for project specific purposes.

           For the avoidance of doubt, if information is not entered by the
           Contractor into the RDMS, the Purchaser shall assume that the action
           has not been completed, except where documentation has been exchanged
           by the Parties and RDMS cannot be updated.

           As long as RDMS is unavailable for use by the Contractor the agreed
           interim solution proposed by the Purchaser shall be practised.

6        DOCUMENTATION

           The Contractor shall provide the Purchaser with documentation
           detailing the information required to be entered into the RDMS or the
           interim solution. All documentation shall be forwarded to the
           Purchaser's office in Dresden unless otherwise directed.

                                                                     Page 6 of 8
<PAGE>

                               European Agreement
                                  Appendix 4 i
                               Project Management

           All documents shall be forwarded to the Purchaser preferably by
           e-mail.

           The format of the documentation shall be defined and if necessary
           updated by the Parties. In some cases this may involve the Contractor
           completing forms that will be used by the Purchaser for data entry.
           All documentation provided by the Contractor shall be clear and
           unambiguous.

           Upon receipt of any documentation received from the Contractor, the
           Purchaser shall provide a dated acknowledgement of receipt of the
           information.

           In the event that the Purchaser has issued no acknowledgement of
           receipt within five (5) working days of submission of the
           documentation to the Purchaser, the Contractor shall be required to
           confirm receipt with the Purchaser or re-send the information. This
           shall apply for documentation that is not personally delivered to a
           member of staff at the Purchaser.

7        CONTRACTOR'S SUBCONTRACTOR

           It is the sole responsibility of Contractor to select the
           subcontractors. At no time the Purchaser may require to select a
           certain subcontractor.

           The Purchaser will assist the Contractor in the selection and
           qualification of subcontractors. The Purchaser shall be entitled to
           propose subcontractors, which are to be engaged for the performance
           of Services under this Contract by the Contractor.

           Subcontractors, which are to be engaged by the Contractor for the
           performance of Services under this Agreement shall be selected by
           both Parties. Such approval shall not be unreasonably withheld and
           shall not relieve the Contractor from its contractual obligations
           towards the Purchaser.

           The Purchaser may require at any time with valid reason that the
           Contractor remove certain subcontractors from the performance of the
           Service under the Agreement. Impacts on the Roll Out of the Network
           and other consequences shall be identified. Purchaser is not allowed
           to claim for damages resulting thereof.

           The Contractor's subcontractors as valid in April 2000 are listed in
           Annex 1 to this section of Appendix 4. It is the Contractor's
           obligation to keep this Annex 1 up to date and to inform the
           Purchaser of any changes. Each Party shall be fully responsible for
           the performance of its subcontractors as for its own performance.

           The Contractor shall require that the subcontractors also adhere to
           the provisions of this Agreement.

                                                                     Page 7 of 8

<PAGE>

ANNEX 1 TO APPENDIX 4 - PROJECT MANAGEMENT

CONTRACTOR'S SUBCONTRACTORS

         SITE ACQUISITION

CoNeCon GmbH,  Ziegelstr. 34B,  89407 Dillingen

Gunter Prinz GmbH, Im Park 8,  56112 Lahnstein

Ingenieurburo Riehle GmbH,  Osterholl,  55545 Bad Kreuznach

TeleCommunication Services GmbH,  Gartenstr. 28, 01445 Radebeul

         CIVIL WORKS

Energie Kom,  Wittener Str. 326,  42279 Wuppertal

R & S,  Postfach 1252,  26894 Esterwegen

Antensan,  Gerhard-Hauptmann-Str. 28,  86415 Mering,

SAG Abel,  Ribbelsbuttler Weg 2,  38518 Gifhorn

VA Tech Elin,  Landsberger Allee 366, 12681 Berlin

TI Projekte,  Fichtenstr. 1A,  02625 Bautzen

Variocom,  Herderstr. 30, 40721 Hilden

Pfleiderer, Tiroler Str. 1, 45659 Recklinghausen

         SITE DESIGN

ECS Engineering Communication Services GbR, Auf dem Anger 1A, 44805 Bochum

M - Plan Consult GmbH & Co. KG, Daimlerstr. 7, 86368 Gersthofen

         OTHER

te com Telekommunikation Technik GmbH, Hessenring 6b, 64546 Morfelden-Waldorf

                                                                    Page 8 of 8

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

                          APPENDIX 4J - DOCUMENTATION

Document

DOCUMENT NAME  Appendix 4j - Documentation
Description    Description of documentation of Appendix 4, Technical
               Services, of the European Agreement between FirstMark
               Europe SA and Siemens AG

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 1 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

TABLE OF CONTENTS

Scope of site documentation
1      Format
2      Contents of the documentation
   2.1 Covering sheet
   2.2 Change overview
   2.3 Table of contents
   2.4 Site-specific network overviews
     2.4.1 Network management
     2.4.2 Synchronisation
     2.4.3 DCN
   2.5 Building and room plan
   2.6 Installation plan
   2.7 Device configurations
     2.7.1 Rack configurations
     2.7.2 Rack safety field
   2.8 Connection cables
   2.9 Power supply
  2.10 Distributor allocation
     2.10.1 Symmetrical signal distributor
  2.11 List of abbreviations
  2.12 Contact persons
  2.13 Site-specific documentation on acquisition and construction work
  2.14 Copyright
3 Product documentation
  3.1 Scope
  3.2 Rights of utilisation
  3.3 Updates

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 2 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

SCOPE OF SITE DOCUMENTATION

The contractor shall compile and supply master documentation for each site on
which his system equipment is installed. This documentation shall describe
all services rendered by the contractor connected with the installation,
configuration and commissioning of the equipment supplied by him. This
site-specific documentation must be delivered to the purchaser in one folder
for each site.

1. FORMAT

1.   The documentation shall be made available in hardcopy and electronic form
     by the contractor at the latest on notification of Site Ready for Field
     Acceptance.
2.   The electronic form of the documentation shall be compiled using the
     following data formats:
     Pictures             *.tlf file
     Plans                *.DWG file AutoCad 13 or 14
     Plans racks          *.VSD (Visio or Deisgner)
     Parts lists          *.xls file   (device level)
     Written documents    *.doc file
     Scan objects         *.tif file
     Overviews            *.ppt file
     The files created using Microsoft Office shall be at least compatible
     with the package MS-Office97 or later.
3.   The documentation in hardcopy form shall be created using the tools
     specified under 2. In each case, a single copy is required.
     Plans in A3 landscape format
     Parts lists in A4 landscape format
     Calculations, written documents in A4
4.   Upgrades or changes to the system structure performed by the contractor
     shall be documented by means of change sheets and updates of the
     electronic documentation.
5.   The update version of the documentation shall be indicated by means of
     the change date.

2.   CONTENTS OF THE DOCUMENTATION

Each sheet of the documentation, with the exception of the covering sheet,
shall contain the markers:
    - Document name
    - Page number
    - Creation date
    - Version number
    - Site identification (Object Identification Code - OIC)

2.1  COVERING SHEET

The covering sheet shall contain at least the following specifications:
- Document name
- Document type
- Version number
- Author
- Creation date
- Date of the last change
- Site name
- Site identification (Object Identification Code - OIC)

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 3 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

2.2   CHANGE OVERVIEW

The documentation shall contain a change overview with specification of the
change-version number and the page numbers affected. In the case of the
replacement of the entire documentation, the change overview shall be
omitted. The current version / date must be specified.

2.3   TABLE OF CONTENTS

The documentation shall contain a table of contents in which all connected
sections of the documentation are listed. The sections shall be arranged in
accordance with the structuring of this document.

2.4   SITE SPECIFIC NETWORK OVERVIEWS

2.4.1 NETWORK MANAGEMENT

1. The documentation shall contain an overview of the network management
   system with the following contents:

-  Overview of network-management architecture with LAN/IP addresses. The
   addressing schema and the allocated addresses / address spaces shall be
   provided by Purchaser.
-  Tabular overview of the deployed NMS systems with the manufacturer's name
   and the serial number.
-  Tabular overview of peripheral devices (e.g. printers) with the
   manufacturer's name and the serial number.

2.4.2 SYNCHRONISATION

1. The documentation shall contain an overview of the clock priorities set in
   the network elements. Purchaser must supply documentation on the manner in
   which the clock is to be fed in / on the location from which the clock is
   to be taken / tapped (synchronisation plan).
   -  Configuration of all DCN components (routers, SiSA, CMX etc.), the data
      for the configuration of the components shall be provided by Purchaser (PI
      addresses, SISA addresses etc.).
   -  The configurations shall be made available as an up-to-date extract from
      the configuration program (LCT or similar) or as a summary of the data.

2.5   BUILDING AND ROOM PLAN

1. The documentation shall contain a to-scale building / room plan with the
   following contents:
   -  The location of the technical room in the building
   -  Depiction of the cable lines and lead-ins
   -  Depiction of other infrastructure equipment (air-conditioning system,
      power supply etc.)
   -  Depiction of antenna holders and antennas, where applicable with static
      documentary evidence
   -  Emergency situation (e.g. escape paths).

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 4 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

2.6   INSTALLATION PLAN

1.    The documentation shall contain a site-specific installation plan with
      the following contents:
      -  the location of the rack in the technical room
      -  the arrangement of the racks and their rack numbers
      -  the description of the racks
2.    The numbering and description of the racks and sub-racks shall be
      performed in accordance with the specifications of Purchaser.

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 5 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

2.7   DEVICE CONFIGURATIONS

2.7.1 RACK CONFIGURATIONS

The documentation shall contain an overview of the device configurations with
the following contents:

   -  the schematic representation of the racks
   -  rack number
   -  the identification number of the rack
   -  the employed voltage supply and the fuse (e.g. 48V /fuse 10 A)
   -  the following data are contained in the Field Acceptance Protocol and
      are a component of the documentation:
        -  the installation location
        -  the description of the slot
        -  the serial number
        -  the hardware version
        -  the firmware version
   -  Manufacturer's documentation for the devices, e.g. certificates

The numbering and description of the racks and sub-racks shall be performed
in accordance with the specifications of Purchaser.

2.7.2 RACK SAFETY FIELD

The documentation shall contain an overview of the installed rack safety
fields with the following contents:
   -  the schematic representation of the rack safety field
   -  the description of the safety field
   -  the rack number
   -  the voltage lead-in and fuse (e.g. 48 V /20 A)
   -  the description of the relevant load or of the safety field connected
      in series.

The description of the safety fields shall be performed in accordance with
the specifications of Purchaser.

2.8   CONNECTION CABLES

The documentation shall contain an overview of all the wiring carried out.
This shall also include structure-specific DCN cabling, synchronisation cabling,
HF and power cabling. The overview shall includes the following contents:
   -  Port description A end, cable description by means of colour codes
      (E1 ports)
   -  Port description B end, cable description by means of colour codes
      (E1 ports)
   -  Remarks (e.g. shield protected by insulation tube)
   -  Type of cable used, type of plug used, attenuation and length in the
      case of HF cables
   -  Cable paths

2.9   POWER SUPPLY

The documentation shall contain an overview of all installed power-supply
units with the following contents:
   -  the schematic representation of the sub-rack
   -  the description of the type of power supply
   -  the voltage lead-in-and fuse (e.g. 230 V / fuse 10 A)
   -  the description of the slot location

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 6 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

   -  the wiring of the power supply
   -  the serial number
   -  the hardware version
   -  the firmware version
   -  the change version / status
   -  parameters settings (threshold values, alarm outputs etc.)

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 7 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

   -  measurement reports of energy-supply company
   -  signed form VBG4
   -  description of battery backup
   -  manufacturer's specifications for the battery, e.g. date of
      manufacture, capacity
   -  measurement report of the battery voltages
   -  documentation of the battery degassing
   -  test report for earthing system

The numbering and description of the racks and sub-racks shall be
performed in accordance with the specifications of the purchaser.

2.10  DISTRIBUTOR ALLOCATION

The documentation shall contain an overview of all the distributor
allocations performed in the course of the system installation. The contents
of the distributor documentation is dependent on which distributor technology
is deployed and is described in the following sub-sections.
In any case, the documentation must ensure an unambiguous localised
description of every single port.

2.10.1 SYMMETRICAL SIGNAL DISTRIBUTOR

The documentation shall contain the following specifications for the
connection of the network element in the direction of the interchange
distributor:

   -  Bay
   -  Strip
   -  Terminal location

2.11  LIST OF ABBREVIATIONS

The list of abbreviations shall indicate what all the abbreviations used
stand for and explain them in German.

2.12  CONTACT PERSONS

Contractor and Purchaser shall both specify at least one contact person for
further discussion of the structure documentation.

2.13  SITE-SPECIFIC DOCUMENTATION ON ACQUISITION AND CONSTRUCTION WORK

Appendix 4c specifies the site-specific documentation to be compiled by the
contractor regarding the site acquisition. Appendix 4d specifies the
documentation for the site-planning work and the construction work.

2.14  COPYRIGHT

On delivery of the site-specific documentation, Purchaser shall receive the
sole copyright and utilisation right to the site-specific documentation to be
compiled by the contractor.

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 8 OF 9

<PAGE>

                               European Agreement
                                  Appendix 4j
                                 Documentation

3.    PRODUCT DOCUMENTATION

3.1   SCOPE

The following product documentation shall be delivered in electronic form to
the purchaser when a system is first delivered:

                    WALKair V3.1; Installation; IMN

                    WALKair V3.1; Operation; OMN:LCI

                    WALKair V3.1; Operation; OMN:NMS

                    WALKair V3.1; Information; TED

3.2   RIGHTS OF UTILISATION

The purchaser shall be permitted to copy the delivered documentation
unrestrictedly for internal purposes. Furthermore, Section 19 of Appendix 1
applies in particular for the documentation.

3.3   UPDATES

Updates of the product documentation shall be made by the contractor. These
shall be made available to the purchaser free of charge and automatically
without an explicit request.

APPENDIX 4J - DOCUMENTATION STATUS 000510                           PAGE 9 OF 9

<PAGE>

                               European Agreement
                                   Appendix 5
                                   Definitions

                                   APPENDIX 5

                                   DEFINITIONS

                                   Page 1 of 6

<PAGE>

APPENDIX 5 DEFINITIONS

AFFILIATE

means, in respect of Siemens AG and FirstMark Communications Europe SA, each of
their subsidiary or parent companies, or any company effectively controlled
directly or indirectly by such parent company either through 51% of the
ownership, control of shares or other securities in such company. Affiliates are
set out in Appendix 6 in respect of the Territories referred to therein, which
shall be updated in due course.

CHANGE ORDER

means the document by which changes to a Contract are agreed and effected.

CONSULTANCY SERVICES

means the provision of Services of an advisory or professional consultancy
nature set out in Appendix 4.

CONTRACT

means the agreement between the Purchaser and the Contractor, evidenced by the
issue by the Purchaser and acceptance by the Contractor of an Order, for the
provision of Systems and/or Services according to the terms of the EUROPEAN
AGREEMENT.

CONTRACTOR

means Siemens AG or the Affiliate of Siemens set out on the Purchaser's Order,
and includes its permitted successors and assigns.

CONTRACT PRICE

means the total Price set out in the Order in respect of the Systems and/or
Services required by the Purchaser.

CPE [Customer Premise Equipment]

means the equipment supplied by the Contractor for installation at the
Purchaser's customer's premises.

CUSTOMER TECHNICAL SUPPORT (CTS)

means the Contractor's field second or third level technical support Services.

CUSTOMER SERVICE REQUEST (CSR)

means the request for second or third level customer technical support (CTS)
Services referred through the SPOC.

                                  Page 2 of 6
<PAGE>

APPENDIX 5 DEFINITIONS

EMERGENCY TECHNICAL ASSISTANCE AND SUPPORT (ETAS)

means the Contractor's emergency technical support organisation available in
accordance with the terms of Appendix 4 as second level support 24 hours a day,
365 days per year.

FAULT CALL

means the request for support Services made by the Purchaser by contacting the
SPOC, against which the Contractor's call management system will allocate a
reference.

FIELD ACCEPTANCE

means verification of the performance of the System after installation by the
Field Acceptance Test as specified in Appendix 4.

FIELD ACCEPTANCE CERTIFICATE

means the certificate issued by the Purchaser upon successful completion of the
Field Acceptance Test demonstrating that the System has been delivered in
accordance with the Contract and the System functions in accordance with the
requirements of Appendix 3.

FIELD ACCEPTANCE TEST

means a series of tests according to Appendix 4, carried out by the Contractor
and at the Contractor's expense concerning the functioning of the System on the
Site of Installation.

FIRST LINE MAINTENANCE

means emergency call service and the on-site repair of the goods delivered by
the Contractor, which only requires the exchange of plug-in modules.

HARDWARE

means the hardware in the System.

IPRS

means all patents, extensions to patents, petty patents, utility models,
trademarks, service marks, applications for any of the foregoing, copyrights,
design rights, moral rights, database rights, rights in unregistered trade
marks, business names, trade secrets, know-how, other confidential information
and other intellectual property rights (whether registered or unregistered)
anywhere in the world.

LABOUR INDEX

                                  Page 3 of 6
<PAGE>

APPENDIX 5 DEFINITIONS

means the labour index of Luxembourg as and when published by STATEC, which is
part of the Statistical Office of Luxembourg

LENDER

means the party or parties or its successors, other than the Purchaser,
executing the Loan Agreement.

LINK

means the transmission path established between CPE and a base station within a
Market.

LOAN AGREEMENT

means the vendor financing package more particularly described in the Loan
Agreement between FirstMark Communications Deutschland GmbH and Deutsche Bank
for the financing of the implementation of the German WLL project of FirstMark
Communications Deutschland GmbH.

MANAGED SERVICE DELIVERY PRIME (MSD)

means the Contractor's appointed customer services manager.

MARKET

means the wireless local loop coverage area or areas designated by the Purchaser
in a single Order submitted by the Purchaser to the Contractor.

MARKET DEPLOYMENT ORDER (MDO)

means a special kind of Order comprising a market which is restricted to a
maximum of 2 (two) "Versorgungsgebiete".

NETWORK ELEMENT

means a multiplexer, cross connect, regenerator, line or radio system, or base
station.

ORDER

means the purchase order issued by the Purchaser to the Contractor for the
provision of Systems and/or Services in accordance with the terms of the
European Agreement. Such written Order will be in agreed form.

PARTY

means either the Purchaser or the Contractor, as the context requires. "PARTIES"
means both the Purchaser and the Contractor.

                                  Page 4 of 6
<PAGE>

APPENDIX 5 DEFINITIONS

PREFERRED SUPPLIER

means that the Purchaser has given to the Contractor at least *** of business in
the relevant country.

PRICE

means the price(s) set out in Appendix 2 payable by the Purchaser in respect of
the supply, installation, implementation and support of the Systems and Services
to be provided to the Purchaser pursuant to an Order.

PURCHASER

means the Affiliate of FirstMark Communications Europe SA issuing the Order, and
includes its permitted successors and assigns.

READY FOR SERVICE

means the date on which the Purchaser receives a written statement from the
Contractor according to which a base station, having a system component, is
ready for connection to CPE.

SECTOR

means a portion of a base station containing its own transceiver and an antenna,
which addresses a discrete set of CPEs.

SERVICE LEVELS

means the response times and other target performance levels set out in Appendix
4 in respect of the provision of Services.

SERVICES

means the provision and installation, commisioning, Field Acceptance Test,
support, Consultancy Services of the services (including but not limited to
Turnkey Services, training and maintenance) set out in Appendix 4.

SINGLE POINT OF CONTACT (SPOC)

means the Contractor's service desk which the Purchaser shall contact in order
to request support Services.

SITE OF INSTALLATION

means the place, buildings and environment where the System is to be installed.

SITE READY FOR FIELD ACCEPTANCE

                                  Page 5 of 6
<PAGE>

APPENDIX 5 DEFINITIONS

means the date on which the System has been installed and commissioned ready for
Field Acceptance Testing to proceed.

SITE READY FOR INSTALLATION

means the date on which the Site of Installation has been prepared ready for
installation of the System to proceed.

SOFTWARE

means the software in object code form, containing the machine readable
instructions for management or operation of the applicable System.

SOFTWARE DOCUMENTATION

means the technical user guides and other Documentation in respect of the
Software.

SPECIAL CONDITIONS

means the conditions set out in Appendix 6 which shall apply to the Contract in
addition to those contained in Appendix 1.

STANDARD SOFTWARE

means the Contractor's standard Software.

SYSTEM

means an operational unit of the Contractor's Hardware and/or Software as
specified in Appendix 3, which also includes access network equipment, network
management Systems and peripheral technology.

SYSTEM SPECIFICATION

means the specification set out in Appendix 3 in respect of the System.

TERRITORY

means the country of the Site of Installation.

THIRD PARTY SOFTWARE

means the Software owned by third parties.

TURNKEY SERVICES

means the services more particularly detailed in Appendix 2d.

"VERSORGUNGSGEBIET"

means the area as defined in Appendix 4 a+b Section 1.

WORKING DAY

means Monday to Friday inclusive.

                                  Page 6 of 6
<PAGE>

                                  European Agreement
                                       Appendix 6
                                  List of Affiliates

                              APPENDIX 6 - LIST OF AFFILIATES

DOCUMENT

<TABLE>

<S>                                      <C>
-----------------------------------------------------------------------------------------------
DOCUMENT NAME                            Appendix 6 - List of Affiliates
-----------------------------------------------------------------------------------------------
BACKGROUND                               Appendix 6 of the European Agreement between FirstMark
                                         Europe SA and Siemens AG

                                         List of Purchaser's and Contractor's affiliates
-----------------------------------------------------------------------------------------------
</TABLE>

The European Agreement shall be valid for the Purchasers Contractors
Affiliates listed hereunder and the respective countries related to it (see
respective countries named by each Affiliate)

<PAGE>

                                  European Agreement
                                      Appendix 6
                                  List of Affiliates

1  FIRSTMARK'S AFFILIATES

     -  FirstMark Communications Deutschland GmbH, Uhlandstrasse 179/180,
        10623 Berlin, Germany

     -  FirstMark Communications GmbH, Teinfalstrasse 8, 1010 Vienna, Austria

     -  FirstMark Communications Belgium SPRL, Montagne du Parc 4, 1000
        Bruxelles, Belgium

     -  FirstMark Communications Denmark, c/o Bech-Brunn & Trolle, Norre
        Farimagsgade 3, 1364 Copenhagen K, Denmark

     -  FirstMark Communications Services Europe Limited, Hillgate House, 26
        Old Bailey, London EC4M 7HS, England

     -  FirstMark Communications Finland Oy, PL 151, 00161 Helsinki, Finland

     -  FirstMark Communications France Sarl, 1 Boulevard Vivier Merle, 69443
        Lyon, Cedex 03, France

     -  FirstMark Communications Hungary, 1112 Budapest, Nagyszalonta u. 49,
        Hungary

     -  FirstMark Communications Italy Srl, Via 20 Settembre, No. 1 00187
        Rome, Italy

     -  FirstMark Communications Luxembourg Sarl, 5 rue Jean Monnet, 2180
        Luxembourg, Luxembourg

     -  FirstMark Communications Netherlands B.V., Strawinskylaan 1725 Toren
        B, 17 ET 1077 XX Amsterdam, Netherlands

     -  FirstMark Communications Norway, Norway

     -  Teleweb, Comunicacoes Interactivas SA, Campo Grande 35-3B, 1700
        Lisboa, Portugal

     -  FirstMark Communications Poland, Poland

     -  FirstMark Communications Espana SL, Paseo de la Castellana 110, 28046
        Madrid Spain

     -  FirstMark Communications Switzerland GmBH, Inhaber Lichsteiner &
        Sauber Rechtsanwalte, Binzmuehlstrasse 14, 8050 Zurich, Switzerland

     -  LambdaNet GmbH, Gunther-Wagner-Allee 13, 30177 Hannover, Germany

     -  LambdaNet, 17 Square Edouard VII, 75009 Paris, France

<PAGE>

                                  European Agreement
                                      Appendix 6
                                  List of Affiliates

2 SIEMENS' AFFILIATES

     - Siemens AG, Germany, Wittelsbacher Platz 2, 80333 Munchen, Germany

     - Siemens Aktiengesellschaft Osterreich, Siemensstrasse 88-92, 1210
       Vienna, Austria

     - Siemens s.a., Belgium, Chaussee de Charleroi 116, 1060 Bruxelles,
       Belgium

     - Siemens A/S, Denmark, Borupvang 3, 2750 Ballerup, Denmark

     - Siemens plc. United Kingdom, England, Siemens House, Oldbury, Bracknell
       RG12 8FZ, United Kingdom

     - Siemens Osakeyhtlo, finland, Majurinkatu 6, P.O.B. 60, 02601, Espoo,
       Finland

     - Siemens S.A., France, 39-47 boulevard Ornano, 93527 Saint-Denis
       CEDEX 2, France

     - Siemens Rt., Hungary, Gizella ut 51-57, 1143 Budapest, Hungary

     - Siemens S.p.A., Italy, Viale Piero e Alberto Pirelli, 10, 20126
       Milano, Italy

     - Siemens S.A., Luxembourg, 20, rue des Peupliers, 2328 Luxembourg-Hamm

     - Siemens Nederland N.V., Netherlands, Prinses Beatrixlaan 26, 2595
       AL Den Haag, Netherlands

     - Siemens A/S, Norway, Ostre Aker vel 90, Postboks 10, Veitvet, 0518
       Oslo 5, Norway

     - Siemens S.A., Portugal, Rua Irmaos Siemens, 1, 2720-093 Amadora,
       Portugal

     - Siemens Sp.z.o.o., Poloand, ul. Zupnicza 11, 03-821 Warszawa, Poland

     - Siemens S.A., Spain, Orense 2, Apartado 155, 28 020 Madrid, Spain

     - Siemens Schweiz AG, Switzerland, Freilagerstrasse 40, Postfach,
       8047 Zurich, Switzerland

<PAGE>

                   FIRSTMARK COMMUNICATIONS DEUTSCHLAND GMBH
                              UHLANDSTRASSE 179/180
                                  10623 BERLIN
                                     GERMANY

Siemens A.G.

20 April 2000

Dear [          ],

RE:  MARKETING AGREEMENT BETWEEN SIEMENS A.G. ("SIEMENS") AND FIRSTMARK
COMMUNICATIONS DEUTSCHLAND GMBH ("FIRSTMARK")

In mutual recognition that time is of the essence hereunder, FirstMark hereby
issues this letter agreement to Siemens in anticipation of FirstMark and Siemens
entering into a full definitive written agreement (hereinafter referred to as
"the Full Agreement") for the marketing of FirstMark products and services in
Germany. The Full Agreement will contain terms and conditions substantially in
the same form as those attached as Annex 1. In addition, the Full Agreement
shall also include terms dealing with the following matters:

-        Default;
-        Termination
-        Effects of Termination;
-        Trademark Use;
-        Intellectual Property;
-        No partnership;
-        Notices;
-        Waiver;
-        Entire Agreeement;
-        Assignment; and
-        Force Majeure.
-        Exclusion of Liability

By acceptance of this letter agreement, FirstMark and Siemens agree to negotiate
promptly and in good faith for the purpose of agreeing and executing the Full
Agreement no later than 30 June 2000.

<PAGE>

PERIOD OF LETTER AGREEMENT

The effective date of this letter agreement is May _________ , 2000. This letter
agreement shall expire on 30 June

2000 unless:-

(a)  the parties, by agreement evidenced in writing, extend the period; or

(b) this letter agreement is terminated in accordance with any of the provisions
contained in the paragraph below headed Termination of Letter Agreement.

TERMINATION OF LETTER AGREEMENT

Execution of the Full Agreement shall supersede and replace all the provisions
contained in this letter agreement which shall thereupon automatically
terminate. This letter agreement may also be terminated by FirstMark or Siemens
upon the failure of FirstMark and Siemens to negotiate and execute the Full
Agreement within the period up to 30 June 2000 (or such later date as may be
agreed between the parties in writing).

GOVERNING LAW

This letter agreement shall be interpreted, construed, governed and enforced in
accordance with the laws of Germany and each of the parties agrees to submit to
the exclusive jurisdiction of the German Courts in relation to any dispute
arising hereunder or out of or in connection with any of the matters the subject
hereof.

This letter agreement and its appendices are produced in duplicate originals. By
signing each original FirstMark and Siemens accept the terms and conditions
contained herein and agrees to be bound by such terms and conditions in all
respects.

Yours faithfully
For and on behalf of

FirstMark Communications Deutschland GmbH

Accepted and agreed by /s/
                      ---------------------------------
                      For and on behalf of Siemens A.G.
<PAGE>

                                      DRAFT

                                MARKETING ANNEX 1

                                     between

                           SIEMENS AKTIENGESELLSCHAFT

                                Berlin and Munich

                    - henceforth referred to as "Siemens" -

                                       and

                       FIRSTMARK COMMUNICATIONS EUROPE, SA

                                     London
                                 United Kingdom

                      - henceforth referred to as "FMCE" -

                (described jointly as the "contractual parties")

                                    Page 1 of 7
<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
SECTION                                                                     PAGE

<S>                                                                         <C>
PREAMBLE.....................................................................3

1    OBJECT OF THE CONTRACT..................................................3

2    COOPERATION BASIS.......................................................4

3    OBLIGATIONS OF FMCE.....................................................4

4    OBLIGATIONS OF SIEMENS..................................................5

5    COMMISSION..............................................................6

6    AREA OF VALIDITY........................................................6

7    DURATION................................................................6

8    DISCONTINUATION CONDITIONS..............................................6

9    CONFIDENTIALITY.........................................................7
</TABLE>

                                  Page 2 of 7
<PAGE>

PREAMBLE

According to German telecommunications law, FMCE operates a telecommunications
network via which telecommunications services are provided to third parties.

Siemens provides its customers with advice on services, prices and benefits and
supports them in the selection and ordering of carrier services and the
integration of these services into customer-specific telecommunications
solutions.

1        OBJECT OF THE CONTRACT

1.1      Arranging of standard telecommunications services

        Siemens will assist FMCE for the conclusion of contracts for the
        provision of FMCE telecommunications services as described and presented
        by FMCE.

        Siemens shall obtain binding customer requests for FMCE for the
        completion of contracts in accordance with the specimens and FMCE
        general terms and conditions of business and transmit these to FMCE.

1.2      Arranging of project-specific telecommunications services

        Within appropriate projects, Siemens shall inform its customers about
        the telecommunications services provided by FMCE and obtain from FMCE
        project-specific offers that differ from the standard telecommunications
        services described under 1.1.

        FMCE has the right to refuse project-specific offers or contracts in
        individual cases. FMCE shall disclose to Siemens the reasons for such a
        refusal.

        Should an offer requested by Siemens result in the completion of a
        project-specific contract between FMCE and the customer supported by
        Siemens, this business shall be considered to have been brokered by
        Siemens.

1.3     The cooperation agreement applies to present and future
        telecommunications services provided by FMCE.

                                  Page 3 of 7
<PAGE>

2       COOPERATION BASIS

2.1     The cooperation between FMCE and Siemens shall be conducted on a
        non-exclusive basis. Both contractual parties shall be at liberty to
        enter into similar agreements with other contractual parties.

2.2     Both contractual parties may act independently of one another in the
        market.

2.3     Neither contractual party shall be authorized to act in the name of the
        other.

2.4     Publications by the contractual parties affecting the object of this
        cooperation must take a form that has been agreed in writing in advance.

3       OBLIGATIONS OF FMCE

3.1     FMCE undertakes to support Siemens in the arranging of its
        telecommunications services to the extent defined in this contract.

3.2     FMCE shall supply Siemens with all the information required to arrange
        these services and, if requested, shall provide Siemens with technical
        support for its telecommunications services.

3.3     FMCE shall supply Siemens with all the documentation needed for the
        brokering of contractual terms, such as order forms, general terms and
        conditions of business and up-to-date price lists in electronic form.

3.4     FMCE shall inform Siemens regularly and well in advance about its
        products and services or any changes in the range of products and
        services available.

        FMCE shall hold sales training courses in agreement with Siemens. These
        training courses, including all course material, shall be provided free
        of charge to Siemens.

3.5     FMCE shall support Siemens indirectly by means of marketing operations.

                                  Page 4 of 7
<PAGE>

3.6     FMCE will use its "best-effort" to ensure that customer requests that
        have been completed correctly and transmitted are processed.

3.7     FMCE shall inform Siemens without delay in the event that a customer
        request brokered by Siemens does not result in completion of a contract
        or that business agreed on the basis of such a customer request is not
        executed.

3.8     FMCE shall initiate the issue of invoices to customers brokered by
        Siemens and shall in particular take responsibility for its own
        collection and dunning procedures.

3.9     Furthermore, the contractual parties shall hold regular discussions to
        promote the cooperation agreed in the contract.

4        OBLIGATIONS OF SIEMENS

4.1     Siemens shall use its best effort to promote the sales of all FMCE
        telecommunications services.

4.2      Siemens' brokering activities shall include:

       -      Consulting with interested parties with regard to FMCE
              telecommunications services;

       -      Obtaining requests from customers for the completion of contracts
              with FMCE in accordance with the specimens and FMCE's general
              terms and conditions of business.

       -      Transmitting customer requests to FMCE without delay in accordance
              with a mutually agreed "Procedural description";

       -      Brokering project-specific business between FMCE and Siemens
              customers in cases where standard communications services are not
              appropriate.

4.3     Siemens undertakes to send only complete and legible customer requests
        to FMCE. If the error rate in request processing by FMCE exceeds 5%,
        FMCE must take appropriate short-term remedial action.

4.4     In its function as broker according to this contract, Siemens shall use
        only those documents, emblems and other sales aids that have been
        released by FMCE in order to preserve FMCE's corporate identity (CI).

4.5     Siemens shall set up a special and dedicated task force for a period of
        initially one year to monitor and to control the implementation of the
        sales cooperation agreement in Germany The task force shall report to
        the management of Siemens AG Carrier Sales and to a designated
        representative for FMCE on a bi-weekly basis. Siemens agrees to dedicate
        its best-effort to make FMCE's entry into the German market a success.

4.6     Siemens agrees to work with FMCE on a best-effort basis to accomplish
        the following timelines for the purposes of investigating the market
        potential and

                                  Page 5 of 7
<PAGE>

        establishing an associated commission plan for the first year of
        operation which will be monitored and managed by the task force defined
        in Section 4.5

        May 9              Kick-off meeting to review products, positioning,
                           pricing and plan for joint introduction of FMCE
                           services to Siemens sales force.

        May  29            Have successfully introduced FMCE products and
                           services to all regional sales heads of sales with
                           Siemens

        Jun 30             Have successfully completed a regional demand
                           forecast for FMCE products and services from the
                           Siemens sales force and have agreed on a mutually
                           acceptable commission agreement.

4.7     Siemens tries to achieve on a "Best Effort" basis the joint goal of a
        revenue target to be mutually defined for the first year of operation of
        this marketing agreement, such target being subject to the mutual
        agreement of the competitive position of FirstMark products and the
        attractiveness of the FMCE commission plan for the Siemens sales force
        (which will be the outcome of Section 4.7) and the Roll-Out for the
        PMP-Technology in Germany.

5        COMMISSION

5.1     FMCE shall pay Siemens a commission in return for arranging the
        brokering of FMCE telecommunications services.

5.2     The structure of the sales commission will be mutually agreed by
        management representatives of Siemens and FMCE by April 15th, 2000

6         AREA OF VALIDITY

       This agreement is valid within Germany

7         DURATION

       This agreement is valid indefinitely until terminated by either
       contractual party at any time with three months' written notice.

8        DISCONTINUATION CONDITIONS

       At any time either party may choose to terminate this Agreement by a
       written three months' notice to the company representative indicated at
       the end of this agreement.

                                  Page 6 of 7
<PAGE>

9        CONFIDENTIALITY

9.1    The contractual parties undertake to treat as confidential any technical
       documents and information, special knowledge of the other party's
       internal affairs and any other information that is classified as
       confidential by its nature or declared explicitly as such. In the absence
       of prior written agreement, the contractual parties shall use the
       information obtained only for the purposes for which it was supplied and,
       in the same way that they would treat their own trade secrets, ensure
       that it is not disclosed to third parties. Furthermore, they shall not
       use this information for their own commercial purposes or other customers
       without the prior written agreement of the other contractual party. This
       obligation does not apply to information that is widely known,
       information that is proven to have been elaborated independently or
       information that has been obtained legally from third parties.

9.2    Both parties shall also impose this obligation on their employees and any
       subcontractors involved in the fulfillment of the project concerned.

9.3    The confidentiality obligation remains in force for a period of two years
       after termination of the agreement. After termination, all documents
       obtained from the other contractual party in this context must be
       returned or destroyed on request.

      Munich, date ...........             Berlin, date ...............

      ..........................           ........................
      Siemens Aktiengesellschaft           FMCE Senior VP Marketing

                                  Page 7 of 7

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