Note:  Certain material has been omitted from this document
pursuant to a request for confidential treatment and has been
filed separately with the SEC.  Notations of  [redacted] have
been used to indicate such an omission.

              NETWORK PRODUCTS PURCHASE AGREEMENT

Northern Telecom Inc., a Delaware corporation having offices at
5555 Windward Parkway, Suite B, Alpharetta, Georgia 30201-3895
("Nortel") and Teligent, Inc., a Virginia corporation,  having
its principal offices and place of business at 8065 Leesburg
Pike, Suite 400, Vienna, Virginia 22182 ("Teligent") agree as
follows:

1.  SCOPE AND TERM

    1.1   Certain terms used in this Agreement shall be defined
          as set forth in Attachment A. In the case of any
          conflict between the main text of this Agreement and
          the Attachments hereto, the main text shall govern.

    1.2   Scope

          1.2.1 This Agreement sets forth the terms and
                conditions under which Teligent shall purchase
                and/or license, as applicable, certain
                Deliverables as set forth herein.

          [redacted]
          [redacted]

    1.3  This Agreement shall be binding on the Parties from
         the date executed, except that if on or prior to
         January 31, 1998 or such other date as Nortel and
         Teligent may mutually agree upon (the "Determination
         Date"), Nortel and Teligent have not entered into the
         Finance Agreement and the security documents
         contemplated thereby for any reason (a "Termination
         Event"), either Party shall have the right to
         terminate all the rights and obligations of both
         Parties under this Agreement, except those with
         respect to Core Deliverables ordered by Teligent, by
         delivery of five (5) days prior written notice of such
         termination.

         With respect to such Core Deliverables, Teligent may
    elect within fifteen (15) days after termination either (a)
    to keep the Core Deliverables, and in which case, Teligent
    shall pay Nortel for the purchase price of the Core
    Deliverables, less [redacted]  and Nortel's support obligations
    shall survive and continue in full force and effect with
    respect to such Core Deliverables; or (b) to return the
    Core Deliverables, paying a re-stocking fee of [redacted]
    of the Core Deliverables returned.


    If Teligent shall fail to make any such election, Teligent
    shall be deemed to have elected to return the Core
    Deliverables to Nortel.  Notwithstanding any election by
    Teligent to keep the Core Deliverables, Teligent may within
    fifteen (15) days after such election elect to return all
    Core Deliverables with respect to which it has not yet paid
    the reduced purchase price described in clause (a) above
    (such purchase price with respect to any item of Core
    Deliverables, the "Item Purchase Price") otherwise as
    provided in clause (b) above.

    If Teligent fails to pay the Item Purchase Price, or any
    portion thereof, for any item of Core Deliverables (each an
    "Item") within thirty (30) days after receipt of Notice
    from Nortel that such amounts were not paid when due, a
    "Return Event" shall be deemed to have occurred. At any
    time after the occurrence and during the continuation of a
    Return Event, Nortel may demand the return of the Item with
    respect to which such Return Event has occurred and
    Teligent shall promptly provide for the return of such Item
    to Nortel as provided below.  Upon the return of any Item
    to Nortel, Nortel shall promptly refund to Teligent an
    amount equal to all payments received by it in respect of
    the Item Purchase Price for such Item [redacted] of such
    Item Purchase Price.

    If Teligent shall, for any reason, be required to return
    any Item under this Section 1. 3, Teligent shall make such
    Item available for return on the premises or facility where
    such Item is then located and Nortel shall be entitled to
    remove such Item during normal business hours or, if
    requested by Nortel, Teligent shall, at Nortel's sole
    expense, deliver such Item, or cause such Item to be
    delivered, to any location in the continental United States
    requested by Nortel.

    Except as expressly set forth in this Section 1.3, Teligent
    shall have no obligation or liability whatsoever in
    connection with the return of any Core Deliverables
    (including, without limitation, in connection with a Return
    Event) arising out of a Termination Event.  Unless Teligent
    expressly elects to keep certain Core Deliverables as
    provided in this Section 1.3, nothing contained in this
    Section 1.3 or in Section 4.6 shall constitute, or be
    deemed to constitute, an obligation of Teligent to purchase
    any Item or to pay any purchase price in respect of an
    Item; provided, that if no Termination Event shall have
    occurred on or prior to the Determination Date, this
    Section 1.3 shall no longer apply and shall have no further
    effect.

    [redacted]

    [redacted]

    [redacted]

    1.5  Turn-Key Services


         1.5.1  Nortel shall offer Buyer the option to purchase
                from Nortel Services on both a full turn-key
                (including engineering services but excluding
                civil works) and a partial turn-key basis as set
                forth in the Statement of Work, attached hereto
                as Attachment H.

         1.5.2  Buyer shall be responsible for any and all civil
                works required under this Agreement, including
                those set forth in the Buyer's Obligation Section
                of the Statement of Work, as set forth in
                Attachment H.  Nortel and Buyer shall mutually
                agree upon civil works ready dates when
                developing detailed Core Deliverables schedules.

         1.5.3  Nortel shall use only its own personnel or
                Nortel-qualified third-party service contractors
                and Nortel shall warrant their performance as set
                forth in Section 10.  Buyer may reasonably
                request the removal of any Nortel personnel or
                third-party service contractor and Nortel shall
                promptly comply.

    1.6  Nortel shall use all reasonable efforts to furnish and
         install Core Deliverables so that such Core
         Deliverables shall comply in all material respects
         with all federal, state and local laws and regulations
         in force on the date of execution of this Agreement,
         which directly impose obligations upon the
         manufacturer, seller or installer thereof.  Notwithstanding
         the foregoing, Buyer acknowledges that certain Core
         Deliverables have not yet received required type
         approval from the Federal Communications Commission
         ("FCC"). Nortel's obligation to furnish Core Deliverables to
         Buyer is expressly conditioned upon Nortel or its
         Teligent-Approved Radio Vendor receiving FCC Core Deliverables
         type approval prior to delivery of such Core Deliverables,
         unless Buyer can reasonably demonstrate to Nortel that such type
         approval is not required for operation of such Core
         Deliverables by Buyer, (e.g., situations where Buyer
         operates the Core Deliverables under an FCC
         experimental license).  The failure of Nortel or its
         Teligent-Approved Radio Vendor to receive necessary
         Core Deliverables type approval from the FCC and to
         meet other federal, state and local regulatory
         requirements shall be regarded as a Force Majeure
         event under Section 13 of this Agreement.

         Nortel warrants that it and its Teligent-Approved
    Radio Vendor are vigorously prosecuting the necessary FCC
    type-approval application(s). Any failure by Nortel or its
    Teligent-Approved Radio Vendor to use all reasonable
    efforts to obtain FCC Type-approval prior to the General
    Availability Dates for such Core Deliverables as specified
    in Attachment F shall be grounds for Material Breach and
    give rise to Teligent's right to terminate for cause.


    1.7  Term

         1.7.1  This Agreement shall be in effect on the date
                last executed and continue for a period of five
                (5) years thereafter ("Term").  This Agreement or
                any part thereof may be terminated in accordance
                with the express provisions of this Agreement
                concerning termination or by written agreement of
                the Parties.

         1.7.2  The termination of this Agreement or any part
                thereof shall not affect the obligations of
                either Party thereunder which have not been fully
                performed with respect to any accepted Order,
                unless such Order is expressly terminated in
                accordance with this Agreement or by written
                agreement of the Parties.

2.  PURCHASES OF CORE DELIVERABLES

    2.1  Deliverables

         2.1.1  For purposes of this Agreement, the definition of
                "Core Deliverables" shall mean any  Services,
                Equipment and Software, including Radio Products,
                drawings, documents, manuals and training,
                supplied directly by Nortel including any
                equipment not Nortel-branded ("OEM Equipment"),
                even if such OEM Equipment is not part of
                Nortel's standard product offerings.

         2.1.2  For purposes of this Agreement, the definition of
                "Adjunct Deliverables" shall mean any
                telecommunications support products supplied by
                third parties, including ancillary services,
                directly to Teligent that are in the categories
                described in Attachment E, attached hereto, and
                used in connection with Core Deliverables.
                Teligent shall have the right to acquire and
                install in its network any Adjunct Deliverable if
                it is compatible with the Core Deliverables and
                in compliance with industry standard interfaces,
                or if Teligent assumes the responsibility for
                such equipment's non-compliance.

         2.1.3  Before procuring any Adjunct Deliverables,
                [redacted].  In the event Buyer purchases any
                Adjunct Deliverable from Nortel, such equipment
                shall be considered to be a Core Deliverable and
                not an Adjunct Deliverable.  Nortel shall provide
                Buyer support of such equipment as if it were
                non-OEM Equipment Core Deliverables.


         2.1.4  Teligent further agrees that by the end of the
                twelfth (12th) month from the effective date of
                this Agreement, as defined in Section 1.7.1
                herein, at least [redacted]  percent [redacted]
                of the total purchase price of Deliverables
                financed by Nortel shall be Core Deliverables. By
                the end of the [redacted]  month of from the
                effective date of this Agreement and on an annual
                basis thereafter, Teligent agrees that at least
                [redacted]  of the total purchase price of all
                Deliverables financed by Nortel from the
                effective date of this Agreement shall be Core
                Deliverables.  These ratios shall include Core
                Deliverables then on order for delivery under the
                Standard Intervals set forth in Section 8.  In
                the event that at the end of the [redacted]
                month from the effective date of this Agreement,
                and for any following [redacted]  month period
                thereafter, Teligent has failed to purchase
                enough Core Deliverables to meet the above
                required percentages, then Teligent shall issue
                within ninety (90) days additional Orders for
                Core Deliverables for delivery within Standard
                Intervals sufficient so as to meet the required
                percentages.

    2.2  Teligent-Approved Radio Vendor

         2.2.1  Microwave transmission Products supplied as Core
                Deliverables shall be made only by Teligent-
                Approved Radio Vendors. Nortel shall be
                responsible for managing Teligent-Approved Radio
                Vendors in connection with this Agreement.

         [redacted]

         2.2.3  The process for establishing other Teligent-
                Approved Radio Vendors shall be as follows:

                - In consultation with Teligent senior
                engineering staff, Nortel shall propose specific
                new Microwave Product(s) to add to the Core
                Deliverables in Attachment G, together with
                pricing and specifications therefor.

                - Teligent may elect to trial the equipment, with
                Nortel and the vendor of the proposed Product,
                according to mutually-agreed costs, tests and
                scheduling, or Teligent may reject the proposal.

                - If, based on the trial results and other
                investigation of the proposed vendor's processes
                and capabilities, Teligent is satisfied that the
                Product should be added to the Core Deliverables
                list, Teligent shall notify Nortel in writing
                that the vendor is a Teligent-Approved Radio
                Vendor for that Product and Attachment G shall
                accordingly be modified.

                - Teligent may refuse to certify a vendor or its
                product in its sole, reasonable discretion and
                shall provide Nortel the technical and business
                reasons for such refusal to certify.

         2.2.4  If a Teligent-Approved Radio Vendor is added or
                dropped, the Parties recognize that changes may
                be necessary to various terms of this Agreement
                including the Future Deliverables set forth in
                Attachment F.  The Parties shall negotiate in
                good faith on such changes.

3.  FORECASTS,  ORDERING AND ADMINISTRATION

    3.1  Forecasts

         3.1.1  Teligent hereby agrees that within one (1) week
                of the effective date of this Agreement, Teligent
                shall provide Nortel an initial forecast covering
                four (4) quarters of  Core Deliverables to be
                purchased during the first year of this
                Agreement.  Such initial forecast shall also
                include a firm Order for Teligent's Core
                Deliverables as required to be purchased under
                Section 3.1.2.

         3.1.2  Teligent shall provide Nortel a rolling twelve
                (12) month forecast ("Yearly Forecast") covering
                Core Deliverables to be purchased. Such Yearly
                Forecast shall detail the Core Deliverables by
                product and quantities.  Teligent shall update
                the Yearly Forecast on a quarterly basis.
                Teligent agrees that the first three (3) months
                of such Yearly Forecast of Core Deliverables
                shall represent a non-reducible binding purchase
                commitment, and at least fifty percent (50%) of
                the second three (3) months of each Yearly
                Forecast of  Core Deliverables shall also be
                binding.

        3.1.3  Nortel shall be obligated to deliver to Buyer up
               to one hundred ten percent (110%) of the first
               three (3) months of the Yearly Forecast for each
               type of Core Deliverable products, if ordered, in
               accordance with the Standard Intervals set forth
               in Section 8.  Core Deliverables in excess of one
               hundred ten percent (110%) of the first three (3)
               months of the Yearly Forecast for such Core
               Deliverables shall be delivered in accordance
               with Nortel's usual delivery intervals or as
               mutually agreed by Nortel and Buyer.

   3.2 Orders

       3.2.1  All purchases of Core Deliverables pursuant to
              this Agreement shall be made by means of Orders
              issued from time to time by Buyer. Such Order
              shall be accepted or rejected by Nortel in
              writing within five (5) business days.  If not
              expressly rejected, an acknowledged Order will be
              deemed accepted.  All Orders shall reference this
              Agreement and shall be governed solely by the
              terms and conditions set forth herein.

       3.2.2  When Buyer desires to order Core Deliverables, if
              any, Buyer shall submit to Nortel's designated
              representative as defined in Section 3.3, an
              Order which shall at a minimum specify the
              following, if applicable:

              (i)    the name of the Buyer placing the Order;

              (ii)   the types and quantities of Core
                     Deliverables, if any, to be furnished by
                     Nortel;

              (iii)  the applicable prices, charges and fees with
                     respect to such  Core Deliverables, if any;

              (iv)   the location or facility to which the Core
                     Deliverables are to be delivered;

              (v)    the incorporation by reference of this
                     Agreement;

              (vi)   the location at which the Core Deliverables
                     are to be installed, if known;

              (vii)  the requested delivery date and/or in-
                     service date;

              (viii) any other information required under this
                     Agreement to be included in an Order.

       3.2.3  Orders shall specify if any Nortel installation
              Services are required, and Buyer shall provide
              Nortel all necessary information related to final
              delivery destination and such installation
              Services at least two (2) weeks prior to the
              delivery date set forth in such Order.

       3.2.4  An Order submitted pursuant to this Agreement,
              and which Nortel has accepted, shall constitute a
              Contract between the Buyer ordering and Nortel.
              As long as this Agreement is effective, Nortel
              may only reject an Order if such Order is not in
              accordance with the provisions of Section 3.2.2
              above, and in that event, Nortel shall
              specifically identify the precise reasons under
              which it rejects such Order.  The foregoing does
              not limit any rights Nortel may have under
              Section 3.1.3.


       3.2.5  Buyer may at any time request additions,
              alterations, deductions or deviations to an Order
              subject to the condition that such changes and
              any adjustments resulting from such changes
              including, but not limited to, schedules and
              prices, shall be mutually agreed upon and, if so
              agreed, subsequently detailed in a written
              revision to the applicable Order  ("Change
              Order").  Buyer acknowledges that a premium
              charge may be applied by Nortel should Nortel
              agree to process a Change Order outside of its
              standard Order processing cycle for a Core
              Deliverable or in the event that a Change Order
              requires an additional amount of work (such as
              engineering) to be undertaken to comply with such
              changes.

       3.2.6  Buyer's original Order for each new System shall
              be so identified. Buyer may place supplemental
              Orders amending the original Order for each
              System to add Node Equipment for sixty (60) days
              from the issuance of the original Order, and to
              add TAS equipment for ninety (90) days from the
              issuance of the original Order, as long as the
              TCO configuration is not changed, unless Nortel
              shall consent to any configuration change.  All
              such Core Deliverables so ordered shall
              constitute the System.

  3.3  Administration

       3.3.1  Each Party shall delegate a Program Manager
              sufficient authority to administer day-to-day
              contract administration matters.

       3.3.2  Five (5) business days prior to the submission of
              each quarterly forecast described in Section
              3.1.2, Nortel's Program Manager shall submit to
              Buyer's Program Manager an "Issues and Status
              Report", identifying issues and matters requiring
              resolution from Nortel's perspective.
              Concurrently with the purchase forecasts
              described in Section 3.1.2, the Buyer's Program
              Manager shall submit to Nortel's Program Manager
              an "Issues and Status Report" identifying issues
              and matters requiring resolution from Buyer's
              perspective. Within ten (10) business days after
              receiving this report, both Program Managers
              shall jointly prepare a report confirming the
              current forecast and addressing the issues and
              matters identified in the two (2) reports,
              proposing specific steps to resolve them.  These
              reports shall be prepared in a manner appropriate
              for submission to senior management responsible
              for oversight of the Parties' relationship.


4. PRICES

   4.1 Preferred Supplier  Pricing

       4.1.1  Price models for Teligent Central Offices
              ("TCOs") and Teligent Nodes ("Nodes"), as set
              forth in Attachment G, include equipment
              engineering, installation, commissioning and
              testing services.  Teligent Access Site ("TASs")
              models, as set forth in Attachment G, are priced
              with and without installation.   If installation,
              commissioning, engineering and professional
              services and any other Core Deliverables,
              including OEM Equipment, are separately priced
              outside the Models, then they shall not be
              subject to the discounts set forth in Section
              4.1.2 or Section 4.2.

       [redacted]

   4.2 [redacted]

       4.2.1  [redacted]

       4.2.2  [redacted]

       4.2.3  [redacted]

       4.2.4  [redacted]

       4.2.5  The percentage discount for Cumulative Purchase
              Volumes shall be determined as follows:

              [redacted]

       4.2.6  [redacted]

       4.2.7  [redacted]

  4.3 Price Adjustments

       4.3.1  Except as specifically provided in this Section,
              the prices for Core Deliverables, whether
              purchased in packaged or component form,
              including Services, standard models, components
              and Merchandise, as set forth in Attachment G,
              [redacted]. If not included in Attachment G,
              prices for Core Deliverables shall be provided to
              Buyer on a quote by quote basis.  [redacted]

       4.3.2  Nortel agrees that pricing for the applicable
              [redacted], as set forth in Attachment
              G, with at least the functionality of Release
              24B2.0 and 16 QAM, shall decline by [redacted]
              effective the later of either two years after the
              effective date of this Agreement or when Buyer's
              aggregate purchases of [redacted],
              including monies paid to Nortel for installation,
              reaches [redacted].

       4.3.3  For the applicable Radio Products, Nortel shall
              offer Buyer additional functionality beyond
              Release 24B2.0 under the same discount schedules
              as applied to other Radio Products.  Any future
              features or functionality developed by Nortel for
              such Radio Products shall not be used as a basis
              for a price increase if they are: (a) not used by
              Buyer, or (b) beyond those identified in
              Attachment F if alternative Radio Products
              conforming to the features identified in
              Attachment F are not available from Nortel.

       4.3.4  Buyer may request TCO pricing to include
              technical support services as set forth in
              Section 18.4 and Nortel shall offer Buyer TCO
              pricing including such technical support for a
              metropolitan area.

       4.3.5  [redacted].

  4.4  [redacted]

  4.5  Nortel will prepay freight charges and the cost of any
       insurance requested by Buyer and invoice Buyer for
       these items at Nortel's [redacted].  These charges will appear
       as separate line items on Nortel's invoice.

  4.6  (a)  In order to secure the Return Obligations (as
       defined below), Buyer hereby grants Nortel a security
       interest in all of its right, title and interest in
       and to any item of the Core Deliverables in which it
       has a right, title and interest. As used in the
       Section 4.6, "Return Obligations" shall mean the
       obligations of Teligent to provide for the return of
       Core Deliverables if a Termination Event shall have
       occurred and Teligent shall be required pursuant to
       Section 1.3 to return said Core Deliverables to
       Nortel.

       (b)  The Buyer shall not sell, lease or otherwise
       dispose of any such item of Core Deliverables or any
       portion thereof, except, (i) to any wholly-owned
       subsidiary of the Buyer or any affiliate of the Buyer
       that is wholly-owned by the parent of the Borrower, or
       (ii) without the prior written consent of Nortel. The
       Buyer shall not permit to exist any liens, security
       interests or other encumbrances ("Liens") on any item of
       Core Deliverables, possession of which has been
       delivered to the Buyer, other than (a) the Liens created
       or contemplated hereby, (b) Liens for taxes or
       assessments, (c) any Liens arising by statute or
       operation of law, (d) Liens of carriers, warehousemen,
       mechanics, materialmen and repairmen, (e) Liens
       contemplated by the Finance Agreement, and (f) and other
       non-consensual Liens arising in the ordinary course of
       business.

       (c)  Buyer agrees to execute such documents and to
       take such other action reasonably requested by Nortel to
       perfect, maintain and preserve Nortel's security
       interest, including, without limitation, UCC financing
       statements.

       (d)  If Teligent shall fail to provide for the
       return of any Core Deliverables as provided in Section
       1.3 (a "Default"), Nortel shall have all of the rights
       and remedies of a secured party under the Uniform
       Commercial Code ("UCC") consistent with the nature of
       the Return Obligations. Upon the occurrence of a
       Default, without limiting the generality of the
       foregoing, to the extent permitted by, and in accordance
       with, all applicable laws, Nortel may without demand or
       notice to the Buyer, collect, receive or take possession
       of the Core Deliverables or any part thereof and for
       that purpose Nortel may enter upon any premises on which
       the Core Deliverables subject to such Default are
       located and remove the Core Deliverables subject to such
       Default therefrom.

       (e)  Nortel's security interests in each item of
       Core Deliverables granted pursuant to Section 4.6(a)
       above (each such item, a "Secured Item", and such items
       collectively, the "Secured Items") shall continue until
       the earlier of (i) the purchase price of such Secured
       Item is paid, or has been deemed to be paid, in full and
       (ii) such Secured Item is required to be returned to
       Nortel pursuant to Section 1.3 and such Secured Item has
       been returned, at which time, with respect to such
       Secured Item, (A) the Buyer's obligations and Nortel's
       rights and remedies under this Section 4.6 shall
       terminate and be of no further effect, (B) Nortel's
       security interest in such Secured Item shall terminate
       and hereby is terminated, and (C) Nortel shall execute
       and deliver such documents and instruments and take such
       other actions as may be reasonably requested by Teligent
       or any lender under the Finance Agreement to effect or
       evidence the termination of the obligations and security
       interests under this Section 4.6, including, without
       limitation, UCC termination statements. In order to
       provide Teligent with more favorable terms under the
       Finance Agreement, upon the request of Teligent or any
       lender under the Finance Agreement, Nortel agrees that
       it shall use reasonable commercial efforts to
       accommodate the requests of Teligent or such lender with
       respect to the priority of its security interests in the
       Secured Items, and shall cooperate with Teligent and
       such lender in amending the provisions hereof on such
       terms as are mutually acceptable to all such Parties.

5. TERMS OF PAYMENT

   5.1 Payments shall be due within [redacted]  calendar days
       from the invoice receipt, but penalties for late payment
       shall not be assessed until [redacted]  calendar days
       from invoice receipt.  Past due amounts shall accrue
       interest at the lending rate made available to Teligent
       as in the Finance Agreement.  Notwithstanding the
       foregoing, the final [redacted]  payment on a System
       shall not be due until the later of [redacted]  after
       invoice or [redacted]  business days after all Punch
       List items have been completed.

   5.2 Invoicing Schedule

       5.2.1  The Core Deliverables and Services in a System
              shall be invoiced as follows:

                   [redacted]  Upon delivery of Core
              Deliverables and/or Services, if any;

                   [redacted]  Upon completion of Turnover,
              as set forth in Section 9.1.2; and

                   [redacted]  Upon successful passage of the
              applicable Soak Period and closure of service-
              affecting items uncovered during the Soak Period.

                    [redacted]

       5.2.2  Orders for Core Deliverables outside of a System,
              including Merchandise, which require no
              installation by Nortel shall be invoiced at
              [redacted]  upon delivery to Buyer.

                    Orders for TASs outside of a System in which
              Nortel provides installation Services, or Orders
              in which the purchase price of Core Deliverables
              requiring Nortel installation Services is less
              than [redacted], shall be invoiced at [redacted]
              upon completion of installation and passage of
              any relevant ATPs.

                    Orders for Nodes and TCO Expansions which are
              not part of a System, and Orders requiring Nortel
              installation Services which exceed [redacted]
              shall be invoiced in accordance with the following
              schedule:

                    [redacted]  upon delivery;
                    [redacted]  upon completion of installation
              Services and passage of relevant ATPs; and
                    [redacted]  upon closure of Punch List.

      5.2.3  The initial list of spare parts for a System, as
             provided in Nortel's recommended spares list set
             forth in Attachment G shall be invoiced as set
             forth in Section 5.2.1.  Subsequent Orders for
             individual Merchandise spare parts, Documentation
             and software releases shall be invoiced [redacted]
             upon delivery.

      5.2.4  [redacted]

      5.2.5  [redacted]

  5.3 [redacted]

      5.3.1  [redacted]

      5.3.2  [redacted]

      5.3.3  [redacted]

  5.4 Nortel shall not be entitled to claim payment for
      partial deliveries where the effect of the partial
      delivery prevents Buyer from making beneficial use of
      the facilities in question.  If Buyer can make
      beneficial use of the facilities in question, then
      Nortel shall be entitled to payment for those goods or
      services delivered and performed.

  5.5 Where Core Deliverables that are part of a System Order
      have not been installed at the time of System ATP
      primarily due to circumstances within Buyer's control,
      then such Core Deliverables shall be deemed installed
      for purposes of invoicing and payment.

6. TAXES

   Unless Buyer furnishes Nortel with tax exemption certificates
   in a form acceptable to taxing authorities, Buyer shall, at
   Nortel's direction and pursuant to a valid invoice therefor,
   promptly pay to Nortel or pay directly to the applicable
   government or taxing authority, if requested by Nortel, taxes
   and charges which may be imposed by any federal, state, or
   local governmental or taxing authority arising hereunder,
   such as, but not limited to all such taxes and charges
   relating to the purchase, license, ownership, possession,
   use, operation and/or relocation of any Equipment, Software,
   or Services furnished by Nortel pursuant to this Agreement,
   excluding, however, all taxes computed upon the net income of
   Nortel.  Nortel shall cooperate with the electronic delivery
   of Software if requested by Teligent.  Teligent shall be
   obligated to pay associated penalties and interest only if
   such charges are imposed materially due to Teligent's
   negligent or deliberate failure to pay after being given
   adequate (at least thirty (30) days) notice of such tax
   liability.  Buyer's obligations pursuant to this Section 6
   shall survive any termination of this Agreement.

   Prices of imported equipment in the Core Deliverables, if
   any, are destination duty paid and applicable duties, if any,
   are included in the price.

7. RISK OF LOSS, TITLE AND DELIVERY

   7.1 Risk of loss or damage and title to Core Deliverables
       (excluding Software) shall pass to Buyer upon delivery
       to the loading dock at the installation site or other
       delivery location specified by Buyer in its Order, and
       Buyer shall keep such Core Deliverables fully insured
       for the total amount then due Nortel for such Core
       Deliverables.  Buyer shall cause its insurers with
       respect to such Core Deliverables to name Nortel as loss
       payee as Nortel's interests may appear. Nortel shall
       remain responsible at all times for loss caused by
       Nortel or its contractors.

   7.2 Buyer shall receive a license to use Software subject to
       the terms set forth in Attachment B.

   7.3 When Buyer submits an Order requesting Nortel provide
       installation, Nortel shall be responsible for all
       staging and delivery of Core Deliverables to the job
       site. When Nortel does not provide installation
       Services, delivery of Core Deliverables, shall be made
       to a designated Buyer warehouse.  In the event Buyer
       requests Nortel provide warehousing of Core Deliverables
       and Nortel has sufficient warehouse space available,
       Nortel shall make such warehouse space available and
       Buyer shall pay the cost of such warehousing, subject to
       the grace period and procedure set forth in Sections
       8.2.1 and 8.2.2.

8. INSTALLATION INTERVALS

   8.1 Installation Schedule

       8.1.1  Prior to Buyer placing an Order for installation
              Services for the First Commercial System, Nortel
              and Teligent shall agree to an installation
              schedule for such First Commercial System.

       8.1.2  Subsequent Systems shall be scheduled based upon
              the following lead times ("Standard Intervals").
              These Standard Intervals shall only apply to
              forecasted items:

                  TCO equipment for a System:
                    [redacted] from acceptance of Order to
                    completion of  installation and passage
                    of the TCO ATPs.

                  Host Digital Terminals ("HDT") and Passport
                  equipment:
                    [redacted] from acceptance of Order to
                    completion of installation and passage
                    of relevant ATPs.

                  Node equipment and TCO expansion equipment:
                    [redacted] from acceptance of Order to
                    completion of installation and passage
                    of the Node ATPs.

                  TAS equipment:
                    [redacted] from acceptance of Order to
                    delivery of complete units; or
                    [redacted] from acceptance of Order to
                    completion of installation, if so
                    specified in the Order, and passage of
                    the TAS ATPs.

  8.2 Installation Reschedule

      8.2.1  [redacted]

      8.2.2  In the event Buyer fails to provide Nortel advance
             notice of its desire as set forth above, Nortel
             shall  be entitled to warehouse such Core
             Deliverables and to invoice Buyer for all
             reasonable and directly associated costs incurred
             by Nortel for such warehousing associated with
             such rescheduling.


9. ACCEPTANCE TESTING, TURNOVER AND ACCEPTANCE

   9.1 Acceptance Testing

       9.1.1  The Parties shall mutually develop acceptance test
              procedures ("ATP") and pass/fail criteria for Core
              Deliverables installed by Nortel.  Such ATP shall
              consist of separate test plans for each of the
              major network elements provided by Nortel
              hereunder and, with respect to a System, an
              additional acceptance test plan for the System  as
              an integrated whole ("System ATP").

       9.1.2  [redacted]

       9.1.3  [redacted]

       9.1.4  [redacted]

       9.1.5  If Nortel does not install the Core Deliverables
              furnished hereunder, Nortel shall, prior to
              delivery of such, perform factory acceptance tests
              in order to confirm that such Core Deliverables
              are in accordance with the applicable
              Specifications.  Nortel shall include with the
              shipment of any such Core Deliverables a certified
              copy of the test results demonstrating passage of
              such factory tests where normally available.
              Unless Buyer notifies Nortel to the contrary
              within [redacted] of the delivery of such Core
              Deliverables, Buyer shall be deemed to have
              accepted such Core Deliverables based upon such
              tests and acceptance shall be deemed to have
              occurred upon the delivery of such Core
              Deliverables.

       9.1.6  Merchandise equipment shall be deemed accepted upon
              delivery to the Buyer.  Services which are
              purchased separately from a System shall be deemed
              to be accepted upon completion of such Services.

       9.1.7  [redacted]

       9.1.8  [redacted]

       9.1.9  [redacted]

       9.1.10 [redacted]

       9.1.11 In the event Buyer notifies Nortel of non-
              acceptance of a Core Deliverable and Nortel
              personnel travels to Buyer's installation site to
              remedy such non-acceptance and determines that
              non-acceptance is due primarily to a deficiency of
              the nature described in Section 9.1.10, Nortel may
              invoice Buyer for investigation of the matter,
              including the standard labor rate for Nortel's
              personnel who travel to Buyer's installation site
              and reasonable travel and living expenses incurred
              by such personnel.

  9.2 Nortel acknowledges that Buyer may from time to time
      install certain Adjunct Deliverables not purchased
      through Nortel, and connect such Adjunct Deliverables to
      Nortel's Core Deliverables through standardized
      interfaces.  Therefore, the Parties hereby agree, that
      during such situations when Adjunct Deliverables are
      installed, by either Nortel or Buyer, at the time of
      acceptance testing, the System ATP shall verify the
      proper function of the relevant standardized interface;
      and where it is verified during such System ATP that
      such Adjunct Deliverables comply with the relevant
      interface specification, the attachment of such Adjunct
      Deliverables to Core Deliverables shall not diminish
      Nortel's warranty on the Core Deliverables.

  9.3 [redacted]

      9.3.1 [redacted]

      9.3.2  [redacted]

  9.4 Nortel agrees that the Core Deliverables, [redacted]
      shall comply with open interface standards TR-08 and TR-
      303 and other relevant Bellcore standards for switch
      interfaces.

  9.5 Nortel shall not ship Core Deliverables unless such Core
      Deliverables have passed Nortel's standard factory
      tests.  Teligent shall have the right to inspect
      Nortel's manufacturing facility upon reasonable notice.
      Teligent shall also have the right to request from
      Nortel an annual quality audit.

10. LIMITED WARRANTIES AND REMEDIES

   10.1 Nortel warrants that the Core Deliverables shall meet or
        exceed the performance Specifications in Attachment L,
        or if Attachment L is silent, in Nortel's current
        published specifications, for the lesser of [redacted]
        from Turnover or [redacted] from delivery ("Warranty
        Period") under normal use and service such equipment and
        will be free from defective material and faulty
        workmanship.  The Warranty Period may be extended at
        Teligent's option for an additional [redacted] upon
        payment of a warranty extension fee.  The foregoing
        warranty shall not apply to items normally consumed
        during operation of Core Deliverables such as, but not
        limited to, lamps and fuses.  Any installation Service
        performed by Nortel will be free from defects in
        workmanship for a period [redacted] from the completion
        date of such Service.  The performance by Nortel of any
        of its obligations described herein shall not extend the
        applicable Warranty Period.

   10.2 Subject to Section 10.9, Nortel's obligation under the
        warranty set forth in Section 10.1 above shall be
        limited to the replacement or repair, at Nortel's option
        and expense, of the defective Core Deliverables, or
        correction of the defective installation Services.
        Replacement Core Deliverables may be new or
        reconditioned at Nortel's option, and shall be warranted
        for the balance of the Warranty Period of the original
        equipment, or for 90 days, whichever is longer.

   10.3 If Core Deliverables are not free from defects in
        material or workmanship and/or fail to comply with the
        applicable Specifications during the Warranty Period,
        Nortel shall repair, replace or modify the Core
        Deliverables so that they do comply with the applicable
        Specifications within [redacted] following receipt of
        such defective Core Deliverables, or within [redacted]
        on an emergency basis, if requested expressly by
        Teligent as set forth in Section 18.3. Subject to the
        provisions of Section 10.9, Nortel's obligation under
        this Section 10.3 shall be limited to repair,
        modification or replacement of the defective Core
        Deliverables or correction of the defective installation
        Services.

   10.4 Nortel warrants that any Software licensed by Nortel to
        Buyer under this Agreement shall function during the
        Warranty Period of the Equipment (but in any event not
        less than [redacted]) with respect to which such
        Software is furnished without any material, service-
        affecting nonconformance to the applicable
        Specifications, provided that Buyer shall have paid all
        Software support fees.  If the Software fails to so
        function, Buyer's sole remedy and Nortel's sole
        obligation under this warranty is for Nortel to correct
        promptly such failure to ensure that the Equipment
        performs to Specifications, if the Specifications
        adequately address the service-affecting aspects of the
        failure, or, if the Specifications do not adequately
        address the service-affecting failure, Nortel shall
        correct promptly such failure to Teligent's reasonable
        satisfaction, through, at Nortel's option, the
        replacement or modification of the Software or such
        other actions as Nortel reasonably determines to be
        appropriate. Any continuing service-affecting Software
        failure that materially affects the performance of Core
        Deliverables shall be treated under Section 10.9, below.

   10.5 Nortel's warranties in Section 10.4 above shall only
        apply to the portion of the Software actually developed
        by Nortel, its Affiliates or Teligent-Approved Radio
        Vendors. All other Software shall be provided by Nortel
        "AS IS". Nortel shall assign to Buyer on a nonexclusive
        basis any warranty on such other Software provided to
        Nortel by the developer of such other Software to the
        extent of Nortel's legal right to do so.  Nortel shall
        identify any such Software and the extent to which such
        warranties are assigned prior to shipment.

   10.6 Major Outage Warranty

        10.6.1 [redacted]  During the System Availability
               Warranty Period, Nortel warrants to Teligent that
               Major Outages, as defined in Section 10.6.2,
               not attributable to Teligent or a third
               party's error, resulting from failures of Nortel's
               Core Deliverables shall be limited to [redacted]
               cumulative during any calendar quarter. Scheduled
               outages for any given System shall not be counted
               against this limit, as long as: (a) a scheduled
               outage is of less than [redacted] duration, and
               (b) there are no more than [redacted] scheduled
               outages during a given calendar quarter.
               [redacted] Excluded from this System Availability
               Warranty are outages due to failure by personnel,
               not contracted or certified by Nortel, to properly
               maintain the Core Deliverables or to follow Nortel
               documents provided to Buyer; third-party events or
               equipment; and Force Majeure events.  Such liquidated
               damages are to be paid in credits that may be applied
               against outstanding invoices and/or future Orders
               placed by Teligent under this Agreement.

        10.6.2 For purposes of this Agreement, "Major
               Outages" shall mean (a) an unscheduled loss of
               engineered and installed call or data processing
               capacity (as measured by the most limiting
               capacity parameter) in excess of [redacted] or
               (b) or any unscheduled service-affecting failure
               in [redacted] or more of the Nodes (but at least
               [redacted] Nodes) at any one time (according to
               the system logs).

        10.6.3 The System Availability Warranty shall apply
               only to Systems in which the Core Deliverables
               affected by the Major Outage are purchased
               according to the models shown in Attachment G, or
               if the Core Deliverables are of non-standard
               configurations or have been re-engineered for
               growth, if the standard recommended spares in
               connection therewith have been purchased and the
               engineered redundancy in the Core Deliverables is
               as recommended by Nortel, such engineered
               redundancy to be consistent with that reflected in
               the standard models.

        10.6.4 In no event shall Nortel's liability for such
               penalties pursuant to this Section 10.6 exceed
               [redacted].

  10.7  Parameter Warranty

        [redacted]


  10.8  Capacity Warranty

        10.8.1 During the Term, Nortel warrants the capacity
               of the Core Deliverables as specified in
               Attachment L and its published Specifications.
               For Radio Products, capacity is limited to that
               specified in Section 10.7(d) minus necessary
               overhead (i.e., for [redacted] available bandwidth
               for payload (user data rate) is [redacted].  For
               [redacted] the available payload is [redacted].)
               [redacted]  Nortel may reduce the capacity based
               on the provisioning and priority given to
               different traffic types, as long as it
               demonstrates to Teligent's satisfaction how it
               proposes such reduction be made. Additional
               equipment and costs directly attributable to this
               breach of this Warranty shall be negotiated by the
               Parties in good faith.

        10.8.2 If Teligent chooses to license a new Software
               release, such upgrade may require changes to the
               capacity or purchases of additional Equipment.
               Each such Software release shall have a revised
               capacity warranty based on Teligent's new
               Equipment and Software configurations.  The
               warranty of the capacity of the Core Deliverables
               shall be contingent upon Buyer having maintenance
               on such Core Deliverables adequately and properly
               performed.


  10.9  During the Warranty Period, in the event Nortel is
        unable to repair or replace a defective Core Deliverable
        which is service affecting, and Nortel's inability to
        repair or replace such material and service affecting
        defective Core Deliverable exceeds a period of
        [redacted] then, at Buyer's election, Nortel shall
        remove such service affecting defective Core
        Deliverable, at Nortel's expense, and reimburse Buyer
        for any costs or expenses Buyer may incur as a result of
        the reinstallation of equivalent non-defective product
        or equipment as well as reimburse Buyer the full Order
        price of the defective Core Deliverable. Buyer shall
        submit to Nortel an invoice for such reinstallation
        costs or expenses and Nortel shall pay Buyer for such
        amounts. The obligations and remedies set forth herein
        shall be subject to the conditions set forth in Section 12.

  10.10 The obligations and remedies set forth in this Section
        10 shall be conditional upon: the Buyer having properly
        installed, repaired and maintained the Equipment using
        Nortel-qualified personnel; the Software not having been
        modified; no material failure of Buyer to comply with
        Buyer's Obligations, as set forth in the Statement of
        Work, any defect or nonconformance not being the result
        of mishandling, abuse, misuse, improper storage,
        maintenance or operation by other than Nortel (including
        use in conjunction with any product which is
        incompatible with the applicable Core Deliverables or of
        inferior performance, except as provided in Section
        9.2), and/or any error, act, or omission of Buyer
        described in Section 12.5; the Core Deliverables not
        having been damaged by fire, explosion, power failure,
        power surge, or other power irregularity, lightning,
        failure to comply with all applicable environmental
        requirements for the Core Deliverables specified by
        Nortel or any other applicable supplier, such as but not
        limited to temperature or humidity ranges, or any act of
        God, nature or public enemy; and written notice of the
        defect having been given to Nortel within the applicable
        Warranty Period.

  10.11 The performance by Nortel of any of its obligations in
        this Section shall not extend the applicable Warranty
        Period, except as specifically stated otherwise herein.

  10.12 Unless Nortel elects to repair or replace defective
        Equipment at Buyer's facility, all Equipment to be
        repaired or replaced, whether in or out of warranty,
        shall be packed by Buyer in accordance with Nortel's
        instructions and shipped at Buyer's expense and risk of
        loss to a location designated by Nortel.  Replacement
        Equipment shall be returned to Buyer at Nortel's expense
        and risk of loss.  Buyer shall ship the defective
        Equipment to Nortel within thirty (30) days of receipt
        of the replacement Equipment.  In the event Nortel fails
        to receive such defective Equipment within such thirty
        (30) day period, Nortel shall invoice Buyer for the
        replacement Equipment at the then-current price in
        effect therefor.

  10.13 If the Core Deliverables returned to Nortel pursuant to
        the immediately preceding paragraph are determined by
        Nortel to be beyond repair or are outside the Warranty
        Period, Nortel shall notify Buyer and if requested
        Nortel shall sell Buyer replacement Core Deliverables at
        the then-current contract price between the Parties for
        such Core Deliverables or if no such contract exists, at
        Nortel's then-current price for such Core Deliverables.
        Such repair and replacement Service and notice of any
        discontinuance of such repair and replacement Service
        shall be available for a minimum period set forth in
        Section 18.  This provision shall survive the expiration
        of this Agreement.

  10.14 Buyer shall bear risk of loss and shall pay for all
        transportation charges for Core Deliverables returned to
        Nortel and Nortel shall bear such risk and pay for
        transportation charges for repaired or replacement Core
        Deliverables shipped to Buyer.

  10.15 Subject to Section 2.1.3, with respect to any OEM
        Equipment furnished by Nortel to Buyer pursuant to this
        Agreement, Nortel shall assign to Buyer on a
        nonexclusive basis any warranty granted by the party
        that supplied such OEM Equipment to Nortel to the extent
        of Nortel's right to do so.

  10.16 Neither Nortel nor Nortel's suppliers, as appropriate,
        shall have any responsibility for warranties offered by
        Buyer to any of its customers. Buyer shall indemnify
        Nortel and Nortel's suppliers, as appropriate, with
        respect thereto.

  10.17 THE WARRANTIES AND REMEDIES SET FORTH IN THIS SECTION
        -----------------------------------------------------
        CONSTITUTE THE ONLY WARRANTIES OF NORTEL WITH RESPECT TO
        --------------------------------------------------------
        THE CORE DELIVERABLES AND SERVICES AND BUYER'S EXCLUSIVE
        --------------------------------------------------------
        REMEDIES IN THE EVENT SUCH WARRANTIES ARE BREACHED.
        --------------------------------------------------
        THEY ARE IN LIEU OF ALL OTHER WARRANTIES, WRITTEN OR
        ----------------------------------------------------
        ORAL, STATUTORY, EXPRESS OR IMPLIED, INCLUDING, WITHOUT
        -------------------------------------------------------
        LIMITATION ANY WARRANTY OF MERCHANTABILITY OR FITNESS
        -----------------------------------------------------
        FOR A PARTICULAR PURPOSE.  WITH RESPECT TO CLAIMS UNDER
        -------------------------------------------------------
        SECTION 10, NORTEL SHALL NOT BE LIABLE FOR ANY
        ----------------------------------------------
        INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY NATURE
        -------------------------------------------------
        WHATSOEVER, BEFORE OR AFTER THE PLACING OF ANY CORE
        ---------------------------------------------------
        DELIVERABLE INTO SERVICE.
        ------------------------

11. LIABILITY FOR BODILY INJURY, PROPERTY DAMAGE AND PATENT
    INFRINGEMENT

    11.1 A party hereto shall defend the other party against any
         suit, claim, or proceeding brought against the other
         party for direct damages due to bodily injuries
         (including death) or damage to tangible property which
         allegedly result from the negligence, act or omission of
         the defending party in the performance of this
         Agreement. The defending party shall pay all litigation
         costs, reasonable attorney's fees, settlement payments
         and such direct damages awarded or resulting from any
         such suit, claim or proceeding.


    11.2 Nortel shall defend Buyer against any suit, claim or
         proceeding brought against Buyer alleging that any Core
         Deliverables, excluding OEM Equipment, furnished
         hereunder infringe any patent, copyright, trademarks or
         trade secrets enforceable in the United States.  Nortel
         shall pay all litigation costs, reasonable attorney's
         fees, settlement payments and any damages awarded or
         resulting from any such suit, claim or proceeding. With
         respect to OEM Equipment, Nortel shall assign any rights
         with respect to infringement of patents, copyrights,
         trademarks, or trade secrets enforceable in the United
         States granted to Nortel by the supplier of such OEM
         Equipment to the extent of Nortel's right to do so.

    11.3 The party entitled to defense pursuant to Section 11.1
         or 11.2 shall promptly advise the party required to
         provide such defense  of the applicable suit, claim, or
         proceeding and shall cooperate with such party in the
         defense or settlement thereof.  The party required to
         provide such defense shall have sole control of the
         defense of the applicable suit, claim, or proceeding and
         of all negotiations for its settlement or compromise.

    11.4 Upon providing Buyer with notice of a potential or
         actual infringement claim, Nortel may (or in the case of
         an injunction, shall), at Nortel's option, either
         procure a right to use, replace or modify, or require
         the return of the affected Core Deliverable for a full
         refund of the purchase price for the Term of the
         Agreement and a refund of the depreciated value of the
         Core Deliverables thereafter.

    11.5 The obligations of Nortel hereunder with respect to any
         suit, claim, or proceeding described in Section 11.2
         shall not apply with respect to Core Deliverables which
         are (a) manufactured or supplied by Nortel in accordance
         with any design or any special instruction furnished by
         Buyer (excluding Buyer's requirement that Nortel's
         products comply with usual and customary industry
         standards), (b) used by Buyer in a manner or for a
         purpose not contemplated by this Agreement, or (c) used
         by Buyer in combination with other products not provided
         by Nortel, including, without limitation, any software
         developed solely by Buyer through the permitted use of
         Core Deliverables furnished hereunder, provided the
         infringement arises from such combination or the use
         thereof. Buyer shall indemnify and hold Nortel harmless
         against any loss, cost, expense, damage, settlement or
         other liability, including, but not limited to,
         attorneys' fees, which may be incurred by Nortel with
         respect to any suit, claim, or proceeding described in
         this Section 11.5.

    11.6 The provisions of Sections 11.2 through 11.5 state the
         entire liability of Nortel and its suppliers and the
         exclusive remedy of Buyer with respect to any suits,
         claims, or proceedings of the nature described in
         Section 11.2.  Nortel's total cumulative liability,
         pursuant to Sections 11.2 shall for each infringement
         claim not exceed [redacted] of the purchase price of the
         Core Deliverables giving rise to such claim.

    11.7 Each party's respective obligations pursuant to this
         Section shall survive any termination of this Agreement.

12. REMEDIES AND LIMITATION OF LIABILITY

    12.1 In the event of any material breach of this Agreement
         which shall continue for thirty (30) or more days after
         written notice of such breach (including a reasonably
         detailed statement of the nature of such breach) shall
         have been given to the breaching party by the aggrieved
         party, the aggrieved party shall be entitled at its
         option to avail itself of any and all remedies available
         at law or equity, except as otherwise provided in this
         Agreement.

    12.2 In addition to any other remedy that may be available to
         Buyer at law or equity, should Nortel fail to meet an
         in-service date as set forth in an accepted Order, and
         the cure period to remedy such failure shall have
         expired without cure, Buyer shall be entitled to cancel
         this Agreement upon thirty (30) days written notice to
         Nortel.  In the event of such cancellation, Buyer shall
         pay Nortel for all Core Deliverables delivered by Nortel
         prior to the cancellation of this Agreement which Buyer
         desires to retain; and Teligent shall not be responsible
         for any True-Up Amount, as set forth in Section 4.2.

    12.3 Nortel shall have the right to suspend its performance
         by written notice to Buyer and forthwith remove and take
         possession of all Core Deliverables that shall have been
         delivered to Buyer, if, prior to payment to Nortel of
         any amounts due pursuant to this Agreement with respect
         to such Core Deliverables, Buyer shall (a) become
         insolvent or bankrupt or cease, be unable, or admit in
         writing its inability, to pay all debts as they mature,
         or make a general assignment for the benefit of, or
         enter into any arrangement with, creditors, (b)
         authorize, apply for, or consent to the appointment of,
         a receiver, trustee, or liquidator of all or a
         substantial part of its assets or have proceedings
         seeking such appointment commenced against it which are
         not terminated within ninety (90) days of such
         commencement, or (c) file a voluntary petition under any
         bankruptcy or insolvency law or under the reorganization
         or arrangement provisions of the United States
         Bankruptcy Code or any similar law of any jurisdiction
         or have proceedings under any such law instituted
         against it which are not terminated within ninety (90)
         days of such commencement.

    12.4 EXCEPT FOR A BREACH BY BUYER OF NORTEL'S SOFTWARE
         LICENSE OR AN INDEMNIFICATION UNDER SECTION 11.1,
         NOTHING IN THIS AGREEMENT SHALL MAKE EITHER PARTY LIABLE
         FOR ANY INCIDENTAL, INDIRECT, CONSEQUENTIAL OR SPECIAL
         DAMAGES OF ANY NATURE WHATSOEVER FOR ANY BREACH OF THIS
         AGREEMENT WHETHER THE CLAIMS FOR SUCH DAMAGES ARISE IN
         TORT, CONTRACT, OR OTHERWISE.

    12.5 A Party shall not be liable for any additional costs and
         expenses resulting from (a) errors, acts or omissions of
         the other Party, including, but not limited to,
         inaccuracy, incompleteness or untimeliness in the
         provision of information by the other Party to the first
         Party or (b) the fulfillment by the other Party of any
         of its obligations under this Agreement.  In such event,
         the other Party shall pay the first Party the amount of
         any such costs and expenses incurred by the first Party.

    12.6 [redacted]

    12.7 [redacted]

    12.8 [redacted]

    12.9 Dispute Resolution

         12.9.1 If Nortel and Buyer are unable to resolve any
                disagreement or dispute arising under this
                Agreement, including without limitation, the
                failure to agree upon any item requiring a mutual
                agreement of the Parties hereunder, then Nortel
                and Buyer resolve the disagreement or dispute as
                follows:

         12.9.2 Either party may refer the matter to a Vice
                President or General Manager of the Parties by
                giving the other party a notice.  Within fifteen
                (15) days after delivery of a notice, the relevant
                officials of both Parties shall meet at a mutually
                acceptable time and place to exchange relevant
                information and to attempt to resolve the dispute.

         12.9.3 If the matter has not been resolved within
                thirty (30) days after delivery of a notice, or if
                the relevant officials fail to meet within fifteen
                (15) days after delivery of a notice, either party
                may initiate mediation.  The Parties shall submit
                the dispute to a sole mediator selected by the
                Parties or, any time at the option of a party, to
                mediation by the American Arbitration Association
                ("AAA").  The mediation proceeding shall be in the
                County of Fairfax, Virginia.  Each party shall
                bear its own expenses and equal share of the
                mediator and fees of the AAA.  The Parties, their
                representatives, other participants and the
                mediator shall hold the existence, content and
                result of mediation in confidence.  If such
                dispute is not resolved by such mediation, the
                Parties shall have the right to resort to any
                remedies permitted by law.  All such defenses
                based on passage of time shall be tolled pending
                the termination of the mediation.  Nothing in this
                clause shall be construed to preclude any party
                from seeking injunctive relief in order to protect
                its rights pending mediation.  A request by a
                party to a court for such injunctive relief shall
                not be deemed a waiver of the obligation to
                mediate.

         12.9.4 The Parties shall agree to binding arbitration
                under AAA rules under the Federal Arbitration Act
                in Fairfax, Virginia, except for claims involving
                antitrust, intellectual property rights and claims
                where a third party can be impleaded.

13. FORCE MAJEURE

    If the performance by a party of any of its obligations under
    this Agreement shall be directly, materially and unavoidably
    interfered with by reason of any circumstances beyond the
    reasonable control of that party, including without
    limitation, unavailability of supplies or sources of energy,
    power failure, breakdown of machinery, or labor difficulties,
    including without limitation, strikes, slowdowns, picketing
    or boycotts, then that party shall be excused from such
    performance for a period equal to the delay resulting from
    the applicable circumstances and such additional period as
    may be reasonably necessary to allow that party to resume its
    performance, as long as that party has diligently pursued
    alternative means of performance, if legally available to it.
    With respect to labor difficulties as described above, a
    party shall not be obligated to accede to any demands being
    made by employees or other personnel.  If Nortel's
    performance is suspended or materially reduced due to force
    majeure for more than six (6) months, Buyer may terminate
    this Agreement for cause.

14. CONFIDENTIAL INFORMATION

    Confidential Information exchanged under this Agreement shall
    be governed by the terms and conditions of the Nondisclosure
    Agreement between the Parties, dated June 6, 1997, attached
    hereto as Attachment M, except that the term of the
    Nondisclosure Agreement shall be extended to conform with the
    Term of this Agreement, and the Parties' obligations under
    the Nondisclosure Agreement shall survive any termination of
    this Agreement.

15. ADDITIONAL OBLIGATIONS OF NORTEL

    15.1 [redacted]

    15.2 Nortel shall, upon Buyer's request, provide Buyer with
         copies of its then current training catalogue and
         schedule of courses whenever Nortel provides such
         catalogue and schedule to Nortel's customers.  Upon the
         request of Buyer, Nortel shall provide Buyer  such
         additional training as Buyer requests, at a time and
         place mutually agreed upon and at the prices to be
         quoted for such training. The cancellation fee set forth
         in the training catalogues shall apply.

    15.3 Nortel shall include its standard Documentation package,
         if any, with each shipment of a Core Deliverable.
         Nortel shall make the Documentation available on its
         choice of media, which may include CD-ROM.  Nortel shall
         provide Buyer with any other Documentation that is
         ordered at its then-current pricing therefor.
         Documentation provided via Nortel's CD-ROM media may be
         printed and copied to the extent necessary for the
         operation and maintenance of the Core Deliverables to
         which the Documentation pertains.  However, Buyer may
         not press any copies of CD-ROM discs.

    15.4 Nortel shall offer installation training to Teligent and
         its contractors whereby such can become certified to
         install Core Deliverables (except for DMS-500 based
         equipment). Proper installations made by such certified
         installers in accordance with Nortel's published
         installation standards shall carry the same warranty on
         the Core Deliverables as if the installation were made
         by Nortel directly.

16. SPECIAL TERMS APPLICABLE TO CERTAIN PRODUCT LINES

    [redacted]

         [redacted]

         [redacted]

         [redacted]

    16.2 Nortel agrees that the base line [redacted] Software
         release to be initially licensed under this Agreement
         and to which modifications and/or enhancements will be
         made is expected to be [redacted].  For all Teligent-
         Approved Radio Vendor Products, Nortel agrees to
         maintain the compatibility of any new Software release
         at the Node with existing TAS equipment in the field
         without requiring a site visit for at least 2 previous
         complete versions, or two (2) years, whichever period is
         longer.  The foregoing compatibility requirement applies
         only when Radio Products are manufactured by the same
         vendor. Teligent recognizes that the installed TAS
         equipment base may not support new functionality or
         features, but such installed equipment base shall
         continue to interface and inter-operate at its then
         current level of functionality and features with such
         new Nodes or TCO software Core Deliverables contingent
         upon the above criteria.

    16.3 [redacted]

17. HAZARDOUS MATERIALS

    17.1 Prior to issuing any Order for Services to be performed
         at Buyer's facilities,  Buyer shall identify and notify
         Nortel in writing of the existence of all Hazardous
         Materials which Nortel may encounter during the
         performance of such Services, including, without
         limitation, any Hazardous Materials known to Buyer
         contained within any equipment to be removed by Nortel.

    17.2 If Buyer breaches its obligations pursuant to Section
         17.1, (a) Nortel may discontinue the performance of the
         appropriate Services until all the applicable Hazardous
         Materials have been removed or abated to Nortel's
         satisfaction by Buyer at Buyer's sole expense, and (b)
         Buyer shall defend, indemnify and hold Nortel harmless
         from any and all damages, claims, losses, liabilities
         and expenses, including, without limitation, attorneys'
         fees, which arise out of Buyer's breach of such
         obligations.  Buyer's obligations pursuant to this
         Section 17.2 shall survive any termination of this
         Agreement.

    17.3 Nortel warrants that it shall not knowingly introduce
         any Hazardous Materials to the premises without Buyer's
         knowledge and consent, and, if it does so, (a) removal
         and abatement of same shall be at Nortel's sole expense
         and (b) Nortel shall defend, indemnify and hold Buyer
         harmless from any and all damages, claims, losses,
         liabilities and expenses, including, without limitation,
         attorneys' fees, which arise out of Nortel's breach of
         such obligations.  Nortel's obligations pursuant to this
         Section 17.3 shall survive any termination of this
         Agreement.

18. CONTINUING AVAILABILITY AND SUPPORT OF CORE DELIVERABLES

    18.1 For a period of [redacted] following the date of last
         sale of the affected Core Deliverable, excluding OEM
         Equipment but including Radio Products, Nortel shall
         make spare parts, or their functional equivalent,
         available for purchase by Buyer, so that Buyer may meet
         existing obligations relative to such Core Deliverable.
         The prices charged for the spare parts following the
         termination of this Agreement shall be Nortel's then
         current published list price or its then current policy.
         Nortel shall use its best endeavors to obtain similar
         terms from OEM suppliers.

    18.2 [redacted]

    18.3 During the Warranty Period, Nortel shall provide Buyer
         emergency replacement for Core Deliverables (new,
         repaired, or functionally equivalent) within [redacted]
         of a verbal request from the Buyer.  This service is
         available twenty-four (24) hours a day, including
         holidays.  After the Warranty Period, emergency service
         shall be provided at Nortel's current rates for such
         service.

    18.4 During the Term, Nortel shall offer Buyer, as an option,
         technical support services, whereby Nortel supplies
         Teligent up to three (3) experts in each metropolitan
         area for a period of up to six (6) months following
         acceptance of a System, extended upon notice by Buyer.
         The Parties agree that initially the experts required
         will be one (1) switching expert, one (1) operations and
         maintenance expert and one (1) radio systems expert, but
         the precise set of skills will be determined on a
         metropolitan area-by-metropolitan area basis as mutually
         agreed to by the Parties.  TCO pricing including such
         technical support services shall be provided to Buyer as
         set forth in Section 4.3.4.

[redacted]

20. SUBCONTRACTING

    Nortel may subcontract any of its obligations under this
    Agreement, but no such subcontract shall relieve Nortel of
    primary responsibility for performance of its obligations and
    for ensuring that any such subcontractors adhere to Nortel's
    relevant obligations in the performance of their duties,
    including, but not limited to, obligations with respect to
    Confidential Information.

21. REGULATORY COMPLIANCE

    In the event of any change in the Specifications or Nortel's
    manufacturing or delivery processes for any Core Deliverables
    as a result of the legally-proper imposition of new and
    material requirements by any government body or agency of
    competent jurisdiction, Nortel may upon notice to Buyer,
    increase its prices, charges and fees to cover the added
    costs and expenses directly incurred by Nortel as a result of
    such change.


22. GENERAL

    22.1 If any of the provisions of this Agreement shall be
         invalid or unenforceable under applicable law and a
         party deems such provisions to be material, that party
         may terminate this Agreement upon notice to the other
         party. Otherwise, such invalidity or unenforceability
         shall not invalidate or render this Agreement
         unenforceable, but this Agreement shall be construed as
         if not containing the particular invalid or
         unenforceable provision and the rights and obligations
         of the Parties shall be construed and enforced
         accordingly.

    22.2 A party shall not release without the prior written
         approval of the other party any advertising or other
         publicity relating to this Agreement wherein such other
         party may reasonably be identified. In addition each
         party shall take reasonable precautions to keep the
         existence and the contents of this Agreement
         confidential so long as this Agreement remains in effect
         and for a period of three (3) years thereafter, except
         as may be reasonably required to enforce this Agreement
         or by law.

    22.3 The construction, interpretation and performance of this
         Agreement shall be governed by the laws of the State of
         New York, except for its rules with respect to the
         conflict of laws.

    22.4 Neither party may assign or transfer this Agreement or
         any of its rights hereunder without the prior written
         consent of the other party, such consent not to be
         unreasonably withheld, except Buyer's consent shall not
         be required for any assignment or transfer by Nortel (a)
         to any Affiliate of all or any part of this Agreement or
         of Nortel's rights hereunder, or (b) to any third party
         of Nortel's right to receive any monies which may become
         due to Nortel pursuant to this Agreement.

    22.5 Notices and other communications shall be transmitted in
         writing by certified United States Mail, postage
         prepaid, return receipt requested, by  guaranteed
         overnight delivery, or by facsimile addressed to the
         Parties as follows:

         To Teligent:  Teligent, Inc.
                       8065 Leesburg Pike
                       Suite 400
                       Vienna, Virginia 22182
                       Attention: Laurence E. Harris
                       Senior Vice President and General Counsel
                       Facsimile: (703) 762-5227
                       Telephone: (703) 762-5225


         with a copy to:
                       Hamid Akhavan
                       Vice President Engineering
                       Facsimile:  (703) 762-5101
                       Telephone:  (703)762-5115

        To Nortel:     Northern Telecom Inc.
                       5555 Windward Parkway, Suite B
                       Alpharetta, Georgia 30201-3895
                       Attention: Vice President & G.M, Access
                       Networks
                       Facsimile:  (770) 661-5272
                       Telephone:  (770) 661-4000

         with a copy to:
                       Attention: Peter Farranto, Esq.
                       General Counsel
                       Facsimile:  (770) 661-5272
                       Telephone:  (770) 661-4000

         Any notice or communication sent under this Agreement
         shall be deemed given upon receipt, as evidenced by the
         United States Postal Service return receipt Mail if
         given by certified United States Mail, on the following
         business day if sent by guaranteed overnight delivery,
         or on the transmission date if given by facsimile during
         the receiving party's normal business hours, with a
         confirming call to the stated individual, his/her named
         assistant, and/or his/her voice mail box.

         The address information listed for a party in this
         Section may be changed from time to time by that party
         by giving notice to the other as provided above.

    22.6 Expiration or termination of the Agreement for any
         reason will not release either party from any
         obligations or liabilities set forth in this Agreement
         which a) the Parties have expressly agree will survive
         or which remain to be performed, or  b) which by their
         nature tended to be applicable following such expiration
         or termination.

    22.7 All headings used herein are for index and reference
         purposes only, and shall not be given any substantive
         effect.  This Agreement has been created jointly by the
         Parties, and no rule of construction requiring
         interpretation against the drafter of this Agreement
         shall apply in its interpretation.

    22.8 Buyer shall not export any technical data received from
         Nortel pursuant to this Agreement, or release any such
         technical data with the knowledge or intent that such
         technical data will be exported or transmitted to any
         country or to foreign nationals of any country, except
         in accordance with applicable U.S. law concerning the
         exporting of such technical data. Buyer shall obtain all
         authorizations from the U.S. government in accordance
         with applicable law prior to exporting or transmitting
         any such technical data as described above.

    22.9 Any changes to this Agreement may only be effected if
         agreed upon in writing by duly authorized
         representatives of the Parties hereto.  No agency,
         partnership, joint venture, or other similar business
         relationship shall be or is created by this Agreement.

    22.10 Nortel will demonstrate that it has normal and customary
          insurance coverage in reasonable levels to be agreed by
          the Parties.

    22.11 This Agreement, including the following Attachments A,
          B, C, D, E, F, G, H, I, J, K, L and M,  constitutes the
          entire agreement of the Parties with respect to the
          subject matter hereof.

NORTHERN TELECOM INC.                               TELIGENT, INC.


By: /s/ J. A. Craig                        By: /s/ K.G. Pickle
   ---------------------                      ----------------------
        (Signature)                              (Signature)

Name:  J.A. Craig                          Name:  K.G.  Pickle
     -------------------                        --------------------
        (print)                                  (print)

Title:  President                          Title:  President
      ------------------                         -------------------

Date:  12/11/97                            Date:   12/11/97
      ------------------                         -------------------


                                ATTACHMENT A
                                ------------
                                DEFINITIONS
                                -----------
   As used in the Agreement (as defined below), the following
initially capitalized terms shall have the following meanings:

   "Adjunct Deliverables" shall be as defined in Section 2.1.2.

   "Affiliate" shall mean Nortel's parent corporation,
Northern Telecom Limited and any corporation controlled directly
or indirectly by Northern Telecom Limited through the ownership
or control of shares or other securities in such corporation.

   "Attachments" shall mean Attachments A, B, C, D, E, F, G,
H, I, J, K, L and M attached hereto, and any additional
Attachments which Nortel and Buyer subsequently agree in writing
shall be incorporated into, and made a part of the Agreement by
reference.

   "Agreement" shall mean the Agreement to which this
Attachment is attached.

   "Buyer" shall mean Teligent and any Strategic Partner
purchasing Core Deliverables hereunder.

   "Confidential Information" shall be defined as in the
Nondisclosure Agreement, set forth in Attachment M.

   "Core Deliverables" shall be as defined in Section 2.1.1.

   "Critical Event" shall mean [redacted]

   "Deliverables" shall collectively mean Core Deliverables

and Adjunct Deliverables.

   "Documentation" shall mean the documents which Nortel
generally makes available to its customers containing
descriptive, operating, installation, engineering and
maintenance information for Core Deliverables, including
Specifications, as such documents may be amended from time to
time.

   "Equipment" shall mean the hardware listed or otherwise
identified in, or pursuant to, Attachment G.

   "Extension" shall mean Core Deliverables which are
engineered by Nortel and installed and which are added to an
Initial System after the Turnover of the Initial System.

   "Finance Agreement" shall mean the Agreement to be entered
into between Nortel and Teligent under which Nortel shall
provide financing for the Deliverables.

   "First Commercial System" shall mean the System installed
in the first city or metropolitan that becomes ready for
commercial service and consists of the following equipment:
[redacted], as more clearly defined in Attachment G.

   "First Soak Period" shall mean [redacted]

   "Hazardous Materials" shall mean any pollutants or
dangerous, toxic or hazardous substances (including, without
limitation, asbestos) as defined in, or pursuant to, the OSHA
Hazard Communication Standard (29 CFR Part 1910, Subpart Z), the
Resource Conservation and Recovery Act of 1976 (42 USC Section
6901, et seq.), the Toxic Substances Control Act (15 USC Section
2601, et seq.), the Comprehensive Environmental Response
Compensation and Liability Act (42 USC Section 9601, et seq.),
and any other federal, state or local environmental law,
ordinance, rule or regulation.

   "Merchandise" shall mean any Hardware or other parts or
components which are not ordered as part of a System and with
respect to which no engineering, installation or other Services
are provided by Nortel.

   "Node" shall mean the Teligent Node Models identified in
Attachment G.

   "OEM Equipment" shall mean any non-Nortel branded products,
but not including Radio Products.

   "Order" shall mean a written purchase order issued by Buyer
to Nortel.  Each Order shall specify on the face of the Order
the types and quantities of Core Deliverables and/or Services to
be furnished by Nortel pursuant to the Order, the applicable
prices, charges and/or fees with respect to such Core
Deliverables and/or Services, Buyer's facility to which the Core
Deliverables are to be delivered, the delivery and/or completion
schedule, and any other information which may be required to be
included in an Order in accordance with the provisions of this
Agreement.

   "Parties" shall mean Teligent, Inc. and Nortel.

   "Post Termination Purchases" shall mean those purchases
described in Section 4.2.1.


   "Preferred Supplier Status" shall be as defined in Section
19.1.

   "Punch List" shall be as defined in Section 9.1.7

   "Radio Products" shall those products identified as radio
products in Attachment G and supplied by a Teligent-Approved
Radio Vendor.

   "Services" shall mean all engineering, installation and
integration, training and testing and other services listed or
otherwise identified in, or pursuant to this Agreement which may
be purchased from or provided by Nortel and which are associated
with the Core Deliverables.

   "Software" shall mean (a) programs in machine-readable code
or firmware which (i) are owned by, or licensed to, Nortel or
any of its Affiliates, (ii) reside in Equipment memories, tapes,
disks or other media, and (iii) provide basic logic operating
instructions and user-related application instructions, and (b)
Documentation associated with any such programs which may be
furnished by Nortel to Buyer from time to time.

   "Specifications" shall mean, with respect to any Core
Deliverables, the specifications identified in Attachment L.
Nortel shall have the right at its sole discretion to modify,
change or amend such specifications at any time, provided that
the capacity and parameter warranties are not degraded, the
provisions of Section 9.4 are retained, and the ATPs are not
modified, without Teligent's prior approval.

   "Strategic Partner" shall mean any company designated by
Teligent through a formal Strategic Partnership Arrangement as
set forth in Section 1.4.2.

   "Strategic Partnership Arrangement" shall mean any of the
conditions set forth in Section 1.4.2.

   "Subsequent System" shall mean the System installed in any
new city or market, as may be configured by Buyer for that city
or market, usually consisting of [redacted].  More than one (1)
Subsequent Initial System may be installed in a given city or
market.

   "Subsequent System Soak Period" shall mean a period of
[redacted] consecutive operational days without a Critical Event
due to Core Deliverables (but not due to Teligent's or a third
party's error) must be demonstrated in a Subsequent System.

   "System" shall mean the First Commercial System and any
Subsequent System.

   "Teligent Approved Radio Vendor" [redacted]

    "Turnover" shall mean [redacted]

   "Third Party Software Vendor" shall mean any supplier of
programs contained in the Software which is not an Affiliate of
Nortel.

                            ATTACHMENT B
                            ------------
                          SOFTWARE LICENSE
                          ----------------

1.  Buyer acknowledges that the Software may contain
    programs which have been supplied by, and are
    proprietary to, Third Party Software Vendors. In
    addition to the terms and conditions herein, Buyer
    shall abide by any additional terms and conditions
    provided by Nortel to Buyer with respect to any
    Software provided by any Third Party Software Vendor.

2.  Upon Buyer's payment to Nortel of the applicable fees
    with respect to any Software furnished to Buyer
    pursuant to this Agreement, Buyer shall be granted a
    personal, non-exclusive, paid-up license to use the
    version of the Software furnished to Buyer only in
    conjunction with Buyer's use of the Equipment with
    respect to which such Software was furnished for the
    life of that Equipment as it may be repaired or
    modified. Buyer shall be granted no title or ownership
    rights to the Software, which rights shall remain in
    Nortel or its suppliers.

3.  As a condition precedent to this license and to the
    supply of Software by Nortel pursuant to the
    Agreement, Nortel requires Buyer to give proper
    assurances to Nortel for the protection of the
    Software.  Accordingly, all Software supplied by
    Nortel under or in implementation of the Agreement
    shall be treated by Buyer as the exclusive property,
    and as proprietary and a TRADE SECRET, of Nortel
    and/or its suppliers, as appropriate, and Buyer shall:
    a) hold the Software, including, without limitation,
    any methods or concepts utilized therein in confidence
    for the benefit of Nortel and/or its suppliers, as
    appropriate; b) not provide or make the Software
    available to any person except to its employees on a
    'need to know' basis; c) not reproduce, copy, or
    modify the Software in whole or in part except as
    authorized by Nortel; d) not attempt to decompile,
    reverse engineer, disassemble, reverse translate, or
    in any other manner decode the Software; e) issue
    adequate instructions to all persons, and take all
    actions reasonably necessary to satisfy Buyer's
    obligations under this license; and f) forthwith
    return to Nortel, or with Nortel's consent destroy,
    any magnetic tape, disc, semiconductor device or other
    memory device or system and/or Documentation or other
    material, including, but not limited to all printed
    material furnished by Nortel to Buyer which shall be
    replaced, modified or updated.  The foregoing
    restrictions shall not apply to the maintenance of the
    Software by Teligent when Nortel no longer offers
    support for such Software or any update thereto.

4.  The obligations of Buyer hereunder shall not extend to
    any information or data relating to the Software which
    is now available to the general public or becomes
    available by reason of acts or failures to act not
    attributable to Buyer.

5.  Buyer shall not assign this license or sublicense any
    rights herein granted to any other party without
    Nortel's prior written consent.

6.  Buyer shall indemnify and hold Nortel and its
    suppliers, as appropriate, harmless from any loss or
    damage resulting from a breach of this Attachment B.
    The obligations of Buyer under this Attachment B shall
    survive the termination of the Agreement and shall
    continue if the Software is removed from service.


                                ATTACHMENT C
                                ------------

                           FAULT CLASSIFICATIONS
                           ---------------------

      As different types of problems require different levels of
      reaction, a Nortel Priority Classification system is set up to
      establish a relationship between the reported problems and appropriate
      level of reaction and resolution.  The Priority System is based upon
      problem's direct or potential effect upon subscriber service.  Each
      reported problem is assigned priority rating accordingly.

      The Priority System has five levels:

            E1    Emergency:   Severe Degradation or Outage

            E2    Emergency:   Potential Degradation or Outage

            S1    Non-Emergency:   Service-Affecting Problem

            S2    Non-Emergency:   Intermittently Service Affecting

            NS    Non-Service Affecting Problem

      The resolution objective for E1 or E2 Emergency classification is
      immediate and continuous assistance until the service level is
      restored to pre-incident operation. For assistance in such E1 or E2
      Emergency, please call [redacted].  The resolution objective for
      non-emergency condition is to provide a status response in [redacted]
      and solution to the problem in [redacted] for S1 Classification
      or [redacted] for S2.  The resolution objective for non-service affecting
      condition is to provide a status response in [redacted] and a fix, if
      applicable, will be scheduled for future standard hardware, software or
      Documentation update or revision.

      In the event that Nortel believes that other actions may be more
      economically or strategically beneficial to the Buyer, Nortel may
      recommend actions different from those described.  In such case, the
      Buyer will not unreasonably withhold its consent to such alternative
      actions.

       The following is a detailed description of priority ratings:

            E1  -  Emergency:  Severe Degradation or Outage

                  i)   System ceased call processing
                 ii)   [redacted] or more subscribers out of service;
                iii)   [redacted] or more trunk circuits out of service;

            E2  -  Emergency:  Potential Degradation or Outage

                  i)   [redacted]
                 ii)   [redacted]

            S1  -  Service Affecting Problem

                  i)   Problems directly and continuously affecting
                       subscriber service, not specified under E1 or E2;
                 ii)   Problems that will seriously impair service after
                       in-service date;

            S2  -  Intermittently Service Affecting Problem

                  i)   Software and hardware faults that only
                       intermittently affect service;
                 ii)   Documentation errors that result service
                       impairments;
                iii)   Problems where operating company can show
                       significant impact upon plant and traffic operations

            NS  -  Non-Service Affecting Problem

                  i)   Service analysis, operational measurements, or
                       system-related Documentation inaccuracies that do
                       not affect call processing or revenue collection
                       capabilities;
                 ii)   Non-service affecting software inconsistencies;
                 iii)  Loss of test facilities for which manual procedures
                       or alternate test equipment can be readily
                       substituted.



                             ATTACHMENT D
                             ------------
                      CORE DELIVERABLES SUPPORT
                      -------------------------

1.  WARRANTY SUPPORT

    Except for the items provided at no additional costs
    specified in Section 19, the following terms apply to
    Warranty Support:

    1.1   Remote (off-site) Assistance

          Technical support offered at no charge to Buyer during
          the Warranty Period includes Remote (off-site)
          assistance to Buyer's trained personnel in resolving
          Core Deliverables operational and compatibility
          problems.

          Remote (off-site) assistance consists of one or more
          of the following:

              a)  Over-the-phone consultations and guidance at
                  1-800-275-8726.

              b)  Interrogation and analysis of systems over
                  data lines from Nortel's service facility.
                  (**Please note:  If system access over data
                  lines is not provided by the customer,
                  regardless of the problem cause, support
                  charges may apply.)

              c)  Other activity directly related to problem
                  resolution, where Nortel travel is not
                  involved.

          If after investigation, Nortel determines that the
          problem was caused by equipment, software, or
          conditions not attributable to Nortel then such
          technical assistance shall be billable to Buyer in
          accordance with Nortel's current rates and procedures
          as set forth in Section 3 of this Attachment.

          Calls to Nortel's service facilities during Nortel's
          off-hours shall be limited to Core Deliverable
          failures directly affecting service that Buyer could
          not resolve by following standard troubleshooting
          procedures, covered by NTPs.

    1.2   Local (on-site) Assistance

          Local (on-site) assistance by Nortel field engineers
          is also available as part of the warranty support.  To
          qualify for Local (on-site) assistance without charge,
          the following efforts must have been exhausted prior
          to the field trip:


              a)  Buyer has determined that the Core
                  Deliverable is the source of the problem; and

              b)  Buyer was unable to resolve the problem by
                  using standard troubleshooting procedures
                  covered by applicable NTP's; and

              c)  Nortel 's engineer could not resolve the
                  problem remotely with full cooperation of
                  Buyer's personnel.

          Local on-site assistance, provided at Buyer's request,
          that does not meet above requirements is billable in
          accordance with Nortel's current rates and procedures
          as set forth in Section 3 of this Attachment.  If
          after investigation, Nortel determines that the need
          for Local (on-site) assistance was not caused by the
          Equipment, Software nor conditions attributable to
          Nortel then, such technical assistance and associated
          travel and living expenses shall be billable to Buyer
          at Nortel's current rates and procedures as set forth
          in Section 3 of this Attachment.

          The following types of assistance fall outside the
          scope of warranty support and are billable;

              a.  Local (on-site) assistance with system
                  verification and pre-service testing, where
                  required by the Buyer.

              b.  Local (on-site) assistance for Software upgrades,
                  where required by the Buyer.

              c.  Analysis to determine origins of the fault and
                  resolution of technical problems associated with
                  equipment or software not furnished by Nortel.

              d.  Non-emergency calls for technical assistance
                  during Service Center off-hours.

              e.  Consultation in excess of [redacted] on matters
                  that are adequately covered by standard
                  Documentation and/or for which training programs
                  are available, including Software upgrades.

2.  OUT-OF-WARRANTY SUPPORT

    Technical assistance as set forth in Section 1 of this
    Attachment is available for out-of-warranty Equipment and
    is billable at the current rates and procedures as set
    forth in Section 1 of this Attachment.


3.  TECHNICAL SERVICE RATES

    All billable technical services are billed at hourly rate
    plus expenses as defined herein.

    Billable expenses include coach air travel, economy car
    rental and mutually-agreed per diem meals and lodging costs
    for Nortel's service representatives, if the job site is
    more than [redacted] from the representative's normal place
    of employment, and long distance telephone and data link
    charges and other costs which are directly related to the
    service effort.  These expenses shall be augmented by
    [redacted] handling and administration charge.

    For Local (on-site) assistance service, both work and
    travel time to the site are included and charged as
    applicable.  Minimum charge for Local (on-site) assistance
    service is [redacted] plus expenses.

    Minimum charge for Remote assistance service shall be one
    (1) hour, billable according to the rate structure listed
    below.

    The following standard rates are in effect for these
    procedures:

    i)   REGULAR WORKING HOURS (STD)-        [redacted]
    ii)  OVERTIME 1 RATE (OT1)               [redacted]
    iii) OVERTIME 2 RATE (OT2)-              [redacted]

    Overtime may only be worked with Teligent's express
    approval. Work required during Overtime periods
    necessitated due to Nortel's or its contractor's acts,
    errors or omissions, shall be billed only at Standard
    rates.

    Buyer's Local Time   0000      0800      16:30       2400
                         Midnight  8:00 a.m.  4:30 p.m.  Midnight
    MON-FRI              OT1        STD                  OT1
    SAT                             OT1                  OT1
    SUN/HOLIDAYS                               OT2

    NOTE:  Nortel observed holidays are:  New Year's Day,
    Memorial Day, Independence Day, Labor Day, Thanksgiving Day
    and the day after, and Christmas week.

    The telephone number for the Broadband Technical Support
    Group is as follows:

    Non-Emergency Support:  1-800-ASK TRAN(1-800-275-8726)
    Emergency Support:  1-800-ASK ETAS (1-800-275-3827)

                              ATTACHMENT E
                          ADJUNCT DELIVERABLES

             Adjunct Deliverables - Section 2.1.2


AC and DC power systems, including rectifiers and batteries
Grounding Systems
Antennas and Coax Cabling Systems
TCO Cabling & Cable Termination Equipment
HVAC Equipment
Stand-By Generators
Fire Protection Systems
Alarm Reporting & Monitoring Systems
Network Management Systems
Provisioning Systems
Billing Systems
Customer Care Systems
Fraud Management Systems
Voice Mail Equipment
Signal Transfer Point (STP) Equipment
Service Control Point (SCP) Equipment
AIN Platform Equipment & Software
Synchronization Equipment
DACS Equipment
Digital cross-connect (DSX) Equipment
Fiber cross-connect Equipment
Multiplex Equipment
Channel Bank Equipment
IP Network Platform Equipment
WAN Network Equipment
Point-to-Point Microwave Equipment

                                   ATTACHMENT F
                       Future Deliverables - Section 4.4

Preamble:  A number of questions have been raised on the measurement
methodology of many of the points below, and Nortel compliance will depend
on the determination of specific test plans which need to be agreed upon.

[redacted] renamed Proximity B product with availability as follows:
     24B1.0  Gate 1B -[redacted]
     24B2.0  General Availability -[redacted]
     24B3.0  General Availability -[redacted]

The failure of Nortel to deliver the features described below by the date
indicated will result in a discount being applied as described in Section
4.4:

Description of Future Deliverable               Discount      Date


1
2                       [redacted]
3
4
5
6
7
8


                                  ATTACHMENT G

                                   PRICING

The following models are as revised by Nortel through December
11, 1997.

Merchandise pricing is as presented by Nortel through November
25, 1997.

TCO component pricing is to be supplied, reflecting net prices.


                    Section 1:  High Level Model Overview
                    -------------------------------------

            [redacted]

In order to simplify ordering, Teligent equipment has been partitioned into
the following stock models for point to multi-point wireless networks.  Each
model is described in detail in the following sections, pricing is at the
Teligent base level and does not include applicable volume discounts.
Additional models for point-point wireless networks are provided in
Appendix 1.


Services Matrix
---------------
Program Management                                I    I     I    O
Engineering, Installation & Testing               I    I     O    O
Power plant (sufficient to Nortel equipment       I    I     I    N/A
On-line technical assistance                      I    I     I    O
Delivery                                          I    N     N    N/A

I = Included, O = Optional, N = Not Included, N/A = Not Applicable

Items Excluded from All Models (except where otherwise stated)
-------------------------------------------------------------
 - Ancillary equipment including but not limited to HVAC, DACS/DSX,
   cable racks
 - Applicable taxes


                    Section 2: Teligent Central Office Models
                    -----------------------------------------

TCO Base Model: [redacted]
--------------
A TCO start-up configuration to serve[redacted] voice lines assuming a
[redacted] concentration level.  This model includes all necessary
DMS-500, AccessNode HDT and Power equipment:

 - One (1) DMS-500 Switch
   Including:

    [redacted]

    [redacted]

    [redacted]

TCO Voice Expansion Model
-------------------------
[redacted] (when ordered and installed at the same time as TCO base model)
[redacted](when ordered and installed after the TCO base model)

   -

  This increases the TCO capability by [redacted] voice lines
  assuming a [redacted] concentration level.  This model includes all
  necessary DMS-500, AccessNode HDT Power equipment.  Since Passport
  equipment also serves data requirements it is provided in a separate
  model.
  DMS-500 Switch Equipment
  Including:
     [redacted]

TCO Trunk Expansion Model
-------------------------
  [redacted] when ordered and installed at the same time as TCO base
   model)

  [redacted] when ordered and installed after the TCO base model)

This increases the TCO capability by [redacted].  This model includes
the following:

  [redacted]

TCO Passport Model (Phase 1): [redacted]
---------------------------
This model provides TCO Passport capability to serve voice and data lines by
[redacted] and includes the following:

  [redacted]

Passport Spares Model (Phase 1): [redacted]
---------------------
Recommended spares kit (per TCO) contains the following:

  [redacted]

TCO Passport Model (Phase 2):   [redacted]
----------------------------
This model provides TCO passport capability to serve voice and data lines by
[redacted] using new development 2 port channelized DS3 card and includes
the following:

   [redacted]

Passport Spares Model (Phase 2): [redacted]
------------------------------
spares kit (per TCO) contains the following:

   [redacted]

TCO Passport Model (Phase 1): DS-3 to OC-3 Upgrade: [redacted]
---------------------------------------------------

   [redacted]


Section 3: Teligent Node Models
-------------------------------

TN's are modeled in increments of [redacted].  The table below shows the
number of components required for each size of TN in terms of DS-1 capacity.
All models contain an MDS50 Power system equipped with 1 HELIOS 15 Amp
rectifier  and [redacted] battery reserve (for full configured system -
820 w).

The provisioning rules are slightly different between Release 1 of the radio
and Release 2 (refer to the technical proposal) - there is no difference in
pricing between the two releases until the base station reaches a capacity of
[redacted].

Release 1 model
--------------
BRU per Sector
--------------
   BSS
   BSU
   BMU
   BRU
   RSM                         [redacted]
   Cable
   Mounting
   Bay
   Power
   Battery
   Doc
  ---------
  TN Price
  BW in OS-1
  ---------


Release 2 model
--------------
BRU per Sector
--------------
   BSS
   BSU
   BMU
   BRU
   RSM                         [redacted]
   Cable
   Mounting
   Bay
   Power
   Battery
   Doc
  ---------
  TN Price
  BW in OS-1
  ---------

Based on the final design, engineering configuration and optimization, the
Parties may agree that fewer component quantities may be required in the
Release 2 Models, commensurate with mutually agreed-upon price
reductions.

TN Spares Kit: [redacted]
------------------------
spares kit contains the following:

    [redacted]

TN Options
----------
The following items provide options to the basic package.  All prices are
incremental to the basic package.


TN Cabinet:  [redacted]
----------------------

    - 5" [redacted] Cabinet Packaging


TN OC-3 Interface: [redacted]
----------------------------

   [redacted]


Section 4: Teligent Access Site Models
--------------------------------------
[redacted] TAS Model: [redacted]
--------------------
Installation: [redacted]

A start-up TAS configuration wired to serve [redacted] with rectifiers and
batteries sufficient for [redacted].  This model includes all necessary
AccessNode Express, Proximity-B Radio and Power equipment including:

       [redacted]

96-Line TAS Model: [redacted]
------------------
Installation: [redacted]                               *********************
A start-up TAS configuration wired to serve            *  supplemental     *
[redacted] lines.  This model includes                 *  exhibit - Diagram*
all necessary AccessNode Express,                      *  filed in paper   *
Proximity-B Radio and Power equipment                  *  format on Form SE*
including:                                             *                   *
                                                       *                   *
    [redacted]                                         *                   *
                                                       *********************
TAS POTS Line Cards:
--------------------
Each line card serves [redacted].

    [redacted]

Upgrades
--------
The following items provide upgrades to
the basic package.  All prices are
incremental to the basic package and
assume purchase and installation with
the basic package.

    [redacted]

              Appendix 1: Supplementary Models for Point-to-Point
              ---------------------------------------------------
                            Wireless Applications
                            ---------------------
The following stock models add point to point wireless capability
to the models included in the previous sections.

    [redacted]

Schedule and shipments:
----------------------
First Shipments of Point to Point systems are scheduled to begin on
[redacted].  Nortel understands Teligent's desire to ship in January and
will make every effort in conjunction with Teligent to improve upon the
existing timeline.

TCO Base M13 Model: [redacted]
------------------
Installation/SLAT:[redacted] (when installed at the same time as TCO
                              base model)
Optional Installation/SLAT: [redacted] (when installed after TCO
                              base model)
A start-up package containing [redacted] to terminate point-
point TN traffic at the TCO.

    [redacted]

TCO M13 Expansion Model: [redacted]
-----------------------
Installation/SLAT: [redacted] installed at the same time as M13
   base model)
Optional Installation/SLAT: [redacted] (when installed after the
   M13 base model)[redacted] to terminate TN traffic at TCO.


   [redacted]

TN Model (Pt-Pt) 8 DS1:[redacted] ( First availability [redacted])
----------------------
TN Spares Kit 8 DS1: [redacted] First availability [redacted])
-------------------
Optional SLAT (excluding installation and civil works):
  [redacted] TN equipped with 4 DIU
Optional RF Planning:           [redacted]/ link
Network management return path:               $TBD

[redacted]

The TN cabinet includes:

    [redacted]

    TN Spares Kit 8 DS1: [redacted]
    -------------------
    Recommended spares kit per TN contains the following:


         [redacted]


    Optional RF Planning: [redacted]
    --------------------
    RF planning include the following activities that may either be
    performed by Nortel or by a subcontractor under Nortel supervision.

         [redacted]



                       Point to Point TAS Models
                       -------------------------
                             [redacted]

                 [redacted] Cabinet Configuration (Preliminary)

                             [redacted]

        [redacted]: [redacted]( First availability [redacted])
        Optional Installation/SLAT (excluding civil works and
        travel): [redacted]
        A start-up TAS configuration for a point to point wireless
        application wired to serve [redacted] with rectifiers and
        batteries sufficient for [redacted] (excluding line cards).
        This model includes all necessary AccessNode Express,
        Innova Radio and Power equipment including:


                 [redacted]

[redacted]: (First availability [redacted])
----------
Optional Installation/SLAT (excluding civil works and travel): [redacted]
A start-up TAS configuration for a point to point wireless
application wired to serve [redacted] excluding line cards).
This model includes all necessary AccessNode Express, Innova
Radio and Power equipment including:


     [redacted]

TAS Line Cards:
--------------
Each line card serves one subscriber line.

    - POTS Line Card: [redacted]
      Supports loop start signaling and CLASS service.
    - 2W Service Adaptive Station Line Card: [redacted]
      supports special 2-wire office services such as ISDN, Meridian
      Business Set (i.e. P-Phone) and CO/DOD PBX trunks.
    - 2W Service Adaptive Office Line Card: [redacted]
      supports special 2-wire office services such as DID PBX
      Trunks and FXO lines.


Upgrades & Options
------------------
The following items provide upgrades to the basic package.
All prices are incremental to the basic package and assume
purchase and installation with the basic package.

-  Duplicated Common Equipment: [redacted]
reduces the impact of equipment failures to one line.
    -  Cable Package: [redacted] Includes Connectors)
       500 feet coax cables reel Belden type 89913 Plennum,
       to connect DIU to RFU.
-  LaMarche 100VA Power Inverter: [redacted]
Provides un-interuptable 120V ac for ancillary equipment.


Section 2   Merchandise and Components

      to be completed

The component and merchandise pricing shown is from Nortel's
telefaxes of November 24 and 25, except that TCO component
pricing is to be revised to be net prices, not list prices.


CUSTOMER:                                    Teligent
PROJECT:                                     Merchandise Price List
CONFIGURATION:                               AccessNode Express

* Prices do not include additional [redacted] contract discount which will be
  added at invoicing

               PRODUCT                         PEC       CPC         UNIT
  ITEM         DESCRIPTION                     CODE      CODE       PRICE
  ---------------------------------------------------------------------------
   #1.0      HOST DIGITAL TERMINAL
             HDT EQUIPMENT
             7' ABM Bay , No CDS pre-wiring   NT4K03BB  A0647794    [redacted]
             Bottom Plate  (Optional)         NT4K13AA  B0231568    [redacted]
             ABM Bay Installation Kit         NT4K0120  A0398539    [redacted]
             ABM Bay Top Support /
               Grounding Material               TBD         TBD     [redacted]
             Termination Plug                 NT7E5072  A0363083    [redacted]
             Wrist Strap                 NPS50332-01L3  A0336175    [redacted]
             Control Network Cable (1M)       NT7E44JB  A0365242    [redacted]
             Control Network Cable (5M)       NT7E44JC  A0365243    [redacted]
             Control Network Cable (10M)      NT7E44JK  A0394840    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
   #2.0      COMMON EQUIPMENT SHELVES
             Access Bandwidth Manager Shelf   NT4K10AA  B0231565    [redacted]
             ABM Label Kit, English           NT4K1022  A0397896    [redacted]
             ABM Shelf Cover                  NT4K1033  A0394065    [redacted]
             Breaker Interface Panel          NT4K14AB  B0239825    [redacted]
             BIP Label Kit, English           NT4K1422  A0397898    [redacted]
             Breaker Interface Panel Cover    NT4K1490  A0395045    [redacted]
             Local Craft Access Panel         NT4K16AA  B0232290    [redacted]
             Cooling Module                   NT4K17BA  A0644781    [redacted]
             Cooling Unit Shelf               NT4K18BA  A0644780    [redacted]
             BIP -to- ABM Power Cable         NT4K84BA  A0375509    [redacted]
             Cooling Unit Power Cable         NT4K84CB  A0398133    [redacted]
             Cooling Unit Interface Cable     NT4K85JA  A0375511    [redacted]
             BIP Control Cable                NT4K85KA  A0375512    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
   #3.0      OPERATIONS CONTROLLER & S/W
             OPC Module with Tape Drive       NT7E24BC  A0399043    [redacted]
             Software Rel. AN14               NT4K90JA  A0684788    [redacted]
             Fiberworld Blank DAT Tape        NT7E24TA  A0379851    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
   #4.0      SOFTWARE CERTIFICATES
             AN14 Software Certificate        NTG370AH  A0679472    [redacted]
             SuperNode Integration
               AN10/11/12/14                  NTG375AD  A0627718    [redacted]
             Data Direct (TR-303 CSC/DMS-100)
               (AN12.31 mini                  NTG634AA  A0663614    [redacted]
             X.25 Interface                   NTG350AA  A0405636    [redacted]
             TL1 Generic Surveillance OS I/F  NTG352AC  A0627727    [redacted]
             DS1 Protection Switching
               (Reqd for HDT)                 NTG353AA  A0405639    [redacted]
             DS1 Performance Monitoring       NTG620AA  A0609080    [redacted]
             Multi-Hosting                    NTG357AB  A0410326    [redacted]
             Standby OPC                      NTG372AA  A0402363    [redacted]
             High Speed Performance Monitor   NTG373AB  A0608836    [redacted]
             Meridian Business Set Feature
                Package                       NTG376AB  A0409696    [redacted]
             ISDN-U Integration AN10          NTG377AB  A0608842    [redacted]
             Enhanced Administration AN10     NTG378AD  A0627719    [redacted]
             Enhanced Maintenance AN10        NTG379AB  A0608843    [redacted]
             Network View  Inventory          NTG624AA  A0609084    [redacted]
             TR-08 Interface                  NTG625AA  A0609085    [redacted]
             TL1 Generic Provisioning OS I/F  NTG626AC  A0627725    [redacted]
             CDS S/W RTU                      NTG368AC  A0634208    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
  #5.0       HDT COMMON EQUIPMENT
             Processor Card                   NT4K52FA  A0628692    [redacted]
             Maintenance Interface Card       NT4K53AC  A0619177    [redacted]
             Test Access Card                 NT4K54AA  A0370303    [redacted]
             Loopback Access Interface Car    NT4K55CA  A0661614    [redacted]
             Transport Interface Card         NT4K56AC  A0409344    [redacted]
             Face Plate 1 Assy, Passive
                 (Slots 30-45)                NT4K5830  A0396781    [redacted]
             Face Plate 2 Assy, Passive
                 (Slots 46-53)                NT4K5840  A0396782    [redacted]
             Alarm Relay Card                 NT4K64AA  A0389031    [redacted]
             TXC Card                         NT4K75AA  A0617179    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
#6.0         HDT DS1 INTERFACE
             DS1 Protection Bridge            NT4K31AA  A0389517    [redacted]
             DS1 Input                        NT4K32AA  A0389518    [redacted]
             DS1 Output                       NT4K33AA  A0389519    [redacted]
             DS1 Enhanced VT Mapper           NT7E04EA  A0652867    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
#7.0         HDT TESTING
             Integrated Test Bypass Pair Card NTN516AA  A0666004    [redacted]
             Auxiliary Shelf                  NTN556AA  A0666007    [redacted]
             Aux Mounting Bracket             NTN55650  A0669059    [redacted]
             ITBP HDT Cable                   NTN558CD  A0679757    [redacted]
             Power Cable                      NTN559NA  A0689038    [redacted]
             Single Shielded Twisted Pair
                Cable                         R0113753  R0113753    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------

#8.0         HDT EXTERNAL CABLING
             Main Power Cable, UL/CSA (35')  NT4K84UA   A0399780    [redacted]
             ABM DS1 Cable (50')             NT4K85HH   A0401069    [redacted]
             9/25-Pin User Interface
                Cable (5M)                   NT7E44EA   A0365239    [redacted]
             Parallel Telemetry Cable (30M)  NT4K85GA   A0375504    [redacted]
             OPC Cable (Port B) 5M           NT7E44RA   A0394185    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
#9.0         ANX REMOTE WALL/ FLOOR/ BAY MOUNT TERM
             Mounting
             --------
             25" ANX Enclosure               NTN473BA   A0675628    [redacted]
             ANX Enclosure Top Cover         NTN47390   A0673315    [redacted]
             Universal L-Frame               NTN474AA   A0651712    [redacted]
             Shell Shelf with Installation
                Kit                          NTN550AA   A0666006    [redacted]
             Aux Mounting Bracket            NTN55650   A0669059    [redacted]
             7'0" Bay Assembly               NT7E70AA   A0364959    [redacted]
             ABM Bay Top Support / Grounding
                Material                       TBD        TBD       [redacted]
             Air Deflectors - VM             NTN55040   A0665980    [redacted]
             Air Deflectors - DM             NTN55044   A0680159    [redacted]

             Air Deflector, Full Width       NTN55045   A0680161    [redacted]
             Auxiliary Shelf
             ---------------
             Auxiliary Shelf                 NTN556AA   A0666007    [redacted]
             Mini-250/48V Power Supply       NTN559JA   A0680567    [redacted]
             Mini-500/48V Power Supply       NTN559HA   A0680566    [redacted]
             Mini-500 48V Rectifier Module   NT5C15AA   A0638309    [redacted]
             Remote Power Cable, 10 ft       NTN55645   A0679756    [redacted]
             Integrated Test Bypass Pair
                 (ITBP) Card                 NTN516AA   A0666004    [redacted]
             ITBP Intershelf Cable, 6 ft     NTN558CA   A0673312    [redacted]
             ITBP Intershelf Cable, 50 ft    NTN558CB   A0678054    [redacted]
             ITBP Intershelf Cable, 150 ft   NTN558CC   A0678055    [redacted]
             ITBP Intershelf Cable,
                  18 inches                  NTN558CF   A0687426    [redacted]
             Single Shielded Twisted
                  Pair Cable                 R0113753   R0113753    [redacted]
             Miscellaneous
             -------------
             PC GUI Software                 NTN591AA   A0684432    [redacted]
             ANX Software RTU                NTN590AA   A0684431    [redacted]
             DS1 Cable, 6 pr 26 awg, 50 ft   NTN558AA   A0673310    [redacted]
             DS1 Cable, 6 pr 26 awg, 6 ft    NTN558AB   A0675633    [redacted]
             50-pair VF Cable (10')          NTN558DA   A0679776    [redacted]
             50-pair  VF Cable (50')         NTN558DB   A0679778    [redacted]
             50-pair  VF Cable (150')        NTN558DC   A0679779    [redacted]
             100-pair VF Cable (10')         NTN558EA   A0679780    [redacted]
             100-pair VF Cable (50')         NTN558EB   A0679781    [redacted]
             100-pair VF Cable (150')        NTN558EC   A0679782    [redacted]
             6' Extension VF Cable           NTN558HA   A0684697    [redacted]
             25-pair VF Cable (50')          NTN558HB   A0684698    [redacted]
             25-pair VF Cable (100')         NTN558HC   A0684699    [redacted]
             Spares
             ------
             Mini-500 48V DC Distribution    NT6C34DB   A0643608    [redacted]
             Mini-500 48V Controller Assy    NT6C34CA   A0643606    [redacted]
             I/O Module for 48L VM           NTN555AA   A0664182    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
#10.0        BATTERY BACKUP OPTION
             ---------------------
             18" ANX Enclosure               NTN473AA   A0651539    [redacted]
             ANX Enclosure Top Cover         NTN47390   A0673315    [redacted]
             Battery Kit  (Cables,
               Tray and Bracket)             NTN559KA   A0680568    [redacted]
             Johnson-Controls TEL12-45
               Battery                       A0672263   A0672263    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
#11.0        TRANSPORT OPTIONS
             -----------------
             18" ANX Enclosure               NTN473AA   A0651539    [redacted]
             ANX Enclosure Top Cover         NTN47390   A0673315    [redacted]
             Westcom T-1 Repeater Shelf
                Model 3192                   A0368502   A0368502    [redacted]
             OC-1 Fiber Shelf                                       [redacted]
             Kit, 28 DS1 Test Panel          NTN559AA   A0675991    [redacted]
             Kit, 28 DS1 Test + DSX Field    NTN559BA   A0675992    [redacted]
             Kit, DSX3 Chassis Module
                and cable                    NTN559CA   A0678690    [redacted]
             Kit, 28 DS1 Wire Wrap Field     NTN559DA   A0678691    [redacted]
             Fiber Splice Tray               NTN559EA   A0678692    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
  #12.0        DATA MODULE EQUIPMENT
             Common Equipment
             ----------------
             Kit, DM + Common Equipment      NTN601AA   A0681135    [redacted]
             NTN601AA Includes equipment with *
             *Data Module Chassis            NTN605AA   A0675651    [redacted]
             Data Module Pwr Supply          NTN610AA   A0675653    [redacted]
             *Data Chassis Power Cable       NTN606AA   A0675684    [redacted]
             Data Module Power Cable (4FT)   NTN606BA   A0682687    [redacted]
             Data Module Power Cable (5FT)   NTN606CA   A0682688    [redacted]
             Interface Card
             --------------
             *8 T1/E1 IF, 128k NVRAM         NTN620AA   A0675655    [redacted]
             CPU Cards & Firmware
             --------------------
             *CPU Card XCON (5.x)            NTN621AA   A0675656    [redacted]
             *Firmware, CPU Host Ver.5.0     NTN62141   A0681136    [redacted]
             Firmware, CPU Host Ver.5.1      NTN62142   A0684429    [redacted]
             TCP/IP/SNMP Telnet/SNMP (s/w)   NTN62131   A0682593    [redacted]
             WAN Interface Cards and Personality Modules
             -------------------------------------------
             WAN Card, 1 x T1/E1             NTN622AA   A0675657    [redacted]
             WAN Card, 2 x T1/E1             NTN622BA   A0675659    [redacted]
             HDSL Card, 2 x T1/E1 HDSL       NTN622CA   A0675660    [redacted]
             WAN Card Module - DSX/CEPT
                Line Interfac                NTN624AA   A0675661    [redacted]
             WAN Card Module - CSU Line
                Interface                    NTN624BA   A0675662    [redacted]
             WAN Card Module - HDSL Line
                Interface                    NTN624CA   A0675663    [redacted]
             User Interface Cards
             --------------------
             E&M/TO Card 2-wire, 8 ports     NTN630AA  A0675664    [redacted]
             E&M/TO Card 4-wire - Extended
                 Range, 4 p                  NTN630BA  A0675665    [redacted]
             HSU Card 2 - port w/ RS-530
                 (DB25)                      NTN631AA  A0675666    [redacted]
             HSU Card 2 - port w/ V.35
                 (DB25)                      NTN631BA  A0675667    [redacted]
             HSU Card 2 - port w/ RS-530/V.35
                 & RS366                     NTN631CA  A0675668    [redacted]
             HSU Card 4 - port w/ RS-530/V.35
                 (DB26)                      NTN631DA  A0675669    [redacted]
             SRU Card, 10-port               NTN632AA  A0675670    [redacted]
             FRAD Card, 10-port, RS-232,
                 HDLC and Syn                NTN633AA  A0675671    [redacted]
             OCU-DP Card 10-Port             NTN634AA  A0675672    [redacted]
             DSO-DP Card, 4-ports            NTN635AA  A0675675    [redacted]
             BRI "S/T" Card 8-port, 4-wire   NTN636CA  A0675678    [redacted]
             Single Port Kit v.25 NTU
                 (20/Pack)                   NTN654AA  A0682591    [redacted]
            Installation Kit FOR SERIES
                  2560 NTU                   NTN654BA  A0683656    [redacted]
            Server Cards
            ------------
            ISDN PRI Server, 2 PRI Channels ?
                  wasn't incl on P           NTN640AA  A0675679    [redacted]
            ACS Card, Frame Relay            NTN641AA  A0675680    [redacted]
            ACS Card, MCC                    NTN641BA  A0675681    [redacted]
            ACS Card, ATM DS3                NTN641CA  A0675682    [redacted]
            ATM Concentrator V1.1 (f/w)      NTN64161  A0682597    [redacted]
            Frame Relay Server V1.5 (f/w)    NTN64141  A0682594    [redacted]
            MCC Firmware Ver 1.0             NTN64151  A0682596    [redacted]
            MCC Firmware Ver 1.1             NTN64152  A0684430    [redacted]
            Other Cards
            -----------
            Steel Filler Panel               NTN611AA  A0675652    [redacted]
            External Alarms, 4-port,
               4 inputs & 4 outputs          NTN612AA  A0675654    [redacted]
            BRI NTU                                                [redacted]
            HDSL NTU                                               [redacted]
            Cables
            ------
            1 Amp (M) to bare end, 6 ft      NTN650AA  A0675685    [redacted]
            2 Amp (M) to bare end, 25 ft     NTN650BA  A0675686    [redacted]
            RJ-48(M) to DB25(M) VT-100
               cable, 15 ft.                 NTN650CA  A0675687    [redacted]
            Gndr chgr: DB25/DB25             NTN650DA  A0675688    [redacted]
            RJ-48 to open end, 10 ft         NTN650EA  A0675689    [redacted]
            DB26(M) to M34(F) Straight-thru,
               6-ft                          NTN651AA  A0675690    [redacted]
            DB26(M) to M34(M) Straight-thru,
               6-ft                          NTN651BA  A0675691    [redacted]
            DB26(M) to DB26(F) V.35 ext'n,
               25 ft                         NTN651CA  A0675693    [redacted]
            DB25(M) to M34(F) Straight-thru
               V.35 cab                      NTN651DA  A0675694    [redacted]
            DB25(M) to M34(M) Straight-thru
               V.35 cab                      NTN651EA  A0675695    [redacted]
            DB15(M) to DB25(F) RS366 s
               traight-thru,                 NTN651FA  A0675696    [redacted]
            RJ48(M) to DB25(F) Straight-thru,
               6-ft,                         NTN652AA  A0675697    [redacted]
           RJ48(M) to DB25(F) Straight-thru,
               6-ft                          NTN652BA  A0675699    [redacted]
           RJ48(M) to DB25(M) Straight-thru,
               6-ft                          NTN652CA  A0675701    [redacted]

           RS530 to V.35 Converter           NTN653AA  A0675702    [redacted]
           RS530 to RS232 Converter          NTN653BA  A0675703    [redacted]
           DB25(M)-to-DB25(M), RS530
               Gender Chgr                   NTN655AA  A0721086    [redacted]
           HSU-Trunk, DTE                    NTN656AA  A0721087    [redacted]
           HSU-Trunk, DCE                    NTN656BA  A0721088    [redacted]
           Personality Module 1252 Cable     NTN656CA  A0721089    [redacted]
  ---------------------------------------------------------------------------
  --------------------------------------------------------------------------
  #13.0      VOICE MODULE EQUIPMENT
           48 Line Voice Module  (VM)        NTN551AA  A0673309    [redacted]
           Common Equipment
           ----------------
          Controller  (Processor)            NTN510AA  A0664179    [redacted]
          PSURA  (Power Supply/Ring Amp)     NTN501AA  A0664181    [redacted]
          TBF (Talk Battery Filter for 96L)  NTN515AA  A0666002    [redacted]
          ITU  (Internal Test Unit)          NTN511AA  A0664180    [redacted]
          Line Cards
          ----------
          Omega 2W Station Line Card         NT4K67AC  A0407068    [redacted]
          Omega 2W Office Line Card          NT4K68AA  A0367099    [redacted]
          Omega 4W Line Card                 NT4K69AA  A0367100    [redacted]
          2-Wire Manual Ringdown Line        NT4K78AA  A0397226    [redacted]
          UVG Station Line Card              NT4K79AB  A0618283    [redacted]
          Epsilon II  (POTS Only)            NTN502AA  A0665474    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
#14.0     ANX REMOTE TERMINAL, OSP
          ANX ModCab
          ----------
         ANX standard OSP (Evergood OSP)    NTN570AA   A0675994    [redacted]
         Johnson-Controls TEL12-45 Battery  A0672263   A0672263    [redacted]
         Mini-500/48V Power Supply          NTN559HA   A0680566    [redacted]
         Mini-500 48V Rectifier Module      NT5C15AA   A0638309    [redacted]
         Auxiliary Shelf                    NTN556BA   A0678056    [redacted]
         Cabinet Mounting
         ----------------
         Anchor Plate Assy Kit              NTN57016   A0679771    [redacted]
         Shim Kit                           A0667167   A0667167    [redacted]
         Pole Mount Kit                     A0688549   A0688549    [redacted]
         Power Pedestal/Load Box Options
         -------------------------------
         Power Ped, 100Amp, UL, Hubbell,
             Sgl Ph                         A0659135   A0659135    [redacted]
         Power Ped, 100A, UL, Crouse Hds,
             Sgl Ph                         A0659138   A0659138    [redacted]
         Power Ped, 100A, CSA, Crouse Hds,
             Sgl Ph                         A0659253   A0659253    [redacted]
         Disc Module (Load Box), 100A       A0659143   A0659143    [redacted]
         Power Ped, 100A, UL, Hubbell,
             Sgl Ph w A                     A0672175   A0672175    [redacted]
         Internal ATS Disconnect Upgrade
             Kit                            A0672177   A0672177    [redacted]
         Protector Blocks/Modules
         ------------------------
        100-pair HF Prot Block 3M MS2       NT3W30CA   B0247186    [redacted]
        100-pair HF Prot Block AT&T 710     NT3W30DA   B0247187    [redacted]
        100-pair VF Prot Block 3M MS2       NT3W30QA   B0247511    [redacted]
        100-pair VF Prot Block AT&T 710     NT3W30RA   B0247512    [redacted]
        100-pair VF Prot Block -to-
            Reliant BP                      NT3W30LA   B0247507    [redacted]
        Binding Post Mounting Bracket       P0843862   P0843862    [redacted]
        Binding Post Test Probe             A0663883   A0663883    [redacted]
        Blue Label Binding Post Kit         R0117879   R0117879    [redacted]
        Green label Binding Post Kit        R0117881   R0117881    [redacted]
        50-pair Binding Post -to- 3M MS2,
            Long                            NT3W31AA   B0247194    [redacted]
        50-pair Binding Post -to- 3M MS2,
            Short                           NT3W31NA   B0247421    [redacted]
        50-pair Binding Post -to- AT&T 710,
            Long                            NT3W31BA   B0247201    [redacted]
        50-pair Binding Post -to- AT&T 710,
            Short                           NT3W31PA   B0247422    [redacted]
        Binding Post Test Kit               NT3W50AG   B0248379    [redacted]
        100-pair Prot Block -to- Nortel BIX NT3W30NA   B0247509    [redacted]
        Nortel BIX Mounting Bracket         P0843861   P0843861    [redacted]
        Blue Label Nortel BIX Kit           P0859944   P0859944    [redacted]
        25-pair Nortel BIX Block -to- 3M
            MS2                             NT3W31GA   B0247195    [redacted]
        25-pair Nortel BIX Block -to-
            AT&T 710                        NT3W31HA   B0247203    [redacted]
        400V 7A Fail Short Gas, Black,
            Tin Pins                        303-0750   A0312598    [redacted]
        300V SS Prot, Black, Gold Pins   303M-11A1G0   A0341959    [redacted]
        300V SS Prot, Black, Tin Pins    303M-11A1TO   A0341961    [redacted]
        300V SS w/Heat Coils Prot, Black,
           Tin Pins                      303M-12A1TA   A0353718    [redacted]
        240V SS Prot, Black, Tin Pins    303M-11A1KO   A0342431    [redacted]
        400V 9A Fail Short Gas, Red,
           Tin Pins                         303-0970   A0298238    [redacted]
        300V SS Prot, Red, Gold Pins     303M-11A3G0   A0341960    [redacted]
        300V SS Prot, Red, Tin Pins      303M-11A3TO   A0341962    [redacted]
        300V SS w/Heat Coils Prot, Red,
           Tin Pins                      303M-12A3TA   A0353719    [redacted]
        240V SS Prot, Red, Tin Pins      303M-11A3KO   A0342434    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
#15.0   ANX-MODCAB TRANSPORT OPTIONS
        T1/HDSL Repeaters
        -----------------
        Westcom Repeater Kit w/ Cables      NTN575BA   A0679784    [redacted]
        Fuse & Alarm Repeater Module         3192-9F   A0368064    [redacted]
        Power Office Repeater Module    NPS5097702L1   A0368063    [redacted]
        Cut-Thru Repeater Module             3192-9C   A0368065    [redacted]
        Bridge Office Repeater Module        3192-9B   A0368066    [redacted]
        Remote Testing Adapters
        -----------------------
        ITBP Adapter Kit                    NTN576AA   A0679790    [redacted]
        4Tel RMU Wiring harness kit         NTN576BA   A0679791    [redacted]
  ---------------------------------------------------------------------------
  ---------------------------------------------------------------------------
 #16.0  DOCUMENTATION
        AN14 NTP'S on Paper                 NT4K00GB   A0688333    [redacted]
        AN14 NTP's on CD-ROM                NT4K00GP   A0685487    [redacted]
        AN14 Quick Reference Guide          NT4K00JG   A0688808    [redacted]
        AN14 Planning Guide                 NTR410GA   A0681055    [redacted]
        ANX Data Module Users Guide         NTN680AA   A0684433    [redacted]
        ABM Bay Installation Guide          P0833108   P0833108    [redacted]
        ANX Maintenance Guide               P0873660   P0873660    [redacted]
        ANX Ordering Guide                  P0873662   P0873662    [redacted]
        PC-GUI Users Guide                  P0873663   P0873663    [redacted]
        ANX-ModCab Installation Guide       P0871629   P0871629    [redacted]
        ANX VM Quick Ref Guide              P0876010   P0876010    [redacted]
        ANX Wall Mt Quick Ref Guide         P0876011   P0876011    [redacted]
        ANX Data Module Quick Ref Guide     P0875696   P0875696    [redacted]
  ---------------------------------------------------------------------------

                      NORTEL MAGELLAN
                      ---------------

                                North American ($US) Prices
--------------------------------------------------------------
  HARDWARE                                      North American
                                               Unit Price ($US)
--------------------------------------------------------------
Packages (Model  160):
--------------------------------------------------------------
--------------------------------------------------------------
AC Seismic Cabinet Package             QMY733B      [redacted]
DC Seismic Cabinet Package             QMY734B      [redacted]
Seismic Cabinet                        NTFN23XX     [redacted]
Anchoring Kit                          QMY709X      [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Passport Shelf - AC Power (16 slot)    NTBP05XX     [redacted]
Passport Shelf - DC Power (16 slot)    NTBP64XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Packages (Model  50):
-------------------
AC Rack Mount Package                  QMY725X      [redacted]
AC Stand-alone Package                 QMY726X      [redacted]
AC Stand-alone Package with Covers     QMY727X      [redacted]
DC Rack Mount Package                  QMY728X      [redacted]
DC Standalone Package                  QMY729X      [redacted]
DC Standalone Package with Covers      QMY730X      [redacted]
Model 50 Shelf Assembly                NTEP39XX     [redacted]
Left Bus Terminator Assembly           NTEP05XX     [redacted]
Shelf Assembly with Cooling Unit Only  NTEP06XX     [redacted]
Right Bus Terminator                   NTBP10XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Packages (Model  50 with CFP1 Base Package Types):
------------------------------------------------
AC Rack Mount Package (with CFP1)      QMY731X      [redacted]
DC Rack Mount Package (with CFP1)      QMY732X      [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Packages (Model  30 with CFP1 Base Package Types):
------------------------------------------------
Passport Model 30 Base Package
   (with CFP1)                         QMY435X      [redacted]
Passport Model 30 N. American Voice Package
   (with CFP1)                         QMY436X      [redacted]
Passport Model 30 European Voice Package
   (with CFP1)                         QMY437X      [redacted]
Model 30 Shelf Assembly                NTHQ01X      [redacted]
Desk Top Kit                           NTHQ05XX     [redacted]
Vertical Mount Kit                     NTHQ08XX     [redacted]
Rack Mount Kit                         NTHQ04XX     [redacted]
Rear Fanout Mount Kit                  NTHQ09XX     [redacted]
Cable Management Unit                  NTHQ10XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
FPs and Interfaces (Model 160, Model  50 and Model 30)
-----------------------------------------------------
Control Processor (Model 160 and
  Model  50)                           NTBP12XX     [redacted]
Control Function Processor (CFP1,
 for Model 50 and Model 30)            NTFP61XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Eight-port V.35 FP,16M                 NTFN46XX     [redacted]
Eight-port V.35 FP,32M                 NTFN73XX     [redacted]
Eight-port V.11 FP,16M                 NTFN45XX     [redacted]
Eight-port V.11 FP,32M                 NTFN49XX     [redacted]
Four-port DS1 FP, 16M                  NTFN47XX     [redacted]
Four-port E1 FP, 16M                   NTFN48XX     [redacted]
Four-port Channelized DS1 FP 16M       NTFN52XX     [redacted]
Four-port Channelized DS1 FP 32M       NTFL04XX     [redacted]
Four-port Channelized E1 FP 16M        NTFN57XX     [redacted]
Four-port Channelized E1 FP 32M        NTFK01XX     [redacted]
Eight-port DS1 Unch.  FP, 16M          NTFN56XX     [redacted]
One-port DS3 FP16M                     NTFN71XX     [redacted]
One-port DS3 FP32M                     NTFN50XX     [redacted]
One-port E3 FP,16M                     NTFN51XX     [redacted]
One-port HSSI  FP,16M                  NTFN58AA     [redacted]
One-port DS3 Channelized, 32M FP       NTFP67XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Three-port DS1 ATM FP                  NTFP30XX     [redacted]
Three-port E1 ATM FP                   NTFP32XX     [redacted]
Four-port DS1 AAL1 CES FP              NTFP80XX     [redacted]
Four-port E1 AAL1 CES FP               NTFP82XX     [redacted]
Eight-port DS1 ATM UNI/IMA FP          NTFN14XX     [redacted]
Eight-port E1 ATM UNI/IMA FP           NTFN16XX     [redacted]
Three-port E3 ATM FP                   NTFP17XX     [redacted]
Three-port DS3 ATM FP                  NTFP18XX     [redacted]
Three-port OC3/STM-1 ATM Multimode FP  NTFP16X      [redacted]
Three-port OC3/STM-1 ATM Singlemode FP NTFP38XX     [redacted]
Two-port 6 Mbps ATM FP                 NTFP58XX     [redacted]
Four-port AAL1 FP                      NTFP80XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Four-port Token Ring FP,16M            NTFN42XX     [redacted]
Six-port Ethernet FP,16M               NTFN59XX     [redacted]
ILS Forwarder FP                       NTFN18XX     [redacted]
One-port FDDI  Multimode FP,16M        NTFN61XX     [redacted]
One-port FDDI  Singlemode FP,16M       NTFN60XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
One-port TTC2M Voice FP                NTBP96XX     [redacted]
One-port DS1 Voice FP                  NTFP41XX     [redacted]
One-port E1 Voice FP                   NTFP43XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Blank Function Processor Face Plate
  (PP160 and PP50)                     NTBP23XX     [redacted]
Blank Power Converter Face Plate
  (PP160)                              NTBP51XX     [redacted]
Blank Power Converter Face Plate (PP50)NTEP41XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Power Supply
------------
AC Power Converter (Model  160)        NTBP09XX     [redacted]
DC Power Converter (Model  160)        NTBP52XX     [redacted]
AC Power Converter (Model  50)         NTEP26XX     [redacted]
DC Power Converter (Model  50)         NTEP27XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Power Cords (Model 160 & 50)
---------------------------
AC Power Cord - N.A., Thailand, Korea,
aiwan and CALA (excl. Argentina)       NTFP83XX     [redacted]
AC Power Cord - Japan                  NTFP84XX     [redacted]
AC Power Cord - U.K., Ireland, and
   Hong Kong                           NTFP85XX     [redacted]
AC Power Cord - Continental Europe and
   Indonesia                           NTFP86XX     [redacted]
AC Power Cord - Australia, New Zealand,
   China, and Argentina                NTFP87XX     [redacted]
AC Power Cord - Switzerland            NTFP88XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Seismic Cabinet Components
--------------------------
Configured Seismic Cabinet Assembly
   (AC Power)                          NTFN26XX     [redacted]
Configured Seismic Cabinet Assembly
   (DC Power)                          NTFN32XX     [redacted]
Seismic Cabinet                        NTFN23XX     [redacted]
Seismic Cabinet Mounting Rail Kit      NTFN36XX     [redacted]
Seismic Cabinet Anchoring Kit          NTFN37XX     [redacted]
Seismic Shelf Mounting Collar Kit      NTFN38XX     [redacted]
Door Alarm Cable                       NTBP42XX     [redacted]
External Alarm Board                   NTBP69XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Cabinet Components (Model  50)
-----------------------------
Front/Rear Cover Kit                   NTEP19XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Cooling Unit Assembly (Model  160)
---------------------------------
Cooling Unit                           NTBP07XX     [redacted]
Air FilterNTBP0702[redacted]
Cooling Unit Drawer                    NTBP0701     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Cooling Components (Model  50)
-----------------------------
Air Filter Replacement Pad             A0626924     [redacted]
Cooling Unit Door Assembly             NTEP13XX     [redacted]
Cooling Unit Assembly                  NTEP14XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Termination Panels (Model  160 and Model  50)
--------------------------------------------
V.35 Termination Panel (2 units high)  NTBP53XX     [redacted]
DS3/E3 Termination Panel (1 unit high) NTBP99AA     [redacted]
V.35 Termination Panel (1 units high)  NTFP08AA     [redacted]
V.11 Termination Panel (1 units high)  NTFP09AA     [redacted]
DS1/E1 Balanced Termination Panel
   (1 units high)                      NTFP10AA     [redacted]
E1 Unbalanced Termination Panel
   (1 units high)                      NTFP11AA     [redacted]
Ethernet Fanout Panel (Passport 160)   NTFP23XX     [redacted]
DS3/E3 ATM Termination Panel
   (Passport 160)                      NTFP99AA     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Termination Panels (Model  50 only)
----------------------------------
Integrated V.35 Termination Panel      NTEP21XX     [redacted]
Integrated V.11 Termination Panel      NTEP22XX     [redacted]
Integrated DS1/E1 Balanced Termination
    Panel                              NTEP23XX     [redacted]
Integrated E1 Unbalanced Termination
    Panel                              NTEP24XX     [redacted]
Integrated DS3/E3 Balanced Termination
     Panel                             NTEP37XX     [redacted]
Integrated Ethernet Fanout Panel       NTEP42XX     [redacted]
Integrated FDDI Fanout Panel           NTEP46XX     [redacted]
DS3/E3 ATM Termination Panel
    (Passport 50)                      NTEP53AA     [redacted]
CFP1 V.35 Termination Panel            NTFN06XX     [redacted]
CFP1 V.11 Termination Panel            NTFN05XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Cable Management Unit (Model 160)      NTBP08XX     [redacted]
Cable Management Unit (Model 30)       NTBP10XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Cables (Models 160, 50 and 30)
-----------------------------
Passport to DPN Interconnect Cable
   (5M)                                NTFP21AA     [redacted]
Passport to DPN Interconnect Cable
   (10M)                               NTFP21AB     [redacted]
DCE V.24 Operator Cable                NTBP25XX     [redacted]
DS1 Termination Panel Cable  (3M)      NTBP27AA     [redacted]
DS1 Termination Panel Cable  (15M)     NTBP27AB     [redacted]
E1 Termination Panel Cable  (3M)       NTBP28AA     [redacted]
E1 Termination Panel Cable  (15M)      NTBP28AB     [redacted]
V.35/V.11 Termination Panel Cable (3M) NTBP29CA     [redacted]
V.35/V.11 Termination Panel Cable
  (10M)                                NTBP29CB     [redacted]
V.35/V.11 Termination Panel Cable
   (15M)                               NTBP29CC     [redacted]
Grounding Cable                        NTBP63XX     [redacted]
Shelf Alarm Interconnect Cable         NTBP73XX     [redacted]
Ethernet Cable (3M) (Passport
   160 only)                           NTFN03XX     [redacted]
Ethernet Cable (15M) (Passport
   160 only)                           NTFN04XX     [redacted]
DS3/E3 Termination Panel Cable (3 M)   NTFP19AA     [redacted]
DS3/E3 Termination Panel Cable (15 M)  NTFP19AB     [redacted]
DS3/E3 Termination Panel Cable w/Ferrite
   (3 M)                               NTFP19AD     [redacted]
DS3/E3 Termination Panel Cable w/Ferrite
   (15 M)                              NTFP19AE     [redacted]
DS3/E3 Interface Cable (3 M)           NTFP20AA     [redacted]
DS3/E3 Interface Cable (15 M)          NTFP20AB     [redacted]
DS3/E3 ATM Termination Panel Control
   Cable (1M)                          NTFP52AA     [redacted]
DS3/E3 ATM Termination Panel Control
   Cable (3M)                          NTFP52AB     [redacted]
DS3/E3 ATM Termination Panel Control
   Cable (15M)                         NTFP52AC     [redacted]
DS1 Termination Cable (3M)
   (8 port DS1 FP)                     NTFP69AA     [redacted]
DS1 Termination Cable (15M)
   (8 port DS1 FP)                     NTFP69AB     [redacted]
HSSI null modem cable  (3M)            NTFP94AA     [redacted]
HSSI null modem cable (50')            NTFP95AA     [redacted]
HSSI 1:1 cable assembly (3M)           NTFP96AA     [redacted]
HSSI 1:1 cable assembly (50')          NTFP97AA     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Cables (Model 50 only)
---------------------
DS1 Integrated Termination Panel
   Cable (32")                         NTEP01XX     [redacted]
E1 Integrated Termination Panel
   Cable (32)                          NTEP02AA     [redacted]
E1/E1V/DS1/DS1V Integrated Termination
   Panel Cable (1M)                    NTEP02BA     [redacted]
V.35/V.11 Integrated Termination Panel
   Cable (1M)                          NTEP03CA     [redacted]
V.35/V.11 Integrated Termination Panel
   Cable (1M) - also used for CFP1     NTEP03DA     [redacted]
FDDI Fiber Optic Cable                 NTFN01XX     [redacted]
Ethernet Cable (1M)                    NTFN02XX     [redacted]
DS3/E3 Termination Panel Cable (1 M)   NTFP19AC     [redacted]
DS3/E3 Termination Panel Cable
   w/Ferrite (1M)                      NTFP19AF     [redacted]
DS3/E3 Interface Cable (0.8 M)         NTFP20AC     [redacted]
DS1 Termination Cable (30)
   - Passport 50                       NTFP70AA     [redacted]
DS1 Termination Cable (36")
   - Passport 50                       NTFP70AB     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Cables (Model 30 only)
---------------------
Ferrite Bead Cable (for CFP1
   LAN ports)                          NTHQ11XX     [redacted]
V.35/V.11 Integrated Termination
   Panel (1M) - also used for CFP1     NTEP03DA     [redacted]
E1/E1V/DS1/DS1V Integrated Termination
   Panel Cable (1M)                    NTEP02BA     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Mounting Kits
-------------
Rack Mounting Kit                      NTEP17XX     [redacted]
Standalone Mounting Kit                NTEP40XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Miscellaneous Items
-------------------
Air Filter Pad (Model  160)            A0383866     [redacted]
Model 160 Anchoring Kit                QMY709 X     [redacted]
Antistatic Wriststrap (Model 160
   and 50)                             A0378999     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Base Software
-------------
Passport 160 Base Software             NTJ200XX     [redacted]
Passport 50 Base Software              NTJ212XX     [redacted]
Passport 30 Base Software              NTJ230XX     [redacted]
CFP1 Software                          NTJ226AE     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Routing Software
----------------
Path Oriented Routing Software         NTJ206XX     [redacted]
Connectionless Routing Software        NTJ203XX     [redacted]
Application Software
--------------------
DPN Gateway Software                   NTJ201XX     [redacted]
Passport- Network Trunk Software       NTJ202XX     [redacted]
Frame Relay UNI Software               NTJ204XX     [redacted]
Frame Relay NNI Software               NTJ205XX     [redacted]
Frame Relay UNI SVC Software           NTJ222XX     [redacted]
Frame Relay / ATM PVC Service
   Interworking                        NTJ227XX     [redacted]
Frame Relay Trace Software             NTJ228AE     [redacted]
ATM Software                           NTJ214XX     [redacted]
Networking Protocols (ECMA & QSIG)     NTJ225XX     [redacted]
Voice Transport Service Software       NTJ207XX     [redacted]
Voice Compression Software             NTJ208XX     [redacted]
Voice Networking Software              NTJ224XX     [redacted]
Lan Protocols                          NTJ216XX     [redacted]
Link Protocols                         NTJ218XX     [redacted]
Filtering Software                     NTJ219XX     [redacted]
Virtual Networking Software            NTJ223XX     [redacted]
Speech Activity Detection Software     NTJ209XX     [redacted]
HDLC Transparent Data Software         NTJ210XX     [redacted]
Bit Transparent Data Software          NTJ211XX     [redacted]
Echo Cancellation Software             NTJ213XX     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Complete Voice Software, includes :    QMYJ201AC    [redacted]
Complete Lan Software, includes :      QMYJ202AA    [redacted]

--------------------------------------------------------------
                                                NA Price ($US)
               NMS
             S/W Licenses            (per copy)  (Site License)
--------------------------------------------------------------
Magellan NMS Optional Package (R10 CDROM)
----------------------------------------
NMS Base                               NTJ100AG     [redacted]
Advisor                                NTJ101AG     [redacted]
DPN Provisioning                       NTJ103AJ     [redacted]
DPN Backup and Restore                 NTJ103AM     [redacted]
Passport Provisioning                  NTJ103AK     [redacted]
Passport Backup and Restore            NTJ103AN     [redacted]
Configuration Server                   NTJ103AL     [redacted]
Passport Global Data Manager           NTJ115AC     [redacted]
Passport Module Manager                NTJ500AC     [redacted]
SNMP Integrator                        NTJ112AC     [redacted]
Network Activation Tool                NTJ118AC     [redacted]
Magellan View                          NTJ126AA     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Magellan Data Provider (per copy)      NTJ113AC     [redacted]
Magellan Data Provider (network
   license)                            NTJ113AC     [redacted]
--------------------------------------------------------------
                                                NA Price ($US)
                                                  (per copy)
--------------------------------------------------------------
X-AMINER Options:
----------------
    Basic Data Reporter (BDR)          NTJ303AA     [redacted]
    Enhanced Statistics Reporter (ESR) NTJ303AB     [redacted]
    Magellan Accounting Reporter (MAR) NTJ303AE     [redacted]
    Passport Data Reporter (PDR)       NTJ303AF     [redacted]
    X.11 Multi-Access Software for
      X-AMINER (up to five users)      NTJ303AD     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
X-PLORER Options:
----------------
    Configurator                       NTJ302AA     [redacted]
    Tariff Coster                      NTJ302AB     [redacted]
    Traffic Modeling                   NTJ302AC     [redacted]
    Model Link                         NTJ302AE     [redacted]
    Architect Link                     NTJ302AJ     [redacted]
    Passport Modeling                  NTJ302AG     [redacted]
    End-to-End Delay                   NTJ302AH     [redacted]
    User Re-Homing                     NTJ302AF     [redacted]
    ATM Modeling                       NTJ302AL     [redacted]
    X.11 Multi-Access Software for X-PLORER
      (up to five users)               NTJ302AK     [redacted]
    Traffic Link                       NTJ302AM     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Service Management Reporter
---------------------------
SMR Core System                        NTJ304AA     [redacted]
Data Populator - Magellan BDF
   Accounting                          NTJ305AA     [redacted]
Data Populator - Magellan Statistics   NTJ306AA     [redacted]
Data Populator - SNMP Statistics       NTJ307AA     [redacted]
Reports - Frame Relay
   Usage/Availability                  NTJ308AA     [redacted]
Reports - Backbone Statistics          NTJ309AA     [redacted]
Reports - Standard Access Usage        NTJ310AA     [redacted]
Reports - Standard Access Daily Calls  NTJ311AA     [redacted]
Reports - LAN Interconnect Reports     NTJ312AA     [redacted]
Reports - X.25 Statistics              NTJ321AA     [redacted]
Reports - ATM Accounting Reports       NTJ319AA     [redacted]
Reports - ATM Trunk Statistics/Usage   NTJ318AA     [redacted]
Reports - ATM Trunk
   Statistics/Exception                NTJ320AA     [redacted]
Multi-Client License - 3 additional
   clients license                     NTJ314AA     [redacted]
Multi-Client License - 10 additional
   clients license                     NTJ315AA     [redacted]
SMR Installation (Travel and Living
   not included)                       NTJ316AA     [redacted]
Training (Travel and Living not
   included)                           NTJ317AA     [redacted]
--------------------------------------------------------------
--------------------------------------------------------------
Service Monitor Pricing                        Unit Price ($US)
-----------------------
Base Packages
-------------
Service Monitor Base (20 VPNs)
   - Electronic                        NTJ114AP     [redacted]
Service Monitor Base (50 VPNs)
   - Electronic                        NTJ114AH     [redacted]
License for Additional 50 VPNs
   - Electronic                        NTJ114AJ     [redacted]
Service Monitor Base (20 VPNs) - CDROM NTJ114AN     [redacted]
Service Monitor Base (50 VPNs) - CDROM NTJ114AC     [redacted]
License for Additional 50 VPNs - CDROM NTJ114AD     [redacted]
Service Monitor Applications
----------------------------
Performance Data Viewer - Electronic   NTJ114AK     [redacted]
Command Application - Electronic       NTJ114AM     [redacted]
HP Open View for Windows Integration
   - Electronic                        NTJ114AL     [redacted]
Performance Data Viewer - CDROM        NTJ114AE     [redacted]
Command Application - CDROM            NTJ114AG     [redacted]
HP Open View for Windows Integration
   - CDROM                             NTJ114AF     [redacted]
Service Report Distribution - CDROM    NTJ114AQ     [redacted]
Connection Manager - CDROM             NTJ114AR     [redacted]
Local Grouping Tool - CDROM            NTJ114AS     [redacted]
Third Party Resource Integration
   - CDROM                             NTJ114AT     [redacted]
-----------------------------------------------------------------


                              ATTACHMENT H

                           STATEMENT OF WORK

DRAFTED             Revision required

         Due by:

         Draft due from:   Teligent

The draft Statement of Work appearing as Appendix D of the
Parties' Letter of Intent is to be revised as necessary to be
made consistent with the Parties' intent as expressed in this
Agreement. Teligent will propose a draft Responsibility Matrix
and other language as necessary to define the Parties'
responsibilities under the Statement of Work, and the Parties
will mutually develop through good faith negotiation the final
Statement of Work.

                               ATTACHMENT I

                         ACCEPTANCE TEST PROCEDURE


1.  ATP for Components:  This will be Nortel NTPs, available now
with the exception of the Radio components.

2.  ATPs for:
                a)    TCOs      due:     from:
                b)    Nodes     due:     from:
                c)    TASs      due:     from:


3.  System ATP                  due:     from:


                              ATTACHMENT J

                           NETWORK MONITORING

This Attachment shall specify the intent of Section 19.1.5.

Due by:    11/18/97
Due from:  Gary Palmer


                             ATTACHMENT K

                    CORPORATE AND REGIONAL SUPPORT TEAM


This Attachment shall specify the intent of Section 19.1.7.

Due by:     11/18/97
Due from:   Mike Lambert



                             ATTACHMENT L

                            SPECIFICATIONS


This Attachment shall capture the capacity and performance
specifications contained in Teligent's RFP and Nortel's response
to such RFP.

Due by:     11/18/97
From:       Ian Viney



                            ATTACHMENT M

                       NONDISCLOSURE AGREEMENT

                   insert June 6, 1997 letter here.