<PAGE>
 
 
 
 
                                  EXHIBIT 10.1
<PAGE>
 
                               GENERAL AGREEMENT
                               
                                    BETWEEN

                          EXCEL SWITCH FACILITY, INC.
                          
                                      AND

                           LUCENT TECHNOLOGIES INC.






Legend:  "Confidential Treatment Requested. A series of ****'s has been inserted
in this exhibit to indicate redactions in such exhibit for which confidential 
treatment has been requested. The redacted portions of this exhibit have been 
separately filed with the Commission."






<PAGE>
 
                               TABLE OF CONTENTS

                    GENERAL AGREEMENT TERMS AND CONDITIONS


<TABLE> 
<CAPTION> 
ARTICLE I - GENERAL PROVISIONS                                  PAGE
<S>                                                                 <C> 
1.1  HEADINGS AND DEFINITIONS:.......................................1
1.2  TERM OF AGREEMENT:..............................................2
1.3  SCOPE:..........................................................2
1.4  CONSTRUCTION OF TERMS AND CONDITIONS:...........................2
1.5  ORDERS:.........................................................3
1.6  CHANGES IN CUSTOMER'S ORDERS:...................................3
1.7  PRICES:.........................................................3
1.8  INVOICES AND TERMS OF PAYMENT:..................................3
1.9  SHIPPING AND PACKING:...........................................4
1.10 TAXES:..........................................................4
1.11 TITLE AND RISK OF LOSS:.........................................4
1.12 PURCHASE MONEY SECURITY INTEREST:...............................4
1.13 WARRANTY:.......................................................4
1.14 CHANGES IN PRODUCTS:............................................6
1.15 INFRINGEMENT:...................................................6
1.16 CUSTOMER'S REMEDIES:............................................7
1.17 USE OF INFORMATION:.............................................8
1.18 LICENSE FOR LICENSED MATERIALS PATENT IMMUNITY:.................8
1.19 TITLE, RESTRICTIONS, AND CONFIDENTIALITY:.......................9
1.20 CANCELLATION OF LICENSE:........................................9
1.21 DOCUMENTATION:..................................................9
1.22 CHANGES IN LICENSED MATERIALS:..................................9
1.23 OPTIONAL SOFTWARE FEATURES:.....................................9
1.24 ADDITIONAL PROVISIONS FOR PRODUCT SPECIFIC LICENSED MATERIALS:..10
1.25 COMPATIBILITY OF SELLER'S PRODUCTS AND LICENSED MATERIALS:......10
1.26 PUBLICITY:......................................................10
1.27 PUBLICATION OF AGREEMENT:.......................................10
1.28 NOTICES:........................................................10
1.29 CUSTOMER RESPONSIBILITY:........................................10
1.30 RIGHT OF ACCESS:................................................11
1.31 FORCE MAJEURE:..................................................11
1.32 INDEPENDENT CONTRACTOR:.........................................11
</TABLE> 



                        Lucent Technologies Proprietary
                                      -1-
<PAGE>
 
<TABLE> 
<CAPTION> 
<S>                                                                                                                             <C> 
1.33  RELEASES VOID: .............................................................................................................11
1.34  SEVERABILITY: ..............................................................................................................11
1.35  SURVIVAL OF OBLIGATIONS: ...................................................................................................11
1.36  NON-WAIVER: ................................................................................................................11
1.37  ASSIGNMENT: ................................................................................................................11
1.38  TERMINATION FOR CONVENIENCE: ...............................................................................................12
1.39  CANCELLATION FOR BREACH: ...................................................................................................12
1.40  PERFORMANCE OF SERVICES: ...................................................................................................12
1.41  APPLICABLE LAW: ............................................................................................................12
1.42  ARBITRATION: ...............................................................................................................12

ARTICLE II - ADDITIONAL PROVISIONS FOR LICENSED MATERIALS

5ESS SWITCH LICENSED MATERIALS
2.1  ADDITIONAL RIGHTS IN SOFTWARE: ..............................................................................................13
2.2  RELATED DOCUMENTATION: ......................................................................................................13

OPERATIONS SYSTEMS ("OS") LICENSED MATERIALS AND TRANSMISSION SYSTEMS LICENSED MATERIALS

2.3  DEFINITIONS: ................................................................................................................14
2.4  ADDITIONAL RIGHTS IN OS AND TRANSMISSION SYSTEMS SOFTWARE: ..................................................................14
2.5  INSTALLATION OF OS AND TRANSMISSION SYSTEMS SOFTWARE: .......................................................................14
2.6  OS SOFTWARE ACCEPTANCE: .....................................................................................................15
2.7  MODIFICATIONS BY CUSTOMER TO USER CONTROLLED MODULES: .......................................................................15

ARTICLE III - PROVISIONS APPLICABLE TO ENGINEERING, INSTALLATION AND OTHER SERVICES

3.1  CONDITIONS OF INSTALLATION AND OTHER SERVICES PERFORMED ON CUSTOMER'S SITE: .................................................15
3.2  ACCEPTANCE OF INSTALLATION: .................................................................................................18
3.3  SITE PREPARATION: ...........................................................................................................19
3.4  WORK OR SERVICES PERFORMED BY OTHERS: .......................................................................................19

ARTICLE IV - ENTIRE AGREEMENT

4.1  ENTIRE AGREEMENT: ...........................................................................................................19
</TABLE> 

                        Lucent Technologies Proprietary
                                      -2-
<PAGE>
 
                    GENERAL AGREEMENT TERMS AND CONDITIONS

                                   ARTICLE I

                              GENERAL PROVISIONS

This General Agreement Number LNM960906MOEXL (hereinafter "General Agreement" or
"Agreement") is made by and between Excel Switch Facility, Inc. a Delaware 
corporation, with offices located at 8750 North Central Expressway, Suite 2000, 
Dallas, Texas 75231 (hereinafter "Customer"), and Lucent Technologies Inc., 
acting through its Network Systems group, a Delaware corporation, with offices 
located at 600 Mountain Avenue, Murray Hill, New Jersey 07984, (hereinafter 
"Seller").

1.1  HEADINGS AND DEFINITIONS:

          All headings used in this Agreement are inserted for convenience only 
and are not intended to affect the meaning or interpretation of this Agreement 
or any clause. For the purpose of this Agreement, the following definitions will
apply:

(a)       "Affiliate" of a corporation means its Subsidiaries, any company of 
     which it is a Subsidiary, and other Subsidiaries of such company. For 
     purposes of this Agreement, no affiliate of Customer, which is a 
     manufacturer of telecommunication products in direct competition with 
     Seller, as reasonably determined, shall be permitted to use or have access 
     to confidential information or licensed materials.

(b)       "Customer Price List" means Seller's published "Ordering and Price
     Guides" or other price notification releases furnished by Seller for the
     purpose of communicating Seller's prices or pricing related information to
     Customer, however, this does not include firm price quotations;

(c)       "Designated Processor" means the Product for which licenses to Use 
     Licensed Materials are initially granted;

(d)       "Firmware" means a combination of (1) hardware and (2) Software 
     represented by a pattern of bits contained in such hardware;

(e)       "Form" means physical shape; "Fit" means physical size or mounting 
     arrangement (e.g. electrical or mechanical connections); and "Function"
     means product features;

(f)       "Hazardous Materials" means material designated as a "hazardous 
     chemical substance or mixture" pursuant to Section 6 of the Toxic Substance
     Control Act; a "hazardous material" as defined in the Hazardous Materials
     Transportation Act (49 U.S.C. 1801, et seq.); "hazardous substance" as
     defined in the Occupational Safety and Health Act Hazard Communication
     Standard (29 CFR 1910.1200);

(g)       "Licensed Materials" means the Software and Related Documentation for 
     which licenses are granted by Seller under this Agreement; no Source Code 
     versions of Software are included in Licensed Materials;

(h)       "Product" means systems, equipment, and parts thereof, but the term 
     does not mean Software whether or not such Software is part of Firmware;

(i)       "Related Documentation" means materials useful in connection with 
     Software such as, but not limited to, flowcharts, logic diagrams and
     listings, program descriptions and Specifications; no Source Code versions
     of Software are included in Related Documentation;

(j)       "Seller's Manufactured Product" means a Product manufactured by Lucent
     Technologies Network Systems Group or purchased by it pursuant to its 
     procurement specifications (e.g., KS or AT);

(k)       "Services" means the performance of work and includes but is not 
     limited to: (1) engineering services such as preparation of equipment 
     specifications, preparation and updating office records, and preparation of
     a summary of material not specifically itemized in an order, (2) 
     installation services such as installation, equipment removal, and cable 
     mining; and (3) other services such as maintenance and repairs;


<PAGE>
 
(l)       "Software" means a computer program consisting of a set of logical 
     instructions and tables of information which guide the functioning of a
     processor; such program may be contained in any medium whatsoever,
     including Hardware containing a pattern of bits representing such program,
     but the term "Software" does not mean or include such medium;

(m)       "Source Code" means any version of Software incorporating high-level
     or assembly language that generally is not directly executable by a
     processor;

(n)       "Specifications" means Seller's or its vendor's technical 
     specifications for particular Products or Software furnished hereunder;

(o)       "Subsidiary" of a company means a corporation the majority of whose 
     shares or others securities entitled to vote for election of directors is 
     now or hereafter owned or controlled by such company either directly or 
     indirectly; but such corporation shall be deemed to be a Subsidiary of such
     company only as long as such ownership or control exists, and

(p)       "Use" with respect to Licensed Materials means loading the Licensed 
     Materials, or any portion thereof, into a processor and the execution of 
     the instructions and tables contained in such Licensed Materials so loaded.

(q)       For the purposes of ordering hereunder, the following shall be 
     included under the definition of Customer. "Customer" means Excel Switch
     Facility, Inc., Excel Communications, Inc., and any parent, subsidiary, or
     other Affiliate of Excel Communications, Inc., including without
     limitation, any present or future corporation, partnership, joint venture,
     or other entity controlled by or under common control by Excel
     Communications, Inc. that is not in competition with Lucent or its
     affiliates.

1.2  TERM OF AGREEMENT:

     The term of this General Agreement shall be effective immediately upon
     signature by both parties and, except as otherwise provided herein, shall
     continue in effect hereafter for an initial period of five (5) years.
     Notwithstanding anything to the contrary, this General Agreement shall be
     null and void if Seller does not execute and deliver a signed copy of this
     General Agreement to Customer within ten (10) business days after this
     General Agreement is signed by Customer. During the initial five (5) year
     term of this Agreement, Customer shall be permitted to submit orders to
     Lucent for Products, Licensed Materials and Services.

     Seller hereby acknowledges and agrees that any Services being performed 
     during the initial term of this General Agreement or any renewal thereof 
     shall be completed in a workmanlike manner and in accordance with industry
     standards, notwithstanding any termination of this Agreement.
     Notwithstanding anything to the contrary, Seller hereby acknowledges and
     agrees that any license granted to Customer pursuant to Section 1.18 hereof
     shall not be affected by the termination of this General Agreement except
     pursuant to Article 1.20 of this Agreement.

1.3  SCOPE:

          The terms of this General Agreement shall apply to all transactions in
which Seller furnishes Products, Licensed Materials, or Services provided by its
Network Systems group to Customer. Customer and Seller agree to be bound to the 
terms set forth in this General Agreement respecting such Products, Licensed 
Materials, or Services as are ordered and provided under this General Agreement.
All Products, Licensed Materials, or Services furnished by Seller to Customer 
pursuant to this General Agreement shall be for Customer's own business 
operations and not for resale unless authorized representatives of both parties 
expressly agree in writing that the terms and conditions of this General 
Agreement, modified where applicable, shall apply to resale transactions.

1.4  CONSTRUCTION OF TERMS AND CONDITIONS:

          To the extent that any terms and conditions in any of the various 
Articles of this General Agreement conflict with the provisions of Article I of 
this General Agreement, the terms and conditions from the various other Articles
of this General Agreement supersede such conflicting provisions of Article I. 
All firm price quotes made by Seller to Customer shall be deemed to incorporate 
and be subject to the terms and conditions of this General Agreement. Any 
conflicting terms and conditions of a firm price quote, signed by an authorized 
Seller representative, will supersede the comparable terms of this General 
Agreement. All electronic price quotes shall be binding on Seller 
notwithstanding the absence of a signature. However, in accordance with 

                        Lucent Technologies Proprietary
                                      -2-
<PAGE>
 
Article 4.1 of this General Agreement, no standard terms and conditions 
contained on any price quote shall be deemed to modify or supplement the terms 
and conditions of this General Agreement.

1.5  ORDERS:

          All orders submitted by Customer for Products, Licensed Materials, and
Services shall be deemed to incorporate and be subject to the terms and 
conditions of this Agreement. Any order submitted pursuant to a firm price 
quotation shall reference and include such firm price quotation number. All 
orders, including electronic orders, shall contain the information necessary for
Seller to fill the order. All schedules and requested dates are subject to 
Seller's concurrence. Electronic orders shall be binding on Customer 
notwithstanding the absence of a signature. All orders are subject to **********
**************************************************************************** 
********************************************************************************
*******************************. Seller reserves the right to place any order on
hold, delay shipment, and/or reject any order due to, Customer's insufficient 
Creditworthiness. ******************************************************* 
****************************************************************************** 
*************************************************************************** 
********************************************************************************
***********************************

1.6  CHANGES IN CUSTOMER'S ORDERS:

          Material changes by Customer to an accepted order shall be treated as 
a separate order unless the parties expressly agree otherwise. If any such
change affects Seller's ability to meet its obligations under the original
order, any price (or discount, if applicable), shipment date or Services
completion date quoted by Seller with respect to such original order is subject
to change.

1.7  PRICES:

          To the extent Customer's order is subject to a firm price quotation 
made by Seller, prices, fees and charges (hereinafter "prices") shall be as set 
forth in Seller's firm price quotation. In all other cases, prices shall be as 
set forth in Seller's Customer Price Lists. In those cases where the price is to
be determined from a Customer Price List, the applicable Price List shall be the
issue which is in effect on the date of Seller's receipt of the order provided
that the shipment or Services commencement date is in accordance with Seller's
published shipping or planning interval or thirty (30) days from the date of 
order receipt, whichever is longer. Prices for Products or Services to be 
shipped or performed beyond the published shipping interval will be established 
by determining an effective order entry date (the date required for order entry 
by Seller in accordance with Customer's requested date) and applying the price 
from the applicable Customer Price List as of that date. Seller may amend its 
prices, other than those subject to firm price quotations, and agrees to provide
thirty (30) days written notice of any increase in prices contained in Seller's 
Customer Price Lists. Notwithstanding the foregoing, if Seller is delayed from 
completion of an order due to any material change requested by Customer or as a 
result of Customer's delay in furnishing material information or in performing 
its material obligations. ************************************************* 
******************************************************************************
********* If Customer fails to cure such non-performance or delay, within this 
15 day cure period, then prices are subject to change. Unless expressly stated 
in writing, Seller's prices are exclusive of charges for transportation and 
other related Services, and any sales or other tax or duty which Seller may be 
required to collect or pay upon the ordered transaction. Seller, in accordance 
with its normal practices, will arrange for prepaid transportation, if 
appropriate, and invoice transportation charges back to Customer. Premium 
transportation will be used only with Customer's concurrence.

1.8  INVOICES AND TERMS OF PAYMENT:

          Products and Licensed Materials (including transportation charges and 
taxes, if applicable) will be billed by Seller when shipped, or as soon 
thereafter as practicable. Engineering will be billed upon main shipment of 
Products. Installation will be billed upon execution by Customer of a notice of 
completion or as soon thereafter as practical. ******************************** 
******************************************************************************* 
*********************************************** Delinquent payments are subject 
to a late payment charge at the rate of ********************************* per 
month, or portion thereof, of the amount due (but not to exceed the maximum 
lawful rate). ******************************************************************
************************************************************************** 
***************************************************************************** 
***************************************************************************** 
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************************ Customer agrees to pay Seller's attorneys' fees and 
other costs incurred by Seller in the collection of any amounts invoiced 
hereunder.

                        Lucent Technologies Proprietary
                                      -3-


<PAGE>
 
1.9  SHIPPING AND PACKING:

          Seller shall, at no additional charge, pack Products in accordance 
with its standard practices for domestic shipments. Where, in order to meet 
Customer's requests, Seller packs Products in other than the more expensive of 
its normal manner or industry standards for domestic shipment, Customer shall 
pay Seller's additional charges for such packing.

1.10 TAXES:

          Customer shall be liable for and shall reimburse Seller for all taxes 
and related charges, however designated, (excluding taxes on Seller's net 
income) imposed upon or based upon the provision, sale, license or use of 
Products, Licensed Materials or Services (if applicable). Such taxes shall be 
separately listed on the invoice. Seller shall not collect the otherwise 
applicable state sales tax if the front of Customer's order indicates that the 
purchase or license is exempt from Seller's collection of such tax and a valid 
tax exemption certificate is furnished by Customer to Seller. Seller's failure 
to collect taxes in accordance herewith shall not be deemed to be an 
authorization to resell Products or Services or sublicense Licensed Materials.

1.11 TITLE AND RISK OF LOSS:

          Title (except as provided in the clauses USE OF INFORMATION and TITLE,
RESTRICTIONS, AND CONFIDENTIALITY) and risk of loss to Products and Licensed 
Materials shall pass to Customer upon delivery to the Customer. Customer shall 
notify Seller promptly of any claim with respect to loss which occurs while 
Seller has the risk of loss and shall cooperate in every reasonable way to 
facilitate the settlement of any claim. For purposes of this clause, "delivery" 
shall mean the point at which Seller or Seller's supplier or agent turns over 
possession of the Product or Licensed Materials to Customer, Customer's 
employee, Customer's warehouse, or other Customer's agent and not necessarily 
the final destination shown on the order. Customer shall not designate which 
transportation carrier to use for any shipment.

1.12 PURCHASE MONEY SECURITY INTEREST:

          Seller reserves and Customer agrees that Seller shall have a purchase 
money security interest in Products or Licensed Materials furnished under this 
Agreement until such time as Seller has been paid in full. Customer also agrees 
that this Agreement may be filed as a financing statement (or as other evidence 
of the Seller's purchase money security interest) with any state or local 
jurisdiction. Customer shall execute and deliver a financing statement or such 
other documents prepared by Seller so that Seller may perfect its security 
interest. When Seller has been paid in full for such products, Seller shall 
execute and deliver a UCC-3 prepared by Customer if a purchase money security 
interest document was filed by the Seller, so that such liens may be released 
and terminated.

1.13 WARRANTY:

          Seller warrants to Customer only, that ***************************
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******************************* With respect to Products or Software or partial 
assembly of Products furnished by Seller but neither manufactured by Seller nor
purchased by Seller pursuant to its procurement specifications ("Vendor Items"),
Seller, to the extent permitted, does hereby assign to Customer the warranties 
given to Seller by its vendor(s) of such Vendor Items. If any vendor does not 
allow the assignment of such warranty, Seller will notify Customer so that 
Customer may arrange to purchase Products or Software directly from the vendor.

                        Lucent Technologies Proprietary
                                      -4-
<PAGE>
 
                  SELLER'S MANUFACTURED PRODUCTS AND SOFTWARE
                              WARRANTY PERIOD/1/


                                                                     Repaired   
                                                                     --------   
                                                  Base Period        Product or 
                                                  -----------        ---------- 
                                                  New Product/2/     Part/3/    
                                                  --------------     -------    
                                                                              
          Switching Systems Products              *********           ********
          Central Office Power Equipment          *********           ********
          Transmission Systems Products                                       
                                                                              
          -All Transmission Products in the                                   
                    "2000 Product Family"         *********           ********
          -D4 Circuit Packs                       *********           ********
          -SLC 96 Circuit Packs                   *********           ********
          -SLC Series 5 Circuit Packs             *********           ******** 
          -T1 Repeaters                           *********           ******** 
          -DDM-1000 Circuit Packs                 *********           ******** 
          -Other Transmission Products            *********           ******** 
          Operations Systems Products                                         
                    (excluding Processors)        *********           ******** 
          Processors Other than in                                            
                    Switching Systems             *********           ******** 
          Network Cable Systems Products          *********           ******** 
          All Other Products                      *********           ******** 
          Switching System Software               *********           ******** 
          All Transmission Software in the                                    
                    "2000 Product Family"         *********           ******** 
          Transmission Systems Software           *********           ******** 
          Operations Systems Software             *********           ********
          All Other Software                      *********           ********
          Software Media                          *********           ********


/1/  The term "Warranty Period" means the period of time listed above which, 
unless otherwise stated, ******************************************************
***************************************************************************** 
****************************************************************************** 
**********

/2/  The Warranty Period for Products ordered for the use in Systems is that of 
the initial Systems or equipment except as may be otherwise noted. Systems shall
mean collectively Systems and Products for purposes of this note.

/3/  The Warranty Period for a Product or part thereof repaired under this
Warranty **********************************************************************
****************************

*************************************************************************
*********************************************************************** 
***********************************

*************************************************************************
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***************************************************************************
************************************************************************
*************************************************************************
*******************************************************

If, under normal and reasonable use, Sellers Manufactured Products or Software 
do not function, adhere, or conform to the warranties given Customer under this 
Agreement, during the applicable Warranty Period and Customer takes reasonable 
steps to promptly notify Seller in writing of such defects, non-adherance, or 
non-conformance and follows Seller's instructions regarding return of such 
defective, non-functioning or non-conforming Product or Software **************
*********************************

                        Lucent Technologies Proprietary
                                      -5-

<PAGE>
 
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******************

With respect to Seller's Manufactured Products which Seller has ascertained are 
not readily returnable for repair, Seller, at its option, may elect to repair or
replace the Products at Customer's site. Customer, at its expense, shall make 
the Products accessible for repair or replacement and restore the site after 
Seller has completed its repairs or replacement.

Seller makes no warranty with respect to defective conditions or 
non-conformities resulting from the following: Customer's modifications, misuse,
neglect, accident or abuse; improper wiring, repairing, splicing, alteration, 
installation, storage or maintenance; use in a manner not in accordance with 
Seller's or its vendor's Specifications, or operating instructions or failure of
Customer to apply previously applicable Seller's modifications or corrections 
(provided such specifications modifications, or corrections are provided to 
Customer in writing prior to any inappropriate action or use by Customer). In 
addition, Seller makes no warranty with respect to Products which have had their
serial numbers or month and year of manufacture removed, altered and with 
respect to expendable items, including, without limitation, fuses, light bulbs, 
motor brushes and the like. No warranty is made that Software will run 
uninterrupted or error free, and in addition Seller makes no warranty with 
respect to defects related to Customer's data base errors.

********************************************************************************
**************************************************************************** 
************************************************************************** 
****************************************************************************** 
******************************************************************************* 
***************************************************************************** 
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************************************************************************** 
************************************************************************

THE FOREGOING WARRANTIES ARE EXCLUSIVE AND ARE IN LIEU OF ALL OTHER EXPRESS AND 
IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO WARRANTIES OR MERCHANTABILITY 
AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMER'S SOLE AND EXCLUSIVE REMEDY 
SHALL BE SELLER'S OBLIGATION TO REPAIR, REPLACE, CREDIT, OR REFUND AS SET FORTH 
ABOVE IN THIS WARRANTY DURING THE WARRANTY PERIOD.

1.14      CHANGES IN PRODUCTS:

           Prior to shipment, Seller may at any time make changes in Products
or modify the drawings and Specifications relating thereto or substitute 
Products of later design, provided the changes, modifications or substitutions 
under normal and proper use do not impact upon Form, Fit, or Function of an 
ordered Product as provided in Seller's Specifications. With respect to
changes, modifications, and substitutions which do affect the Form, Fit, or
Function of an ordered Product, Seller shall notify Customer in writing thirty
(30) days prior to their effective dates. In the event any such change is not
desired by Customer, Customer shall notify Seller within thirty (30) days from
the date of notice and Seller shall not furnish any such changed Products to
Customer on any orders in process at the time Seller is so notified.

1.15      INFRINGEMENT:

           For the purposes of this Article, Licensed Materials include 
Firmware. In the event of any claim, action, proceeding or suit by a third party
against Customer alleging an infringement of any ***** or a violation of any 
trade secret or proprietary rights by reason of the use, in accordance with 
Seller's Specifications, of any Product or Licensed Materials furnished by 
Seller to Customer under this Agreement. Seller, at its expense, will defend 
Customer, subject to the 

                        Lucent Technologies Proprietary
                                      -6-


<PAGE>
 
conditions and exceptions stated below. Seller will reimburse Customer for any 
reasonable cost, expense or attorneys' fees, incurred at Seller's request or 
authorization, and will indemnify Customer against any liability assessed 
against Customer by final judgment on account of such infringement or violation
arising out of such use. Customer hereby agrees not to place any product or 
licensed materials furnished by Seller, by this Agreement, in such countries 
that Seller does not do business, now or in the future. The Exhibit B list 
provides countries in which Seller does business.

If Customer's use shall be enjoined or in Seller's opinion is likely to be
enjoined, Seller will, at its expense and at its option, either (1) replace the
enjoined Product or Licensed Materials furnished pursuant to this Agreement with
a suitable substitute free of any infringement ******* (2) modify it so that it
will be free of the infringement; or (3) procure for Customer a license or other
right to use it. If none of the foregoing options are practical, ***.

Each party shall use reasonable efforts to give the other party prompt written 
notice of all such claims, actions, proceedings or suits alleging infringement 
or violation and Seller shall have full and complete authority to assume the 
sole defense thereof, including appeals, and to settle same. Customer at its 
expense, shall have the option to have its own counsel participate in any such 
proceeding. Customer shall, upon Seller's request and at Seller's expense, use
reasonable efforts to furnish all information and assistance available to
Customer and cooperate in every reasonable way to facilitate the defense and/or
settlement of any such claim, action, proceeding or suit.

No undertaking of Seller under this clause shall extend to any such alleged 
infringement or violation to the extent that it: (1) arises from adherence to 
design modifications, specifications, drawings, or written instructions which 
Seller is directed by Customer to follow, but only if such alleged infringement 
or violation does not reside in corresponding commercial Product or Licensed 
Materials of Seller's design or selection; or (2) arises from adherence to 
instructions to apply Customer's trademark, trade name or other company 
identification; or (3) resides in a Product or Licensed Materials which are not
of Seller's origin and which are furnished by Customer to Seller for use under 
this Agreement; or (4) is based upon Products or Licensed Materials provided by
Seller in combination with other Products or Licensed Materials, provided either
by Seller or others, which combination was not provided by Seller to Customer as
a system.

The liability of Seller with respect to any and all claims, actions, proceedings
or suits by third parties alleging infringement of patents, trademarks or
copyrights or violation of trade secrets or proprietary rights because of, or in
connection with, any Products or Licensed Materials furnished pursuant to this
Agreement shall be limited to the specific undertakings contained in this
clause: ***. The existence of an infringement will not be considered a breach.

1.16      CUSTOMER'S REMEDIES:

           A.  CUSTOMER'S EXCLUSIVE REMEDIES AND THE ENTIRE LIABILITY OF SELLER,
           ITS AFFILIATES AND THEIR EMPLOYEES, AND AGENTS, AND ITS SUPPLIERS FOR
           ANY CLAIM, LOSS, DAMAGE OR EXPENSE OF CUSTOMER OR ANY OTHER ENTITY
           ARISING OUT OF THIS AGREEMENT, OR THE USE OR PERFORMANCE OF ANY
           PRODUCT, LICENSED MATERIALS, OR SERVICES, WHETHER IN AN ACTION FOR OR
           ARISING OUT OF BREACH OF CONTRACT, TORT, INCLUDING NEGLIGENCE,
           INDEMNITY, OR STRICT LIABILITY, SHALL BE AS FOLLOWS:

               1)   FOR INFRINGEMENT-THE REMEDY SET FORTH IN THE "INFRINGEMENT" 
               CLAUSE;

               2)   FOR THE PERFORMANCE OR NONPERFORMANCE OF PRODUCTS, SOFTWARE,
               AND SERVICES OR CLAIMS THAT THEY DO NOT CONFORM TO A WARRANTY--
               THE REMEDY SET FORTH IN THE APPLICABLE "WARRANTY" CLAUSE;

               3)   FOR TANGIBLE PROPERTY DAMAGE AND PERSONAL INJURY CAUSED BY 
               SELLER'S NEGLIGENCE--THE AMOUNT OF THE DIRECT DAMAGES;

               4)   FOR EVERYTHING OTHER THAN AS SET FORTH ABOVE--THE AMOUNT OF 
               THE DIRECT DAMAGES NOT TO EXCEED ***** INCLUDING AWARDED COUNSEL
               FEES AND COSTS.

                        Lucent Technologies Proprietary
                                      -7-

<PAGE>
 
           B.  NOTWITHSTANDING ANY OTHER PROVISION OF THIS AGREEMENT, SELLER, 
           ITS AFFILIATES AND THEIR EMPLOYEES, AND AGENTS, AND ITS SUPPLIERS
           SHALL NOT BE LIABLE FOR ANY INCIDENTAL, INDIRECT, OR CONSEQUENTIAL
           DAMAGES OR LOST PROFITS, REVENUES OR SAVINGS ARISING OUT OF THIS
           AGREEMENT, OR THE USE OR PERFORMANCE OF ANY PRODUCT, LICENSED
           MATERIALS, OR SERVICES, WHETHER IN AN ACTION FOR OR ARISING OUT OF
           BREACH OF CONTRACT, TORT, INCLUDING NEGLIGENCE, OR STRICT LIABILITY.
           THIS CLAUSE, 1.16(B), SHALL SURVIVE FAILURE OF AN EXCLUSIVE OR
           LIMITED REMEDY.

           C.  CUSTOMER SHALL GIVE SELLER PROMPT WRITTEN NOTICE OF ANY CLAIM.
           ANY ACTION OR PROCEEDING AGAINST SELLER MUST BE BROUGHT WITHIN 
           TWENTY-FOUR (24) MONTHS AFTER THE CAUSE OF ACTION ACCRUES.

1.17      USE OF INFORMATION:

           All technical and business information in whatever form recorded 
which bears a legend or notice restricting its use, copying, or dissemination 
or, if not in tangible form, is described as being proprietary or confidential 
at the time of disclosure and is subsequently summarized in a writing so marked 
and delivered to the receiving party within thirty (30) days of disclosure to 
the receiving party (all hereinafter designated "Information") shall remain the 
property of the furnishing party. The furnishing party grants the receiving 
party the right to use such Information only as follows: Such Information (1) 
shall not be reproduced or copied, in whole or part, except for use as 
authorized in this Agreement; and (2) shall, together with any full or partial 
copies thereof, be returned or destroyed when no longer needed. Moreover, when 
Seller is the receiving party, Seller shall use such Information only for the 
purpose of performing under this Agreement, and when Customer is the receiving 
party, Customer shall use such Information only (1) to order; (2) to evaluate 
Seller's Products, Licensed Materials and Services; or (3) to install, operate 
and maintain the particular Products and Licensed Materials for which it was 
originally furnished. Unless the furnishing party consents in writing, such 
Information, except for that part, if any, which is known to the receiving party
free of any confidential obligation, or which becomes generally known to the 
public through acts not attributable to the receiving party, shall be held in 
confidence by the receiving party. The receiving party may disclose such 
Information to other persons, upon the furnishing party's prior written 
authorization, but solely to perform acts which this clause expressly 
authorizes the receiving party to perform itself and further provided such other
person agrees in writing (a copy of which writing will be provided to the 
furnishing party at its request) to the same conditions respecting use of 
Information in this clause.

1.18      LICENSE OR LICENSED MATERIALS PATENT IMMUNITY:

           For the purposes of this Article, Licensed Materials include
           Firmware.

           Upon delivery of Licensed Materials pursuant to this Agreement,
Seller grants to Customer and its affiliates aperpetual, nontransferable (except
as provided in Article 1.37), and nonexclusivefully paid up (upon receipt of the
associated payment), irrevocable (unless breached in accordance with Article
1.20 of this Agreement) license to Use Licensed Materials on a Designated
Processor for Customer's own business operations. No license is granted to
Customer to sublicense such Licensed Materials furnished by Seller. Customer
shall not decompile or disassemble Software furnished as object code to generate
corresponding source code. Unless otherwise agreed in writing by Seller, ****,
Customer shall not materially modify Software furnished by Seller under this
Agreement. If the Designated Processor becomes temporarily inoperative, Customer
shall have the right to Use the Licensed Materials temporarily on a backup
processor until operable status is restored and processing on the backup
processor is completed.

            ******.

<PAGE>
 
1.19      TITLE, RESTRICTIONS, AND CONFIDENTIALLY:

               All Licensed Materials (whether or not part of Firmware) 
furnished by Seller, and all copies thereof made by Customer, including 
translations, compilations, and partial copies are, and shall remain, the 
property of Seller. Except for any part of such Licensed Materials which is or 
becomes generally known to the public through acts not attributable to Customer,
Customer shall hold such Licensed Materials in confidence, and shall not, 
without Seller's prior written consent, disclose, provide, or otherwise make 
available, in whole or in part, any Licensed Materials to anyone, except to its 
employees agents, consultants, and contractors having a need-to-know. Customer 
shall not copy Software embodied in Firmware. (Customer agrees to fully and 
reasonably cooperate with Seller should any agent, consultant, or contractor 
breach this obligation of confidentiality and further agrees that all such 
agents, consults, and contractors will sign a confidentiality agreement, 
substantially in the form attached hereto as Exhibit A). Customer shall not make
any copies of any other Licensed Materials except as necessary in connection 
with the rights granted hereunder. Customer shall reproduce and include any 
Seller copyright and proprietary notice on all such necessary copies of the 
Licensed Materials. Customer shall also mark all media containing such copies 
with a warning that the Licensed Materials are subject to restrictions contained
in an agreement between Seller and Customer and that such Licensed Materials are
the property of Seller. Customer shall maintain records of the number and 
location of all copies of the Licensed Materials. Customer shall take 
appropriate action, by instruction, agreement, or otherwise, with the persons 
permitted access to the Licensed Materials so as to enable Customer to satisfy 
its obligations under this Agreement. If Customer's license is canceled or 
terminated, or when the Licensed Materials are no longer needed by Customer, 
Customer shall return all copies of such Licensed Materials to Seller or follow 
written disposition instructions provided by Seller. Seller hereby represents 
and warrants that during the entire term of this Agreement and any license it 
has all right, title, ownership interest and/or marketing rights necessary to 
grant the rights and license to Customer set forth herein. Customer's entire 
right and exclusive remedies for breach of the preceeding sentence shall be 
governed entirely Article 1.15, INFRINGEMENT, and, notwithstanding the 
preceding sentence, Seller shall have no obligations under this Agreement with 
respect to infringements except those set forth in Article 1.15.

1.20      CANCELLATION OF LICENSE:

               Notwithstanding any other clause in this Agreement to the 
contrary, if Customer fails to comply with any of the material terms and 
conditions of this Agreement with respect to the Use of Licensed Materials or 
Firmware, and such failure continues beyond *********** days after receipt of 
written notice thereof by Customer, Seller, upon written notice to Customer, 
may cancel any affected license for Licensed Materials or Firmware. ********* 
************************************************************************** 
****************************************************************************** 
***************************************************************************** 
********************************

1.21      DOCUMENTATION:

               Seller shall furnish to Customer, **************************** 
**** of the documentation for Products provided hereunder sufficient to operate 
and maintain such Products and/or one copy of the Related Documentation for 
Software furnished by Seller pursuant to this Agreement. Such documentation will
be that customarily provided by Seller to its customers at no additional charge.
Such documentation shall be provided either prior to, included with, or shortly 
after shipment of Products and/or Software from Seller to Customer. ********** 
*******************************************************************************

1.22      CHANGES IN LICENSED MATERIALS:

               Prior to shipment, Seller may at any time modify the 
Specifications relating to its Licensed Materials. Seller may substitute 
modified Licensed Materials to fill an order, provided the modifications, under 
normal and proper Use, are functionally equivalent to the ordered Licensed 
Materials, and Seller shall advise Customer in writing at least fifteen (15) 
days prior to implementation of such changes. Unless otherwise agreed, such
substitution shall not result in any additional charges to Customer with respect
to licenses for which Seller has quoted fees to Customer. Seller acknowledges 
and agrees that all modified Licensed Materials shall have and comply with all 
of the warranties described hereunder.

1.23      OPTIONAL SOFTWARE FEATURES:

               Software provided to Customer under this Agreement may contain 
optional features which are contained in the switch features handbook which are 
separately licensed and priced. Customer agrees that such optional features will
not be activated

                        Lucent Technologies Proprietary
                                      -9-
<PAGE>
 
without written authorization from Seller and Customer's payment of the 
appropriate license fees. ******************************************************
*************************************************************************** 
****************************************************************************** 
***************************************************************************** 
***************

1.24  ADDITIONAL PROVISIONS FOR PRODUCT SPECIFIC LICENSED MATERIALS:

          In addition to the provisions applicable to the furnishing of Licensed
Materials as set forth above in clauses "License for Licensed Materials," 
"Title, Restrictions and Confidentiality," "Cancellation of License,"
"Documentation," and "Changes in Licensed Materials," additional provisions
regarding the furnishing of Product specific Licensed Materials are set forth in
Article II attached hereto.

1.25  COMPATIBILITY OF SELLER'S PRODUCTS AND LICENSED MATERIALS:

          Seller makes no representations or warranties whatsoever that Products
or Licensed Materials will be compatible with any equipment currently or
hereafter owned by Customer or any other entity (all such equipment hereinafter
for purposes of this clause referred to as "Other Equipment"). Customer shall be
responsible for any and all modifications or additions which may be required to
Other Equipment so that such Other Equipment operates satisfactorily with
Products or Licensed Materials furnished and installed by Seller. If Customer
requests Seller to make any such modifications or additions, Seller, at its
discretion, may elect to do so, and in such case, the modifications and
additions will be made as requested by Customer and shall be billed to and paid
for by Customer at prices determined by Seller as a separate item in addition to
any other amounts due and payable by Customer. Seller shall have no liability to
Customer for any such modifications or additions to Other Equipment except to
the extent Seller fails to follow Customer's instructions or to perform such
work in a workmanlike manner.

1.26  PUBLICITY:

          Each party shall submit to the other proposed copy of all advertising 
wherein the name, trademark, code, specification or service mark of the other 
party or its Subsidiaries or Affiliates is mentioned. Neither party shall 
publish or use such advertising without the other's prior written approval. Such
approval shall be granted as promptly as possible (usually within ten [10]
days), and may be withheld only for good cause.

1.27  PUBLICATION OF AGREEMENT:

          The parties shall keep the provisions of this Agreement and any order 
submitted hereunder confidential except as reasonably necessary for performance 
hereunder and except to the extent disclosure may be required by applicable laws
or regulations, in which latter case, the party required to make such disclosure
shall promptly inform the other prior to such disclosure not to exceed 24 hours 
to enable such other party to make known any objections it may have to such 
disclosure. The disclosing party shall take all reasonable steps to secure a 
protective order or otherwise assure that the Agreement or order will be 
withheld from the public record.

1.28  NOTICES:

          All notices under this Agreement shall be in writing (except where 
otherwise stated) and shall be addressed to the addresses set forth at the 
beginning of this Agreement or to such other address as either party may 
designate by notice pursuant hereto. Such notices shall be deemed to have been 
given when received.

1.29  CUSTOMER RESPONSIBILITY:

          Customer shall, at no charge to Seller, provide Seller with such 
electrical and environmental conditions, technical information, data, technical 
support or assistance as may reasonably be required by Seller in Seller's
documentation submitted to Customer to fulfill its obligations under this
Agreement, any subordinate agreement or order. If Customer fails to provide the
required conditions, technical information, data, support or assistance, Seller
shall provide Customer reasonable notice after which Seller shall be discharged
from any such obligation until such time as Customer has reasonably provided
such support described in this Article 1.29.

                        Lucent Technologies Proprietary
                                     -10-

<PAGE>
 
1.30  RIGHT OF ACCESS:

          Each party shall provide the other access to its facilities resonably
required in connection with the performance of the respective obligations under
this Agreement. No charge shall be made for such access. Reasonable prior 
notification will be given when access is required.
 
1.31  FORCE MAJEURE: 

          Neither party shall be held responsible for any delay or failure in 
performance to the extent that such delay or failure is caused by fires, 
strikes, embargoes, explosions, earthquakes, floods, wars, water, the elements, 
labor disputes*****************, government requirements, civil or military 
authorities, acts of God or by the public enemy, inability to secure raw 
materials or transportation facilities, or acts or omissions of carriers or 
suppliers of third parties. ****************************************************
********************************************************************* 
*******************************************************************

1.32  INDEPENDENT CONTRACTOR: 
    
          All work performed by either party under this Agreement shall be 
performed as an independent contractor and not as an agent of the other, and no 
persons furnished by the performing party shall be considered the employees or 
agents of the other.

1.33  RELEASES VOID:

          Neither party shall require releases or waivers of any personal rights
from representatives or employees of the other in connection with visits to its
premises, nor shall such parties plead such releases or waivers in any action or
proceeding.

1.34  SEVERABILITY:

          If any provision in this Agreement shall be held to be invalid or 
unenforceable, the remaining portions shall remain in effect. In the event such 
invalid or unenforceable provision is considered an essential element of this 
Agreement, the parties shall promptly negotiate a replacement.

1.35  SURVIVAL OF OBLIGATIONS:

          The rights and obligations of the parties which by their nature would 
continue beyond the termination, cancellation, or expiration of this Agreement, 
shall survive such termination, cancellation or expiration.

1.36  NON-WAIVER:

          No waiver of the terms and conditions of this Agreement, or the
failure of either party to strictly enforce any such term or condition on one or
more occasions shall be construed as a waiver of the same or of any other terms
or conditions of this Agreement on any other occasion.

1.37  ASSIGNMENT:

          Except as provided in this clause, neither party shall assign this 
Agreement or any right or interest under this Agreement, nor delegate any work 
or obligation to be performed under this Agreement, (an "assignment") without 
the other party's prior written consent. Any attempted assignment in 
contravention of this shall be void and ineffective. Nothing shall preclude a 
party from employing a subcontractor in carrying out its obligations under this 
Agreement. A party's use of such subcontractor shall not release the party from 
its obligations under this Agreement. Seller has the right to assign this 
Agreement and to assign its rights and delegate its duties under this Agreement,
in whole or in part, at any time and without Customer's consent, to any present 
or future Subsidiary or Affiliate of Seller or to any combination of the 
foregoing. Such assignment or delegation shall release Seller from any further 
obligation or liability thereon. Seller shall give Customer prompt written 
notice of the assignment. ******************************************************
****************************************************************************** 
******************************************************************************* 
************************************************************************** 
********************************************************************************
************************************************************************** 
************************* For purposes of this

                        Lucent Technologies Proprietary
                                     -11-
<PAGE>
 
clause, the term "Agreement" includes this Agreement, any subordinate agreement 
placed under this Agreement and any order placed under this Agreement or 
subordinate agreement.

1.38  TERMINATION FOR CONVENIENCE:

          Customer may, upon written notice to Seller, terminate an order under 
this Agreement or a portion thereof except with respect to Products and Licensed
Materials that have already been shipped and Services that have already been 
performed. For those Products and Licensed Materials not shipped and considered 
stock items, Customer agrees that it will pay Seller an order fee equal to 
********************* of the price or license fee for such items up to ******** 
and ***************** for any higher priced items. For those Products and 
Licensed Materials not shipped and considered customized or non-stock items, 
Customer agrees to pay a fee based upon Seller's incurred reasonable expenses 
(after adjustment for recoveries and/or salvage value, if any), including 
associated general and administrative expenses plus a reasonable profit. 
Customer may issue "holds" on orders or suspend performance under this 
Agreement, in whole or in part, with Seller's prior written consent and upon 
terms that will compensate Seller for any demonstrable loss, damages, or 
expenses.

1.39  CANCELLATION FOR BREACH:

          In the event either party is in material breach or default of the 
material terms of this Agreement and such breach or default continues for a 
period of *************** days after the receipt of written notice, then the 
party not in breach or default shall have the right to cancel this Agreement 
without any charge, obligation or liability except for Products or Licensed 
Materials already delivered and Services already performed. The party not in 
breach or default shall provide full cooperation to the other in every 
reasonable way to facilitate the remedy of the breach or default hereunder 
within such *************** day period. *********************************** 
********************************************************************************
********************************

1.40  PERFORMANCE OF SERVICE:

          Services shall be performed by Seller in accordance with the ******* 
** its standard practices and industry standards. Specific provisions applicable
to engineering, installation and other Services performed by Seller are set 
forth in Article III attached hereto. In no event shall Seller perform services 
in less than a workmanlike manner.

1.41  APPLICABLE LAW:

          The construction and interpretation of, and the rights and obligations
of the parties pursuant to this Agreement, shall be governed by the laws of the 
State of New York.

1.42  ARBITRATION:

          If any dispute claim of other difference arises out of or relates to 
this Agreement, or its breach, the parties agree to submit the dispute to a 
panel of three (3) mediators selected by the parties or, at any time at the 
option of a party, to mediation by the American Arbitration Association ("AAA").
If not thus resolved, it shall be referred to a panel of three (3) arbitrators 
selected by the parties within thirty (30) days of the mediation or, in the 
absence of such selection, to AAA arbitration which shall be governed by the 
United States Arbitration Act, and judgment on the award may be entered in any 
court having jurisdiction. The arbitrator may determine issues of arbitrability,
but may not award punitive damages or limit, expand or otherwise modify the 
terms of this Agreement. The parties, their representatives, other participants 
and the mediator and arbitrator shall hold the existence, content and result of 
mediation and arbitration in confidence.

                        Lucent Technologies Proprietary
                                     -12-

<PAGE>
 
                                  ARTICLE II

                 ADDITIONAL PROVISIONS FOR LICENSED MATERIALS

GENERAL:  The provisions of this Article II also apply to the granting of 
licenses by Seller to Customer for 5ESS(R) Switch Licensed Materials, Operations
Systems (OS) Licensed Materials, and Transmission Systems Licensed Materials. In
the event of any conflict or inconsistency between the provisions of this
Article II and those in Article I, the provisions of this Article II shall
govern.

                        5ESS SWITCH LICENSED MATERIALS

2.1   ADDITIONAL RIGHTS IN SOFTWARE:

      (a)  TRANSFER OF 5ESS SWITCH SOFTWARE RIGHT-TO-USE: Customer may transfer
           its right-to-use 5ESS Switch Software furnished under this Agreement
           without the payment of an additional right-to-use fee by transferee,
           except where size sensitive units are a factor. Such transfer can be
           made ****************** but not to competitors of Seller in the
           business of manufacturing comparable systems and only under the
           following conditions:

               (i)   Such Software shall be Used only within the United States;
                     however, Seller will not unreasonably withhold its consent
                     to Use outside the United States provided the proprietary
                     information associated with the Use can be adequately
                     protected;

               (ii)  Except as otherwise provided in the Agreement, the right to
                     Use such Software may be transferred only together with the
                     5ESS Switch Product with which Customer has a right to Use
                     such Software, and such right to Use the Software shall
                     continue to be limited to Use with such Product:

               (iii) Before any such Software shall be transferred, Customer
                     shall notify Seller of such transfer and the transferee
                     shall have agreed in writing (a copy of which will be
                     provided to Seller at its request) to keep such Software in
                     confidence and to corresponding conditions respecting Use
                     of Licensed Materials as those imposed on Customer; and

               (iv)  Within the United States, the transferee shall have the
                     same right to Software warranty or Software maintenance for
                     such Software as the transferor, provided the transferee
                     continues to pay the fees, if any, associated with such
                     Software or Software maintenance.

      (b)  RELOCATION OF 5ESS SWITCH SOFTWARE: Upon advance written notice to
           Seller, Customer may remove 5ESS Switch Software or optional feature
           packages, for which Customer has the right to Use, from one Customer-
           owned 5ESS Switch Product and relocate them to another Customer-owned
           5ESS Switch Product within the same company as Customer. Customer
           shall not be required to pay additional right-to-use fees as a result
           of such relocation, except where size sensitive units are a factor.
           Seller may charge Customer for Services requested by Customer in
           support of such relocation. Such Software shall not be Used or
           transferred to Customer's Affiliate that is a manufacturer of
           telecommunication products in direct competition with Seller ****.

      (c)  ****.

2.2   RELATED DOCUMENTATION:

      Seller will provide to Customer **** the most recent text and drawing CD-
ROM **** to the 5ESS Switch Documentation Dial-Up Service for each new
host/standalone Switch site. No documentation will

                        Lucent Technologies Proprietary
                                     -13-

<PAGE>
 
be provided to RSMs or ORMs. In addition, Seller will provide updates ***** 
****** to the host/standalone site ***************************** following 
Switch turnover. After the initial ************ update period, Customer may 
purchase an update subscription at the standard subscription rate.

               OPERATIONS SYSTEMS ("OS") LICENSED MATERIALS AND
                    TRANSMISSION SYSTEMS LICENSED MATERIALS

2.3   DEFINITIONS:

          In addition to the definitions in Article I of this Agreement, the 
following terms, for purposes of this Article II, shall have the meanings 
indicated below as to Operations Systems ("OS") Licensed Materials and 
Transmission Systems Licensed Materials as applicable:

(a)       "Acceptance Date" means the date on which the OS Software successfully
     completes the Acceptance Test;

(b)       "Acceptance Period" means the period of time in days agreed to by the 
     parties and specified in the applicable order, or if not so specified, the
     period specified in clause 2.6 entitled "OS Software Acceptance;"

(c)       "Acceptance Test" means the test which may be performed by Customer 
     during the Acceptance Test Period to determine whether OS Software meets
     the Specifications;

(d)       "Delivery Date" means the date by which all deliverables ordered by 
     Customer are delivered to the destination specified in the order;

(e)       "Installation Complete Date" means the date on which OS Software or 
     Transmission Systems Software is installed by Seller at the location
     specified in the order and ready for Use by Customer;

(f)       "OS Software" means the object code Software, embodied in any medium, 
     including Firmware, for Operations Systems;

(g)       "Seller's Standard Charges" means Seller's applicable rates and
     charges for labor and materials as determined from Seller's Customer Price
     Lists and other pricing information provided by Seller to Customer, less
     any discounts applicable thereto.

2.4   ADDITIONAL RIGHTS IN OS AND TRANSMISSION SYSTEMS SOFTWARE:

(a)       Upon thirty (30) days advance written notice, Customer may relocate 
     the Software permanently to a new processor of Customer. This new processor
     shall then become the Designated Processor in lieu of the former Designated
     Processor.

(b)       Customer may retain an archival copy of the Software for as long as 
     such Software is relevant to Customer's operations.

2.5   INSTALLATION OF OS AND TRANSMISSION SYSTEMS SOFTWARE:

(a)       Where Customer is responsible for Software installation, Seller's 
     responsibility is to deliver the Software to Customer on or before the
     scheduled Delivery Date agreed to by Seller. However, if the order
     specifies that Seller is responsible for such installation, Seller shall
     deliver the Software to Customer in sufficient time for it to be installed
     on or before the scheduled Installation Complete Date agreed to by Seller,
     and Seller shall complete its installation and associated testing on or
     before such date.

(b)       Where Customer has assumed responsibility for the installation of 
     newly licensed Software, Seller will, at Customer's request *****, provide
     for the first such installation a reasonable level of technical assistance
     when Customer encounters installation difficulties. For all subsequent
     installations of such Software by Customer, Seller ***** Customer for any
     technical assistance provided in response to Customer's request for
     assistance.

                        Lucent Technologies Proprietary
                                     -14-




<PAGE>
 
2.6       OS SOFTWARE ACCEPTANCE:

(a)       Customer has the right to operate the OS Software furnished by Seller
     on the Designated Processor to conduct an Acceptance Test to determine if
     such Software is operating in accordance with Seller's Specifications
     therefor and with Seller's warranties described herein. Unless otherwise
     agreed by the parties, Customer shall have *** consecutive calendar days to
     conduct this test from receipt if Customer performs installation or ***
     days from the Installation Complete Date if Seller performs installation.
     The Software shall be deemed accepted by Customer unless Customer notifies
     Seller in writing to the contrary within the applicable Acceptance Test
     Period described above. If the Software fails the Acceptance Test during
     the Acceptance Test Period, the Acceptance Date shall be extended on a day-
     to-day basis until the Software, as modified, is accepted or until Customer
     determines that the OS Software will not be modified in a manner that will
     pass acceptance testing within a reasonable period of time.

(b)       If Customer elects in the order not to perform Acceptance Tests for
     any OS Software, the Acceptance Date for such Software shall be the
     Delivery Date if not installed by Seller or the Installation Complete Date
     if installed by Seller, as applicable.

(c)       For the first Acceptance Test conducted by Customer on newly licensed
     OS Software, Seller will, at Customer's request ***, provide a reasonable
     level of technical assistance to Customer when difficulties are encountered
     by Customer. For all subsequent Acceptance Tests of such OS Software,
     Seller *** Customer for assistance provided in response to Customer's
     request for such assistance. Such charges shall be in accordance with
     Seller's standard rates then in effect.

(d)       If Customer performs installation and elects to perform applicable
     tests for any OS Software, the warranty for such OS Software shall commence
     upon Acceptance as defined in sub-paragraph (a) above.

2.7       MODIFICATIONS BY CUSTOMER TO USER CONTROLLED MODULES:

          Customer may add to, delete from, or modify user controlled (refers to
modules designed for data population and manipulation by the user, i.e., user 
driven) OS Software modules or menus, if available from Seller. Such changes or
modifications, however extensive, shall not affect Seller's title to the 
licensed Software; ***.


                                  ARTICLE III

                     PROVISIONS APPLICABLE TO ENGINEERING,
                       INSTALLATION, AND OTHER SERVICES

GENERAL:  The provisions of this Article III additionally apply to the 
furnishing by Seller of Services to Customer. Such Services include, but are not
limited to, (1) engineering Services such as preparation of equipment 
specifications, preparation and updating of office records, and preparation of a
summary of material not specifically itemized in the order; (2) installation 
Services such as installation, equipment removal, and cable mining; and (3) 
other Services such as repairs.

3.1       CONDITIONS OF INSTALLATION AND OTHER SERVICES PERFORMED ON CUSTOMER'S 
          SITE:

ITEMS PROVIDED BY CUSTOMER

Customer will be responsible for furnishing the following items (as required by 
the conditions of the particular installation or other on-site Service, 
hereinafter collectively referred to as the "Service[s]") at no charge to Seller
and these items are not included in Seller's price for the Services. Should
Seller incur expense as a result of Customer's failure to provide any of these
items, additional billing will be rendered to and paid by Customer.

Access to Building and Work Site - Allow employees of Seller and its 
--------------------------------
subcontractors reasonable access to premises and facilities during normal 
business hours during the scheduled Service or at such other times as are 
mutually agreed. Customer shall obtain for Seller's and its subcontractors' 
employees any necessary identification and clearance credentials to enable 
Seller and its subcontractors to have access to the work site.

                        Lucent Technologies Proprietary
                                     -15-
<PAGE>
 
General Building Conditions - Take such action as may be necessary to insure
---------------------------
that the premises will be dry and free from dust and Hazardous Materials,
including but not limited to asbestos, and in such condition as not to be
injurious to Seller's or its subcontractors' employees or to the Products to be
installed. Prior to commencement of the Services and during the performance of
the Services, Customer shall, if reasonably requested by Seller, use reasonable
efforts to provide Seller with sufficient data to assist Seller or its
subcontractor in evaluating the environmental conditions at the work site
(including the presence of Hazardous Materials). The price quoted by Seller for
Services does not include the cost of removal or disposal of the Hazardous
Materials from the work site. Customer is responsible for removing and disposing
of the Hazardous Materials, including but not limited to asbestos, prior to
commencement of Services.

Sensitive Equipment - Prior to commencement of Services, inform Seller of the 
-------------------
presence of any sensitive equipment at the work site (e.g., equipment sensitive 
to static electricity or light).
         
Repairs to Buildings - Prior to Services start date, make such alterations and 
--------------------
repairs as are necessary for proper installation of Products.

Openings in Buildings - Prior to Services start date, furnish reasonably 
---------------------
suitable openings in buildings to allow Products to be placed in position, and
provide necessary openings and ducts for cable and conductors in floors and
walls as designated on engineering drawings furnished by Seller. At least twelve
(12) weeks prior to the Services start date, Seller shall provide such drawings
to Customer. Customer shall fireproof (with steel covers) all unopened paths
throughout the building.

Surveys - Prior to Services start date, furnish surveys (describing the physical
-------
characteristics, legal limitations, and utility locations for the work site) and
a legal description of the site.

Electrical Current, Heat, Light, and Water - Provide electric current for 
------------------------------------------ 
charging storage batteries and for any other necessary purposes with suitable
terminals where work is to be performed; provide temperature control and general
illumination (regular and emergency) in rooms in which work is to be performed
or Products stored, equivalent to that ordinarily furnished for similar purposes
in a working office; provide exit lights; provide water and other necessary
utilities for the proper execution of Services.

Building Evacuation - Prior to Services start date, provide building evacuation 
-------------------
plans in case of a fire or other emergency.

Ceiling Inserts - Provide ceiling inserts as reasonably required using Seller's
---------------
standard spacing arrangement for ceiling support equipment.
 
Materials Furnished by Customer - Unless expressly stated to the contrary, 
-------------------------------
Seller's prices do not include costs for any Customer furnished material nor 
does it include any Seller charges for engineering, installation, modification, 
or repair Services to Customer furnished material. New or used material 
furnished by Customer shall be in such condition that it requires no repair and 
no adjustment or test effort in excess of that normal for new equipment.
Customer assumes all responsibility for the proper functioning of such material.
Customer shall also provide the necessary information for Seller to properly
install such material.

Toilet Facilities and Evewash Station - Provide proper and easily accessible 
-------------------------------------
toilet facilities and supplies, such as towels and soap, in buildings in which
Services are in progress. Where temporary facilities are required, Customer will
provide suitable, portable facilities including supplies and custodial Services.
Provide emergency eyewash station in power room near battery stands.

Floor Space and Storage Facilities - Provide, during progress of the Services, 
----------------------------------
suitable reasonable, and easily accessible floor space and storage facilities
(a) to permit storing major items of Products and other material closely
adjacent to where they will be used; (b) for administrative and luncheon
purposes; (c) for Seller's and its subcontractors' employees' personal effects;
and (d) for tools and property of Seller and its subcontractors. Where the
Services are to be performed outside of a building or in a building under
construction, Customer shall, in addition to the above requirements, as
appropriate, permit or secure permission for Seller and its subcontractors to
maintain at the work site, storage facilities (such as trailers) for Products,
material, tools, and equipment needed to complete the Services.

Easements, Permits, and Rights of Way - Prior to Services start date, provide
-------------------------------------
all rights-of-way, easements, licenses to come upon land to perform the
Services; permits and authority for installation of Products and other material;
permits for opening sidewalks, streets, alleys, and highways; and construction
and building permits.

                        Lucent Technologies Proprietary
                                     -16-
<PAGE>
 
Watch Service - Provide normal and reasonable security necessary to prevent 
-------------
admission of unauthorized persons to building and other areas where installation
Services are performed and to prevent unauthorized removal of the Products and 
other materials.  Seller will inform Customer as to which storage facilities at 
the work site Seller will keep locked.  Such storage facilities will remain 
closed to Customer's building surveillance.

Use of Available Testing Equipment - Customer shall make available to Seller: 
----------------------------------
(1) the maintenance test facilities which are embedded in equipment to which the
Product being installed will be connected or added; and (2) meters, test sets, 
and other portable apparatus that is unique to the Product being installed. 
Seller's use of such test equipment shall not interfere with Customer's normal 
equipment maintenance functions.

Hazardous Materials Cleanup - At the conclusion of the Services, Customer shall 
---------------------------
be responsible for the cleanup, removal, and proper disposal of all Hazardous 
Materials present at Customer's premises unless such hazardous materials were 
brought to the site by Seller, in which case, Seller shall be responsible for 
the hazardous materials cleanup, removal, and proper disposal.

Access to Existing Facilities - Customer shall permit Seller reasonable use of 
-----------------------------
such portions of the existing plant or equipment as are necessary for the proper
completion of such tests as require coordination with existing facilities.  Such
use shall not interfere with the Customer's normal maintenance of equipment.

Grounds - Customer shall provide reasonable access to suitable and isolated 
-------
building ground during business hours as required for Seller's standard 
grounding of equipment.  Where installation is outside or in a building under 
construction, Customer shall also furnish lightning protection ground.

Requirements for Customer Designed Circuits - Customer shall furnish information
-------------------------------------------
covering the proper test and readjust requirements for apparatus and
requirements for circuit performance associated with circuits designed by
Customer or standard circuits modified by Customer's drawings.

Standby Engine/Alternator Facilities - Customer shall provide suitable fuel, 
------------------------------------
storage, gas, water, antifreeze, sewer, and exhaust facilities as required with
piping terminating within the building and within ten (10) feet of the location 
of the engine/alternator to be installed, or terminating within the engine room
if engine/alternator is housed in a separate room. If Seller tests the
engine/alternator outdoors, Customer shall also provide lightning protection
ground.

Cross-Connecting Main Distributing Frames and Installing Heat Coils - Customer
-------------------------------------------------------------------
shall install such cross-connections and heat coils.

Clearing Equipment for Modifications - Customer shall remove cross- connections,
------------------------------------
transfer service on trunks and sundry working equipment, and make other 
arrangements required to permit Seller to modify existing plant.

Designation Strips - Customer shall number all jack designation strips described
------------------
in job requirements.

Fire Protection Apparatus - Customer shall install the permanent fire protection
-------------------------
apparatus and furnish such temporary apparatus as may be necessary for the 
protection of the Product and other equipment stored prior to installation.

Battery Room Ventilation - Customer shall provide the required ventilation for 
------------------------
battery rooms or areas.

House Service Panel - Customer shall provide electric power from the Customer's 
-------------------
service panel to the Seller's power board and shall run all leads between said 
service panel and power board.

Through Tests and Trunk Tests - Customer shall make required through tests and 
-----------------------------
trunk tests to other offices after Seller provides its notice of completion or 
notice of advanced turnover.

ITEMS TO BE FURNISHED BY SELLER 

The following items will be furnished by Seller (if required by the conditions 
of the particular Services) and the price thereof is included in Seller's price 
for Services:

                        Lucent Technologies Proprietary
                                     -17-
<PAGE>
 
Protection of Equipment and Buildings - Seller shall provide protection for 
-------------------------------------
Customer's equipment and buildings during the performance of the Services in 
accordance with Seller's standard practices.

Method of Procedure - Seller shall prepare a detailed Method of Procedure 
-------------------
("MOP") before starting work on live equipment. Customer shall review the MOP
and any requested changes shall be negotiated. Customer shall give Seller
written acceptance of the MOP prior to start of this work.

Power Circuit - Seller shall install power conduit and wire as described in 
-------------
Customer's job requirements.

Frame and Aisle Lighting - Seller shall install conduit, wire, fixtures, and 
------------------------
other necessary material for frame and aisle lighting as described in Customer's
job requirements.

Fireproofing - Seller shall fireproof (with steel covers) all openings it makes 
------------
in the building in the course of providing the Services.

Restoration - Where it is necessary in the performance of the Services to open 
-----------
sidewalks, driveways, curbing, alleys, streets, or other property, Seller shall 
restore said property to at least its former condition.

Cross-Connections Other than to Outside Cable Terminations - Seller shall run 
----------------------------------------------------------
cross-connections in accordance with the Customer's cross-connection list.

The following items may be furnished by Seller if requested by Customer, but 
Customer will be billed and shall pay for them in addition to Seller's standard 
of firm quoted price for Services:

Protection of Buildings and Equipment - Seller may provide protection of 
--------------------------------------
buildings and equipment in accordance with special practices of Customer 
differing from Seller's standard practices.

Readjusting Apparatus - Seller may provide readjustment (in excess of that 
---------------------
normally required on new apparatus) of apparatus associated with relocated or 
rewired circuits.

Rerunning Cross-Connections - Seller may rerun permanent cross-connections in 
---------------------------
accordance with revised cross-connection lists furnished by Customer.

Handling, Packing, Transportation, and Disposition of Removed and Surplus 
-------------------------------------------------------------------------
Customer Equipment - Seller may pack, transport, and dispose of surplus and 
------------------
removed Customer equipment as agreed by the parties.

Premium Time Allowances and Night Shift Bonuses - Seller may have its Services 
-----------------------------------------------
personnel work premium time and night shifts to the extent that Seller may deem
such to be necessary to effect the required coordination of installing and 
testing operations or other Services because of Customer's requirements.

Emergency Lighting System - Seller may provide new emergency lighting system 
-------------------------
(other than the original ceiling mounted stumble lighting) to satisfy
illumination and safety needs of Products of certain heights.

3.2  ACCEPTANCE OF INSTALLATION:

        At reasonable times during the course of Seller's installation, 
Customer, at its request may, or upon Seller's request shall, inspect completed 
portions of such installation.  Upon Seller's further request, and upon 
sufficient and reasonable notice to Customer, Customer shall observe Seller's 
testing of Products and Licensed Materials being installed to determine that 
such testing and the test results are in accordance with Seller's acceptance
standards or acceptance procedures. The job shall be considered complete and
ready for acceptance by Customer when Products and Licensed Materials have been
installed and tested by Seller in accordance with its standard procedures which
are no less than industry standards, and Seller represents such Products and
Licensed Materials to be in working order. Upon completion of the installation,
Seller will submit to Customer a notice of completion or, if Customer has
elected advance-turnover of subsystems, a notice of completion of advance-
turnover.

                        Lucent Technologies Proprietary
                                     -18-
<PAGE>
 
Customer shall promptly make its final inspection of substantial conformance 
with the Specifications. Seller will promptly correct any defects for which it 
is responsible. The job will be considered as fully accepted unless Seller 
receives notification to the contrary within thirty (30) days after submitting 
its notice of completion.

3.3       SITE PREPARATION:

           Where Services are to be performed by Seller, Customer shall be 
responsible for insuring that the premises where the work is to be performed are
accessible to Seller and ready and suitable for the Services to be performed in 
accordance with Seller's site-preparation conditions. Such conditions include, 
but are not limited to, (a) site readiness; and (b) access to adequate storage 
space, working space, personal facilities, heat, light, ventilation, telephone, 
electrical current, and outlets, all provided within a reasonable distance of 
the area where the work is to be performed. Seller's representative shall have 
the right to inspect the site prior to Services start date. Should Customer fail
to comply with the site-preparation conditions after Seller provides Customer 
notice, Seller may perform such work or furnish such items and charge Customer 
for them in addition to the prices otherwise charged by Seller for such 
Services.

3.4       WORK OR SERVICES PERFORMED BY OTHERS:

           Work or Services performed at the site by Customer or its other 
vendors or contractors shall not interfere with Seller's performance of 
Services. Seller shall have no responsibility or liability with respect to such 
work or Services performed by others. If Customer or its other vendors or 
contractors fail to timely complete the site readiness or if Customer's or its 
other vendors' or contractors' work interferes with Seller's  performance, the 
scheduled completion date of Seller's Services under this Agreement shall be 
extended as necessary to compensate for such delay or interference.

                                  ARTICLE IV

                               ENTIRE AGREEMENT

4.1       ENTIRE AGREEMENT:

           The terms and conditions contained in this General Agreement 
supersede all prior oral or written understandings between the parties with 
respect to the subject matter hereof and constitute the entire agreement between
the parties with respect to such subject matter. The preprinted terms and 
conditions on Customer's purchase orders or Seller's sales forms are deleted. 
The typed or handwritten provisions of an order which are consistent with the 
terms of this General Agreement along with the terms of this General Agreement 
shall constitute the entire Agreement between the parties relating to said 
order. Terms shall not be modified or amended except by a writing signed by 
authorized representative of both parties.

IN WITNESS WHEREOF, the parties have caused this Agreement to be executed by 
their duly authorized representatives on the date(s) indicated.

EXCEL SWITCH FACILITY, INC.                  LUCENT TECHNOLOGIES, INC.

By:/s/ Kenny A. Troutt                       By:/s/ Bill Plunkett
   ---------------------------------            ------------------------------

Name:  Kenny A. Troutt                       Name:  Bill Plunkett
     -------------------------------              ----------------------------

Title: President and CEO                     Title: VP Sales
      ------------------------------               ---------------------------

Date: January 27, 1997                       Date: January 27, 1997
     -------------------------------              ----------------------------


       APPROVED AS TO FORM 
       BY Legal /TBS
         -----------------
       DATE 1/27/97
           ---------------

                        Lucent Technologies Proprietary
                                     -19-

<PAGE>
 
                                                                       EXHIBIT A

                           NON-DISCLOSURE AGREEMENT
                           ------------------------

This Agreement is made and entered into effective _____________, 1996 by and 
between __________________, a corporation with an office located at _______
__________________________________ (the "Corporation") and Lucent Technologies
Inc., a Delaware corporation with offices located at 600 Mountain Avenue, Murray
Hill, New Jersey 07974 ("Lucent"), for itself and its affiliated companies.

Whereas, both parties, for their mutual benefit, desire to have Lucent disclose 
to the Corporation certain specifications, designs, plans, drawings, software, 
data, prototypes, or other business and/or technical information related to the 
operation and use of Products and Licensed Materials provided or being 
considered by Excel Switch Facility Inc. or its affiliates ("INFORMATION"), 
which INFORMATION is proprietary to Lucent or its affiliated companies.

Now therefore, the Corporation and Lucent agree as follows:

1.   This Agreement pertains to INFORMATION disclosed from the effective date 
and shall continue for a period of three (3) years unless terminated earlier in 
writing by both parties. The Corporation, shall hold such INFORMATION in 
confidence, shall use such INFORMATION only for the purpose of providing support
and consulting services to Excel Switch Facility Inc. or its affiliates, shall 
reproduce such INFORMATION only to the extent necessary for such purpose, shall 
restrict disclosure of such INFORMATION to its employees with a need to know 
(and advise such employees of the obligations assumed herein), and shall not 
disclose such INFORMATION to any third party without prior written approval of 
Lucent.

These restrictions on the use or disclosure of INFORMATION shall not apply to 
                                                                 ---
any INFORMATION:

     i.   which is independently developed by the Corporation or lawfully
     received free of restriction from another source having the right to so
     furnish such INFORMATION; or

     ii.  after it has become generally available to the public without breach 
     of this Agreement by the Corporation; or

     iii. which at the time of disclosure to the Corporation was known to the
     Corporation free of restriction as evidenced by documentation in the
     Corporation's possession; or

     iv.  which Lucent agrees in writing is free of such restrictions.
<PAGE>
 
2.   No license, under any trademark, patent, copyright, mask work protection 
right or any other intellectual property right, is either granted or implied by 
the conveying of INFORMATION to the Corporation. None of the INFORMATION which 
may be disclosed by Lucent shall constitute any representation, warranty,
assurance, guarantee, or inducement by Lucent of any kind, and, in particular,
with respect to the non-infringement of trademarks, patents, copyrights, mask 
work protection rights, or any other intellectual property rights, or other 
rights of third persons.

3.   Neither this Agreement nor the disclosure or receipt of INFORMATION shall 
constitute or imply any promise or intention to enter into any contract or other
business relationship or to make any purchase of products or services by either 
party or its affiliated companies or to make any commitment by either party or 
its affiliated companies with respect to the present or future marketing of any 
product or service.

4.   All INFORMATION shall be returned upon written request or upon the 
Corporation's determination that it no longer has a need for such INFORMATION.

5.   The Corporation acknowledges that any products, software, and technical 
information (including, but not limited to, services and training) provided 
under this Agreement are subject to U.S. export laws and regulations and any use
or transfer of such products, software, and technical information must be 
authorized under those regulations. Corporation agrees that it will not use, 
distribute, transfer, or transmit the products, software, or technical 
information (even if incorporated into other products) except in compliance with
U.S. export regulations. If requested by Lucent, Corporation also agrees to sign
written assurances and other export-related documents as may be required for 
Lucent to comply with U.S. export regulations.

6.   The Corporation agrees that all of its obligations undertaken herein shall 
survive and continue after any termination of this Agreement.

7.   This Agreement constitutes the entire understanding between the parties
hereto as to the INFORMATION and merges all prior discussions between them
relating thereto.

8.   No amendment or modification of this Agreement shall be valid or binding on
the parties unless made in writing and signed on behalf of each of the parties 
by their respective duly authorized officers or representatives.

9.   This Agreement shall be construed under and governed by the substantive 
laws of the State of New Jersey.
<PAGE>
 
10.  If a dispute arises with respect to this Agreement, either party may submit
the dispute to a sole mediator selected by the parties or, at any time, to 
mediation by the American Arbitration Association ("AAA"). If not thus resolved,
it may be referred by either party to a sole arbitrator selected by the parties
or to AAA arbitration. The arbitration shall be governed by the United States
Arbitration Act and judgment on the award may be entered by any court having
jurisdiction. The arbitrator shall not limit, expand or modify the terms of the
Agreement nor award damages in excess of compensatory damages, and each party
waives any claim to such excess damages. A request by a party to a court for
interim protection shall not affect either party's obligation hereunder to
mediate and arbitrate. Each party shall bear its own expenses and an equal share
of all cost and fees of the mediation and/or arbitration. Any mediator or
arbitrator selected shall be competent in the legal and technical aspects of the
subject matter of this Agreement. The content and result of mediation and/or
arbitration shall be held in confidence by all participants, each of whom will
be bound by an appropriate confidentiality agreement.

IN WITNESS WHEREOF, the parties have executed this Agreement.


By: _________________________________      By: _______________________________
           (Signature)                                  (Signature)


_____________________________________      ___________________________________
           (Typed Name)                                 (Typed Name)     


_____________________________________      ___________________________________
              (Title)                                      (Title)
 

_____________________________________      ___________________________________
           (Date Signed)                                 (Date Signed)
<PAGE>
 
                              [MAP APPEARS HERE]

<TABLE> 
     INTERNATIONAL       
     <S>                   <C>                <C>                     <C>                
     ARGENTINA:            GERMANY:           THE NETHERLANDS:        TAIWAN:           
     Buenos Aires          Bonn               Hilversum               Taipel            
                           Frankfurt          Hulzen                                    
     AUSTRALIA:            Hamburg            Leidschendam            THAILAND:                                               
     Sydney                Munich             Nieuwegein              Bangkok                                                 
                           Nuremberg                                                                                          
     BELGIUM:                                 NICARAGUA:              UNITED KINGDOM:        [PICTURE OF ISABELLE COLUCCI     
     Brussels              HONDURAS:          Managua                 Birmingham             APPEARS HERE]                    
                           San Pedro Sula                             Bracknell              Isabelle Colucci, secretary,     
     BRAZIL:                                  PERU:                   Cardiff                Telecommunications Radioelectriques
     San Paulo             HONG KONG          Lima                    Chippenham             et Telephoniques of Paris (TRT), Le 
                                                                      Farnborough            Plessis Robinson, Paris             
     CHILE:                INDIA:             PHILIPPINES:            Leeds                                                      
     Santiago              New Delhi          Manila                  London                 [PICTURE OF A.S. KRISHNAKUMAR       
                                                                      Malmesbury             (KRISHNA), APPEARS HERE]            
     CHINA:                INDONESIA:         POLAND:                 Manchester             A.S. Krishnakumar (Krishna),         
     Beijing               Jakarta            Bydgoszcz               Winchester             Wireless Networking and Mobile    
     Chengdu                                  Warsaw                                         Computing Research department head,    
     Guangzhou             IRELAND:                                   VENEZUELA:             Bell Labs, Nieuwegein, the Netherlands
     Shanghai              Dublin             RUSSIA:                 Caracas                        
     Shenyang                                 Almaty                                                 
     Wuhan                 ITALY:             Ekaterinburg            [PICTURE OF EMMA GRIFFITHS     
                           Milan              Kiev                    APPEARS HERE]                  
     COLOMBIA:             Rome               Moscow                  Emma Griffiths,                
     Bogota                                   St. Petersburg          market analyst,                
                           JAPAN:             Vilnius                 Network Systems, Malmes-       
     DENMARK:              Tokyo              Vladivostok             bury, United Kingdom           
     Bronby                                                                                          
                           KOREA:              SAUDI ARABIA:          Red-shaded areas have cities    
     EL SALVADOR:          Seoul               Damman                 with 50 or more employees.      
     San Salvador                              Jeddah                                                 
                           MALAYSIA:           Riyadh                 Illustration by Wendy Grossman  
     FRANCE:               Kuala Lumpur                                                               
     Lannion                                   SINGAPORE                                              
     Paris                 MEXICO:                                                                    
     Rennes                Mexico City         SPAIN:                                                 
     Rouen                 Guadalajara         Tres Cantos                                            
     Saumur                Matamoros                                                                  
                           Monterrey                                                                  
                           Reynosa

                                                                                                   Lucent Magazine July/August 1996 
</TABLE> 

<PAGE>
 
                          ADDENDUM NUMBER ONE TO THE

                           GENERAL AGREEMENT BETWEEN

                          EXCEL SWITCH FACILITY, INC.

                         AND LUCENT TECHNOLOGIES INC.

This is Addendum Number One to General Agreement LNM960906MOEXL (Agreement) 
                                                 --------------
between Excel Switch Facilities, Inc, a corporation with offices located at 8750
N. Central Expressway, Suite 2000, Dallas, Texas 75231 (hereinafter "Customer"),
and Lucent Technologies Inc., operating through its Network Systems Division, a 
Delaware corporation with offices located at 600 Mountain Avenue, Murray Hill, 
New Jersey 07984, (hereinafter "Seller").

WHEREAS, THE PARTIES HAVE ENTERED INTO A GENERAL AGREEMENT (AGREEMENT):

WHEREAS, this Addendum and the non-conflicting terms of the Agreement shall 
govern the purchase for use by Customer of Seller's Products and Licensed 
Materials.

WHEREAS, the parties desire to establish prices, terms and conditions applicable
if Customer purchases specified levels of 5ESS-2000(R) Switch Products and other
related products and Licensed Materials.

NOW THEREFORE, the parties agree as follows:

This Addendum shall be effective for a five (5) year period beginning with the 
execution of this Addendum. Customer hereby agrees to purchase a minimum of ****
initial 5ESS-2000 Switch Systems from the Seller at the prices listed in 
Attachment A during the term of this Addendum.

During the term of this Addendum, Customer hereby agrees to license each 
consecutive annual generic software release for each switch system (after 
generic release 5E11) for a Right To Use (RTU) fee of ******* per release per 
switch for the first **** software releases following the initial switching 
system up to a maximum of ****. This ***** license fee ************ 
***************************************************************************** 
****************************************************************************** 
The obligation to license the first **** software releases shall not survive
the expiration of this Addendum.

***************************************************************************** 
************************************************************************** 
*************************************************************************** 
************************************************************************** 
*************************************************************

For the purposes of this Agreement, the following terms and their definitions 
shall apply:

     "Growth means any additions, including, but not limited to circuit packs,
     additional memory, hardware extensions, Software retrofits, new
     Administrative Modules (AMs), Communications Models (CMs) or Switch Modules
     (SMs), which are ordered, installed or activated after a New Switch System
     has been placed into service.

Customer hereby agrees to purchase a minimum of **** power systems at the 
prices listed in Attachment B during the term of this Addendum. *************
****************************************************************************
*************************************

****************************************************************************** 
*************************************************************************
***************************************************************************** 
************************************************************************* 
***********************************************************************
********************************************************************************
***************************************

                                      -1-
                              LUCENT PROPRIETARY


<PAGE>
 
*******************************************************************************
***************************************************************************
******************************************************************************
*****************************************************************************
*****************************************************************************
*******************************************************************************
*************************************************************************
************************************************************************
*********

*******************************************************************************
******************************************************************************* 
********************************************

************************************************************************** 
****************************************************************************** 
******************************************************************************* 
********************************************************************************
**************************************************************************** 
**************************

ENTIRE AGREEMENT

The terms and conditions contained in this Addendum Number One and those 
nonconflicting terms and conditions of General Agreement LNM960906MOEXL 
                                                         --------------
supersede all prior oral and written understandings between the parties and 
shall constitute the entire agreement between the parties with respect to the 
subject matter herein. This Addendum Number One shall not be modified or amended
except by a writing signed by an authorized representative of both parties.

IN WITNESS WHEREOF, the parties have caused this Addendum Number One to be 
executed by their duly authorized representatives on the date(s) indicated.

EXCEL SWITCH FACILITY, INC.                  LUCENT TECHNOLOGIES INC.

By: /s/ Kenny A. Troutt                      By: /s/ Bill Plunkett
   ----------------------------                 ----------------------------  

Typed Name:  Kenny A. Troutt                 Typed Name:  Bill Plunkett
           --------------------                         --------------------

Title: President and CEO                     Title: VP Sales
      -------------------------                    -------------------------

Dated: January 27, 1997                      Dated: January 27, 1997
      -------------------------                    -------------------------




          APPROVED AS TO FORM
          BY  Legal / TBS
            -----------------
          DATE  1/27/97
              ---------------


                                      -2-

                              LUCENT PROPRIETARY
<PAGE>
 
                                 Attachment A

                          EXCEL SWITCH FACILITY, INC.
                                PRICING SUMMARY

SCHEDULE OF PRICES
------------------
(All pricing is on a per switch basis)


A.   INITIAL SWITCH PRICING

5ESS SWITCH EQUIPPED W/**** TRUNKS

TOTAL EF&I PRICE                                            *****

ADDITION OF **** TRUNKS TO THE INITIAL SWITCHES

TOTAL EF&I PRICE                                            *****

ADDITION OF **** TRUNKS TO THE INITIAL SWITCHES

TOTAL EF&I PRICE                                            *****


B. INITIAL SWITCH PRICING

5ESS SWITCH EQUIPPED W/**** TRUNKS

TOTAL EF&I PRICE                                            *****

ADDITION OF **** TRUNKS

TOTAL EF&I PRICE                                            *****


C. INITIAL SWITCH PRICING

5ESS SWITCH EQUIPPED W/**** TRUNKS

TOTAL EF&I PRICE                                            *****


                    Lucent Technologies, Inc. - Proprietary





<PAGE>
 
                                EQUIPMENT LIST
                         EXCEL TELECOMMUNICATIONS INC.
                       INITIAL SWITCH WITH ** TRUNKS

<TABLE> 
<CAPTION> 
--------------------------------------------------------------------------------
  SPEC    SYMBOL    DESCRIPTION                                       QTY
--------------------------------------------------------------------------------
  <S>     <C>       <C>                                               <C> 
   310    CDX3811   3811 DATA SET - STANDALONE MOD                    **
--------------------------------------------------------------------------------
   310    CDXNMBD   3000 CARRIER RACK NIM BOARD                       **
--------------------------------------------------------------------------------
   310    CDXPANL   3000 CARRIER RACK NIM BOARD                       **
--------------------------------------------------------------------------------
   310    CDXRACK   3000 CARRIER RACK (3811 MODEMS)                   **
--------------------------------------------------------------------------------
   336    A16A60    16A ANN 60 SEC BLD3 CP                            **
--------------------------------------------------------------------------------
   336    AS16A     16A ANN UNIT                                      **
--------------------------------------------------------------------------------
   336    AUDCSW    AUDIBLE ALARM PANEL                               **
--------------------------------------------------------------------------------
   336    CNIRG2    CNI-2K                                            **
--------------------------------------------------------------------------------
   336    DCINV     DC TO AC INVERTER                                 **
--------------------------------------------------------------------------------
   336    DF56DS1   DIG FACILITY ACCESS DATA SYSTEM                   **
--------------------------------------------------------------------------------
   336    DFAADP1   DFA ADAPTER CIRCUIT                               **
--------------------------------------------------------------------------------
   336    DFACAB2   DFS-2K                                            **
--------------------------------------------------------------------------------
   336    DFADF1    DIGITAL FACILITY ACCESS UNIT                      **
--------------------------------------------------------------------------------
   336    DFAPWR1   DATA SET POWER CONVERTER                          **
--------------------------------------------------------------------------------
   336    DLN30     ATT. PROC. 30 3B INTERFACE                        **
--------------------------------------------------------------------------------
   336    ESMU      EXTERNAL SANITY MONITOR UNIT                      **
--------------------------------------------------------------------------------
   336    EXPILP    EXIT PILOT LAM ASSEMBLY                           **
--------------------------------------------------------------------------------
   336    LN2       LN2                                               **
--------------------------------------------------------------------------------
   336    LNSHF2    LINK SHELF                                        **
--------------------------------------------------------------------------------
   336    M         MISCELLANEOUS CABINET                             **
--------------------------------------------------------------------------------
   336    MRP       MISC RESISTOR PANEL AND FUSES                     **
--------------------------------------------------------------------------------
   357    5ELDBCP   5E LONG DIST. BASIC CALL PROCESS.                 **
--------------------------------------------------------------------------------
   357    AIASP1B   ASP-RELEASE 0.1B RTU                              **
--------------------------------------------------------------------------------
   357    ASPSRTU   ASP SVCE SWITCHING POINT RTU                      **
--------------------------------------------------------------------------------
   357    ASPSSPE   ASP-SSP ENHANCEMENTS RTU                          **
--------------------------------------------------------------------------------
   357    BAS10CR   5E11 OPERATING SYSTEM RTU                         **
--------------------------------------------------------------------------------
   357    BAS10RT   5E11 BASE APPLICATIONS RTU                        **
--------------------------------------------------------------------------------
   357    BASFGBC   FGB CIC EXPANSION                                 **
--------------------------------------------------------------------------------
   357    BASFGD    FGD CIC EXPANSION RTU                             **
--------------------------------------------------------------------------------
   357    BRCUNIV   UNIVERSAL BRCS RTU                                **
--------------------------------------------------------------------------------
   357    C7NIRTU   CCS7 NETWORK INTERCONNECT RTU                     **
--------------------------------------------------------------------------------
   357    CCE30SL   CCS7 CAP ENH (DLN30)                              **
--------------------------------------------------------------------------------
   357    CCS7SL    CCS7                                              **
--------------------------------------------------------------------------------
   357    CLAS4SL   CLASS 4X OFFICE (ISP)                             **
--------------------------------------------------------------------------------
   357    CMDRSTR   COMMAND RESTRICTION FEATUR RTU                    **
--------------------------------------------------------------------------------
   357    ELINKRT   E-LINK ACCESS/ALTER A-LINK                        **
--------------------------------------------------------------------------------
   357    FANIPE    FLEX ANI PROV. ENHANCEMENT                        **
--------------------------------------------------------------------------------
   357    FANIRTU   FLEX ANI INFO DIG ASSNMNT RTU                     **
--------------------------------------------------------------------------------
   357    FIFIDDD   15 DIGIT IDDD RTU                                 **
--------------------------------------------------------------------------------
   357    FPCPRTU   FULL POINT CODE ROUTING                           **
--------------------------------------------------------------------------------
   357    INPARTU   INTERCHANGEABLE NPA CODES RTU                     **
--------------------------------------------------------------------------------
   357    INTRAPC   ICLATA                                            **
--------------------------------------------------------------------------------
   357    ISBRIDS   ISDN BRI DATA SERVICES PKG                        **
--------------------------------------------------------------------------------
   357    ISDN1     ISDN1 - BASIC RTU                                 **
--------------------------------------------------------------------------------
   357    ISDNKOA   ISDN OA&M PACKAGE                                 **
--------------------------------------------------------------------------------
   357    LACBPN    AC BLOCKED TO PRIVATE #                           **
--------------------------------------------------------------------------------
   357    LDANI     5E LONG DIST. ANI TABLE                           **
--------------------------------------------------------------------------------
   357    NI5E10    NISDN 5E10 BRI PACKAGE RTU                        **
--------------------------------------------------------------------------------
</TABLE> 

                    Lucent Technologies - Proprietary            GS 96-310246-A1
                                 Page 1                             January 1997
<PAGE>
 
                                EQUIPMENT LIST
                         EXCEL TELECOMMUNICATIONS INC.
                         INITIAL SWITCH WITH ** TRUNKS

<TABLE> 
<CAPTION> 
--------------------------------------------------------------------------------
 SPEC     SYMBOL        DESCRIPTION                               QTY
--------------------------------------------------------------------------------
<S>      <C>            <C>                                       <C> 
 357     NIS1BSW        NATIONAL ISDN BASE/SWITCH                 **
--------------------------------------------------------------------------------
 357     NIS1CSD        DELUXE CSD/STANDARD BRI RTU               ** 
--------------------------------------------------------------------------------
 357     NIS1DAT        BASIC DATA/STANDARD BRI RTU               ** 
--------------------------------------------------------------------------------
 357     NIS1PSD        DELUXE PSD/STANDARD BRI RTU               ** 
--------------------------------------------------------------------------------
 357     NIS1SBB        STANDARD BRI BASE PER BRI                 ** 
--------------------------------------------------------------------------------
 357     NIS2RTU        NATIONAL ISDN 2 RTU                       ** 
--------------------------------------------------------------------------------
 357     NISBPRI        BASIC NATL PRI W/NFAS & DC                **
--------------------------------------------------------------------------------
 357     NPA888         800 EXHAUST RTU                           **
--------------------------------------------------------------------------------
 357     RTU800         800 SERVICES RTU FEE                      **
--------------------------------------------------------------------------------
 357     SSPRTU         SERVICE SWITCHING POINT RTU               **
--------------------------------------------------------------------------------
 357     TRACPRT        TRANSACTION CAPABILITY RTU                **
--------------------------------------------------------------------------------
 369     PCFDEST        POWER DISTRIBUTION CABINET                **
--------------------------------------------------------------------------------
 369     PDFCPAN        PWR DIST CABINET PART EQUIP               **
--------------------------------------------------------------------------------
 369     PDFDPAN        PWR DIST PANEL 48 FUSES                   **
--------------------------------------------------------------------------------
 378     ASYNCP         ASYNCHRONOUS LINK CKT PACK                **
--------------------------------------------------------------------------------
 378     KLW40          AM MEM - KLW40 / 3B21D                    **
--------------------------------------------------------------------------------
 378     PWRC3          POWER UNIT FOR PC COMMUNITY               **
--------------------------------------------------------------------------------
 378     SCSD           SCANNER SIGNAL DISTRIBUTOR                **
--------------------------------------------------------------------------------
 378     SCSI1GB        SCSI - 1 GIGABYTE MHD - 3B21D             **
--------------------------------------------------------------------------------
 378     SCSI21D        3B21D COMPUTER SYSTEM                     **
--------------------------------------------------------------------------------
 378     SYN21D         SYNCHRONOUS LINK CKT PACKS                **
--------------------------------------------------------------------------------
 378     TAPE21D        TAPE UNIT - 3B21D                         **
--------------------------------------------------------------------------------
 384     CABCM3         CM2 BASIC CABINET WITH TMS                **
--------------------------------------------------------------------------------
 384     CKTCAB         SPARE CIRCUIT CABINET                     **
--------------------------------------------------------------------------------
 384     CM2197         COMM MOD 2 UN197 CKT PACK                 **
--------------------------------------------------------------------------------
 384     CM2310         COMM MOD 2 UN310 CKT PACK                 **
--------------------------------------------------------------------------------
 384     CM2312         COMM MOD 2 UN312 CKT PACK                 **
--------------------------------------------------------------------------------
 384     CM2DF          COMM MOD 2 DATA LINK DUAL                 **
--------------------------------------------------------------------------------
 384     CM2EBUS        COMM MOD 2 E BUS                          **
--------------------------------------------------------------------------------
 384     CM2LP          CM2 ADDITIONAL EQUIPMENT LIST             **
--------------------------------------------------------------------------------
 384     CM2PC          CM2 PERIPHERAL CONTROLLERS                **
--------------------------------------------------------------------------------
 384     CM3DL14        COMM MOD 2 DATA LINK LIST                 **
--------------------------------------------------------------------------------
 384     CM3DL16        COMM MOD 2 DATA LINK LIST                 **
--------------------------------------------------------------------------------
 384     CMACABD        CM2 ADD CAB DUAL LINK FABRIC              **
--------------------------------------------------------------------------------
 384     CMPCM2         COMMUNICATION MODULE PROC                 **
--------------------------------------------------------------------------------
 384     DLTU2          TOTAL DLTU2(S)                            **
--------------------------------------------------------------------------------
 384     DSU2SHF        DIGITAL SERVICE UNIT 2                    **
--------------------------------------------------------------------------------
 384     ISLU2          ISLU2 COMMON SHELF                        **
--------------------------------------------------------------------------------
 384     ISLU2HL        ISLU2 HLSC CP(S)                          **
--------------------------------------------------------------------------------
 384     ISLU2MN        ISLU2 MAN CP(S)                           **
--------------------------------------------------------------------------------
 384     ISLU2SF        ISLU LINE SHELF                           **
--------------------------------------------------------------------------------
 384     LU3            LINE UNIT MODEL 3                         **
--------------------------------------------------------------------------------
 384     LU3C4B         LU3 4:1 LCR - CARBON BLOCK                **
--------------------------------------------------------------------------------
 384     LU4CONN        INST NON-CONN CABLES 4:1 LCR              **
--------------------------------------------------------------------------------
 384     MCTLCPS        MMSU CONTROL CKT PACKS                    **
--------------------------------------------------------------------------------
 384     MDISTCP        MMSU DISTRIBUTE POINT CKT PKS             **
--------------------------------------------------------------------------------
 384     MGDXCP         MMSU GDX COMPENSATION CKT PKS             **
--------------------------------------------------------------------------------
 384     MMSUACP        MMSU METALLIC ACCESS CKT PKS              **
--------------------------------------------------------------------------------
 </TABLE> 

                       Lucent Technologies - Proprietary         GS 96-310246-A1
                                    Page 2                          JANUARY 1997
<PAGE>
 
                                EQUIPMENT LIST
                         EXCEL TELECOMMUNICATIONS INC.
                       INITIAL SWITCH WITH ** TRUNKS

<TABLE> 
<CAPTION> 
---------------------------------------------------------------------
 SPEC      SYMBOL         DESCRIPTION                           QTY
--------------------------------------------------------------------- 
<S>        <C>            <C>                                   <C> 
  384      MMSUSHF        MMSU SHELVES                          **
--------------------------------------------------------------------- 
  384      MMTIB          MMSU MTIB CKT PACK PAIR               **
--------------------------------------------------------------------- 
  384      MSCANCP        MMSU SCAN POINT CKT PKS               **  
--------------------------------------------------------------------- 
  384      NC2LD          NETWORK CLOCK 2 FOR DOM LO            **
--------------------------------------------------------------------- 
  384      PH4TOT         PROTOCOL HANDLER 4                    **
--------------------------------------------------------------------- 
  384      PSU2           PSU2 UNIT-1ST SHELF                   **
--------------------------------------------------------------------- 
  384      QGPWR          GATEWAY PWR/CONTROL CKT PK            **
--------------------------------------------------------------------- 
  384      QLI2CP         QUAD LINK INTERFACE-2 CKT             **
--------------------------------------------------------------------- 
  384      QLPSCP         QUAD LINK PACKET SWITCH CK            **
--------------------------------------------------------------------- 
  384      QWPCP          GATEWAY PROCESSOR CKT PK              **
--------------------------------------------------------------------- 
  384      SASASP         SAS ASP APPLICATION                   **
--------------------------------------------------------------------- 
  384      SASBASE        SERVICE ANN. SYSTEM                   **
--------------------------------------------------------------------- 
  384      SASBRCS        SAS BRCS APPLICATION                  **
--------------------------------------------------------------------- 
  384      SLIM2          SUBSCRIB LOOP MEAS 1                  **
--------------------------------------------------------------------- 
  384      SM2K64M        64MB MEMORY CIRCUIT PACK PAIRS        ** 
--------------------------------------------------------------------- 
  384      SM2KDN1        DNU-S DATA GROUP 0                    ** 
--------------------------------------------------------------------- 
  384      SM2KDN2        DNU-S DATA GROUP 1                    **
--------------------------------------------------------------------- 
  384      SM2KDN3        EQP. FOR ADDITIONAL STSX-1            **
---------------------------------------------------------------------
  384      SM2KDSC        ADDITIONAL DIGITAL SERVICE CKT        **
---------------------------------------------------------------------
  384      SM2KDX         ADDL DATA EXPANSION PACK PAIRS        **
---------------------------------------------------------------------
  384      SM2KLTP        SM-2000 LTP CABINET ASSEMBLY          **
---------------------------------------------------------------------
  384      SM2KMH         ADDL MESSAGE HANDLER PAIRS            **
---------------------------------------------------------------------
  384      SM2KNLI        ADDL DUPLICATED NLI PAIRS             **  
---------------------------------------------------------------------
  384      SM2KPBD        ADDL POWER MODULE PAIRS               **
---------------------------------------------------------------------
  384      SM2KSLC        ADDL TSI SLICE PAIRS                  **
---------------------------------------------------------------------
  384      SM2KSM         SM-2000 SMC CABINET ASSEMBLY          **
---------------------------------------------------------------------
  384      T1DFI2         DFI2 PACKS REQUIRED FOR T1            **
---------------------------------------------------------------------
  384      T8             ISLU2 T CARD                          **
---------------------------------------------------------------------
  384      U8             ISLU2 U CARD                          **
---------------------------------------------------------------------
  385      COTPR          COT PRINTER                           **
---------------------------------------------------------------------
  385      CSTLWS         STLWS COLOR VIDEO TERM & PRINTER      **
---------------------------------------------------------------------
  385      MCCS           MASTER CONTROL CENTER-STRAIGHT        **
---------------------------------------------------------------------
  385      ORP1           OFFICE RECORD PRINTER                 **
---------------------------------------------------------------------
  385      WSROPC         WORK STA PRINTER STAND-CON            **
---------------------------------------------------------------------
  385      XSTLWSS        SUPP'L TLWS CONSOLE - IN LINE         **
---------------------------------------------------------------------
  390      16A60SP        SPARE 8-60 ANNC.                      **
---------------------------------------------------------------------
  390      64MEMSP        64MB MEMORY CIRCUIT PACK SPARE        **
---------------------------------------------------------------------
  390      AP30SP         SPARE AP30                            **
---------------------------------------------------------------------
  390      AUALMSP        3B20D AUD ALM - 1/CODE SPARE          **
---------------------------------------------------------------------
  390      ANALUSP        MMSU CIRCUIT PACK SPARES              **
---------------------------------------------------------------------
  390      CM10NSP        CM2 CIRCUIT PACK SPARES               **
---------------------------------------------------------------------
  390      CM2FSSP        CM2 SGL OR DUAL FABRIC SPARE          **
---------------------------------------------------------------------
  390      CM2SP          CM2 1/CODE SPARE                      **
---------------------------------------------------------------------
  390      CMPUSP         CMP CIRCUIT PACK SPARES               **
---------------------------------------------------------------------
  390      DFASP          SPARE DFA                             **
---------------------------------------------------------------------
  390      BHLSCSP        LU-HLSC CIRCUIT PACK SPARES           **
---------------------------------------------------------------------
  390      DLTUSP         DLTU/DLTU2/DCLU SPARES                **
---------------------------------------------------------------------
  390      DNUSSP         DNU-S SPARES PACKAGE                  **
---------------------------------------------------------------------
</TABLE> 

                       Lucent Technologies - Proprietary         GS 96-310246-A1
                                     Page 3                         January 1997
<PAGE>
 
                                EQUIPMENT LIST
                         EXCEL TELECOMMUNICATIONS INC.
                       INITIAL SWITCH WITH ** TRUNKS

<TABLE> 
<CAPTION> 
--------------------------------------------------------------------------------
  SPEC         SYMBOL    DESCRIPTION                                  QTY
--------------------------------------------------------------------------------
<S>            <C>       <C>                                          <C> 
   390         DSC3SP    SPARE GDSF                                   **
--------------------------------------------------------------------------------
   390         DSU2SP    DSU-2 SPARES                                 **
--------------------------------------------------------------------------------
   390         HLSC2SP   SPARE HLSC                                   **
--------------------------------------------------------------------------------
   390         ISLU2SP   ISLU2 SPARE PACKS                            **
--------------------------------------------------------------------------------
   390         LU3SP     LINE UNIT - MODEL 3 SPARES                   **
--------------------------------------------------------------------------------
   390         LUCBSP    INTEGRATED SECONDARY PROTECT                 **
--------------------------------------------------------------------------------
   390         MAN2SP    SPARE MAN                                    **
--------------------------------------------------------------------------------
   390         NC2MSP    NC2 MED STABILITY CKT PK SPARES              **
--------------------------------------------------------------------------------
   390         NCTLKSP   FIBER OPTIC NCT LINK CONN                    **
--------------------------------------------------------------------------------
   390         NE56SP    LN NON-ENCRYPT 56K BAUD SPARE                **
--------------------------------------------------------------------------------
   390         PH4SP     PH4 SPARE CP                                 **
--------------------------------------------------------------------------------
   390         PSU2SP    PSU2 SPARE PACKS                             **
--------------------------------------------------------------------------------
   390         PWCSP     POWER CONVERTER SPARES                       **
--------------------------------------------------------------------------------
   390         QGPCPSP   QLPS GATEWAY CP SPARE                        **
--------------------------------------------------------------------------------
   390         QLI2SP    QL12 SPARES PACKAGE                          **
--------------------------------------------------------------------------------
   390         QLPSSP    QLPS SPARES PACKAGE                          **
--------------------------------------------------------------------------------
   390         RNCSP     SPARE CNI                                    **
--------------------------------------------------------------------------------
   390         SASASSP   SPARE ASP                                    **
--------------------------------------------------------------------------------
   390         SASBRSP   SPARE BRCS                                   **
--------------------------------------------------------------------------------
   390         SASSP     SPARE SAS                                    **
--------------------------------------------------------------------------------
   390         SC21DSP   3B21D SPARE CKT PACKS                        **
--------------------------------------------------------------------------------
   390         SLIM2SP   SPARE SLIM2                                  **
--------------------------------------------------------------------------------
   390         SM2KSP    SM-2000 SPARES PACKAGE                       **
--------------------------------------------------------------------------------
   390         T1DF2SP   DLTU2 TRUNK CKTS SPARES                      **
--------------------------------------------------------------------------------
   390         T8SP      ISLU2 T CARD SPARE CP                        **
--------------------------------------------------------------------------------
   390         U8SP      ISLU2 U CARD SPARE CP                        **
--------------------------------------------------------------------------------
</TABLE> 

                    Lucent Technologies - Proprietary            GS 96-310246-A1
                                 Page 4                             January 1997
<PAGE>
 
                                EQUIPMENT LIST
                         EXCEL TELECOMMUNICATIONS INC.
                        1997 GROWTH WITH ****** TRUNKS

<TABLE> 
<CAPTION> 
--------------------------------------------------------------------------------
  SPEC         SYMBOL    DESCRIPTION                                  QTY
--------------------------------------------------------------------------------
<S>            <C>       <C>                                          <C> 
   336         DF56DS1   DIG FACILITY ACCESS DATA SYSTEM              **
--------------------------------------------------------------------------------
   336         DFAADP1   DFA ADAPTER CIRCUIT                          **
--------------------------------------------------------------------------------
   336         DFADF1    DIGITAL FACILITY ACCESS UNIT                 **
--------------------------------------------------------------------------------
   336         LN2       LN2                                          **
--------------------------------------------------------------------------------
   336         NE56BPS   NON-ENCRYPTED 56K LINK NODE                  **
--------------------------------------------------------------------------------
   357         CCE30SL   CCS7 CAP ENH (DLN30)                         **
--------------------------------------------------------------------------------
   357         CCS7SL    CCS7                                         **
--------------------------------------------------------------------------------
   357         CLAS4SL   CLASS 4X OFFICE (ISP)                        **
--------------------------------------------------------------------------------
   369         PDFDPAN   PWR DIST PANEL 48 FUSES                      **
--------------------------------------------------------------------------------
   384         CM2197    COMM MOD 2 UN197 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2310    COMM MOD 2 UN310 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2311    COMM MOD 2 UN311 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2313    COMM MOD 2 UN313 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2500    COMM MOD 2 UN500 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2501    COMM MOD 2 UN501 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2EBUS   COMM MOD 2 E BUS                             **
--------------------------------------------------------------------------------
   384         CM2PC     CM2 PERIPHERAL CONTROLLERS                   **
--------------------------------------------------------------------------------
   384         CM3DL16   COMM MOD 2 DATA LINK LIST                    **
--------------------------------------------------------------------------------
   384         CMACABD   CM2 ADD CAB DUAL FABRIC                      **
--------------------------------------------------------------------------------
   384         QLI2CP    QUAD LINK INTERFACE-2 CKT                    **
--------------------------------------------------------------------------------
   384         QWPCP     GATEWAY PROCESSOR CKT PK                     **
--------------------------------------------------------------------------------
   384         SM2K64M   64MB MEMORY CIRCUIT PACK PAIRS               **
--------------------------------------------------------------------------------
   384         SM2KDN1   DNU-S DATA GROUP 0                           **
--------------------------------------------------------------------------------
   384         SM2KDN2   DNU-S DATA GROUP 1                           **
--------------------------------------------------------------------------------
   384         SM2KDN3   EQP. FOR ADDITIONAL STSX-1                   **
--------------------------------------------------------------------------------
   384         SM2KLTP   SM-2000 LTP CABINET ASSEMBLY                 **
--------------------------------------------------------------------------------
   384         SM2KMH    ADDL MESSAGE HANDLER PAIRS                   **
--------------------------------------------------------------------------------
   384         SM2KNLI   ADDL DUPLICATED NLI PAIRS                    **
--------------------------------------------------------------------------------
   384         SM2KPBD   ADDL POWER MODULE PAIRS                      **
--------------------------------------------------------------------------------
   384         SM2KSLC   ADDL TSI SLICE PAIRS                         **
--------------------------------------------------------------------------------
   384         SM2KSM    SM-2000 SMC CABINET ASSEMBLY                 **
--------------------------------------------------------------------------------
</TABLE> 

               Lucent Technologies - Proprietary                 GS 96-310246-A1
                              Page 1                                January 1997
<PAGE>
 
                                EQUIPMENT LIST
                         EXCEL TELECOMMUNICATIONS INC.
                        1998 GROWTH OF ****** TRUNKS

<TABLE> 
<CAPTION> 
--------------------------------------------------------------------------------
  SPEC         SYMBOL    DESCRIPTION                                  QTY
--------------------------------------------------------------------------------
  <S>          <C>       <C>                                          <C> 
   336         DF56DS1   DIG FACILITY ACCESS DATA SYSTEM              **
--------------------------------------------------------------------------------
   336         DFAADP1   DFA ADAPTER CIRCUIT                          **
--------------------------------------------------------------------------------
   336         LN2       LN2                                          **
--------------------------------------------------------------------------------
   336         NE56BPS   NON-ENCRYPTED 56K LINK NODE                  **
--------------------------------------------------------------------------------
   336         PWR30     POWER                                        **  
--------------------------------------------------------------------------------
   357         CCE30SL   CCS7 CAP ENH (DLN30)                         **
--------------------------------------------------------------------------------
   357         CCS7SL    CCS7                                         **
--------------------------------------------------------------------------------
   357         CLAS4SL   CLASS 4X OFFICE (ISP)                        **
--------------------------------------------------------------------------------
   369         PD32PAN   PWR DIST PANEL 32 FUSES                      **
--------------------------------------------------------------------------------
   384         CM2197    COMM MOD 2 UN197 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2310    COMM MOD 2 UN310 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2311    COMM MOD 2 UN311 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2313    COMM MOD 2 UN313 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2500    COMM MOD 2 UN500 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2501    COMM MOD 2 UN501 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2503    COMM MOD 2 UN503 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2504    COMM MOD 2 UN504 CKT PACK                    **
--------------------------------------------------------------------------------
   384         CM2EBUS   COMM MOD 2 E BUS                             **
--------------------------------------------------------------------------------
   384         CM3DL16   COMM MOD 2 DATA LINK LIST                    **
--------------------------------------------------------------------------------
   384         CMACABD   CM2 ADD CAB DUAL FABRIC                      **
--------------------------------------------------------------------------------
   384         QLI2CP    QUAD LINK INTERFACE-2 CKT                    **
--------------------------------------------------------------------------------
   384         SM2K64M   64MB MEMORY CIRCUIT PACK PAIRS               **
--------------------------------------------------------------------------------
   384         SM2KDN1   DNU-S DATA GROUP 0                           **
--------------------------------------------------------------------------------
   384         SM2KDN2   DNU-S DATA GROUP 1                           **
--------------------------------------------------------------------------------
   384         SM2KDN3   EQP. FOR ADDITIONAL STSX-1                   **
--------------------------------------------------------------------------------
   384         SM2KLTP   SM-2000 LTP CABINET ASSEMBLY                 **
--------------------------------------------------------------------------------
   384         SM2KMH    ADDL MESSAGE HANDLER PAIRS                   **
--------------------------------------------------------------------------------
   384         SM2KNLI   ADDL DUPLICATED NLI PAIRS                    **
--------------------------------------------------------------------------------
   384         SM2KPBD   ADDL POWER MODULE PAIRS                      **
--------------------------------------------------------------------------------
   384         SM2KSLC   ADDL TSI SLICE PAIRS                         **
--------------------------------------------------------------------------------
   384         SM2KSM    SM-2000 SMC CABINET ASSEMBLY                 **
--------------------------------------------------------------------------------
</TABLE> 

               Lucent Technologies - Proprietary                 GS 96-310246-A1
                              Page 1                                January 1997

<PAGE>
 
Proposal No. 97-870206-A1          Model ****               Excel Communications

                                     POWER
                             SYSTEM CONFIGURATION
                             --------------------

Item
----

1)   Install Qty **** LINEAGE **** Power Plant consisting of the following:

     Qty **** equipped with
             Qty **** Options)
             Qty **** equipped with
                     Qty **** Positions
             Qty **** equipped with
                     Qty **** 
             Qty ****

2)   Install Qty ****

3)   Run power wire and conduit to new rectifiers from a telco provided AC 
     distribution panel equipped with Qty ****.

4)   Run Qty ****; provide framework ground for the power board, rectifier and
     battery stand lineups.

5)   Install Qty **** (see Battery Options).

6)   Mount busbar assembly equipped with ****
     run Qty **** to the control bay, and Qty **** to the 
     distribution ground bar.

7)   Provide Qty **** Qty **** and Qty ****, utilize a **** for the following 
     approximate cable runs:

<TABLE> 
<CAPTION> 
                              LOADS     NO. OF RUNS    CABLE      LENGTH
                              -----     -----------    -----      ------
<S>                           <C>       <C>            <C>        <C> 
GPDF****                     **** Amp       ****       No.****    **** ft.
GPDF****                     **** Amp       ****       No.****    **** ft.
1 ****                       **** Amp       ****       No.****    **** ft.
</TABLE> 

8)   Run alarm leads from the power plant to the ****.

9)   Provide cable rack and associated material required to support the 
     described power configuration.

                              LUCENT-PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS
<PAGE>
Proposal No. 97-870206-A1         Model ****               Excel Communications 


                              CONTROLLER OPTIONS
                              ------------------


Item
----


1B1)      **** equipped with remote access circuit pack.

                                      OR

1B2)      **** equipped with remote access circuit pack.


                                BATTERY OPTIONS
                                ---------------

Item
----

5A)       Install Qty **** battery strings, each consisting of Qty
          **** stackable battery modules ****

                                      OR

5B)       Install Qty **** battery strings, each consisting of Qty
          **** and mount each string on Qty ****




                             LUCENT - PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS
<PAGE>
 
PROPOSAL NO. GS-97-870206-A1   MODEL **** POWER PLANT    EXCEL COMMUNICATIONS
                                   POWER CRITERIA
                                   ATTACHMENT B(1)

<TABLE> 
<CAPTION> 
------------------------------------------------------------------------------------------------------------------------------------
                                                                                      UNIT              UNIT               EXT
ITEM                     DESCRIPTION                     PART NO.        QTY       LIST PRICE        DISC PRICE        DISC PRICE
------------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                     <C>            <C>    <C>     <C>              <C>               <C>  
1A         INITIAL DIST BAY E/W 1300 AMP BAR       J85500A-2      L-1A     ***        ***                 ***                ***   
           FAJ ALARM PANEL                         J85500A-2      L-6      ***        ***                 ***                ***
           ADD'L 1300 AMP BAR FOR LOWER HALF       J85500A-2      L-AA     ***        ***                 ***                ***
           3" BLANK PANEL                          J85500A-2      L-C      ***        ***                 ***                ***
           6" BLANK PANEL                          J85500A-2      L-E      ***        ***                 ***                ***
           9" BLANK PANEL                          J85500A-2      L-F      ***        ***                 ***                ***
           INPUT BATTERY BAR FOR 7-12 LEADS        J85500A-2      L-U      ***        ***                 ***                ***
           MATERIAL FOR FAJ ALARM PANEL            J85500A-2      L-R      ***        ***                 ***                ***
           STILE STRIP APPEARANCE PACKAGE          J85500A-2      L-KA     ***        ***                 ***                ***
           END COVER                               J85500A-2      L-KD     ***        ***                 ***                ***
                                                                                                                   
1C         CRKT BRKR PNL 12 1-110 AMP PSTNS        ED83018-31     G-15     ***        ***                 ***                ***
           60 AMP CRKT BRKR                        ED83018-31     G-P      ***        ***                 ***                ***
           CRKT BRKR PNL 100-600 AMP PSTNS         ED83018-31     G-16     ***        ***                 ***                ***
           125 AMP CRKT BRKR                       ED83018-31     G-AA     ***        ***                 ***                ***
                                                                                                                   
2          -48V, ***, 208/240 VAC                  *********      ***      ***        ***                 ***                ***
           SIDE COVER                              *********      ****     ***        ***                 ***                ***
           REAR COVER                              *********      ****     ***        ***                 ***                ***

3,4, 6-9   MISCELLANEOUS MATERIAL                  VARIOUS                 ***         ***                 ***                ***


           POWER EQUIPMENT PRICE                                                                                             ***
           ENGINEERING AND DRAFTING PRICE                                                                                    ***
           INSTALLATION PRICE*                                                                                               ***
           TRANSPORTATION PRICE                                                                                              ***

           TOTAL PRICE                                                                                                       ***
</TABLE> 

       * THIS AVERAGE PRICE WITHIN THE *** TO *** PRICE RANGE IS DUE TO AREA
         PRICE DIFFERENTIALS ********.

Page 1                             LUCENT - PROPRIETARY              ALB 1/15/97

<PAGE>
 

PROPOSAL NO. GS-97-870206-A1     MODEL **** CONTROLLERS     EXCEL COMMUNICATIONS
                                    POWER CRITERIA
                                    ATTACHMENT B(2)

<TABLE> 
<CAPTION> 
-------------------------------------------------------------------------------------------------------------
                                                                        UNIT          UNIT           EXT     
ITEM           DESCRIPTION                  PART NO.         QTY      LIST PRICE    DISC PRICE    DISC PRICE
-------------------------------------------------------------------------------------------------------------
<S>  <C>                                 <C>                 <C>     <C>            <C>           <C>           
CONTROLLER OPTIONS                                                                                            
                                                                                                              
1B   **********************              **************       ***     ***           ***           ***
     ***************                     **************       ***     ***           ***           ***
                                                                                                              
     TRANSPORTATION PRICE                                                                         ***
                                                                                                               
     ******************************                                                               ***
                                                                                                              
1B   *********************               **************       ***     ***           ***           ***
     ***************                     ***************      ***     ***           ***           ***
     RECTIFIER INTERFACE *** RECTS       ***************      ***     ***           ***           ***
     FERRO RECTIFIERS INTERFACE          ***************      ***     ***           ***           ***
     INTELLIGENT CIRCUIT PACK            ***************      ***     ***           ***           ***
     REMOTE ACCESS                       ***************      ***     ***           ***           ***
                                                                                                              
     TRANSPORTATION PRICE                                                                         ***
                                                                                                              
     *****************************                                                                ***
</TABLE> 

Page 2                               LUCENT - PROPRIETARY            ALB 1/15/97

<PAGE>
 
PROPOSAL NO. GS-97-870206-A1      MODEL **** BATTERIES      EXCEL COMMUNICATIONS
                                     POWER CRITERIA
                                      ATTACHMENT C

<TABLE> 
<CAPTION> 
----------------------------------------------------------------------------------------------------------
                                                                   UNIT            UNIT           EXT
ITEM                DESCRIPTION         PART NO.       QTY      LIST PRICE      DISC PRICE     DISC PRICE        
----------------------------------------------------------------------------------------------------------
<S>  <C>                           <C>                 <C>     <C>             <C>            <C> 
BATTERY OPTIONS 

5    **********************        ***********         ***      ***             ***             ***

     TRANSPORTATION PRICE                                                                       ***
 
     *************************                                                                  ***
5A   *********************         ***********         ***      ***             ***             ***
5B   *************                 *********    ***    ***      ***             ***             ***
TRANSPORTATION PRICE                                                                            ***

     TOTAL PRICE                                                                                ***
</TABLE> 

PAGE 3                             LUCENT PROPRIETARY                ALB 1/15/97
<PAGE>
 
Proposal No. 97-870206-A1          Model ****               Excel Communications

                                     POWER
                             SYSTEM CONFIGURATION
                             --------------------

Item
----

1)   Install Qty *** LINEAGE ***  Power Plant consisting of the following:

     Qty *** equipped with
             Qty *** Options)
             Qty *** equipped with
                     Qty *** positions 
             Qty *** equipped with
                     Qty ***
             Qty ***
                     
2)   Install Qty *** .
     
3)   Run power wire and conduit to new rectifiers from a telco provided AC 
     distribution panel equipped with Qty ***

4)   Run Qty *** provide framework ground for the power board, rectifier and
     battery stand lineups.

5)   Install Qty *** (see Battery Options).

6)   Mount busbar assembly equipped with *** run Qty *** to the control bay, and
     ***to the distribution ground bar.

7)   Provide Qty *** Qty *** and Qty ***,utilize a *** for the following
     approximate cable runs:

<TABLE> 
<CAPTION> 
                              LOADS     NO. OF RUNS    CABLE     LENGTH
                              -----     -----------    -----     ------
<S>                           <C>       <C>            <C>       <C> 
GPDF***                       *** Amp       ***         No.***    *** ft
GPDF***                       *** Amp       ***         No.***    *** ft.
1 ***                         *** Amp       ***         No.***    *** ft.
</TABLE> 

8)   Run alarm leads from the power plant to the ***.

9)   Provide cable rack and associated material required to support the 
     described power configuration.

                              LUCENT-PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS

<PAGE>
 
Proposal No. 97-870206-A1          Model ****           Excel Communications 


                              CONTROLLER OPTIONS
                              ------------------

Item
----

1B1) *** equipped with remote access circuit pack.

                                      OR

1B2) *** equipped with remote access circuit pack.


                                BATTERY OPTIONS
                                ---------------

Item
----

5A)  Install Qty *** battery strings, each consisting of Qty *** stackable 
     battery modules ***.

                                      OR

5B)  Install Qty *** battery strings, each consisting of Qty *** and mount each 
     string on Qty ***.

                             LUCENT - PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS
<PAGE>
 
PROPOSAL NO. GS-97-870206-A1   MODEL **** POWER PLANT    EXCEL COMMUNICATIONS
                                   POWER CRITERIA
                                   ATTACHMENT B(1)

<TABLE> 
<CAPTION> 
------------------------------------------------------------------------------------------------------------------------------------
                                                                                      UNIT              UNIT               EXT
ITEM                     DESCRIPTION                     PART NO.        QTY       LIST PRICE        DISC PRICE        DISC PRICE
------------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                     <C>            <C>    <C>     <C>              <C>               <C>  
1A         INITIAL DIST BAY E/W 1300 AMP BAR       J85500A-2      L-1A   ***           ***               ***               ***  
           FAJ ALARM PANEL                         J85500A-2      L-6    ***           ***               ***               ***    
           ADD'L 1300 AMP BAR FOR LOWER HALF       J85500A-2      L-AA   ***           ***               ***               ***    
           3" BLANK PANEL                          J85500A-2      L-C    ***           ***               ***               ***    
           6" BLANK PANEL                          J85500A-2      L-E    ***           ***               ***               ***    
           9" BLANK PANEL                          J85500A-2      L-F    ***           ***               ***               ***    
           INPUT BATTERY BAR FOR 7-12 LEADS        J85500A-2      L-U    ***           ***               ***               ***    
           MATERIAL FOR FAJ ALARM PANEL            J85500A-2      L-R    ***           ***               ***               ***    
           STILE STRIP APPEARANCE PACKAGE          J85500A-2      L-KA   ***           ***               ***               ***    
           END COVER                               J85500A-2      L-KD   ***           ***               ***               ***    
                                                                                                                   
1C         CRKT BRKR PNL 12 1-110 AMP PSTNS        ED83018-31     G-15   ***           ***               ***               ***    
           60 AMP CRKT BRKR                        ED83018-31     G-P    ***           ***               ***               ***    
           CRKT BRKR PNL 100-600 AMP PSTNS         ED83018-31     G-16   ***           ***               ***               ***    
           125 AMP CRKT BRKR                       ED83018-31     G-AA   ***           ***               ***               ***    
                                                                                                                   
2          -48V, ***************, 208/240 VAC      *********      ***    ***           ***               ***               ***    
           SIDE COVER                              *********      ****   ***           ***               ***               ***    
           REAR COVER                              *********      ****   ***           ***               ***               ***    

3,4, 6-9   MISCELLANEOUS MATERIAL                  VARIOUS               ***           ***               ***               ***   


           POWER EQUIPMENT PRICE                                                                                           ***
           ENGINEERING AND DRAFTING PRICE                                                                                  *** 
           INSTALLATION PRICE*                                                                                             ***
           TRANSPORTATION PRICE                                                                                            ***

           TOTAL PRICE                                                                                                     ***
</TABLE> 

      * THIS AVERAGE PRICE WITHIN THE *** TO *** PRICE RANGE IS DUE TO AREA
        PRICE DIFFERENTIALS ****************************************.

PAGE 1                             LUCENT - PROPRIETARY              ALB 1/15/97
<PAGE>
 
PROPOSAL NO. GS-97-870206-A1     MODEL **** CONTROLLERS     EXCEL COMMUNICATIONS
                                      POWER CRITERIA
                                      ATTACHMENT B(2)

<TABLE> 
<CAPTION> 
-------------------------------------------------------------------------------------------------------------------
                                                                              UNIT           UNIT           EXT
ITEM                 DESCRIPTION             PART NO.            QTY       LIST PRICE     DISC PRICE     DISC PRICE 
-------------------------------------------------------------------------------------------------------------------
<S>   <C>                               <C>            <C>       <C>  <C>             <C>             <C> 

CONTROLLER OPTIONS


1B     **********************           *********      ***        ***   ***             ***             ***
       *************                    *********      ***        ***   ***             ***             ***
                                                                                                                     
       TRANSPORTATION PRICE                                                                             *** 
                                                                                                                     
       ******************************                                                                   ***
                                                                                                                     
                                                                                                                     
1B     *********************            *********      ***        ***   ***             ***             ***
       **************                   *********      ****       ***   ***             ***             ***
       RECTIFIER INTERFACE *** RECTS    *********      ****       ***   ***             ***             ***
       FERRO RECTIFIERS INTERFACE       *********      ****       ***   ***             ***             ***
       INTELLIGENT CIRCUIT PACK         *********      ****       ***   ***             ***             ***
       REMOTE ACCESS                    *********      ****       ***   ***             ***             ***

       TRANSPORTATION PRICE                                                                             ***

       **************************                                                                       ***
</TABLE> 

Page 2                       LUCENT - PROPRIETARY                    ALB 1/15/97
<PAGE>
 
PROPOSAL NO. GS-97-870206-A1    MODEL **** BATTERIES     EXCEL COMMUNICATIONS
                                   POWER CRITERIA
                                    ATTACHMENT C

<TABLE> 
<CAPTION> 
------------------------------------------------------------------------------------------------------------------------------------
                                                                                      UNIT              UNIT               EXT
ITEM                     DESCRIPTION                     PART NO.        QTY       LIST PRICE        DISC PRICE        DISC PRICE
------------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                     <C>            <C>    <C>     <C>              <C>               <C>  
BATTERY OPTIONS

5          **********************                  ***********           ***           ***                ***             ***

           TRANSPORTATION PRICE                                                                                           ***

           *************************                                                                                      ***


5A         ********************                    ***********           ***           ***                ***             ***
5B         *************                           *********      ***    ***           ***                ***             ***

           TRANSPORTATION PRICE                                                                                           ***

           TOTAL PRICE                                                                                                    ***
</TABLE> 

Page 1                           LUCENT - PROPRIETARY                ALB 1/15/97
<PAGE>
 
Proposal No. 97-870206-A1        Model ****            Excel Communications



                                     POWER
                             SYSTEM CONFIGURATION
                             --------------------

Item
----

1)   Install Qty *** LINEAGE **** Power Plant consisting of the following:

     Qty *** equipped with
             Qty *** Options)
             Qty *** equipped with
                     Qty *** Positions
             Qty *** equipped with
                     Qty ***
             Qty ***

2)   Install Qty ***.

3)   Run power wire and conduit to new rectifiers from a telco provided AC 
     distribution panel equipped with Qty ***.

4)   Run Qty ***, provide framework ground for the power board, rectifier and
     battery stand lineups.

5)   Install Qty *** (see Battery Options).

6)   Mount busbar assembly equipped with ***; run Qty *** to the control bay,
     and Qty *** to the distribution ground bar.

7)   Provide Qty *** Qty *** and Qty ***; utilize a *** for the following
     approximate cable runs:

<TABLE> 
<CAPTION> 
                                   LOADS     NO. OF RUNS     CABLE      LENGTH
                                   -----     -----------     -----      ------

     <S>                           <C>       <C>             <C>       <C> 
     GPDF-***                      *** Amp       ***         No. ***    ***  ft.
     GPDF-***                      *** Amp       ***         No. ***    ***  ft.
     1 ***                         *** Amp       ***         No. ***    ***  ft.
</TABLE> 

8)   Run alarm leads from the power plant to the ***.

9)   Provide cable rack and associated material required to support the 
     described power configuration.


                             LUCENT - PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND 
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS

<PAGE>
 
Proposal No. 97-870206-A1        Model ****            Excel Communications


                              CONTROLLER OPTIONS
                              ------------------

Item
----

1B1) *** equipped with remote access circuit pack.

                                      OR

1B2) *** equipped with remote access circuit pack.



                                BATTERY OPTIONS
                                ---------------


Item
----

5A)  Install Qty *** battery strings, each consisting of Qty *** stackable
     battery modules ***

                                      OR

5B)  Install Qty *** battery strings, each consisting of Qty *** and mount 
     each string on Qty ***


                             LUCENT - PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND 
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS
<PAGE>
 
PROPOSAL NO. GS-97-870206-A1   MODEL **** POWER PLANT    EXCEL COMMUNICATIONS
                                   POWER CRITERIA
                                   ATTACHMENT B(1)

<TABLE> 
<CAPTION> 
------------------------------------------------------------------------------------------------------------------------------------
                                                                                      UNIT              UNIT               EXT
ITEM                     DESCRIPTION                     PART NO.        QTY       LIST PRICE        DISC PRICE        DISC PRICE
------------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                     <C>            <C>    <C>     <C>              <C>               <C>  
1A         INITIAL DIST BAY E/W 1300 AMP BAR       J85500A-2      L-1A   ***           ***               ***               ***
           FAJ ALARM PANEL                         J85500A-2      L-6    ***           ***               ***               ***  
           ADD'L 1300 AMP BAR FOR LOWER HALF       J85500A-2      L-AA   ***           ***               ***               ***
           3" BLANK PANEL                          J85500A-2      L-C    ***           ***               ***               ***
           6" BLANK PANEL                          J85500A-2      L-E    ***           ***               ***               ***
           9" BLANK PANEL                          J85500A-2      L-F    ***           ***               ***               ***
           INPUT BATTERY BAR FOR 7-12 LEADS        J85500A-2      L-U    ***           ***               ***               ***
           MATERIAL FOR FAJ ALARM PANEL            J85500A-2      L-R    ***           ***               ***               ***
           STILE STRIP APPEARANCE PACKAGE          J85500A-2      L-KA   ***           ***               ***               ***
           END COVER                               J85500A-2      L-KD   ***           ***               ***               ***
                                                                                                                   
1C         CRKT BRKR PNL 12 1-110 AMP PSTNS        ED83018-31     G-15   ***           ***               ***               ***
           60 AMP CRKT BRKR                        ED83018-31     G-P    ***           ***               ***               ***
           CRKT BRKR PNL 100-600 AMP PSTNS         ED83018-31     G-16   ***           ***               ***               ***
           125 AMP CRKT BRKR                       ED83018-31     G-AA   ***           ***               ***               ***
                                                                           
2          -48V, *****************, 208/240 VAC    *********      ***    ***           ***               ***               ***
           SIDE COVER                              *********      ****   ***           ***               ***               ***
           REAR COVER                              *********      ****   ***           ***               ***               ***

3, 4, 6-9  MISCELLANEOUS MATERIAL                  VARIOUS               ***           ***               ***               ***


           POWER EQUIPMENT PRICE                                                                                           ***
           ENGINEERING AND DRAFTING PRICE                                                                                  ***
           INSTALLATION PRICE*                                                                                             ***
           TRANSPORTATION PRICE                                                                                            ***

           TOTAL PRICE                                                                                                     ***
</TABLE> 

           * THIS AVERAGE PRICE WITHIN THE *** TO *** PRICE RANGE IS DUE TO AREA
             PRICE DIFFERENTIALS **************************************.

PAGE 1                          LUCENT - PROPRIETARY              ALB 1/15/97
<PAGE>
 
PROPOSAL NO. GS-97-870206-A1     MODEL **** CONTROLLERS     EXCEL COMMUNICATIONS
                                     POWER CRITERIA
                                     ATTACHMENT B(2)

<TABLE> 
<CAPTION> 
------------------------------------------------------------------------------------------------------------------------------------
                                                                                      UNIT              UNIT               EXT
ITEM                     DESCRIPTION                     PART NO.        QTY       LIST PRICE        DISC PRICE        DISC PRICE
------------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                     <C>            <C>    <C>     <C>              <C>               <C>  

CONTROLLER OPTIONS

1B         **********************                  *********      ***    ***          ***               ***                *** 
           *************                           *********      ***    ***          ***               ***                *** 

           TRANSPORTATION PRICE                                                                                            ***

           ******************************                                                                                  ***

1B         *********************                   *********      ***    ***          ***               ***                *** 
           **************                          *********      ****   ***          ***               ***                *** 
           RECTIFIER INTERFACE *** RECTS           *********      ****   ***          ***               ***                *** 
           FERRO RECTIFIERS INTERFACE              *********      ****   ***          ***               ***                *** 
           INTELLIGENT CIRCUIT PACK                *********      ****   ***          ***               ***                *** 
           REMOTE ACCESS                           *********      ****   ***          ***               ***                *** 

           TRANSPORTATION PRICE                                                                                            ***

           *****************************                                                                                   ***
</TABLE> 

Page 2                      LUCENT - PROPRIETARY                     ALB 1/15/97
<PAGE>
 

PROPOSAL NO. GS-97-870206-A1      MODEL **** BATTERIES      EXCEL COMMUNICATIONS
                                     POWER CRITERIA
                                      ATTACHMENT C

<TABLE> 
<CAPTION> 
----------------------------------------------------------------------------------------------------------------------------------
                                                                                UNIT             UNIT                 EXT
ITEM                DESCRIPTION                   PART NO.        QTY        LIST PRICE        DISC PRICE          DISC PRICE
----------------------------------------------------------------------------------------------------------------------------------
<S>                                         <C>                   <C>        <C>             <C>                   <C> 
BATTERY OPTIONS


5    ***********************                 ***********          ***            ***              ***                  ***

     TRANSPORTATION PRICE                                                                                              ***

     *************************                                                                                         ***


5A   ********************                    ***********          ***            ***              ***                  ***
5B   *************                           *********     ***    ***            ***              ***                  ***

     TRANSPORTATION PRICE                                                                                              ***

     TOTAL PRICE                                                                                                       ***
</TABLE> 

Page 3                          LUCENT - PROPRIETARY                 ALB 1/15/97

<PAGE>
 
Proposal No. 97-870206-A1          Model ***                Excel Communications


                                    POWER 
                             SYSTEM CONFIGURATION
                             --------------------


Item
----

1)   Install Qty ***.

2)   Run power wire and conduit to new rectifiers from a telco provided AC 
     distribution panel equipped with Qty ***.


                             LUCENT - PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND 
             IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE 
                          WITH APPLICABLE AGREEMENTS

<PAGE>
 
Proposal No. 97-870206-A1         Model ***                 Excel Communications




                                    POWER 
                             SYSTEM CONFIGURATION
                             --------------------

Item
----

1)   Install Qty *** battery string consisting of Qty *** stackable battery 
     modules *** to the existing power plant.

2)   Run No. *** cable from the battery string to the existing shunt and busbar
     assembly.




                             LUCENT - PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND 
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS

<PAGE>
 
Proposal No. 97-870206-A1         Model ***                 Excel Communications




                                    POWER 
                             SYSTEM CONFIGURATION
                             --------------------

Item
----

1)   Install Qty *** battery string consisting of Qty *** and mount the string
     on Qty *** .

2)   Run No. *** cable from the battery string to the existing shunt and busbar
     assembly.




                             LUCENT - PROPRIETARY
         THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF LUCENT AND 
              IS NOT TO BE DISCLOSED OR USED EXCEPT IN ACCORDANCE
                          WITH APPLICABLE AGREEMENTS


<PAGE>
 
<TABLE> 
<CAPTION> 
PROPOSAL NO. GS-97-870206-A1                              MODEL ** RECTIFIER                      EXCEL COMMUNICATIONS
                                                            POWER CRITERIA
                                                           ATTACHMENT B(1)
----------------------------------------------------------------------------------------------------------------------------------
                                                                                UNIT             UNIT                 EXT
ITEM                DESCRIPTION                   PART NO.        QTY        LIST PRICE        DISC PRICE          DISC PRICE
----------------------------------------------------------------------------------------------------------------------------------
<S>                                          <C>                 <C>         <C>             <C>                   <C> 
1    -48V, *****************, 208/240 VAC    *********    ***    ***            ***               ***                 ***
     REAR COVER                              *********    ****   ***            ***               ***                 ***

2    MISCELLANEOUS MATERIAL                  VARIOUS             ***            ***               ***                 ***


     POWER EQUIPMENT PRICE                                                                                            ***       
     ENGINEERING AND DRAFTING PRICE                                                                                   ***       
     INSTALLATION PRICE*                                                                                              ***       
     TRANSPORTATION PRICE                                                                                             ***       

     TOTAL PRICE                                                                                                      ***       
</TABLE> 

* THIS AVERAGE PRICE WITHIN THE *** TO *** PRICE RANGE IS DUE TO AREA PRICE
  DIFFERENTIALS FOR *******************************************.



Page 1                           LUCENT - PROPRIETARY                ALB 1/15/97

<PAGE>
 
PROPOSAL NO. GS-97-870206-A1     MODEL *** BATTERIES     EXCEL COMMUNICATIONS
                                   POWER CRITERIA
                                   ATTACHMENT B(1)

<TABLE> 
<CAPTION> 
------------------------------------------------------------------------------------------------------------------------------------
                                                                                      UNIT              UNIT               EXT
ITEM                     DESCRIPTION                     PART NO.        QTY       LIST PRICE        DISC PRICE        DISC PRICE
------------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                     <C>                   <C>     <C>              <C>               <C>  

1          ***********************                  ***********          ***            ***             ***                ***

2          MISCELLANEOUS MATERIAL                  VARIOUS               ***            ***             ***                ***

           POWER EQUIPMENT PRICE                                                                                           ***
           ENGINEERING AND DRAFTING PRICE                                                                                  ***
           INSTALLATION PRICE*                                                                                             ***
           TRANSPORTATION PRICE                                                                                            ***

           TOTAL PRICE                                                                                                     ***
</TABLE> 

           *THIS AVERAGE PRICE WITHIN THE **** TO **** PRICE RANGE IS DUE TO
            AREA PRICE DIFFERENTIALS FOR **************************.


Page 2                          LUCENT - PROPRIETARY                 ALB 1/15/97
<PAGE>
 
PROPOSAL NO. GS-97-870206-A1     MODEL *** BATTERIES     EXCEL COMMUNICATIONS
                                   POWER CRITERIA
                                   ATTACHMENT B(1)

<TABLE> 
<CAPTION> 
------------------------------------------------------------------------------------------------------------------------------------
                                                                                      UNIT              UNIT               EXT
ITEM                     DESCRIPTION                     PART NO.        QTY       LIST PRICE        DISC PRICE        DISC PRICE
------------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                     <C>                   <C>     <C>              <C>               <C>  

1A         ********************                    ***********           ***          ***               ***               ***
1B         *************                           *********      ***    ***          ***               ***               ***

2          MISCELLANEOUS MATERIAL                  VARIOUS               ***          ***               ***               ***

           POWER EQUIPMENT PRICE                                                                                          ***
           ENGINEERING AND DRAFTING PRICE                                                                                 ***
           INSTALLATION PRICE*                                                                                            ***
           TRANSPORTATION PRICE                                                                                           ***

           TOTAL PRICE                                                                                                    ***
</TABLE> 

           *THIS AVERAGE PRICE WITHIN THE $*** TO $*** PRICE RANGE IS DUE TO
            AREA PRICE DIFFERENTIALS FOR ***************************.


PAGE 2                          LUCENT - PROPRIETARY                 ALB 1/15/97