AGREEMENT#: 365

                       VALUE ADDED RESELLER AGREEMENT

THIS RESELLER Agreement for the purchase of Equipment and license of Programs
(hereinafter 'Agreement") Is between Summa Four, Inc,, a Delaware Corporation,
with Its principal place of business at 25 Sundial Avenue, Manchester. New
Hampshire 02103-7281 (hereinafter "Summa Four) and the Reseller whose name and
address Is set forth below (hereinafter "Reseller"),

Reseller:   Computer Business Sciences, Inc.
Address: 80-02 Kew Gardens Rd.
City: Kew Gardens
State: New York
ZIP: 11415

WHEREAS, Summa Four is engaged in the manufacturing, sale and license worldwide
of communications equipment, and WHEREAS, Re~ markets and distributes
communications equipment and other services and support to its Customers and
desires to purchase and license Summa Few products and to combine such products
with Reseller's products, WHEREAS, Summa Four and Reseller desire to establish a
matter set of terms and conditions pursuant to which Summ Four shall sell and/or
license certain of its products to Reseller for subsequent resale and/or
sublicense by Reseller together With Re value added products and services to
Its; customers.

NOW THEREFORE the Parties agrees as follows:

I.    In this Agreement the following expressions have the following meanings
      unless the context denotes otherwise:

      "Purchase Order", "Order means the Reseller's purchase order which shall
      be subject to the terms of this Agreement whether referenced or not.

      "Equipment" means the hardware equipment and peripheral devices purchased
      by Reseller under this Agreement including that Equipment which is
      identified by the Product numbers in Summa Four's published Price
      Schedule.

      'Designated Equipment" means the Equipment upon which Programs shall be
      Installed and which is designated with a single Summa Four system serial
      number.

      "Documentation" means the user manuals, handbooks, demonstration software
      packages and other materials provided by Summa Four for use in conjunction
      with the Equipment and the Programs.

      "Programs" means the software programs In object code form provided to the
      Reseller pursuant to this Agreement by Summa Four as licensor or
      sub-licensor, Including any subsequent updates, Improvements or
      modifications which may be delivered to Reseller hereunder.
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      "Products" means the Equipment, the Programs and the Documentation,
      collectively. Summa Four reserves the right to modify. add to or delete
      from this Agreement the Products which may be available hereunder.

      'Value Added Reseller, "Reseller" means a purchaser of Products which adds
      substantial value to such Products (including but not limited to
      application programs, hardware equipment, support, services, functional
      and/or performance enhancements, etc.) ("Value Added Products" and resells
      such Value Added products to its end-user Customers.

2.    Appointment

2.1   Subject to the terms and conditions of this Agreement, Summa Four hereby
      appoints the Reseller as a limited and non-exclusive Reseller to resell
      the Value Added Products and sublicense the Programs to Its end user
      customers. The Reseller shall not appoint a secondary or sub-distributor
      or any other reseller to distribute the Value Added Products without Summa
      Four's prior written notice. With respect to any sales contemplated by
      Reseller outside of the United States, the provisions of Article 21 hereto
      shall apply. 

2.2   It is understood and agreed by Reseller that Summa Four shall have and
      shall retain and any of Summa Four's affiliates, subsidiaries,
      distributors, agents or other resellers may have and may retain at all
      times the right, directly or Indirectly, to promote, market, sell, license
      or otherwise distribute Products in any manner and to any and all
      customers at all times throughout the world.

3.    Reseller Obligations

3.1   In recognition of the particular expertise necessary to market and
      distribute the Products and in consideration of the right to remain on
      authorized Reseller of this Products throughout the duration of this
      Agreement Reseller warrants and undertakes that:

3.1.1 It has and shall maintain tie capacity, facility, resources and personnel
      necessary to perform Its obligations under this Agreement,

3.1.2 It shall use its best efforts to purchase and license the minimum
      quantities of the Products in accordance with Reseller's Business Plan
      forecast set out In Attachment A to Schedule 11:

3.1.3 It shall actively promote the Products and resell Value Added Products
      only to its end-users all in a manner which reflects favorably an the
      Products and reputation of Summa Four,

3.1.4 It shall make available to Its customers professional, prompt and
      workmanlike Installation, timing, warranty and maintenance services;

3.1.5 It shall advise Summa Four regarding pertinent market information
      concerning Summa Four, the Products, market developments and customer
      inquiries regarding Products;

3.1.6 It shall license all Programs as specified In this Agreement:

3.1.7 It shall submit upon the date hereof and each quarter thereafter a rolling
      forecast of Resellers requirements for the Products for the following
      twelve (12) month period;

3.1.5 Upon execution of this Agreement by Reseller, Reseller will piece an order
      for at lead one (1) Product system for Its sole use in the development and
      support of additional application features and/or demonstration purposes.
      The configurations and prices for such system will be determined by mutual
      agreement of the parties.

4.    Obligations of Summa Four


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4.1   Summa Four shall:

4.1.1 Provide to Reseller such sales aids, data sheets end product brochures In
      such quantities as may be required In support Its customers and In no
      event any less than that which Is provided to other resellers;

4.1.2 Provide to Reseller technical assistance, Product updates and other
      Information with respect to the Products as generally provided to other
      resellers and/or as otherwise agreed to In the attached consulting
      addendum;

4.1.3 Make available training classes for the operation and support of the
      Products at times, rates and charges which are available to other
      resellers and/or as specified In the attached consulting addendum.

5.    Purchase of Equipment and License of Programs

5.1   From time to time throughout the term of this Agreement, Reseller may
      place purchase Orders for Products and upon receipt and acceptance by
      Summa Four, Summa Four will acknowledge such Order and advice Reseller of
      the scheduled shipment date. All such Purchase Orders shall reference the
      Agreement number specified above,

52    Except as otherwise provided for heroin. Reseller acknowledges and accepts
      responsibility for the selection and subsequent use of the Products and
      the results obtained thereby. Reseller also accepts responsibility for the
      selection, operation, and results obtained from any other third party
      equipment, programs, or services used In conjunction with the Products.

Prices and Discounts

0.1   The prices, license Ins, and other charges for the Products are got forth
      in Summa Fours then current published Price Schedule which may be amended
      by Summa Four from time to time throughout the term of this Agreement.
      Summa Four's current published Pam Schedule Is attached hereto as Schedule
      1. Such Products shall be discounted In accordance with Summa Four's then
      current Reseller Discount Schedule. - Summa Four's current Reseller
      Discount Schedule Is attached hereto as Schedule II. All orders accepted
      by Summa Four before the effective date of any price Increase shall be
      Invoiced at the price originally accepted by Summa Four if shipment of
      such Order is completed within ninety (90) days of such price increase.
      All prices are expressed and all payments must be made In U.S dollars.

6.2   Prices are exclusive of all extraneous or additional charges includng all
      federal, state, local, municipal, or other excise, sales, value added,
      use, occupation, or similar taxes now In force or enacted In the future,
      all of which we the responsibility of and shall be paid by the Reseller.
      To the extent Summa Four is required to pay any such charges or taxes.
      Summa Four shall Invoice the Reseller for any such payments and Reseller
      shallI reimburse Summa Four for such payment; within thirty (30) days of
      the date of the invoice therefore. It shall be the Reseller's
      responsibility to provide prior written verification to Summa Four of any
      applicable tax exemptions.

7.    Payment Terms

      Payment terms for Products shall be 50% of the value of the order upon
      placement of the order and the remaining 50% prior to the shipment from
      Summa Four.

7.2   If Reseller fails to pay any amounts when payment Is due, the Reseller
      shall pay Summa Four a late payment fee which shall be the lesser of 1.5%
      per month or the maximum rate allowed by law on such unpaid amounts,
      together with all costs and expenses Incurred by Summa Four in collecting
      such overdue amounts.


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8.    Delivery Lead Time

      Summa Four's normal delivery lead time for standard released Products is
      within (30) days after receipt and acceptance by Summa Four of an Order.
      Nevertheless, Summa Four shall always provide Reseller an acknowledgment
      of the actual scheduled shipment date. Summa Four will use reasonable
      efforts to meet the Reseller's requested delivery date If less than thirty
      (30) days and will advise the Reseller if additional charges are required
      to facilitate such expedited delivery. Summa Four will meet acknowledged
      scheduled shipment dates subject to the extent that such Products are
      standard, released Products which had been previously forecasted in
      Reseller's quarterly Product forecasts. In such event Summa Four also
      reserves the right to make early and/or partial shipment of Products, to
      Reseller.

9.    Shipment, Risk of Loss and Title

9.1   Unless otherwise requested by Reseller and agreed by the Parties, Summa
      Four will select the methods and routes of shipment. All Products under
      this Agreement shall be shipped to the Reseller, FOB, Summa Four's
      factory, Manchester, New Hampshire (unions designated otherwise by Summa
      Four). All transportation, rigging, cartage, and handling charges shall be
      paid directly by the Reseller. Summa Four may, however. Invoke the
      Reseller for any such charges If Summa Four is required to make any
      payments or prepayments directly to the carrier. Summa Four shall have no
      liability In connection with any shipment or for any loss or damage to the
      Products while In transit. Upon request, shipments may be insured by Summa
      Four at the Reseller's expense, In any went the Reseller shall be
      responsible for making claims with carriers, insurers, warehousemen, and
      others for misdelivery, non-delivery, loss, damage, or delay.

9.2   Title to Equipment and risk of loss for the entire Order shall pass to the
      Reseller upon shipment at the F.O.B. point stated above (title to Programs
      shall always remain vested In Summa Four or Its; licensors), Nevertheless,
      until all Products are fully paid for by the Reseller. the passing of
      title pursuant to the Uniform Commercial Code shall be deemed conditional.

10.   Force Majeure

      Neither Party will be liable for any failure to perform or delay In
      performance of Its obligations hereunder (except Reseller's obligation to
      make payments when due) caused by circumstances beyond its control
      Including acts of God, fires, strikes, floods or other natural emergencies
      or other unforseen and/or uncontrolliable events which makes performance
      commercially impracticable.

11.   Program License and Sublicense

11.1  In consideration of Reseller's payment of the appropriate license fees
      -and charges, Summa Four hereby grants to Reseller (subject to the terms
      and conditions of this Agreement) a non-exclusive non-transferable license
      to use and/or sublicense the use of each Program to its customers only on
      the Designated Equipment.

11.2  Title to Programs. Title to and ownership of Me Programs, including all
      patents, copyrights. trade secrets and proprietary rights applicable
      thereto, shall at all times remain solely and exclusively with Summa Four
      (and/or Summa Four's third party licensor) and the Reseller agrees not to
      take any action inconsistent with such title and ownership. Reseller
      acknowledges and agrees that the Programs and Documentation are
      proprietary to Summa Four, were developed at private expense and that no
      portion of such Programs shall be construed as In the public domain.

11.3  Protection of Programs. Reseller and Reseller's customer shall protect
      such Programs to no less extent" Reseller protects Its own proprietary
      Programs. In any event and always in accordance with subarticle 11.6
      below, Reseller and Its customers shall not, without the prior written
      consent of Summa Four (which shall not be unreasonably withheld), disclose
      or otherwise make available such Programs, In any form, to any third
      person or entity. Neither Reseller nor Its customers shall translate,
      reverse engineer, decompile or disassemble the Programs without the prior
      written consent of 


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      Summa Four. Reseller and/or Resellers customers may make one (1) copy of
      each Program for back-up or archival purposes. Nevertheless, neither the
      Reseller nor its customer shall remove or obscure any copyright patent,
      trademark, trade secret, or similar notice affixed to any Program arid
      shall reproduce and affix any such notice to any such copies of the
      Programs.

11.4  Term of License. Summa Four may terminate any license of the Program
      granted under this Agreement by written notice to the Reseller (who shall
      notify its customer directly, If applicable) If the Reseller or its
      customer falls to comply with any of the terms or conditions of this
      Section 11. Within thirty (30) days after discontinued use of the Programs
      by Reseller or Its end-user customer, as appropriate, or within ten (10)
      days after Summa Four has terminated any license, the Reseller shall
      return to Summa Four the original and all copies (Including partial
      copies) of such Programs and certify, in writing, to Summa Four that it
      has done so. The obligations of the Reseller and Its customers to protect
      the proprietary nature of the Programs shall survive the termination of
      any such license or this Agreement.

11.5  Equitable Relief. Summa Four reserves all rights and remedies It may have
      In lww or In equity to enforce the terms of this Agreement, including but
      not limited to injunctive relief and specific performance.

11.6  Sublicense Agreement. Resellers license to sublicense copies of Program to
      Its customer Is expressly conditional upon the prior receipt by Reseller
      of end-user software license terms, signed by a duly authorized officer of
      each such customer, which, In total, constitute sublicense terms which are
      no less comprehensive than the license terms of this Agreement.

11.1  Shrink-wrap Programs. Unless otherwise agreed by Summa Four, for all
      Programs which may be "pre- packaged" or "shrink wrapped" by Summa Four
      with preprinted license terms as an Integral part of such packaging,
      Reseller shall sublicense and/or distribute all such Programs in its
      original package and In the manner and form In which it was received from
      Summa Four. In such event, the license term which form a part of such
      Program will specifically apply to such Programs in lieu of the terms
      hereof. Reseller shall make no modifications or alterations in the
      packaging including the breaking of the seal of the Program license.

12.   United Warranty

12.1  All warranty obligations of Summa Four as set forth in this Section 12 are
      given by Summa Four solely to Reseller and may be enforced solely by
      Reseller. In no event shall Summa Four have any direct warranty or support
      obligations to any customers of Reseller unless Summa Four's then current
      service and/or support agreements have been entered Into directly between
      such customer and Summa Four.

12.2  Equipment. Summa Four warrants that upon shipment to Reseller, the
      Equipment shall be In good working condition, free from defects in
      material and workmanship and shall perform under normal use end operating
      conditions in accordance with Summa Four's then current published
      specifications for a period of one (1) year after the date of shipment.
      Summa Four's sole obligation with respect to claims of non-conformance
      made within this one (1) year warranty period described above shall be, at
      Its option, to repair or replace any part of Equipment which Summa Four.
      In Its sole discretion, determines to be defective. Reseller shall obtain
      a return authorization number from Summa Four prior to returning any
      Equipment to Summa Four under this warranty. Reseller shall prepay
      shipping charges for Equipment returned to Summa Four for warranty
      service, arid Summa Four shall pay freight charges for the return of the
      Equipment to the Reseller, excluding customers duties or taxes, if any.
      Replacement Equipment shall be new or Iike new In performance (or the same
      Item repaired if Identified and agreed to In the return authorization) and
      shall be warranted for the remaining duration of the warranty term of the
      non-conforming Equipment or ninety (00) days, whichever Is longer. All
      replaced Equipment shall become the property of Summa Four. Any claims of
      defects not made within such one (1) year period shall be deemed waived by
      Reseller.


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12.3  Programs Unless Otherwise specified by Summa Four, Summa Four warrants
      that the Programs shall substantially conform to Summa Four's then
      applicable Program specifications for a period of one (1) year after the
      date of shipment to the Reseller. Summa Four's sole obligation with
      respect to claims of material non-conformance shall be to use the effort
      Identified In Article 3.3 of Addendum A hereto to Identify, Isolate and
      thereafter Initiate remedial efforts to remedy the material non-Remedial
      efforts may include bug fixes, patches, work wounds or other
      recommendations which Summa Four may provide to Reseller. Any such
      remedial efforts will be given a high priority status consistent with that
      given to Summa Four's other high priority Resellers. Reseller acknowledges
      that Summa Four does not warrant that a Program's performance shall be
      uninterrupted or error free or that all non-conformances will be remedied.

12.4  Warranty Exclusions.

      Summa Four's warranty obligations hereunder are expressly conditioned upon
      (I)) the Products being property Installed, used and maintained at all
      times by Reseller and or its customers; (II) the Products not being
      subject to unusual mechanical stress or unusual electrical or
      environmental condtions or other acts of God; (iii) the Products not being
      subjected to misuse, accident or any unauthorized Installation/
      deinstallation by Reseller and/or its customers or other third parties
      end; (iv) the Products not being alter or modified, unldes authorized In
      writing or performed by Summa Four. Summa Four does not warrant that the
      Products will operate In any specific combination which may be selected
      for use by Reseller or Its customers or that the operation of the Products
      will be uninterrupted or error free, or that all non-conformance or
      defects will be remedied. Additionally, Summa Four shall have no warranty
      obligations for any failure of the Products to conform to the applicable
      Product specifications resulting from the combination of any Product(s)
      with hardware and/or software not supplied by Summa Four. If Summa Four
      determines that any Products(s) reported as defective or non-conforming by
      Reseller during the warranty period Is not defective or non-conforming,
      Summa Four may, at Its option. charge labor provided and expenses incurred
      by Summa Four In connection with such determination, at Summa Four's then
      current rates or as otherwise agreed to in the consulting addendum.

12.5  THE WARRANTIES OF SUMMA FOUR AND REMEDIES OF RESELLER SET FORTH IN THIS
      SECTION 12, LIMITED WARRANTY, ARE EXCLUSIVE AND ARE GIVEN BY SUMMA FOUR
      AND ACCEPTED BY RESELLER IN LIEU OF ANY AND ALL OTHER WARRANTIES, WHETHER
      EXPRESSED OR IMPLIED, INCLUDING WITHOUT LIMITATION, ALL WARRANTIES OF
      MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL SUCH OTHER
      WARRANTIES BEING HEREBY EXPRESSLY AND UNEQUIVOCALLY DISCLAIMED BY SUMMA
      FOUR AND WAIVED BY RESELLER.

13.   Limitation of Damages

13.1  Summa Four's liability for damages to the Reseller under this Agreement
      for any cause or claim whatsoever regardless of the form of action,
      whether for breach of warranty, contract or In tort (including negligence
      and product liability) or otherwise, shall not exceed the greater of the
      aggregate price paid for the Products which caused, or allegedly caused
      the liability or $200,000. No action arising out of or In connection with
      this Agreement may be brought by Reseller more than two (2) years after
      the cause of action has occurred.

13.2  Furthermore, in no event will Summa Four be liable to Reseller or any
      other person for loss of use of Products, data, or profits, or any other
      special, indirect, incidental or consequential damages, arising out of or
      in connection with the use or performance of any Products, even if Summa
      Four has been advised of the possibility of such damages. Reseller shall
      indemnify Summa Four against all such claims which may be asserted by
      other third parties including its Customers.

14.   Documentation


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      All documentation provided by Summa Four together with each system of
      Products shall be delivered with such Products by Reseller to its
      customers. All other Documentation which may be furnished to Reseller
      under this Agreement is solely for Reseller's internal use. Reseller may
      make copies of such Documentation only to satisfy its internal
      requirements, provided that all such copies include the appropriate
      copyright and proprietary information notices. No other copies or use of
      such Documentation or any portion thereof, shall be made without the prior
      written approval of Sum.. Four. All such Documentation, and copies thereat
      shall be maintained In secure promises by Reseller and Reseller shall take
      appropriate measures to prevent the unauthorized disclosure thereof.

13. Patent and Copyright Indemnity

15.1  If notified promptly In writing of any action (and all prior claim
      relating to such action) brought against Reseller based on a claim that
      any of the Product supplied infringes a United States patent copyright or
      other intellectual property right Summa Four shall defend such action at
      its expense and pay any costs or damages finally awarded against Reseller
      In such action which am found to be attributable to such claim: provided
      that Summa Four shall have sole control of the defense (with reasonable
      assistance from Reseller) of any such action and all negotiations for its
      settlement or compromise; and further provided Reseller or Its customers
      shall promptly cease to use Products if so requested by Summa Four. If a
      final injunction is obtained against the use of any of the Products by
      reason of infringement of a patent copyright, or other intellectual
      property right, or If In Summa Fours opinion any of the Product supplied
      to Reseller hereunder Is likely to become the subject of a successful
      claim of infringement of a patent, copyright, or other intellectual
      property right Summa Four shall, at its option and expense, either procure
      for Reseller the right to continue using such Product, replace or modify
      the same so that it becomes non-infringing, or grant Reseller a reasonable
      credit for the return of such Product.

18.2  Notwithstanding the foregoing, Summa Four shall not have any liability to
      Reseller ort its customers under the foregoing provisions if the
      Infringement or claim Is based upon (i) the use of any of the Products in
      combination with other equipment or software which is not furnished by
      Summa Four. or (II) use of the Products which have been modified to
      Reseller's or its customers" designs, specifications or instructions. No
      costs or expenses shall be Incurred on behalf of Summa Four without the
      prior written consent of Summa Four. The foregoing provisions state the
      entire liability of Summa Four with respect to infringement of patents,
      copyrights, trademarks and other Intellectual property rights by any of
      the products or any part thereof or by their operation.

16.   Support Service

      Reseller may elect to purchase service and support for the Products In
      accordance with the then current Summa Four agreement therefore.

17.   Customer Support

17.1  As an authorized Reseller of Summa Four Products. Reseller is required to
      provide support for its end-user customers. At a minimum. all problems or
      questions from Reseller's customers regarding Summa Four Products shall be
      addressed directly by the Reseller (and not Summa Four) in accordance with
      the Reseller Support Obligations attached hereto as Addendum A.

17.2  If not already done so at the time of execution of this Agreement as soon
      as practicable thereafter, Summa Four and Reseller shall establish the
      minimum level of required service and support expertise that will be made
      available by Reseller directly to an of Its end-user customers throughout
      the Term of this Agreement. Such support program (by way of example and
      not, by limitation) may include the following: 1) requirements for the
      annual completion of Summa Four's Reseller Support, Services and
      Maintenance Certification Program and, 2) requirements for Reseller's
      on-going and expected participation at specified Summa Four hardware arid
      software training courses and, 3) the required spans parts Inventory that
      Reseller shall purchase in order to support Reseller's customers.


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18.   Term and Termination

18.1  Term. The term of this Agreement shall commence on the Effective Date and
      shall continue (unless terminated as hereinbefore provided) for twelve
      (12) months thereafter ("Term"). After such Initial Term, this Agreement
      will remain in effect unless and until either Party terminates this
      Agreement upon thirty (30) days prior written notice to the other Party or
      this Agreement Is terminated as hereinafter stated.

18.2  Termination. This Agreement may be terminated:

      (i) At any time by either Party, If the other Party ha materially breached
      Its obligations under this Agreement and if the defaulting Party has not
      cured such default within thirty (30) days following the date upon which
      the non-defaulting Party has given written notice specifying the facts
      constituting the default;

      (ii) At any time by either Party, upon notice, If the other Party flies
      for or consents to any assignment for the benefit of creditors, files a
      petition In bankruptcy or liquidation, is adjudicated bankrupt or
      Insolvent or takes similar actions under laws of any jurisdiction for the
      general benefit of creditors of an Insolvent or financially troubled
      debtor.

      (iii) By Summa Four upon the breach by Reseller of Articles 11 and/or 21
      In the event Reseller fails to immediately caste "or remedy the breach;

      (iv) By either Party, with or without cause, upon ninety (90) days written
      notice. In the event Summa Four should choose to terminate this Agreement
      without cause, Summa Four shall nevertheless honor any orders which May
      have been previously accepted by Summa Four and which remain In the
      backlog.

16.3  Effect of Termination. Upon termination of this Agreement for any reason,
      all lights and obligations of the Parties under this Agreement shall
      cease, except as follows:

      (i)The Reseller's obligation for fees and other charges accrued prior to
      the termination date shall become immediately due and payable.

      (ii) To the extent that this Agreement IS terminated for reasons not
      attributable to a breach by Reseller or Its customers, all sublicenses
      previously granted by Reseller to its customers under this Agreement to
      use the Programs and/or Documentation shall not be affected by the
      termination of this Agreement.

      (iii) The provisions of Sections 11, 11. 12, 13, 14.16 and 21 shall
      survive the termination of this Agreement

19.   Cancellation. The cancellation of any order previously acknowledged by
      Summa Four will only be permitted with Summa Four's prior written approval
      and payment by Reseller of cancellation charges as follows:

                               Cancellation Charge
     Days Remaining Until Scheduled Shipment (Percentage of Purchase Price)

            20 - 30 Days                          20%
            10 - 19 Days                          40%
              5 - 9 Days                          60%
                0-4 Days                         100%

20.   Reseller Subsidiaries

      To the extent the Parties should choose to expand the Scope Of this
      Agreement to accommodate transactions between Summa Four and any of
      Reseller's subsidiaries, Addendum 8, Reseller ordering Locations may be
      added to this Agreement by amendment hereto. In such event Reseller agrees
      in be ultimately responsible for the prompt and faithful performance of
      any such subsidiary in accordance with the terms of this Agreement.


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21.   International Transactions

21.1  All Products are of United States origin. In the event Reseller should
      elect to export Products from the U.S., Reseller acknowledges that the
      export of such Products from the United States may be Subject to
      regulation by the U.S. Export Administration Act of 1979, as amended, and
      the rules and regulations promulagated thereunder, which restrict exports
      and re-exports of certain computer hardware, software media, technical
      data, and direct products of technical date, Reseller agrees to comply
      with all U.S. Export Administration Regulations as aare in effect from
      time to time (including, without limitation, all record-keeping
      requirements Imposed thereunder), and will not export or reexport the
      Products in violation of such Regulations.

21.2  Indemnification. Reseller agrees to indemnify and hold Summa Four harmless
      from any and all fines, damages, losses, costs and expenses (including
      reasonable attorneys fees) incurred by Summa Four. as a result of the
      breach of this Section 21 by the Reseller.

21.3  Territory. This Agreement contemplates only domestic U.S. transactions
      between the Parties. An such, nothing In this section 21 should give rise
      to the presumption that Reseller has been granted the right to resell,
      distribute or transfer Products and/or Value Added Products to its
      customers outside of the United States. To the extent the Parties agree to
      extend the applicability of this Reseller Agreement to include
      International transactions by Reseller or between Reseller's International
      subsidiaries and Summa Four, the parties shall amend this Agreement by
      Including Addendum C, International Transactions, hereto.

22.   Independent Contractors

      The relationship between Summa Four and Reseller shall at all times be
      that of Independent Contractors. Nothing contained in this Agreement shall
      be construed as creating a joint venture, partnership or any other legal
      relationship between the Parties other than that of buyer/seller. In no
      event and under no circumstances shall Reseller represent or purport to
      represent Summa Four or make any warranties, commitments or other
      representations on its behalf.

23.   Notices

      All notices given by either Party to the other Party under this Agreement
      shall be In writing and personally delivered or sent by registered or
      certified mail, return receipt requested to the other Party at its address
      set forth above. The date of personal delivery or the date of receipt, as
      the case may be, shall be deemed to be the date on which such notice is
      given.

24.   Assignment

      Reseller may not assign this Agreement or any of Its rights Or obligations
      thereunder, without the prior written consent of Summa Four.

26.   General

25.1  Section headings are for descriptive purposes only and shall not control
      or alter the meaning of this Agreement.

26.2  The failure of either Party, in any one or more Instances to enforce any
      of the items of this Agreement shall not be construed as a waiver of
      future enforcement of that or any other term.

25.3  If any provision(s) of this Agreement shall, for any reason, be held to be
      illegal or unenforceable such provision shall be deemed separable from the
      remaining provisions of this Agreement and shall in no way affect or
      impair the validity or enforceability of the remaining provisions of this
      Agreement.


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<PAGE>

25.4  Summa Four makes no representations to the Reseller except as expressly
      set forth herein. The Reseller further agrees that this Agreement,
      (together with any addendums Or schedules hereto), is to complete and
      exclusive understanding of the Parties regarding the subject hereof and
      that this Agreement supersedes and cancels all previous and
      contemporaneous written and/or oral agreement and communications relating
      to the subject matter of this Agreement. The terms of this Agreement shall
      apply notwithstanding any proposed variations or additions which may be
      contained in any Reseller Purchase Order or other communications submitted
      by the Reseller. This /agreement may only be modified by written
      correspondence signed by an authorized representative of both Parties.

25.5  The validity, construction and interpretation of this Agreement and the
      rights and duties of the Parties hereto shall be governed by and construed
      in accordance with the laws of the Commonwealth of Massachusetts.

26.   The following Schedules and Addendums we attached hereto and made a part
      of this Agreement as of the Effective Date above:

          Schedule I - Price Schedule                    Yes
          Schedule It - Reseller Discount Schedule                   Yes
          Appendix A to Schedule II                      No
          Addendum A - Reseller Support Obligations                  Yes
          Addendum 8 - Reseller Ordering Locations                   ___
          Addendum C - International Transactions                    ___
          Other - Consulting Addendum                    ___
                                          
Reseller acknowledges and agrees that it has read this Agreement and understands
and agrees to be bound by its terms and conditions.

IN WITNESS WHEREOF, the Parties have caused this Agreement to be signed by its
duly authorized representatives.

RESELLER                            SUMMA FOUR, INC.

Authorized Signature                Authorized Signature

/s/ Doron Cohen                     /s/ Robert J. Heggerich
------------------------            -------------------------
Doron Cohen                         Robert J. Heggerich
President                           Director, contracts
3/19/97                             3/19/97


                                       10
<PAGE>

                                   SCHEDULE II
                                       TO
                               RESELLER AGREEMENT

                           RESELLER DISCOUNT SCHEDULE

I.    Reseller Forecast; Initial Forecast; Discounts

      A)    Reseller's business plan and Product. purchase foam Is attached
            hereto as Attachment A. In accordance therewith, Reseller forecasts
            that in the Initial Term, Reseller shall purchase and take delivery
            of that quantity of Products, whose aggregate list price shall be no
            less than $3,000,000.

      B)    In consideration of such forecast, all hardware Products on Purchase
            Orders placed by Reseller during the initial Term shall be
            discounted at a discount percentage of 40%. Programs and services
            are not entitled to any discount unless specifically noted as being
            eligible therefor on Summa Four's then currant price list.

      C)    Should this Agreement be extended either monthly or for additional
            terms after the Initial Term the discount percentage which shall be
            applied to Hardware Products an all subsequent Reseller Purchase
            Orders accepted by Summa Four shall be that then current discount
            which Summa Four grants to other Reseller's which is associated with
            the actual level of Aggregate List Price Dollar purchases of
            Products shipped to Reseller in the preceding Term. Summa Four's
            current Discount Schedule is detailed below.

II.   Discount schedule

         Aggregate Dollar Volume
         of Reseller Purchases In     Discount Percentage
         Preceding Year               On Hardware Purchases
         --------------               ---------------------
         (in $thousands)
         LESS than $100                        0%
         $100-500                             25%
         $500-1500                            30%
         $1500-3000                           35%
         $3000+                               40%
<PAGE>

                                   ADDENDUM A

                          RESELLER SUPPORT OBLIGATIONS

1.0 RESELLER RESPONSBILITIES

RESELLER will be the primary customer contact point for questions, problems and
assistance concerning the Products whether or not Products an under warranty or
extended support from Summa Four. RESELLER shall provide support Services to its
customers for the Products which shall include but not necessarily be limited to
the following:

      a)    telephone Customer response line to respond to questions regarding
            installation and use of the Products;

      b)    telephone customer response line to respond to customer's suspected
            code defects and documentation error regarding installation and
            operation of the Products;

      c)    Product maintenance through Maintenance Modifications to customers;

      d)    RESELLER personnel are Summa Four support trained:

      e)    Have available an adequate supply of recommended spare parts;

      f)    RESELLER to contact Summa Four Technical Support and obtain the
            appropriate Return Authorization (RA) prior to returning defective
            components, and

      g)    RESELLER will provide general technical assistance and levels 1& 2
            support as set in Section 3.1 and 3.2 below.

2.0 SUMMA FOUR RESPONSIBILITIES

Summa Four will provide Level 3 and general technical assistance as set forth In
Article 3.3, below.

3.0   WORK SPECIFICATIONS

3.1   RESELLER's customers will initiate requests for support by contacting
      RESELLER directly. The RESELLER representative will contact the request
      originator and initiate remedial action on the problem. RESELLER will
      perform the following Level I and Level 2 support responsibilities:

      Level I support is defined as a problem which is completely disabling a
      previously working service or one which is preventing Reseller's customer
      from using 4 service. Level I Support includes, but is not limited to:


                                       -2-
<PAGE>

      a)    create the Problem Description (PD);

      b)    call the customer and obtain a description of the problem and verify
            its severity;

      c)    search the RESELLER data base for known problems,

      d)    provide available resolution If known problem;

      e)    recommend local RESELLER assistance as required;

      f)    it no resolution, pass PD to Level 2; and update PD, documenting
            Level I actions;

      Level 2 support Is defined as a problem which is imputing a Reseller
customer's ability to provide a stable service, or which is preventing the
launch of a now service for which them is no viable workaround Second level
support includes, but Is not limited to:

      a)    receive the PD from Level 1;

      b)    analyze the problem symptoms and gather additional date from
            customer as required;

      c)    search the RESELLER database for known problems.

      d)    provide available resolution if known problem;

      e)    recommend local RESELLER assistance as required,

      f)    recreate problem on RESELLER Test System, if possible or at customer
            site via remote seem;

      g)    determine if error is. due to Improper installation of the Products
            by the customer;

      h)    determine if suspected error Is due to peripheral or other 3rd party
            equipment or software at the customer location or as part of the
            Integrated system;

      i)    attempt bypass at circumvention for high impact problems, i.e.,
            Severity I and 2;

      j)    if no resolution and problem appears to be a newly discovered code
            or documentation error, create Escalated Problem Description (EPD)
            record,


                                       -3-
<PAGE>

      k)    if suspected error appears to be in a Licensed Program(s), notify
            Summa Four of the EPD providing problem description and supporting
            documentation and materials.

      l)    at Summa Four's request, RESELLER will assist in obtaining
            additional information or materials from customer to support EPD,
            problem Source Identification and problem resolution;

      m)    update EPD documenting Level 2 actions; and

      n)    RESELLER will provide detailed product and problem information to
            Summa Four as a prerequisite to Invoking Level 3 Support. Such
            information should include, but not limited to, system serial
            number, location, problem description and print out of error log,
            updated EPD and a list describing what RESELLER attempts were made
            to fix problem.

3.3   Summa Four will perform the following Level 3 support responsibilities to
      the extent such Products are under warranty to RESELLER or covered under
      an extended support Agreement with RESELLER.

      Level 3 support is defined as a problem which is affecting (but not
      preventing) the customer's ability to operate or support their network and
      which may be addressed by Summa four in a subsequent Program maintenance
      release, Typically a functional or configuration matter that can be
      worked-around Level 3 support includes but may not be limited to:

      a)    receive the EPD from RESELLER, supporting documentation and
            materials and issue a call ticket number, 30 minute telephone
            response time an a 7 day by 24 hours to emergency calls. The Summa
            Four support center is staffed Sam to 5pm, Monday through Friday
            Eastern Time for all other call requests;

      b)    analyze the problem symptoms and diagnose the suspected error;

      c)    notify RESELLER Level 2 Support if additional information materials
            or documentation is required;

      d)    attempt to recreate the problem on Text System, if required;

      e)    assist RESELLER In attempting to develop a workaround or
            circumvention for high Impact problems e.g., Severity 1 and 2;

      f)    determine if maintenance modifications are required to the Licensed
            Program(s);


                                       -4-
<PAGE>

      g)    if maintenance modifications are required to the Licensed
            Program(s), and such modifications are agreed to be provIded, Summa
            Four will provide code correction to RESELLER;

      h)    return call documentation to RESELLER with one of the defined PD
            Closing Cods assigned, including describing the resolution of in
            the, event a code error was found, provide the rational for the
            closing of the ticket number;

      i)    Provide final documentation for the purpose of updating or closing
            the trouble ticket, when appropriate;

      j)    receive from RESELLER technical questions (regardless of whether
            severity Level 1, 2 or 3) and supporting documentation and
            materials;

      k)    analyze the technical questions and provide answers;

      l)    provide technical backup support to RESELLER an Products including
            assistance in Problem Determination, Problem Source Identification
            and Problem Diagnosis. In addition Summa Four shall provide
            assistance in answering questions that may arise concerning the
            operation and use of the Licensed Program(s) that cannot be resolved
            by RESELLER;

      m)    In accordance with Summa Four's then current standard operating
            procedures, Summa Four may provide a corrected version of the
            Licensed Program(s) that includes all maintenance modifications to
            the Licensed Program(s), if available, Additional corrected versions
            of the Licensed Program will be provided as determ ined by Summa,
            Four and based upon the severity of the problem.

      n)    Summa Four will maintain procedures to endeavor to ensure that new
            fixes are compatible with previous fixes;

      p)    packaging of maintenance modifications and migration code will be
            done as mutually agreed to by RESELLER and Summa Four; and

      q)    If on site Summa Four support is requested by RESELLER, Summa Four
            will respond an a best efforts basis but within two business days,
            and RESELLER will be billed at the then current ad published rates
            and charges. Such response time is limited to critical, Severity I
            problems.


                                       -5-
<PAGE>

                                  ADDENDUM "B"
                                       TO
                               RESELLER AGREEMENT

                           RESELLER ORDERING LOCATIONS

In accordance with section 19 of the above referenced Agreement, the following
Reseller subsidiaries may place orders under this Agreement. As such, each such
subsidiary shall be subject to the terms and conditions of this Agreement:


1.____________________________________________________________

2.____________________________________________________________

3.____________________________________________________________

4.____________________________________________________________

5.____________________________________________________________


                                       -6-
<PAGE>

                                   ADDENDUM C
                                       TO
                               RESELLER AGREEMENT

                           INTERNATIONAL TRANSACTIONS

In accordance with Section 20.3 of the above referenced Agreement, the following
International subsidiaries of Reseller which are identified on Addendum A may
place orders subject to the following additional conditions:

      1.    All Products shall be shipped by Summa Four, EXW Summa Four's
            Factory, Manchester, New Hampshire.

      2.    In addition to Reseller's responsibility for all costs, expenses and
            charges identified in Section 2.1 of the above referenced Agreement
            Reseller also agrees to be liable for all other costs and expenses
            associated with the export or import of such Products (excluding the
            cost to obtain any required export licenses from the United States)
            Including any duties, value added taxes (VAT) or Other local
            charges,

      3.    Notwithstanding the payment terms of Section 7 and unless otherwise
            agreed by Summa Four all payments shall be made In U.S. dollars
            through a confirmed, irrevocable sight letter of credit drawn art a
            U.S. bank (of Summa Four's choice) in form and substance
            satisfactory to Summa Four.

      4.    Reseller acknowledges that all Products and/or Proprerty Information
            which may be provIded hereunder are of United States Origin and are
            licensed for toe only In the country of original destination and as
            such, are subject to all applicable United States Government Laws
            and regulations governing or relating to the export of such Products
            from the U.S.

            Furthermore, Reseller acknowledges that it shall comply fully with
            all such export/re-export related laws and regulations (including
            local country regulation or other applicable multinational
            conventions) which may be applicable to the Reseller's import use,
            resale or re-export of such Products from rich country of original
            destination.

      5.    Reseller's obligations stated above shall survive termination or
            expiration of this Agreement


                                       -7-
<PAGE>

      a.    Type Approvals. Reseller acknowledges that Summa Pour makes no
            representations or warranties tot the Products comply with any local
            country telecommunications approvals safety or other standards (Type
            Approvals) which may be established from time to time by the local
            PTT or other authorities.


                                       -8-