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                                                                    EXHIBIT 10.1

                                  OEM AGREEMENT

                                     BETWEEN

                              NORTHERN TELECOM INC.

                                       AND

                              VOICETEK CORPORATION




                                                                          Page 1

                    CONFIDENTIAL MATERIAL OMITTED AND FILED
                  SEPARATELY WITH THE SECURITIES AND EXCHANGE
                     COMMISSION. ASTERISKS DENOTE OMISSIONS.
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THIS OEM AGREEMENT is made and entered into by and between Northern Telecom
Inc., a Delaware corporation, with offices located at 2305 Mission College
Boulevard, Santa Clara, California 95054-1591 (hereinafter "NTI") and Voicetek
Corporation, a Massachusetts corporation, having its principal place of business
at 19 Alpha Road, Chelmsford, Massachusetts 01824-4175
(hereinafter "VOICETEK").

                                    RECITALS

WHEREAS, NTI shall assume the role of an original equipment manufacturer that
procures products from VOICETEK for incorporation into a number of Northern
Telecom applications;

AND WHEREAS, NTI wishes to obtain the nonexclusive rights and VOICETEK agrees to
extend nonexclusive rights to NTI to purchase, resell and distribute VOICETEK's
standard product(s) and/or services at NTI's option as enumerated in VOICETEK's
Price List;

AND WHEREAS, NTI wishes to obtain exclusive rights and VOICETEK agrees to extend
exclusive rights to NTI to purchase, resell, and distribute VOICETEK's
product(s) and/or services which VOICETEK has, or will in the future, as the
case may be, modify according to specifications agreed upon by NTI and VOICETEK
and for which NTI has paid development fees to VOICETEK under one or more
development agreements and/or annexes applicable to development agreements
unless otherwise negotiated;

AND WHEREAS, NTI wishes to obtain the nonexclusive rights and VOICETEK agrees to
extend nonexclusive rights to NTI to purchase hardware not manufactured by
VOICETEK (an example of which is Dialogic-manufactured circuit pack assemblies),
direct from VOICETEK's external supplier(s) for installation in and use with
SELF-HOSTED UNITS only, without such direct purchase and installation by NTI or
NTI's qualified technicians of such non-VOICETEK-manufactured hardware voiding
and/or negatively affecting any and all warranties granted to NTI, NORTHERN
TELECOM COMPANIES or MANUFACTURING LICENSEES for SELF-HOSTED UNITS herein;

AND WHEREAS, the procured products have specific utilitarian functions to carry
out within the Northern Telecom applications into which they are incorporated;

AND WHEREAS, the parties desire to establish a stable and dependable business
relationship to ensure the smooth flow of products between the parties and
timely resolution of performance-related issues identified in the products
supplied by VOICETEK;

NOW THEREFORE, in consideration of the mutual covenants and obligations
hereinafter set forth, and for other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, THE PARTIES HERETO
AGREE AS FOLLOWS:

                             ARTICLE I - DEFINITIONS

Terms in the Agreement (other than names of parties and Article headings) which
are in capital letters shall have the meanings set forth in this Article I for
all purposes in connection with the Agreement.

1.1  "AGREEMENT" as used herein shall mean this OEM Agreement, as amended,
     modified, supplemented or otherwise altered from time to time.

1.2  "ANNUAL SUPPORT SERVICES PERIOD" as used herein shall mean the particular
     twelve (12) month period for which NTI has paid the requisite annual fee
     for RESELLER SUPPORT SERVICES.

1.3  "APPLICATION PROCESSOR" or "APPLICATION PROCESSORS" as used herein shall
     mean the computing platform used specifically to develop and/or execute
     GENERATIONS-based software in a client-server environment.

1.4  "AUTHORIZED DISTRIBUTOR" or "AUTHORIZED DISTRIBUTORS" as used herein shall
     mean any company which has signed a Distributorship Agreement (or the
     equivalent) with NTI, a NORTHERN TELECOM COMPANY or a MANUFACTURING
     LICENSEE granting such company the right to distribute one or more of the
     Northern Telecom product lines.


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1.5  "AUTHORIZED TERRITORY" as used herein shall mean the countries listed in
     Schedule A, which is attached hereto and is by this reference made a part
     of the AGREEMENT.

1.6  "BLANKET ORDER" or "BLANKET ORDERS" as used herein shall mean an ORDER
     which does not set forth a DELIVERY DATE.

1.7  "CANCELLATION PERIOD" as used herein shall mean the period commencing on
     VOICETEK's receipt of an ORDER or ORDER RELEASE and ending thirty (30) days
     immediately prior to the SHIPMENT DATE thereof.

1.8  "CRITICAL PROBLEM" or "CRITICAL PROBLEMS" as used herein shall mean
     problems characterized by one or more of the following: (i) system is
     inoperable, or (ii) causes software reloads or initializations, or (iii)
     substantially impairs a major application feature, or (iv) an error in USER
     DOCUMENTATION and/or MODIFIED USER DOCUMENTATION which requires an
     immediate revision and/or an immediate letter to NTI, and/or NORTHERN
     TELECOM COMPANIES and/or MANUFACTURING LICENSEES and/or AUTHORIZED
     DISTRIBUTORS in order to correct such problem(s).

1.9  "DELIVERY DATE" as used herein shall mean the date when PRODUCTS shall be
     delivered to the DELIVERY LOCATION.

1.10 "DELIVERY LOCATION" as used herein shall mean the NTI, NORTHERN TELECOM
     COMPANY or MANUFACTURING LICENSEE location where PRODUCTS shall be
     delivered.

1.11 "EFFECTIVE DATE" as used herein shall mean the date upon which the latter
     of the parties to execute the AGREEMENT performs that function.

1.12 "GENERAL AVAILABILITY" as used herein shall mean the date when the
     PRODUCTS, or any of them, have been released for unrestricted commercial
     sale and are available for sale by AUTHORIZED DISTRIBUTORS in any part of
     the AUTHORIZED TERRITORY.

1.13 "GENERATIONS" as used herein shall mean the object-oriented applications
     development and runtime environment developed and owned by VOICETEK.

1.14 "HARDWARE" as used herein shall mean all items that are designated as
      hardware in a PRICE LIST including, but not limited to, VTK Base Systems,
      Voice Ports/Network Interfaces, Voice Storage, APPLICATION PROCESSORS,
      Parts and Spares, Technical Documentation, KEYLOCKS, VOICE RESPONSE UNITS,
      SELF-HOSTED UNITS and Marketing Materials.

1.15 "HARDWARE PRODUCTS" as used herein shall mean either STANDARD HARDWARE
     PRODUCTS or MODIFIED HARDWARE PRODUCTS or both, as the context requires.

1.16 "KEYLOCK" or "KEYLOCKS" as used herein shall mean the VOICETEK-supplied
     hardware and keycode in object form functioning as a software lock and
     preventing unauthorized use and/or duplication of SOFTWARE PRODUCTS
     purchased by NTI, NORTHERN TELECOM COMPANIES or MANUFACTURING LICENSEES
     hereunder.

1.17 "MANUFACTURING LICENSEE" or "MANUFACTURING LICENSEES"as used herein shall
     mean those third parties properly authorized and empowered by NTI or a
     NORTHERN TELECOM COMPANY to manufacture and market product lines
     including, but not limited to, Northern Telecom proprietary hardware
     systems such as the Meridian 1 PBX, under its or their own corporate
     name(s), under a private brand, or under a Northern Telecom name and, as a
     result, require certain rights to SOFTWARE PRODUCTS which are
     substantially similar in scope to those granted directly to NTI by the
     AGREEMENT.

1.18 "MARKS" as used herein shall mean the trademarks, trade names and service
     marks now owned by, licensed to, or hereafter obtained by VOICETEK as may
     from time to time be added to Schedule C, which is attached hereto and by
     this reference made a part of the AGREEMENT.


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1.19 "MAXIMUM DELIVERY PERIOD" as used herein shall mean thirty (30) days for
     HARDWARE PRODUCTS and two (2) days or less for SOFTWARE PRODUCTS commencing
     on the date that VOICETEK receives an ORDER or an ORDER RELEASE therefor.

1.20 "MINOR PROBLEM" or "MINOR PROBLEMS" as used herein shall mean a problem
     with the SOFTWARE PRODUCTS which causes or may cause degradation of feature
     operation, or a problem with USER DOCUMENTATION, respectively, both for
     which an acceptable workaround is available and the problem can persist
     without customer complaint for a limited time.

1.21 "MODIFIED HARDWARE PRODUCT or "MODIFIED HARDWARE PRODUCTS" as used herein
     shall mean any and all HARDWARE modified at NTI's direction and expense
     under one or more Technology Development Agreements and annexes or addenda
     thereto, and which may or may not be enumerated in Schedules D and/or E
     which are attached hereto and are by this reference made a part of the
     AGREEMENT and which are products VOICETEK sells exclusively to NTI,
     NORTHERN TELECOM COMPANIES and MANUFACTURING LICENSEES.

1.22 "MODIFIED PRODUCT" or "MODIFIED PRODUCTS" as used herein shall mean either
     MODIFIED HARDWARE PRODUCTS or MODIFIED SOFTWARE PRODUCTS or both, as the
     context requires.

1.23 "MODIFIED SOFTWARE PRODUCT" or "MODIFIED SOFTWARE PRODUCTS" as used herein
     shall mean any and all SIGNATURES, USER DOCUMENTATION, and software
     modified at NTI's direction and expense under one or more Technology
     Development Agreements and annexes or addenda thereto, and which may or may
     not be enumerated in Schedules D and/or E and which are products VOICETEK
     sells exclusively to NTI, NORTHERN TELECOM COMPANIES and MANUFACTURING
     LICENSEES.

1.24 "MODIFIED USER DOCUMENTATION" as used herein shall mean USER DOCUMENTATION
     and/or user manuals created by VOICETEK for the PRODUCTS and modified at
     NTI's direction to reflect, but are not restricted to, such changes as
     NTI's naming convention, product names, NTI-supplied platforms and removal
     of options or features not sold by NTI and which may contain all or parts
     of the USER DOCUMENTATION and/or user manuals.

1.25 "NORTHERN TELECOM COMPANY" or "NORTHERN TELECOM COMPANIES" as used herein
     shall mean Northern Telecom Limited, the parent company of NTI, and all
     subsidiaries or affiliates wholly or at least majority owned, directly or
     indirectly, by Northern Telecom Limited, but not including NTI.

1.26 "OPTION PERIOD" as used herein shall mean the three (3) month period
     immediately following conclusion of the TERM for which NTI can elect to
     extend the AGREEMENT on these stated terms while a renewal hereof or a new
     agreement are being negotiated by the parties.

1.27 "ORDER" or "ORDERS" as used herein shall mean the document issued or output
     of an electronic "paperless" process initiated by NTI by which PRODUCTS are
     ordered.

1.28 "ORDER RELEASE" or "ORDER RELEASES" as used herein shall mean the document
     issued or output of an electronic "paperless" process initiated by NTI
     pursuant to a BLANKET ORDER by which the DELIVERY DATE for such BLANKET
     ORDER, or a portion thereof, is established.

1.29 "POINT RELEASE" or "POINT RELEASES" as used herein shall mean revision(s)
     of any SOFTWARE PRODUCTS included as part of the applicable cost of
     RESELLER SUPPORT SERVICES and supplied by VOICETEK at no additional charge
     to NTI, NORTHERN TELECOM COMPANIES or MANUFACTURING LICENSEES, the
     principle function of which is to provide bug fixes to the SOFTWARE
     PRODUCTS but which can include minor new functionality, an example of which
     would be a change from 3.xx to 3.xy.

1.30 "PRICE LIST" as used herein shall mean the Voicetek Corporation Price Book
     For North America and Asia, and the Voicetek Corporation International
     Pricebook, respectively, identified and incorporated by reference in
     Schedule 8, that are in effect at the time NTI or NORTHERN


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      TELECOM COMPANIES or MANUFACTURING LICENSEES procure(s) STANDARD PRODUCTS
      from VOICETEK.

1.31  "PRODUCT" or "PRODUCTS" as used herein shall mean either STANDARD PRODUCTS
      or MODIFIED PRODUCTS or both, as the context requires.

1.32  "RESCHEDULING PERIOD" as used herein shall mean the period commencing on
      VOICETEK's receipt of an ORDER or ORDER RELEASE and ending thirty (30)
      days immediately prior to the SHIPMENT DATE thereof.

1.33  "RESELLER SUPPORT SERVICES" as used herein shall mean those support
      services enumerated in Article XIII and Schedule F, which is attached
      hereto and is by this reference made a part of the AGREEMENT.

1.34  "RMA" as used herein shall mean Return Material Authorization.

1.35  "SELF-HOSTED UNIT" or "SELF-HOSTED UNITS" as used herein shall mean any
      SYSTEM configuration comprised of SOFTWARE PRODUCTS executable on a single
      hardware platform performing the combined functions of APPLICATION
      PROCESSOR and VOICE RESPONSE UNIT.

1.36  "SERIOUS PROBLEM" or "SERIOUS PROBLEMS" as used herein shall mean a
      problem that is characterized by a substantial reduction in service and/or
      missing or incorrect USER DOCUMENTATION and/or MODIFIED USER DOCUMENTATION
      of major functionality for which there is not an acceptable workaround or
      interim solution available.

1.37  "SHIPMENT DATE" as used herein shall mean the date when PRODUCTS shall be
      shipped by VOICETEK to the DELIVERY LOCATION.

1.38  "SIGNATURE" or "SIGNATURES" as used herein shall mean the
      VOICETEK-supplied code(s) which are branded into the firmware of HARDWARE
      components not manufactured by VOICETEK (examples of which are Dialogic
      boards) which enable PRODUCTS (HARDWARE and software combined) to
      compatibly perform their functions together as a SYSTEM.

1.39  "SOFTWARE PRODUCTS" as used herein shall mean either STANDARD SOFTWARE
      PRODUCTS or MODIFIED SOFTWARE PRODUCTS or both, as the context requires.

1.40  "SOURCE CODE MATERIALS" as used herein shall mean the first version of the
      following items and all subsequent POINT RELEASES, UPDATES, VERSION
      RELEASES and enhancements thereof: (a) one copy of the source code of
      SOFTWARE PRODUCTS in machine-readable form, and (b) one copy of all
      development tools, editors and compilers normally supplied by VOICETEK in
      making use of source code of the SOFTWARE PRODUCTS, and (c) any
      documentation describing source code of SOFTWARE PRODUCTS normally
      supplied by VOICETEK in making use of source code of SOFTWARE PRODUCTS.

1.41  "SPECIFICATIONS" as used herein shall mean the most current version of the
      document or documents published by VOICETEK and applicable to PRODUCTS
      that define the applicable PRODUCTS including, but not limited to,
      materials, dimensions, quality performance criteria, Mean Time Between
      Failures (MTBF), SYSTEM architecture, physical configuration, product
      capabilities, functionality, functional parameters, performance standards,
      operating characteristics and compliance with corresponding commercial and
      regulatory requirements.

1.42  "STANDARD HARDWARE PRODUCT" or "STANDARD HARDWARE PRODUCTS" as used herein
      shall mean HARDWARE as enumerated in the PRICE LIST and/or Schedule D
      and/or Schedule E which are the same products VOICETEK sells to its
      general customer base and which products have not been modified by
      VOICETEK in any unique and/or specific manner to suit any NTI customer or
      specific group of NTI customers.


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1.43  "STANDARD PRODUCT" or "STANDARD PRODUCTS" as used herein shall mean either
      STANDARD HARDWARE PRODUCTS or STANDARD SOFTWARE PRODUCTS or both, as the
      context requires.

1.44  "STANDARD SOFTWARE PRODUCT" or "STANDARD SOFTWARE PRODUCTS" as used herein
      shall mean software and USER DOCUMENTATION as enumerated in the PRICE LIST
      and/or Schedule D and/or Schedule E which are the same products VOICETEK
      sells to its general customer base and which products have not been
      modified by VOICETEK in any unique and/or specific manner to suit any NTI
      customer or specific group of NTI customers.

1.45  "SUPPORT ORGANIZATION" as used herein shall mean the identified NTI or
      NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE whose primary contact
      persons are authorized to contact VOICETEK for warranty service during the
      WARRANTY PERIOD or for RESELLER SUPPORT SERVICES thereafter, as the case
      may be.

1.46  "SYSTEM" or "SYSTEMS" as used herein shall mean any combination of
      PRODUCTS, USER DOCUMENTATION and/or MODIFIED USER DOCUMENTATION together
      required to assemble, (load in the case of software), install and operate
      as fully functional interactive voice response product(s).

1.47  "TERM" as used herein shall mean the three (3) year period from and
      after the EFFECTIVE DATE.

1.48  "TRAINING MATERIALS" as used herein shall mean available course materials
      such as instructor's notes, presentation materials, binders, slides,
      videos and software examples, but not including equipment or HARDWARE.

1.49  "TRAINING PROGRAM" or "TRAINING PROGRAMS" as used herein shall mean the
      VOICETEK-supplied instruction courses covering the subjects of, but not
      limited to, Administration, Applications Development and Installation
      and Maintenance.

1.50  "UPDATE" or "UPDATES" as used herein shall mean a release included as part
      of the applicable cost of RESELLER SUPPORT SERVICES and supplied by
      VOICETEK to NTI, NORTHERN TELECOM COMPANIES or MANUFACTURING LICENSEES of
      SOFTWARE PRODUCTS in which minor new functionality has been added in
      addition to the normal complement of bug fixes supplied, an example of
      which would be a change from 3.x to 3.y.

1.51  "USER DOCUMENTATION" as used herein shall mean VOICETEK's user manuals,
      technical manuals, release notes including advisements for PRODUCTS,
      installation and operation, promotional materials and other data and
      documentation describing the use of PRODUCTS normally supplied to
      customers of VOICETEK.

1.52  "VERSION RELEASE" or "VERSION RELEASES" as used herein shall mean a
      release of SOFTWARE PRODUCTS that is not included in the scope of RESELLER
      SUPPORT SERVICES in which major new functionality has been added in
      addition to any complement of bug fixes supplied, an example of which
      would be a release from 3.x to 4.x, and for which NTI or NORTHERN TELECOM
      COMPANIES or MANUFACTURING LICENSEES would be expected to pay a fee in
      addition to the requisite annual fee for RESELLER SUPPORT SERVICES.

1.53  "VOICE RESPONSE UNIT" or "VOICE RESPONSE UNITS" as used herein shall mean
      the computing platform used to execute VRS.

1.54  "VRS" as used herein shall mean the voice response server software, also
      known as TSP, developed and owned by VOICETEK and executable on VOICE
      RESPONSE UNITS whether supplied by NTI or VOICETEK.

1.55  "WARRANTY PERIOD" as used herein shall mean fifteen (15) months in the
      case of SOFTWARE PRODUCTS and twelve (12) months in the case of HARDWARE
      PRODUCTS beginning on the date of receipt thereof (in the case of SOFTWARE
      PRODUCTS duplicated by NTI on the date of receipt of gold standard master)
      by NTI, NORTHERN TELECOM COMPANIES, or MANUFACTURING LICENSEES.


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1.56  "WARRANTY REPAIR PERIOD" as used herein shall mean ten (10) calendar days
      which shall commence on the date that VOICETEK receives HARDWARE PRODUCTS
      which do not conform to the warranty set forth in Section 11.1 at
      VOICETEK's repair facility in Chelmsford, Massachusetts, except that in
      the case of HARDWARE PRODUCTS destined for locations outside of the United
      States and Canada, the understanding is that the repaired or replaced item
      will have been shipped but not necessarily received by a NORTHERN TELECOM
      COMPANY or a MANUFACTURING LICENSEE within the ten (10) day period as
      stated herein due to potential extended transit time for shipments outside
      of North America and which actual transit time would be the shortest
      period of time available from the carrier designated by NTI, NORTHERN
      TELECOM COMPANIES or MANUFACTURING LICENSEES.

                      ARTICLE II - WARRANTIES OF OWNERSHIP

2.1   VOICETEK warrants that it has developed, it is the owner of, and/or it
      possesses all necessary rights to market the use of STANDARD SOFTWARE
      PRODUCTS and owns and/or has the right to use as of the EFFECTIVE DATE
      certain MARKS and VOICETEK's goodwill of the businesses symbolized
      thereby.

2.2   VOICETEK warrants and represents that STANDARD SOFTWARE PRODUCTS, or any
      substantial portions thereof, have not been published or otherwise made
      available to third parties without appropriate copyright and/or other
      proprietary notices to preserve VOICETEK's ownership and proprietary or
      licensed rights therein.

2.3   VOICETEK warrants that it is either the owner, or is otherwise in
      possession of sufficient licensed rights pertaining to any portion of the
      proprietary and intellectual property rights owned by third parties, of
      all proprietary and intellectual property rights in and to all STANDARD
      HARDWARE PRODUCTS. VOICETEK further warrants that title to all STANDARD
      HARDWARE PRODUCTS shipped to NTI and/or NORTHERN TELECOM COMPANIES and/or
      MANUFACTURING LICENSEES pursuant to the AGREEMENT shall pass to NTI or a
      NORTHERN TELECOM COMPANY or a MANUFACTURING LICENSEE, as the case may be,
      free and clear of any liens, charges, encumbrances, restrictions or rights
      created in, by or against the STANDARD HARDWARE PRODUCTS or against
      VOICETEK, except any intellectual property rights of VOICETEK and/or one
      or more of VOICETEK's licensors in the STANDARD HARDWARE PRODUCTS, if any.
      Without investigating the nature and scope of any intellectual property
      rights that may exist in or to the STANDARD HARDWARE PRODUCTS, the parties
      agree that NTI undertakes no obligation to protect any such intellectual
      property rights as may be claimed by VOICETEK and/or one or more of
      VOICETEK's licensors in the STANDARD HARDWARE PRODUCTS in connection with
      purchase and sale of STANDARD HARDWARE PRODUCTS pursuant to the AGREEMENT.

2.4   VOICETEK warrants that USER DOCUMENTATION or any substantial portions
      thereof, have not been published or otherwise made available to third
      parties without appropriate copyright and/or other proprietary notices to
      preserve VOICETEK's ownership and proprietary or licensed rights therein.

2.5   VOICETEK warrants and represents that no prior license or other agreement
      is violated by or is inconsistent with the terms and conditions of the
      AGREEMENT.

                   ARTICLE III - GRANT OF NONEXCLUSIVE RIGHTS

3.1   In accordance with and subject to the terms and conditions of the
      AGREEMENT, VOICETEK hereby grants to NTI the nonexclusive right:

      (a)  to market and distribute STANDARD HARDWARE PRODUCTS and to market and
           sublicense STANDARD SOFTWARE PRODUCTS only in object form and/or USER
           DOCUMENTATION under the MARKS respectively applicable, if any, or, at
           NTI's option, under NTI's trademarks and/or trade dress, directly or
           indirectly, as components of a Northern Telecom-manufactured
           application to AUTHORIZED DISTRIBUTORS and/or


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           end-user customers in the AUTHORIZED TERRITORY, and to grant these
           same rights to MANUFACTURING LICENSEES.

      (b)  to use, adapt, merge, copy and incorporate, as necessary, the
           STANDARD SOFTWARE PRODUCTS, or portions thereof, as a part of a
           Northern Telecom-manufactured application, and to grant these same
           rights to MANUFACTURING LICENSEES. The right to reproduce copies of
           STANDARD SOFTWARE PRODUCTS, or portions thereof, shall include the
           right to have such reproduction performed by another party on NTI's
           behalf, provided such party has signed a substantially unmodified
           version of NTI's Reproduction Services Agreement, a copy of which is
           attached hereto as Schedule G and is by this reference made a part
           hereof.

      (c)  to use, modify, translate, reproduce and distribute, either directly,
           or through AUTHORIZED DISTRIBUTORS to customers in the AUTHORIZED
           TERRITORY, and to use, translate and reproduce for internal use,
           copies of the USER DOCUMENTATION delivered to NTI under the AGREEMENT
           and to grant all of these same rights to MANUFACTURING LICENSEES. The
           right to reproduce copies of USER DOCUMENTATION shall include the
           right to have such reproduction performed by another party on NTI's
           behalf, provided such party has signed a substantially unmodified
           version of NTI's Reproduction Services Agreement.

      (d)  to manufacture and distribute copies of POINT RELEASES, UPDATES and
           VERSION RELEASES [for STANDARD SOFTWARE PRODUCTS only] either
           directly or indirectly, to end-user customers in the AUTHORIZED
           TERRITORY.

      (e)  to purchase HARDWARE not manufactured by VOICETEK (an example of
           which is Dialogic-manufactured circuit pack assemblies), direct from
           VOICETEK's external supplier(s) for installation and use in
           VOICETEK-supplied components without such direct purchase, sale,
           distribution and installation by NTI or NTI's qualified technicians
           of such HARDWARE not manufactured by VOICETEK voiding and/or
           negatively affecting in any way the warranties granted to NTI,
           NORTHERN TELECOM COMPANIES or MANUFACTURING LICENSEES elsewhere in
           the AGREEMENT.

      (f)  to brand SIGNATURES for any HARDWARE purchased under the rights
           granted to NTI under subsection (e) above at NTI's option and at no
           additional cost to NTI, NORTHERN TELECOM COMPANIES and MANUFACTURING
           LICENSEES and to have such branding of SIGNATURES not void and/or
           negatively affect in any way the warranties granted to NTI elsewhere
           in the AGREEMENT.

                     ARTICLE IV - GRANT OF EXCLUSIVE RIGHTS

4.1   In accordance with and subject to the terms and conditions of the
      AGREEMENT, VOICETEK hereby grants to NTI the exclusive right:

      (a)  to market and distribute MODIFIED HARDWARE PRODUCTS and to market and
           sublicense MODIFIED SOFTWARE PRODUCTS only in object form and/or
           MODIFIED USER DOCUMENTATION under NTI's trademarks and/or trade
           dress, directly or indirectly, as components of a Northern Telecom
           application to AUTHORIZED DISTRIBUTORS and/or end-user customers in
           the AUTHORIZED TERRITORY, and to grant these same rights to
           MANUFACTURING LICENSEES.

      (b)  to use, adapt, merge, copy and incorporate, as necessary, the
           MODIFIED SOFTWARE PRODUCTS, or portions thereof, as a part of a
           Northern Telecom application, and to grant these same rights to
           MANUFACTURING LICENSEES. The right to reproduce copies of MODIFIED
           SOFTWARE PRODUCTS shall include the right to have such reproduction
           performed by another party on NTI's behalf, provided such party has
           signed a substantially unmodified version of NTI's Reproduction
           Services Agreement.

      (c)  to use, modify, translate, reproduce and distribute, either directly,
           or through AUTHORIZED DISTRIBUTORS to customers in the AUTHORIZED
           TERRITORY, and to


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           use, translate and reproduce for internal use, copies of the MODIFIED
           USER DOCUMENTATION and to grant all of these same rights to
           MANUFACTURING LICENSEES. The right to reproduce copies of MODIFIED
           USER DOCUMENTATION shall include the right to have such reproduction
           performed by another party on NTI's behalf, provided such party has
           signed a substantially unmodified version of NTI's Reproduction
           Services Agreement.

      (d)  to manufacture and distribute copies of POINT RELEASES, UPDATES and
           VERSION RELEASES [for MODIFIED SOFTWARE PRODUCTS only], either
           directly or indirectly, to end-user customers in the AUTHORIZED
           TERRITORY.

                    ARTICLE V - DISTRIBUTION AND SUBLICENSING

5.1   Subject to the terms and conditions set forth herein, VOICETEK agrees to
      sell [or license, in the case of SOFTWARE PRODUCTS] and NTI shall have the
      right to purchase or otherwise procure, as the case may be, PRODUCTS at
      the license fees and/or prices set forth in Schedule B, Schedule D or
      Schedule E, as the case may be, during the TERM.

5.2   Except as may otherwise be required by VOICETEK's agreements with its
      suppliers of STANDARD PRODUCTS, NTI reserves the right to market and
      distribute HARDWARE PRODUCTS and to market and sublicense SOFTWARE
      PRODUCTS in object form under its own trademarks, service marks and/or
      trade dress associated with the various Northern Telecom applications into
      which such PRODUCTS are incorporated. NTI and/or NORTHERN TELECOM
      COMPANIES and/or MANUFACTURING LICENSEES may request that a Northern
      Telecom logo or other form of trade dress be placed on MODIFIED PRODUCTS
      by NTI or a NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE itself or
      by VOICETEK. Regardless of which party places a Northern Telecom logo or
      other form of trade dress on MODIFIED PRODUCTS, it is the understanding of
      the parties that any MODIFIED PRODUCTS provided with a warranty pursuant
      to the AGREEMENT shall carry the same warranty from VOICETEK whether or
      not Northern Telecom logos and/or trade dress are applied thereto.

5.3   If NTI or any NORTHERN TELECOM COMPANY, MANUFACTURING LICENSEE OR
      AUTHORIZED DISTRIBUTOR desires to distribute the PRODUCTS in object form
      in countries outside of the AUTHORIZED TERRITORY, NTI shall first submit
      the name of such country or countries to VOICETEK for VOICETEK's prior
      written approval, which approval shall not be unreasonably withheld. In
      the event a particular country is not approved by VOICETEK, the parties
      shall arrange to discuss the merits of proceeding with the proposed
      distribution in such country and the reservations and/or objections of
      VOICETEK in an effort to reach a mutually satisfactory resolution.

5.4   NTI understands and agrees that the PRODUCTS, and any copies thereof
      acquired or reproduced hereunder, and any direct product thereof, are
      subject to the export control laws and regulations of the United States,
      and any amendments thereof. NTI hereby assures (and shall require any
      NORTHERN TELECOM COMPANIES and/or MANUFACTURING LICENSEES and/or
      AUTHORIZED DISTRIBUTORS receiving rights directly or indirectly from NTI
      hereunder) VOICETEK that it does not intend to and will not knowingly,
      without the prior written consent, if required, of the Office of Export
      Licensing of the U.S. Department of Commerce, P.O. Box 273, Washington,
      D.C. 20230, transmit directly or indirectly:

      (i)  PRODUCTS and/or technical information provided in relation to
           PRODUCTS; or

      (ii) any immediate products (including processes and services) produced
           directly by the use of PRODUCTS and/or associated technical
           information;

      to (1) Afghanistan, The Federal Republic of Yugoslavia (Serbia and
      Montenegro), Haiti, Iraq, the People's Republic of China or any Group Q,
      S, W, Y or Z country specified in Supplement No. 1 to Part 370 of the
      Export Administration Regulations issued by the U.S. Department of
      Commerce or (2) any citizen or resident of the foregoing countries.
      Country Groups Q, S, W, Y and Z currently include the following: Albania,
      Armenia, Azerbaijan, Belarus, Bulgaria, Cambodia, Cuba, the Czech
      Republic, Estonia, Laos, Latvia, Libya, Lithuania, Mongolia, North Korea,
      Poland, Romania,


                                                                         Page 11
   10
      Russia, Tajikistan, Turkmenistan, Ukraine, Uzbekistan and Vietnam. NTI
      further assures VOICETEK that it will not transmit, sell, convey or
      transfer any PRODUCTS or any other commodities or technical information
      received under or in connection with the AGREEMENT to any individuals or
      entities listed in the Table of Denial orders as published in Supplement
      Nos. 1 and 2 to Part 788 of the above-referenced regulations.

5.5   NTI and all NORTHERN TELECOM COMPANIES and MANUFACTURING LICENSEES agree
      to reproduce, upon each copy of the SOFTWARE PRODUCTS in object form and
      the USER DOCUMENTATION and MODIFIED USER DOCUMENTATION, respectively,
      made, the copyright notice attributing ownership of the copyright rights
      therein as delivered to NTI under Article VII of the AGREEMENT. In the
      event that NTI and/or a NORTHERN TELECOM COMPANY and/or a MANUFACTURING
      LICENSEE creates modifications to the USER DOCUMENTATION, NTI and/or such
      NORTHERN TELECOM COMPANY and/or such MANUFACTURING LICENSEE shall have the
      right to include its own copyright notice therewith in addition to
      VOICETEK's or VOICETEK's suppliers' copyright notice, if any, which
      VOICETEK requires to be used under the terms of this Section 5.5.

5.6   For SOFTWARE PRODUCTS in object form which NTI distributes either (i)
      directly to end-user customers, or (ii) indirectly through NORTHERN
      TELECOM COMPANIES, MANUFACTURING LICENSEES and through AUTHORIZED
      DISTRIBUTORS, NTI shall, as appropriate, require every such end-user
      customer to execute or contractually impose upon such NORTHERN TELECOM
      COMPANIES, MANUFACTURING LICENSEES and AUTHORIZED DISTRIBUTORS the
      obligation to distribute SOFTWARE PRODUCTS to their end-user customers
      under the software agreement (or an agreement in which such language is
      contained) that NTI uses in distributing NTI's own proprietary software
      applications, as set forth in Schedule H, which is attached hereto and is
      by this reference made a part of the AGREEMENT. Any MANUFACTURING LICENSEE
      receiving rights through NTI pursuant to Section 3.1 and Section 4.1 shall
      be bound in a written sublicense by terms and conditions no less stringent
      than those applicable to NTI herein.

5.7   The parties understand and acknowledge that NTI may elect to license the
      SOFTWARE PRODUCTS to United States government customers. In order to
      obviate the unintentional grant of rights to such customers pursuant to
      existing federal regulations, the parties hereby agree that the following
      legend shall appear on copies of the SOFTWARE PRODUCTS distributed to
      United States government customers:

            RESTRICTED RIGHTS LEGEND

            Use, duplication, or disclosure by the U.S. Government is subject to
            restrictions as set forth in subdivision (c)(1) of FAR 52.227-19 or
            (c)(1)(ii) of DFAR 52.227-7013.

            Northern Telecom Inc., 2305 Mission College Blvd., Dept. 0521,
            Santa Clara, CA 95054-1591.

5.8   NTI, and any NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES and
      AUTHORIZED DISTRIBUTORS receiving rights to the SOFTWARE PRODUCTS directly
      or indirectly from NTI, may transfer rights to use copies of the SOFTWARE
      PRODUCTS in object form to their customers for any fee which NTI, and said
      NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES and AUTHORIZED
      DISTRIBUTORS individually deem appropriate.

5.9   VOICETEK hereby grants to NORTHERN TELECOM COMPANIES the same scope of
      rights as are granted by VOICETEK to NTI in the AGREEMENT, subject to such
      NORTHERN TELECOM COMPANIES being bound in a written sublicense by NTI to
      terms and conditions equivalent to those set forth in the AGREEMENT or by
      manifesting their consent to abide by the terms and conditions of the
      AGREEMENT in a signed writing directed to VOICETEK referencing the name,
      date and parties to the AGREEMENT. Any MANUFACTURING LICENSEES receiving
      rights through NTI pursuant to Section 5.2 and Section 5.3 or through a
      NORTHERN TELECOM COMPANY pursuant to this Section 5.9 and/or Section 3.1
      and/or Section 4.1 shall also be bound in a written sublicense by terms
      and conditions no less stringent than those applicable to


                                                                         Page 12
   11
      NTI herein. A grant of rights by NTI or a NORTHERN TELECOM COMPANY to a
      MANUFACTURING LICENSEE shall not relieve NTI or such NORTHERN TELECOM
      COMPANY of its obligations under the AGREEMENT.

5.10  Except as provided herein, VOICETEK reserves all rights, title and
      interest in and to the SOFTWARE PRODUCTS, including the underlying ideas,
      inventions, processes and data embodied in the SOFTWARE PRODUCTS, and NTI
      acknowledges that no rights, title or interest in or to the SOFTWARE
      PRODUCTS is granted under the AGREEMENT other than the specified limited
      rights set forth in Articles III and IV, which, subject to Section 18.4,
      shall continue only so long as the AGREEMENT remains in effect.

                               ARTICLE VI - MARKS

6.1   VOICETEK warrants that it owns and/or has the right to use, as of the
      EFFECTIVE DATE, certain MARKS and VOICETEK's and/or VOICETEK's suppliers'
      goodwill of the businesses symbolized thereby.

6.2   VOICETEK hereby grants to NTI the nonexclusive right during the TERM to
      use for itself, and to grant directly or indirectly to NORTHERN TELECOM
      COMPANIES and AUTHORIZED DISTRIBUTORS, the right to use the MARKS listed
      in Schedule C of the AGREEMENT in association with the advertising and
      distribution of PRODUCTS in the AUTHORIZED TERRITORY subject to VOICETEK
      quality control review. Upon the request of VOICETEK, NTI, a NORTHERN
      TELECOM COMPANY or an AUTHORIZED DISTRIBUTOR shall deliver to VOICETEK any
      media containing the MARKS to be used by NTI or a NORTHERN TELECOM COMPANY
      or an AUTHORIZED DISTRIBUTOR, as the case may be, in advertising or
      promotional materials. NTI, NORTHERN TELECOM COMPANIES and AUTHORIZED
      DISTRIBUTORS shall abide by any and all guidelines promulgated by VOICETEK
      regarding use of the MARKS in such advertising and promotions. VOICETEK
      may advise NTI or a NORTHERN TELECOM COMPANY or an AUTHORIZED DISTRIBUTOR
      of any corrections or modifications to such use of the MARKS, and NTI or
      the NORTHERN TELECOM COMPANY or the AUTHORIZED DISTRIBUTOR shall effect
      such changes within a reasonable period of time. NTI, NORTHERN TELECOM
      COMPANIES and AUTHORIZED DISTRIBUTORS shall at least once in the most
      prominent first usage of the MARKS, cause "TM" to be placed adjacent to
      the MARKS on all advertising, marketing and other promotional material
      and, when so instructed by VOICETEK, shall cause "(R)" to replace "TM"
      within a reasonable period of time.

6.3   NTI and NORTHERN TELECOM COMPANIES hereby acknowledge and agree that
      nothing herein gives them any right, title or interest in the MARKS and
      that, upon termination of the AGREEMENT by expiration or for any other
      reason, NTI, NORTHERN TELECOM COMPANIES and AUTHORIZED DISTRIBUTORS shall
      no longer use the MARKS in advertising or in any other manner. NTI,
      NORTHERN TELECOM COMPANIES and AUTHORIZED DISTRIBUTORS shall not challenge
      the validity of VOICETEK's ownership of or right to use any of the MARKS,
      nor otherwise impair the interest of VOICETEK in the MARKS. NTI, NORTHERN
      TELECOM COMPANIES and AUTHORIZED DISTRIBUTORS shall not use any MARK which
      is confusingly similar to, or a colorable imitation of, any MARK.

6.4   In the event NTI and/or NORTHERN TELECOM COMPANIES discover apparent
      infringing activity involving the MARKS by third parties, then NTI,
      NORTHERN TELECOM COMPANIES and/or MANUFACTURING LICENSEES, as the case may
      be, shall promptly notify VOICETEK of such apparent infringing activity.

                       ARTICLE VII - ORDERING AND DELIVERY

7.1   With one exception, NTI may, but shall not be obligated to, issue ORDERS
      during the TERM. Regardless of other considerations, NTI shall issue an
      ORDER for RESELLER SUPPORT SERVICES as specifically enumerated in
      paragraph 1 of Schedule F no later than GENERAL AVAILABILITY. ORDERS may
      also be issued directly by one or more NORTHERN TELECOM COMPANIES that
      have been sublicensed by NTI pursuant to the terms of Section 5.9 of the
      AGREEMENT. In the event NTI provides VOICETEK with a forecast or estimate
      of the quantity


                                                                         Page 13
   12
      that may be ordered, whether set forth in Schedule B or otherwise,
      VOICETEK acknowledges that NTI shall not be obligated to submit an ORDER
      for any portion of such forecast or estimate.

7.2   VOICETEK shall accept any ORDER issued by NTI, provided such ORDER is
      consistent with the AGREEMENT. The AGREEMENT shall continue to apply to
      any ORDER issued during the TERM until all obligations herein are
      performed. The terms and conditions of the AGREEMENT shall supersede any
      preprinted terms and conditions appearing on any purchase order form used
      by NTI and/or any NORTHERN TELECOM COMPANY and/or MANUFACTURING LICENSEE.

7.3   An ORDER shall reference the AGREEMENT and shall set forth a description
      of the following: (a) PRODUCTS and/or TRAINING MATERIALS and/or TRAINING
      PROGRAMS ordered, (b) price, (c) DELIVERY LOCATION, (d) the location where
      the invoice shall be rendered for payment, (e) method of shipment, (f)
      quantity and (g) SHIPMENT DATE.

7.4   Within two (2) business days of the date of VOICETEK's receipt of an ORDER
      or an ORDER RELEASE or a modification by NTI to ORDERS or ORDER RELEASES,
      VOICETEK shall either provide verbal confirmation of the SHIPMENT DATE or
      propose an alternate SHIPMENT DATE. Any verbal confirmations issued by
      VOICETEK pursuant to this Section 7.4 shall be followed up by a written or
      electronic acknowledgment within ten (10) calendar days of the date of
      VOICETEK's receipt of such ORDER or ORDER RELEASE and/or modifications
      thereto. If VOICETEK fails to respond, it shall be deemed to have agreed
      to the SHIPMENT DATE and/or modification(s) set forth by NTI. If VOICETEK
      proposes an alternate SHIPMENT DATE, then NTI shall within two (2)
      business days of its receipt of notice of such alternate SHIPMENT DATE
      notify VOICETEK that either such alternate SHIPMENT DATE is acceptable or
      that such ORDER or ORDER RELEASE is canceled. Notwithstanding the above,
      VOICETEK shall comply with any SHIPMENT DATE specified by NTI which is to
      occur on or after the end of the MAXIMUM DELIVERY PERIOD.

7.5   An ORDER or an ORDER RELEASE may not be delivered in partial shipments
      unless otherwise specified by NTI. In the event VOICETEK fails to ship (or
      present in the case of TRAINING PROGRAMS) PRODUCTS and/or TRAINING
      MATERIALS and/or TRAINING PROGRAMS by the SHIPMENT DATE, NTI may cancel,
      without charge, the ORDER or ORDER RELEASE, as the case may be, or
      applicable portion thereof, seven (7) calendar days following the SHIPMENT
      DATE therefor.

7.6   Except as provided in Subsection 7.6.1 below, NTI may, without charge,
      postpone the SHIPMENT DATE for an ORDER or an ORDER RELEASE at any time
      during the RESCHEDULING PERIOD applicable to such ORDER or ORDER RELEASE.
      If NTI cancels an ORDER or an ORDER RELEASE during the CANCELLATION PERIOD
      for such ORDER or ORDER RELEASE there shall be no charge to NTI, except as
      provided in Subsection 7.6.1 below. No cancellations shall occur after a
      CANCELLATION PERIOD unless mutually agreed upon by the parties.

      7.6.1 The following PRODUCTS are excepted out from the rescheduling and
            cancellation rights afforded to NTI in Section 7.6:

           Order Code             Product Description
           ----------             -------------------

           HL-5250-HW-S           5250 Synchronous Interface (SSI HW & SW)
           HL-5250-HW-TR          5250 Token Ring Interface (SSI HW & SW)
           HL-3270-HW-S           3270 Synchronous Interface (SSI HW & SW)
           HL-3270-HW-TR          3270 Token Ring Interface (SSI HW & SW)
           HCOM-SC08-VT100        VT100 for 8 ports on the PC
           HCOM-SC016-VT100       VT100 for 16 ports on the PC
           HCOM-SC032-VT100       VT100 for 32 ports on the PC
           17-852066-02           2 Channel Fax Option
           17-852066-01           4 Channel Fax Option
           17-852066-00           8 Channel Fax Option
           17-852062-00           DMX Option
           PMT-000-NT             Notch Filter


                                                                         PAGE 14
   13
            Order Code            Product Description
            ----------            -------------------

            TTS-04-LH             TTS 4-port Assembly
            17-852072-00          Audio Interface Unit
            PT-30-E1              E1 Interface Card (Aculab)

            Also, single orders for 15 or more Rackmount units or 30 or more
            Tower units will not be candidates for unlimited rescheduling or
            cancellation without charge.

7.7   During the RESCHEDULING PERIOD NTI may modify ORDERS and/or ORDER RELEASES
      and VOICETEK shall confirm such ORDERS and/or ORDER RELEASES at the prices
      set forth in the AGREEMENT.

7.8   Upon providing VOICETEK at least thirty (30) days notice prior to the end
      of the TERM, NTI shall have the right to extend the TERM for the OPTION
      PERIOD, in which event NTI and VOICETEK shall have the rights and
      obligations in the AGREEMENT during the OPTION PERIOD, including, without
      limitation, NTI's right to purchase at the prices and applicable discount
      levels set forth or incorporated by reference, as the case may be, in
      Schedules B, D, E and/or G, the last of which is attached hereto and is by
      this reference made a part of the AGREEMENT.

7.9   Except in the case of a change for health or safety reasons, VOICETEK
      shall notify NTI at least one hundred twenty (120) days prior to
      implementing any change which affects the form, fit or function of any
      STANDARD PRODUCTS. Changes which do not affect form, fit or function, and
      changes made to HARDWARE PRODUCTS for health or safety reasons may be
      implemented at any time. In the event a change to HARDWARE PRODUCTS is
      made for health or safety reasons, VOICETEK shall retrofit NTI's existing
      inventory of such HARDWARE PRODUCTS purchased from VOICETEK, free of
      charge, with such retrofit being limited to the replacement of the
      specific item that is deemed to be the cause of the retrofit. Unless a
      change is designed by VOICETEK to eliminate or reduce a safety or health
      hazard, NTI, at its option, may issue ORDERS or ORDER RELEASES under the
      terms and conditions of the AGREEMENT for such PRODUCTS as they existed
      prior to the change in form, fit or function, for a period of at least one
      hundred eighty (180) days following the date of NTI's receipt of
      VOICETEK's change notification.

                 ARTICLE VIII - PRICE, PAYMENT AND RISK OF LOSS

8.1   Prices for PRODUCTS, RESELLER SUPPORT SERVICES, TRAINING MATERIALS and
      TRAINING PROGRAMS, respectively, purchased and/or licensed hereunder shall
      be list price according to the then current PRICE LIST or the prices set
      forth in Schedule E, as the case may be, less the current discount level
      where applicable as established in Schedule 1, which is attached hereto
      and is by this reference made a part of the AGREEMENT.

8.2   Special pricing for PRODUCTS, RESELLER SUPPORT SERVICES, TRAINING
      MATERIALS and TRAINING PROGRAMS, respectively, purchased and/or licensed
      hereunder which may or may not be included in the then current PRICE LIST
      shall be as indicated in Schedule E.

8.3   Prices for SYSTEMS, RESELLER SUPPORT SERVICES, TRAINING MATERIALS and
      TRAINING PROGRAMS, respectively, for internal use by NTI, NORTHERN TELECOM
      COMPANIES or MANUFACTURING LICENSEES shall be as set forth in Schedule D
      and shall be applicable only up to a total quantity of twenty-five (25)
      SYSTEMS. The allocation of SYSTEMS for internal use by NTI, NORTHERN
      TELECOM COMPANIES and/or MANUFACTURING LICENSEES shall be as directed by
      the NTI contact designated in Section 26.2.

8.4   Subject to any applicable discount as enumerated in Schedule 1, prices for
      (i) products and/or services, and (ii) right-to-use fees not enumerated in
      Schedule B, Schedule D and/or Schedule E shall be as mutually agreed upon
      by the parties prior to the time NTI issues ORDERS and/or ORDER RELEASES
      therefor.



                                                                         Page 15
   14
8.5   Prices and license fees set forth in Schedules B, D, and/or E or otherwise
      agreed upon pursuant to Section 8.4 are (a) in U.S. dollars and shall
      apply during the TERM; (b) exclusive of any applicable excise and sales
      taxes now existing or hereafter imposed by any applicable taxing
      authority; (c) exclusive of the transportation charges and duty applicable
      between the SHIPPING LOCATION and the DELIVERY LOCATION; and (d) inclusive
      of all other taxes, transportation charges, duties and charges for
      packaging and handling. Such taxes, transportation charges and duty for
      which NTI is liable shall be separately stated on the invoice. VOICETEK
      agrees not to assess any applicable excise or sales tax where NTI
      furnishes VOICETEK a tax exemption certificate, a certificate of
      authority, a direct pay permit and/or any equivalent acceptable to the
      applicable taxing authority.

8.6   VOICETEK may issue invoices to NTI, NORTHERN TELECOM COMPANIES and
      MANUFACTURING LICENSEES, respectively, issuing ORDERS and/or ORDER
      RELEASES for PRODUCTS and/or TRAINING MATERIALS upon consignment to the
      carrier designated by NTI for such PRODUCTS and/or TRAINING MATERIALS.
      [*]

8.7   VOICETEK may issue invoices to NTI, NORTHERN TELECOM COMPANIES or
      MANUFACTURING LICENSEES, respectively, issuing ORDERS and/or ORDER
      RELEASES for RESELLER SUPPORT SERVICES and/or TRAINING PROGRAMS at the
      beginning of an ANNUAL SUPPORT SERVICES PERIOD and, in the case of
      TRAINING PROGRAMS, upon presentation of such TRAINING PROGRAMS. [*]

8.8   For copies of SOFTWARE PRODUCTS manufactured by NTI, NORTHERN TELECOM
      COMPANIES and MANUFACTURING LICENSEES, respectively, VOICETEK shall, upon
      receipt of quarterly notices from a copying location, as set forth in
      Section 9.1, invoice such copying location for the total amount of per
      copy fees due, if any, for the period covered by the notice. Any
      MANUFACTURING LICENSEE copying location shall be required to report its
      activity to the NORTHERN TELECOM COMPANY by which it was sublicensed to
      make copies of SOFTWARE PRODUCTS in sufficient time to enable such
      NORTHERN TELECOM COMPANY to include the details of such activity in its
      quarterly notice to VOICETEK. [*]

                          ARTICLE IX - REPORTS; AUDITS

9.1   Within fifteen (15) calendar days after the end of each calendar quarter,
      each copying location will send to VOICETEK a written report summarizing
      its internal use and its external distribution of copies of the SOFTWARE
      PRODUCTS in object form manufactured under the AGREEMENT. Each quarterly
      report will specify:

      (a)  The total number of copies of the SOFTWARE PRODUCTS by individual
           product in object form made and distributed during the reporting
           period by a copying location for any of the following purposes:

           -     for internal use by NTI, or by NORTHERN TELECOM COMPANIES or
                 MANUFACTURING LICENSEES granted manufacturing rights directly
                 or indirectly by such copying location;

           -     for distribution by a copying location directly to end users;

            -    for distribution by a copying location for further
                 distribution by NORTHERN TELECOM COMPANIES, by MANUFACTURING
                 LICENSEES or by AUTHORIZED DISTRIBUTORS to end users.


                                                                         Page 16

   CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
                EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS
   15
      (b)  The total amount of license fees due to VOICETEK for the reporting
           period from the copying location submitting the report, which shall
           be determined by multiplying the total number of copies reported
           under Section 9.1 a) by the applicable license fee(s) referenced in
           Article VIII.

9.2   Upon VOICETEK's written request, NTI will, not more frequently than once
      during each twelve (12) month period of the AGREEMENT, cause an authorized
      representative of NTI to certify to VOICETEK the accuracy of the quarterly
      reporting of the number of copies of the SOFTWARE PRODUCTS in object form
      made by NTI, NORTHERN TELECOM COMPANIES and MANUFACTURING LICENSEES for
      distribution to customers or to internal use sites during such twelve 
      (12) month period. Further, upon VOICETEK's written request, NTI will
      permit, at the end of each twelve (12) month period of the AGREEMENT, a
      mutually acceptable independent certified public accountant paid by
      VOICETEK to examine the necessary books and records of NTI to audit such
      quarterly reporting, provided such accountant shall undertake in writing
      with NTI to protect the confidentiality of the business data and records
      of NTI and to disclose to VOICETEK only the accuracy or inaccuracy of the
      reporting hereunder. In the event an audit reveals a discrepancy between
      what is properly due to VOICETEK and what has been reported and paid to
      VOICETEK, and such discrepancy results in a shortfall in the amounts paid
      to VOICETEK that is both (i) a minimum of twenty (20) units, and (ii) at
      least ten percent (10%) of the amount actually due to VOICETEK for the
      twelve (12) months covered by the audit, then in addition to full payment
      by NTI of such shortfall NTI shall reimburse VOICETEK for all reasonable
      and customary costs incurred by VOICETEK related to such audit.

9.3   For all MANUFACTURING LICENSEES that are authorized by NTI or a NORTHERN
      TELECOM COMPANY to make copies of the SOFTWARE PRODUCTS in object form,
      NTI shall either:

      (i)     retain for itself, or require that the NORTHERN TELECOM COMPANY
              granting rights to a MANUFACTURING LICENSEE retain, the right to
              audit the books and records of any such MANUFACTURING LICENSEE; or

      (ii)    require that the MANUFACTURING LICENSEE agree, in writing, to
              permit, upon the written request of VOICETEK to NTI, a mutually
              acceptable independent certified public accountant paid by NTI
              or such MANUFACTURING LICENSEE to examine the necessary books
              and records of any such MANUFACTURING LICENSEE, provided that
              such accountant shall undertake in writing to such
              MANUFACTURING LICENSEE to protect the confidentiality of the
              business data and records of such MANUFACTURING LICENSEE and to
              disclose to VOICETEK only the accuracy or inaccuracy of the
              reporting required hereunder.  Where such audits are requested
              by VOICETEK, they shall be arranged through NTI.

      In no event shall the identities of any MANUFACTURING LICENSEE and/or
      end-users be disclosed to VOICETEK.

                    ARTICLE X - SOFTWARE PERFORMANCE WARRANTY

10.1  VOICETEK warrants that, during the WARRANTY PERIOD, SOFTWARE PRODUCTS,
      as delivered to NTI

      (i)   will be compatible with and will operate in accordance with
            VOICETEK's then most current USER DOCUMENTATION delivered with
            SOFTWARE PRODUCTS for the then most recent release of SOFTWARE
            PRODUCTS, and

      (ii)  to the best of VOICETEK's knowledge, shall be substantially free
            of CRITICAL PROBLEMS and SERIOUS PROBLEMS, and

      (iii) that the accompanying USER DOCUMENTATION shall be substantively
            complete and accurate.


                                                                         Page 17
   16
10.2  During the WARRANTY PERIOD for SOFTWARE PRODUCTS, VOICETEK shall provide
      to NTI promptly, upon release by VOICETEK, a copy of all corresponding
      POINT RELEASES and UPDATES.

10.3  During the WARRANTY PERIOD, VOICETEK shall provide unlimited telephone
      support between the hours of 8:00 a.m. and 6:00 p.m. Monday through Friday
      (EDT or EST, as applicable) to the SUPPORT ORGANIZATION for SOFTWARE
      PRODUCTS. VOICETEK's telephone "hotline" shall be staffed by technical
      personnel with a detailed, working knowledge of the PRODUCTS. VOICETEK
      shall make all reasonable efforts to have each call made on the "hotline"
      returned by a qualified technical expert possessing the ability to discuss
      the details of problems as follows:

              (a)  CRITICAL PROBLEMS  =   less than 30 minutes;

              (b)  SERIOUS PROBLEMS   =   less than 2 hours;

              (c)  MINOR PROBLEMS     =   less than 2 days;

      VOICETEK shall issue a call number to each problem reported by NTI. A bug
      report must contain sufficient information, on machine readable media if
      possible, for VOICETEK to reproduce the bug on VOICETEK premises. As a
      follow-up to any bug reports the SUPPORT ORGANIZATION may issue verbally
      to VOICETEK through the telephone "hotline," the SUPPORT ORGANIZATION
      shall provide such bug report details in writing to VOICETEK in a timely
      manner. VOICETEK's telephone "hotline' support shall be available for
      unlimited use by the SUPPORT ORGANIZATION for the PRODUCTS during the
      WARRANTY PERIOD.

10.4  Upon receiving notice from NTI of a bug or error in any SOFTWARE PRODUCTS
      during the WARRANTY PERIOD therefor, VOICETEK shall verbally acknowledge
      receipt of such notice. A bug report must contain sufficient information,
      on machine-readable media if possible, for VOICETEK to reproduce the bug
      on VOICETEK premises. VOICETEK's acknowledgment shall contain a unique
      number identifying the particular bug or error for tracking purposes.
      VOICETEK shall provide NTI with a status on any bug or error logged for
      NTI, provided that NTI identifies the particular bug or error by the
      tracking number assigned to it by VOICETEK. NTI may make inquiries
      regarding the status of any bug or error logged for NTI either orally or
      in writing. VOICETEK shall provide NTI with a response (i) verbally via
      the SUPPORT ORGANIZATION, or (ii) in writing, by number, describing the
      closing resolution of the bug or error, including the projected date that
      the necessary fix will be released and the nature of any known workaround.
      Each bug or error logged for NTI shall remain open until closure
      notification is received by NTI.

10.5  Patches or workarounds, made to fix reliability or specific performance
      deficiencies not reported by NTI in SOFTWARE PRODUCTS, may be made by
      VOICETEK when required, and, upon request, shall be either delivered to
      NTI within fourteen (14) days or made available to NTI through electronic
      means or electronic bulletin board (BBS) (e.g. Compuserve, Internet), if
      requested. Each patch and/or workaround requires a written description of
      the problem that the patch and/or workaround addresses and the requisite
      installation procedure.

10.6  VOICETEK shall make all reasonable efforts to provide a workaround or
      resolution for SOFTWARE PRODUCTS and any associated changes to the
      accompanying USER DOCUMENTATION, or MODIFIED USER DOCUMENTATION as
      applicable according to the following schedule:

      (a)  CRITICAL PROBLEMS - within twenty-four (24) hours of receipt of
           notice of existence from NTI;

      (b)  SERIOUS PROBLEMS - within five (5) days of receipt of notice of
           existence from NTI;

      (c)  MINOR PROBLEMS - fixed in the next POINT RELEASE or UPDATE issued by
           VOICETEK.

      The parties acknowledge and understand the potentially idiosyncratic
      nature of any bug or error in SOFTWARE PRODUCTS. Recognizing this, the
      turnaround times set forth previously in this


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      Section 10.6 constitute targeted goals of warranty services to be provided
      by VOICETEK to NTI. Repetitive failure to meet these targeted goals, as
      implied by the language of Section 10.7, is required before NTI is
      entitled to pursue its remedies as set forth in Section 10.7 and/or
      Article XVIII of the AGREEMENT. Sporadic failures by VOICETEK to meet or
      beat these targeted turnaround times do not constitute a default on the
      AGREEMENT.

10.7  In the event that, while NTI is receiving services under Article X for any
      SOFTWARE PRODUCTS from VOICETEK during a WARRANTY PERIOD, VOICETEK
      repeatedly fails to perform its obligations (after written notice to
      VOICETEK to such effect and specification of the nature of such failures)
      or VOICETEK unilaterally decides to discontinue warranty support for one
      or more SOFTWARE PRODUCTS so as to seriously jeopardize the ability of NTI
      to support the use of SOFTWARE PRODUCTS by NORTHERN TELECOM COMPANIES,
      MANUFACTURING LICENSEES, AUTHORIZED DISTRIBUTORS and/or end-user
      customers, then NTI shall have the right, after giving notice of its
      intentions to VOICETEK, to send one (1) or more qualified engineering
      personnel to VOICETEK's facilities, where such personnel shall have access
      to the source code form of the SOFTWARE PRODUCTS to which the failure to
      receive required warranty support pertains, the remaining SOURCE CODE
      MATERIALS related to such SOFTWARE PRODUCTS and the assistance of
      VOICETEK's engineering personnel in connection with such failure.
      VOICETEK's and NTI's engineering personnel shall have sixty (60) days from
      the date of arrival of the NTI engineering personnel to remedy the
      consequences of failure to receive the required warranty services from
      VOICETEK. Access to the source code form of any SOFTWARE PRODUCTS and the
      remaining SOURCE CODE MATERIALS related to such SOFTWARE PRODUCTS granted
      to NTI's engineering personnel pursuant to this Section 10.7 shall not
      include the right to retain any copies thereof upon leaving VOICETEK's
      facilities.

10.8  All notifications required pursuant to this Article X, except those sent
      pursuant to Section 10.7 shall be sent to NTI at the address set forth for
      other communications in Section 26.1.

10.9  VOICETEK has established a written formal escalation procedure, as set
      forth in Schedule J, which is attached hereto and is by this reference
      made a part of the AGREEMENT, that identifies contact persons and
      telephone numbers within VOICETEK's management that NTI may notify in the
      event VOICETEK personnel fail to:

      (a)  provide a response within two (2) hours to a CRITICAL PROBLEM and/or
           a SERIOUS PROBLEM;

      (b)  provide a workaround or resolution within twenty-four (24) hours to a
           CRITICAL PROBLEM;

      (c)  deliver a workaround or resolution that fixes a SERIOUS PROBLEM
           within five (5) days.

10.10 The exclusive remedy of NTI or a NORTHERN TELECOM COMPANY and the sole
      measure of recoverable damage by NTI or a NORTHERN TELECOM COMPANY for
      breach of the performance warranty on SOFTWARE PRODUCTS is, in VOICETEK's
      sole discretion, to provide NTI with (i) instructions for curing such
      nonconformity, or (ii) updated versions of SOFTWARE PRODUCTS which are
      free of such nonconformity, or (iii) a functionally equivalent software
      package which is free of such nonconformity and which, following delivery,
      will be regarded as a particular STANDARD SOFTWARE PRODUCT and/or MODIFIED
      SOFTWARE PRODUCT under the AGREEMENT. In the event VOICETEK is unable to
      accomplish (i), (ii) and/or (iii) above, it shall accept a return of the
      SOFTWARE PRODUCTS in question and fully refund to NTI the license and/or
      sublicense fees paid therefor pursuant to Article VIII.

                   ARTICLE XI - HARDWARE PERFORMANCE WARRANTY

11.1  VOICETEK warrants to NTI (or a NORTHERN TELECOM COMPANY) that each unit of
      HARDWARE PRODUCTS as delivered by VOICETEK hereunder will, under normal
      use and service, be free from defects in materials and workmanship during
      the WARRANTY PERIOD and shall conform to the SPECIFICATIONS in effect on
      the SHIPMENT DATE. VOICETEK's sole obligation and NTI's sole remedy under
      this HARDWARE performance warranty are limited to the


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   18
      repair or replacement, at VOICETEK's option, of the defective HARDWARE
      PRODUCTS. VOICETEK's obligation and NTI's remedy under this Section 11.1
      are conditioned upon:

      (a)  VOICETEK's receipt of written notice of a defect in HARDWARE PRODUCTS
           from NTI within the WARRANTY PERIOD; and

      (b)  the HARDWARE PRODUCTS not having been altered or repaired BY others
           without VOICETEK's written consent except in cases where NTI
           purchases hardware not manufactured BY VOICETEK direct from
           VOICETEK's suppliers) and such direct purchase and installation is
           undertaken by NTI or NTI's qualified technicians; and

      (c)  the alleged defect not being the result of mishandling, improper
           servicing or improper operation (including use in conjunction with
           hardware electrically or mechanically incompatible).

      This warranty shall survive inspection, acceptance and payment.

11.2  VOICETEK warrants to NTI and/or NORTHERN TELECOM COMPANIES that all
      HARDWARE PRODUCTS shipped pursuant to the AGREEMENT will be manufactured
      and/or assembled from new and unused components.

11.3  No HARDWARE PRODUCTS shall be returned to VOICETEK without VOICETEK's
      authorization pursuant to an RMA issued by VOICETEK's designated repair
      coordinator. The costs and risk of loss associated with shipping defective
      HARDWARE PRODUCTS to VOICETEK's factory shall be borne by NTI, a NORTHERN
      TELECOM COMPANY or MANUFACTURING LICENSEE. Costs and risk of loss
      associated with returning repaired or replacement HARDWARE PRODUCTS to NTI
      or a NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE shall be borne by
      VOICETEK. VOICETEK shall return the repaired HARDWARE PRODUCTS or a
      replacement within the WARRANTY REPAIR PERIOD. In all cases, an RMA shall
      be issued within one (1) business day of a request therefor by NTI or a
      NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE.

11.4  In the event NTI or a NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE
      contacts VOICETEK and requests an RMA, and the defective HARDWARE PRODUCTS
      are circuit boards under warranty, VOICETEK shall upon request by NTI,
      NORTHERN TELECOM COMPANIES or MANUFACTURING LICENSEES ship replacement
      boards within twenty-four (24) hours to the requesting office of NTI or
      NORTHERN TELECOM COMPANIES or MANUFACTURING LICENSEES or AUTHORIZED
      DISTRIBUTORS, as the case may be. In the event the original boards are not
      received by VOICETEK within ten (10) calendar days, VOICETEK shall have
      the right to invoice the NTI, NORTHERN TELECOM COMPANY or MANUFACTURING
      LICENSEE location requesting the replacement boards.

                      ARTICLE XII - LIMITATION OF WARRANTY

12.1  EXCEPT IN THE CASE OF WARRANTIES OF OWNERSHIP SET FORTH IN ARTICLE II, THE
      WARRANTIES SET FORTH IN ARTICLE X AND ARTICLE XI OF THE AGREEMENT ARE MADE
      TO AND FOR THE BENEFIT OF NTI ONLY, EXCEPT THAT VOICETEK ACKNOWLEDGES THAT
      NTI SHALL RELY UPON SUCH WARRANTIES IN PROVIDING WARRANTIES TO NORTHERN
      TELECOM COMPANIES, MANUFACTURING LICENSEES, AUTHORIZED DISTRIBUTORS AND
      END-USER CUSTOMERS. SUCH WARRANTIES CONSTITUTE THE ONLY LIABILITIES OF
      VOICETEK FOR BREACH OF WARRANTY AND ARE IN LIEU OF ALL OTHER WARRANTIES,
      WRITTEN OR ORAL, STATUTORY, EXPRESS OR IMPLIED IN REGARD TO STANDARD
      PRODUCTS AND/OR MODIFIED PRODUCTS, INCLUDING THE IMPLIED WARRANTIES OF
      MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE WHICH ARE HEREBY
      DISCLAIMED BY VOICETEK AND EXCLUDED FROM THE AGREEMENT.

                    ARTICLE XIII - RESELLER SUPPORT SERVICES

13.1  Upon payment of the requisite annual fee by NTI, VOICETEK shall provide
      RESELLER SUPPORT SERVICES to NTI for an ANNUAL SUPPORT SERVICES PERIOD in
      accordance with


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      the terms and conditions of the support program set forth in Schedule F.
      RESELLER SUPPORT SERVICES shall not include support for application
      development which is available at standard rates as described in the PRICE
      LIST.

13.2  In consideration of the provision of RESELLER SUPPORT SERVICES, NTI shall
      pay VOICETEK in accordance with the RESELLER SUPPORT SERVICES pricing
      structure set forth in Schedule F.

13.3  During an ANNUAL SUPPORT SERVICES PERIOD for which NTI has paid the
      requisite annual fee, VOICETEK shall provide RESELLER SUPPORT SERVICES
      with respect to the current VERSION RELEASE and for the last two (2)
      VERSION RELEASES immediately prior to the current one.

13.4  From time to time VOICETEK may develop corrections, enhancements and major
      improvements to SOFTWARE PRODUCTS. After the WARRANTY PERIOD has expired
      and in the event NTI does not request and pay for RESELLER SUPPORT
      SERVICES, then VOICETEK shall be under no obligation to issue any further
      POINT RELEASES and UPDATES to NTI. However, promptly upon issuance of any
      such POINT RELEASES and UPDATES by VOICETEK to any licensee holding a
      license similar in scope to the AGREEMENT, VOICETEK shall offer such POINT
      RELEASES and UPDATES to NTI.

13.5  Fees for POINT RELEASES and UPDATES shall be included in the annual fee
      paid by NTI for an ANNUAL SUPPORT SERVICES PERIOD, but in the event NTI
      has elected not to purchase RESELLER SUPPORT SERVICES, then the applicable
      fee for POINT RELEASES and UPDATES shall be as specified in Schedule B or
      as otherwise agreed upon in writing by VOICETEK and NTI. Each POINT
      RELEASE and UPDATE shall be regarded as the applicable SOFTWARE PRODUCT as
      denoted in the PRICE LIST or elsewhere, and shall upon release to NTI be
      subject to all of the terms and conditions of the AGREEMENT.

                            ARTICLE XIV - ACCEPTANCE

14.1  The acceptance of PRODUCTS is subject to inspection at the DELIVERY
      LOCATION and such acceptance shall be deemed to occur thirty (30) days
      after receipt of such PRODUCTS at the DELIVERY LOCATION unless NTI shall
      have provided VOICETEK with notice of nonacceptance within such period.

14.2  HARDWARE PRODUCTS will be inspected by NTI for major defects, with major
      defect being defined as (i) any functional failure, or (ii) a workmanship
      defect that is highly likely to cause infant mortality or significantly
      reduced product life, or (iii) a cosmetic or visual defect that is highly
      likely to cause the customer to request a replacement unit.

14.3  SOFTWARE PRODUCTS will be inspected by NTI for major defects, with major
      defects being defined as (i) SOFTWARE PRODUCTS missing labels, or (ii)
      SOFTWARE PRODUCTS with labels lacking accurate information as to the
      identity and POINT RELEASE, UPDATE or VERSION RELEASE contained therein,
      or (iii) defective media.

14.4  It any unit of PRODUCT does not conform to the requirements of an ORDER or
      an ORDER RELEASE or to the warranties set forth in Articles X and XI, as
      determined by NTI's inspection pursuant to the terms stated in Section
      14.2 and Section 14.3, the entire quantity delivered with such PRODUCT may
      be returned to VOICETEK at VOICETEK's expense, subject to failure
      verification by VOICETEK, unless the only defect found by NTI's inspection
      pursuant to the terms of Section 14.3 is a quantity of media with labels
      missing in which case NTI shall work with VOICETEK to obtain such label(s)
      without returning the entire quantity of PRODUCTS to VOICETEK. Payment
      shall neither be deemed to constitute acceptance nor be a waiver to NTI's
      right to cancel any ORDER or ORDER RELEASE.

            ARTICLE XV - INTELLECTUAL PROPERTY INFRINGEMENT INDEMNITY

15.1  VOICETEK shall defend, indemnify and hold NTI, NORTHERN TELECOM COMPANIES,
      MANUFACTURING LICENSEES and AUTHORIZED DISTRIBUTORS receiving rights
      directly or


                                                                         Page 21
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      indirectly (from NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES
      and/or AUTHORIZED DISTRIBUTORS) through NTI harmless from any and all
      claims, costs, expenses, damages or other liability, including reasonable
      and customary attorneys' fees, which is the result of patent, trademark or
      copyright infringement claims or claims based on misappropriation OF trade
      secret rights arising out of or relating to the use, copying or
      distribution of any of the SOFTWARE PRODUCTS in the AUTHORIZED TERRITORY
      or damages resulting from use of the MARKS in connection with such
      distribution in the AUTHORIZED TERRITORY. NTI, NORTHERN TELECOM COMPANIES,
      MANUFACTURING LICENSEES and/or AUTHORIZED DISTRIBUTORS shall notify
      VOICETEK promptly, in writing, In the event of any such claim, and grant
      to VOICETEK the right, at VOICETEK's expense, to control the defense
      thereof, including the sole right to settle any such claim or suit on such
      terms as VOICETEK shall deem desirable. If the use, copying or
      distribution of any SOFTWARE PRODUCTS or use of the MARKS under which the
      SOFTWARE PRODUCTS are distributed is held to constitute an infringement
      and enjoined in one or more countries within the AUTHORIZED TERRITORY,
      VOICETEK shall, at its own expense and option, (i) procure for NTI,
      NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES and AUTHORIZED
      DISTRIBUTORS the right to continue using and distributing the allegedly
      infringing SOFTWARE PRODUCTS, or (ii) modify the allegedly infringing
      SOFTWARE PRODUCTS so that they become noninfringing, while maintaining to
      the extent possible the same form and function, or (iii) replace the
      allegedly infringing SOFTWARE PRODUCTS with noninfringing substitutes,
      while maintaining to the extent possible the same form and function, or
      (iv) arrange for the return of all allegedly infringing SOFTWARE PRODUCTS
      shipped to NTI, NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES and/or
      AUTHORIZED DISTRIBUTORS the total amount of license fees paid therefor
      plus all transportation and handling costs incurred for cooperating in the
      return effort.

      15.1.1  VOICETEK shall not have any liability to NTI under Section 15.1
              for infringement and/or misappropriation, or claims thereof,
              that are based upon (i) the use of SOFTWARE PRODUCTS in
              combination with hardware and/or software furnished to NTI or a
              NORTHERN TELECOM COMPANY or a MANUFACTURING LICENSEE or an
              AUTHORIZED DISTRIBUTOR by a third party (unless approved by
              VOICETEK) if such infringement and/or misappropriation, or
              claim thereof, would have been avoided by the use of SOFTWARE
              PRODUCTS in combination with different hardware and/or software
              or, to the extent such use is possible, use of the SOFTWARE
              PRODUCTS without any combination, or (ii) the modification
              and/or enhancement of the SOFTWARE PRODUCTS by NTI, a NORTHERN
              TELECOM COMPANY, a MANUFACTURING LICENSEE, an AUTHORIZED
              DISTRIBUTOR or an end-user customer of any of the foregoing if
              such infringement and/or misappropriation, or claim thereof,
              would have been avoided by using the SOFTWARE PRODUCTS in their
              unmodified or unenhanced form.

15.2  VOICETEK shall defend, indemnify and hold NTI, NORTHERN TELECOM COMPANIES,
      MANUFACTURING LICENSEES, AUTHORIZED DISTRIBUTORS and, if applicable, their
      end-user customers harmless from any and all claims, costs, expenses,
      damages or other liability, including reasonable and customary attorneys'
      fees, which is the result of patent or trademark infringement claims
      arising out of or relating to the use, sale and/or distribution of
      HARDWARE PRODUCTS in the AUTHORIZED TERRITORY or damages resulting from
      use of the MARKS in connection with such distribution in the AUTHORIZED
      TERRITORY. NTI, a NORTHERN TELECOM COMPANY, a MANUFACTURING LICENSEE or an
      AUTHORIZED DISTRIBUTOR, as the case may be, shall notify VOICETEK
      promptly, in writing, in the event of any such claim, and grant to
      VOICETEK the right, at VOICETEK's expense, to control the defense thereof,
      including the sole right to settle any such claim or suit on such terms as
      VOICETEK shall deem desirable. If the use, sale and/or distribution of
      HARDWARE PRODUCTS or use of the MARKS under which the HARDWARE PRODUCTS is
      distributed are held to constitute an infringement and enjoined in one or
      more countries within the AUTHORIZED TERRITORY, VOICETEK shall, at its own
      expense and option, (i) procure for NTI, NORTHERN TELECOM COMPANIES,
      MANUFACTURING LICENSEES and AUTHORIZED DISTRIBUTORS the right to continue
      using, selling and distributing the allegedly infringing HARDWARE
      PRODUCTS, or (ii) modify the allegedly infringing HARDWARE PRODUCTS so
      that it becomes noninfringing, while maintaining to the extent possible
      the same form and function, or (iii) provide a noninfringing substitute
      for HARDWARE PRODUCTS which is acceptable to NTI, or (iv) arrange for the
      return of all allegedly infringing HARDWARE PRODUCTS


                                                                         Page 22
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      shipped to NTI, NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES and
      AUTHORIZED DISTRIBUTORS pursuant to the AGREEMENT in the countries within
      the AUTHORIZED TERRITORY in which the injunction is in effect and
      reimburse NTI, NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES and/or
      AUTHORIZED DISTRIBUTORS the total purchase price therefor plus all
      transportation and handling costs incurred for cooperating in the return
      effort.

      15.2.1  VOICETEK shall not have any liability to NTI, NORTHERN TELECOM
              COMPANIES, MANUFACTURING LICENSEES and/or AUTHORIZED DISTRIBUTORS
              under Section 15.2 for infringement, or claims thereof, that are
              based upon the use of HARDWARE PRODUCTS in combination with
              hardware and/or software furnished to NTI or a NORTHERN TELECOM
              COMPANY or a MANUFACTURING LICENSEE or an AUTHORIZED DISTRIBUTOR
              by a third party if such infringement, or claim thereof, would
              have been avoided by the use of HARDWARE PRODUCTS in combination
              with different hardware and/or software or, to the extent such use
              is possible, use of the HARDWARE PRODUCTS without any combination,
              or (ii) the modification of the HARDWARE PRODUCTS by NTI, a
              NORTHERN TELECOM COMPANY, a MANUFACTURING LICENSEE, an AUTHORIZED
              DISTRIBUTOR or an end-user customer of any of the foregoing if
              such infringement and/or misappropriation, or claim thereof, would
              have been avoided by using the HARDWARE PRODUCTS in its unmodified
              or unenhanced form.

15.3  SECTION 15.1 THROUGH SUBSECTION 15.2.1 INCLUSIVE STATE THE ENTIRE AND SOLE
      LIABILITY OF VOICETEK TO NTI AND OF NTI TO VOICETEK WITH RESPECT TO
      INFRINGEMENT AND/OR MISAPPROPRIATION OF INTELLECTUAL PROPERTY RIGHTS
      PURSUANT TO THIS AGREEMENT.

15.4  The indemnity obligations set forth in Section 15.1 through Subsection
      15.2.1, inclusive, of the AGREEMENT shall survive the termination or
      expiration of the AGREEMENT.

                ARTICLE XVI - LIMITATION OF LIABILITY AND DAMAGES

16.1  EXCEPT AS PROVIDED IN ARTICLE II AND ARTICLE XV, RESPECTIVELY, IN NO EVENT
      WILL EITHER PARTY BE LIABLE TO THE OTHER FOR ANY SPECIAL, INDIRECT,
      INCIDENTAL OR CONSEQUENTIAL DAMAGE OR LOSS OF ANY NATURE (e.g., DAMAGE TO
      PROPERTY, LOSS OF PROFITS, BUSINESS INTERRUPTION, LOST SAVINGS, LOSS OF
      USE, LOST OR DAMAGED FILES OR DATA, INJURY TO PERSON, OR ANY CLAIMS OF
      THOSE NOT A PARTY TO THE AGREEMENT) WHICH MAY ARISE IN CONNECTION WITH THE
      USE, ADAPTATION, MERGER, INCORPORATION, DISTRIBUTION, INSTALLATION,
      REMOVAL OR SUPPORT OF STANDARD PRODUCTS AND/OR MODIFIED PRODUCTS
      (SEPARATELY OR IN COMBINATION WITH OTHER HARDWARE OR SOFTWARE NOT PROVIDED
      BY VOICETEK) BY NTI, NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES
      AND AUTHORIZED DISTRIBUTORS PURSUANT TO THE AGREEMENT, REGARDLESS OF
      WHETHER SUCH CLAIMS ARE BASED OR REMEDIES ARE SOUGHT IN WARRANTY,
      CONTRACT, NEGLIGENCE, STRICT TORT, PRODUCTS LIABILITY OR OTHERWISE, EVEN
      IF THE PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE OR LOSS.
      EXCEPT AS PROVIDED IN ARTICLE II AND ARTICLE XV, RESPECTIVELY, THE MAXIMUM
      LIABILITY FOR ANY BREACH OF THE AGREEMENT BY EITHER PARTY SHALL IN NO
      EVENT EXCEED THE SUM OF ONE MILLION DOLLARS ($1,000,000.00) OR THE
      AGGREGATE AMOUNT OF PRICES AND/OR LICENSE FEES PAID UNDER THE AGREEMENT
      OVER THE IMMEDIATELY PRECEDING FOUR CONSECUTIVE QUARTERS, WHICHEVER IS
      GREATER.

                      ARTICLE XVII - REGULATORY COMPLIANCE

17.1  To the extent applicable, and unless otherwise provided in Schedule B
      and/or Schedule D and/or Schedule E, all HARDWARE PRODUCTS delivered to
      NTI or a NORTHERN TELECOM COMPANY by VOICETEK under the AGREEMENT shall :

      (a)   be approved and listed by Underwriter's Laboratories ("U.L.") and
            bear appropriate U.L. approval labeling;


                                                                         PAGE 23
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      (b)  be approved and listed by the Canadian Standards Association
           ("C.S.A.") and bear appropriate C.S.A. approval labeling;

      (c)  be verified, accepted, approved and in compliance with Class A
           limits, as applicable, under Part 15 of the Regulations of the U.S.
           Federal Communications Commission and bear the appropriate labels and
           warning notices as required;

      (d)  be verified, accepted, approved and in compliance with Part 68 of the
           Regulations of the U.S. Federal Communications Commission and bear
           the appropriate labels and warning notices as required;

      (e)  be verified, accepted, approved and in compliance with each of the
           following European Union (EU) regulatory requirements:

           (i)   EN 60 950                     Safety
           (ii)  EN 55 022       Class B       EMC
           (iii) EN 50 082-1                   EMC

      (f)  be verified, accepted, approved and in compliance with other EU
           regulatory requirements provided that NTI has requested VOICETEK to
           secure such compliance and has paid to VOICETEK the requisite fee
           specified in the applicable development agreement and applicable
           annexes and addenda thereto to cover (TUV) testing and administrative
           costs as agreed by NTI and VOICETEK thereunder.

17.2  To the extent applicable, all user manuals or other operator manuals
      and/or written material supplied with the HARDWARE PRODUCTS shall contain
      any warning notices required by any of the regulatory or testing bodies
      referenced in Section 17.1.

17.3  Upon the EFFECTIVE DATE, both parties acknowledge that if all approvals
      have not been issued by the appropriate agencies as defined in Section
      17.1 above, and in the event any of the agencies fail to certify such
      HARDWARE PRODUCTS within ninety (90) days of the EFFECTIVE DATE, provided
      any delay in approvals is attributable solely to VOICETEK's obligations
      hereunder and not delayed by the appropriate agencies or NTI, the
      AGREEMENT may be terminated at the option of NTI. VOICETEK agrees that it
      shall ship no HARDWARE PRODUCTS prior to issuance of the approvals as set
      forth in Section 17.1 without the prior written consent of NTI.

17.4  Subject to the terms of Subsection 17.4.1, VOICETEK agrees that any
      HARDWARE PRODUCTS shipped prior to securing all of the necessary
      certificates, as defined in Section 17.1 above, will be made to comply
      with those respective agency requirements. VOICETEK will bear any cost
      necessary to modify or update any STANDARD HARDWARE PRODUCTS delivered to
      meet those specifications relative to any HARDWARE delivered to NTI, a
      NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE. VOICETEK shall
      indemnify and hold NTI, NORTHERN TELECOM COMPANIES, MANUFACTURING
      LICENSEES and AUTHORIZED DISTRIBUTORS harmless from any and all claims,
      suits, or actions brought against NTI, NORTHERN TELECOM COMPANIES,
      MANUFACTURING LICENSEES, and/or AUTHORIZED DISTRIBUTORS by end-user
      customers for any damages, including reasonable and customary attorney's
      fees, for the failure of VOICETEK to obtain the necessary certificates, as
      defined in Section 17.1, prior to shipment of any STANDARD HARDWARE
      PRODUCTS.

      17.4.1  In the event of any shipment having been made at NTI's written
              request, as described in Section 17.3, NTI, NORTHERN TELECOM
              COMPANIES, MANUFACTURING LICENSEES, or AUTHORIZED DISTRIBUTORS
              shall indemnify and hold VOICETEK harmless from any and all
              claims, suits, or actions brought against NTI, NORTHERN TELECOM
              COMPANIES, MANUFACTURING LICENSEES, or AUTHORIZED DISTRIBUTORS by
              end-user customers, for any damages including reasonable and
              customary attorney's fees, for the failure of VOICETEK to obtain
              the necessary certificates as defined in Section 17.1, prior to
              the shipment of any STANDARD HARDWARE PRODUCTS.


                                                                         Page 24
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                     ARTICLE XVIII - DEFAULT AND TERMINATION

18.1 Any of the following shall constitute sufficient cause for a party to the
     AGREEMENT to seek the remedies available to a nondefaulting party, as
     provided in Sections 18.2 through 18.4:

     (a)  The failure of the other party to perform any material term, condition
          or covenant of the AGREEMENT, which shall constitute a default of the
          AGREEMENT, and such default has not been corrected within thirty (30)
          days of the date of receipt of written notice of such default given by
          the nondefaulting party;

     (b)  The other party is or becomes insolvent, or a party to any bankruptcy
          or receivership proceeding or any similar action affecting the
          financial condition of such other party, or seeks to make a
          compromise, arrangement or assignment for the benefit of its
          creditors, or ceases doing business in the normal course.

18.2  In the event any act of default constituting sufficient cause pursuant to
      either Section 18.1(a) or Section 18.1(b) shall occur, the party not in
      default shall have the right to and may elect any or all of the following
      remedies, which shall be cumulative and not exclusive:

      (a)  Declare the AGREEMENT to be immediately terminated;

      (b)  Pursue each and every remedy available at law and in equity.

18.3  In the event VOICETEK is the defaulting party pursuant to Section 18.1(b)
      above, NTI shall, in lieu of terminating the AGREEMENT, have the option of
      furnishing written notice to VOICETEK of NTI's intention to continue to
      perform the AGREEMENT under the following terms and conditions:

      (i)  Each end-user customer's rights, with respect to any and all copies
           of SOFTWARE PRODUCTS distributed directly or indirectly (through
           NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES or AUTHORIZED
           DISTRIBUTORS) to end-user customers, pursuant to the AGREEMENT, shall
           remain in full force and effect;

      (ii) With the exception of any SOURCE CODE MATERIALS not proprietary to
           VOICETEK (unless the required rights to such have been granted to
           VOICETEK by VOICETEK's suppliers), NTI shall have a right of access,
           by written notice given to VOICETEK, to gain possession of the source
           code form of the SOFTWARE PRODUCTS and the remaining SOURCE CODE
           MATERIALS and make use of them free of charge solely for the purposes
           of directly granting rights to use copies of SOFTWARE PRODUCTS
           incorporated into HARDWARE PRODUCTS to customers and for support
           activities. Upon receipt of written notice, VOICETEK or its trustee
           or receiver in bankruptcy, as the case may be, shall immediately and
           forthwith deliver SOURCE CODE MATERIALS, including specifically the
           source code form of SOFTWARE PRODUCTS, to NTI. NTI shall have the
           right to use, make bug fixes in and recompile the source code form of
           SOFTWARE PRODUCTS and the right to distribute object code copies of
           SOFTWARE PRODUCTS to customers in the AUTHORIZED TERRITORY, either
           directly or through NORTHERN TELECOM COMPANIES, MANUFACTURING
           LICENSEES and AUTHORIZED DISTRIBUTORS, provided NTI pays to VOICETEK
           right-to-use fees for such SOFTWARE PRODUCTS at the prices set forth
           in Schedule B or Schedule E, subject to application of the applicable
           discount levels set forth in Schedule H. VOICETEK hereby agrees and
           acknowledges that either the failure of VOICETEK or its trustee or
           receiver in bankruptcy to deliver all SOURCE CODE MATERIALS,
           including specifically the source code form of SOFTWARE PRODUCTS
           hereunder or, in the event SOURCE CODE MATERIALS for SOFTWARE
           PRODUCTS are deposited in escrow, affirmative actions or omissions by
           VOICETEK in any way hindering the release of SOURCE CODE MATERIALS
           from escrow will cause irreparable harm to NTI for which there is no
           adequate remedy at law and, therefore, NTI shall be entitled to
           specific performance of such delivery obligation and, in addition,
           and without being an election of remedies, NTI may pursue each and
           every remedy available at law or in equity;


                                                                         Page 25
   24
      (iii) In the event VOICETEK's Section 18.1(b) default is resolved in such
            a way that VOICETEK resumes its operations as they pertain to NTI in
            a manner substantially equivalent to its operations prior to the
            occurrence of such default, NTI shall promptly return the source
            code form of SOFTWARE PRODUCTS and the other SOURCE CODE MATERIALS
            made available to NTI by VOICETEK solely pursuant to Section
            18.2(b), Section 18.3(ii) and/or Section 19.2, but not otherwise.

18.4  In the event the AGREEMENT is terminated by VOICETEK for default by NTI,
      VOICETEK shall permit NTI to retain limited rights to use the SOFTWARE
      PRODUCTS thereafter for up to one (1) year following the date of
      termination of the AGREEMENT by VOICETEK in order to allow NTI to satisfy
      its then existing contractual obligations for support for SOFTWARE
      PRODUCTS to NORTHERN TELECOM COMPANIES, MANUFACTURING LICENSEES,
      AUTHORIZED DISTRIBUTORS and end-user customers. Exceptions to VOICETEK's
      obligation to permit NTI to continue to exercise such limited rights shall
      include the case where such default by NTI relates to the payment of
      applicable prices or license fees, as set forth in Sections 8.1 through
      8.8 inclusive, which are not reasonably in dispute, or any obligation that
      would unreasonably jeopardize VOICETEK's intellectual property rights in
      one or more SOFTWARE PRODUCTS or VOICETEK's confidential information in
      which event only the SOFTWARE PRODUCTS to which intellectual property
      rights in jeopardy and/or VOICETEK's confidential information pertain
      would not be subject to the continued exercise of limited rights by NTI.
      The limited rights to use the SOFTWARE PRODUCTS, as provided in this
      Section 18.4, shall survive the termination or expiration of the AGREEMENT
      for up to one (1) year.


18.5  Subject to the provisions of Section 18.3 and Section 18.4, respectively,
      it is understood that, upon termination of the AGREEMENT, NTI shall,
      within thirty (30) days following such termination, destroy its copies of
      the SOFTWARE PRODUCTS and any whole or partial reproductions thereof in
      any form, and all materials related to the SOFTWARE PRODUCTS which are
      still under the control of NTI, and so certify in writing to VOICETEK,
      except that NTI may retain a sufficient number of copies of such SOFTWARE
      PRODUCTS as is reasonably necessary for NTI to fulfill its contractual
      obligations, as set forth in Section 18.4.

                     ARTICLE XIX - SOURCE CODE ESCROW OPTION

19.1  NTI shall, in its sole discretion, have the option to require that the
      SOURCE CODE MATERIALS (excluding those not proprietary to VOICETEK unless
      the right to deposit them in escrow has been granted to VOICETEK by
      VOICETEK's suppliers) for any or all SOFTWARE PRODUCTS be deposited in
      escrow. If requested by NTI, the parties shall, in good faith, negotiate
      the selection of a fair, impartial and competent escrow agent and deposit
      the SOURCE CODE MATERIALS for any or all SOFTWARE PRODUCTS in escrow for
      the benefit of NTI or, if such SOURCE CODE MATERIALS were previously
      deposited by VOICETEK, designate NTI as a registered beneficiary. The
      express purpose for depositing the SOURCE CODE MATERIALS in escrow or
      designating NTI as a registered beneficiary, as the case may be, shall be
      to secure a means of access to all materials reasonably necessary or
      useful in enabling NTI to maintain, modify, enhance and/or support the
      SOFTWARE PRODUCTS in order to maintain the functionality of the SOFTWARE
      PRODUCTS with limited assistance or without assistance from VOICETEK. In
      any event, NTI shall pay the costs and expenses assessed for the deposit
      of any SOURCE CODE MATERIALS not proprietary to VOICETEK into escrow. In
      no event shall NTI be required to pay more than the proportionate costs
      and expenses attributable to the deposit of VOICETEK's proprietary SOURCE
      CODE MATERIALS into escrow, if all or any portion of VOICETEK's
      proprietary SOURCE CODE MATERIALS have been, or during the TERM are,
      deposited into escrow at the request of and for the benefit of any third
      party.

19.2  In the event VOICETEK is or becomes insolvent, or a party to any
      bankruptcy or receivership proceeding or any similar action affecting the
      financial condition of VOICETEK, or seeks to make a compromise,
      arrangement or assignment for the benefit of its creditors, or ceases
      doing business in the normal course, and NTI provides written notice to
      VOICETEK, as required by Section 18.3(ii), NTI shall be given access to
      and rights to use the SOURCE CODE MATERIALS held in escrow, beginning ten
      (10) days after receipt by VOICETEK of NTI's written notice demanding
      access to such SOURCE CODE MATERIALS.


                                                                         Page 26
   25
                           ARTICLE XX - FORCE MAJEURE

20.1  If the performance of the AGREEMENT (including, without limitation, any
      deliveries hereunder) is interfered with by reason of any circumstance
      beyond the reasonable control of the party affected including, without
      limitation, fire, act of God, labor unrest, and discontinuance of
      manufacture of sole-sourced components, then the party affected shall be
      excused from such performance on a day-for-day basis to the extent of such
      interference (and the other party shall likewise be excused from
      performance on a day-for-day basis to the extent such party's obligations
      relate to the performance so interfered with; provided that the party so
      affected shall use reasonable efforts to remove such causes of
      nonperformance.

                          ARTICLE XXI - CONFIDENTIALITY

21.1  Any information designated as "Confidential", "Restricted" or 
      "Proprietary" in writing by the disclosing party prior to disclosure shall
      be considered confidential information under the AGREEMENT. In the case of
      any oral disclosure of confidential information, such information shall be
      treated as confidential if the disclosing party (a) states that such
      information is confidential at the time of disclosure, and (b) summarizes
      such information in a writing setting forth the date, nature and extent of
      the oral disclosure and indicating the same to be confidential, and
      delivers such written summary to the other party within thirty (30) days
      after the date of such oral disclosure.

21.2  The parties shall use reasonable efforts and at least the same care that
      each uses to protect its own confidential information of like importance,
      to prevent unauthorized dissemination or disclosure of the other party's
      confidential information during and for three (3) years following the last
      day of the TERM.

21.3  The confidentiality obligations set forth in this Article XXI will not
      apply to any information that:

      (a)   becomes known to the general public without fault or breach on
            the part of the receiving party;

      (b)   either party, disclosing its own confidential information,
            customarily provided to others without restriction on disclosure;

      (c)   the receiving party obtains from a third party without breach of
            a nondisclosure obligation and without restriction on disclosure;

      (d)   is furnished to a third party by the disclosing party without a
            similar restriction on such third party's rights;

      (e)   can by written records be shown to have been known by the
            receiving party at the time of disclosure;

      (f)   can by written records be shown to have been developed independently
            by the receiving party without using any information as defined in
            Section 21.1 which is received from the disclosing party.

21.4  The parties agree and acknowledge that any confidential and proprietary
      information of the other party in its possession shall, upon termination
      of the AGREEMENT and upon the request of the other party, be returned to
      the disclosing party.

21.5  Neither party shall publicly disclose any information regarding the terms
      and conditions contained herein without having received prior approval, in
      writing, from the other party.

21.6  NTI agrees not to (a) attempt to reverse engineer, decompile, or reverse
      assemble the SOFTWARE PRODUCTS, or create or attempt to create any
      derivative work of the SOFTWARE PRODUCTS, nor (b) directly or indirectly,
      through a third party, use the SOFTWARE PRODUCTS, or a derivative thereof,
      or any confidential or proprietary information of VOICETEK to create any
      computer software program or documentation which is functionally,
      visually, or otherwise


                                                                         Page 27
   26
      substantially similar to any SOFTWARE PRODUCT, whether or not such
      SOFTWARE PRODUCT is then available for license or sale by VOICETEK.

                       ARTICLE XXII - LAWS AND REGULATIONS

22.1  At no additional charge to NTI, VOICETEK shall comply with and obtain all
      licenses and permits required by, and PRODUCTS shall be in conformance
      with, all applicable laws and governmental orders and regulations in
      effect at the time of shipment of PRODUCTS including without limitation
      the following United States laws and regulations:

            Comprehensive Environmental Response, Compensation and Liability Act
            of 1980, Consumer Product Safety Act, Toxic Substances Control Act,
            Occupational Safety and Health Act of 1970, Radiation Control for
            Health and Safety Act of 1968, Resource Conservation and Recovery
            Act of 1976, Clean Air Act, Clean Water Act, Hazardous Materials
            Transportation Act, Vietnam Era Veterans Readjustment Assistance Act
            of 1972, Rehabilitation Act of 1973 and the clauses set forth in
            Federal Acquisition Regulations (subject to "Contractor,"
            "Subcontractor" and "Contract' used in such clauses meaning NTI,
            VOICETEK and AGREEMENT, respectively) 52.219-8, 52.219-9, 52.219-13,
            52.220-3, 52.220-4, 52.222-1, 52.222-4, 52.222-20, 52.222-21,
            52.222-26 (subparagraphs b(l) - b(11), 52.222-35 and 52.222-36,
            which clauses are incorporated by reference, with the same force and
            effect as it they were given in full text.

                            ARTICLE XXIII - INSURANCE

23.1  VOICETEK shall maintain during its performance under the AGREEMENT General
      Liability Insurance, including contractual, products liability and broad
      form vendors' property damage endorsement with the limits of either
      $5,000,000.00 combined single limit per occurrence for bodily injury and
      property damage or $3,000,000.00 bodily injury per occurrence and
      $2,000,000.00 property damage per occurrence.

23.2  Insurance requirements stated in Section 23.1 shall be primary and
      noncontributory with respect to any insurance which NTI may have, and NTI
      shall under such insurance be named as an additional insured with a
      cross-liability endorsement. Prior to the commencement of the TERM,
      VOICETEK shall furnish to NTI a certificate of insurance evidencing that
      such insurance is in effect. The certificate shall also state that NTI
      shall be notified by VOICETEK's insurance carrier(s) within thirty (30)
      days of any cancellation, material change or exhaustion of the
      aforementioned limits. VOICETEK shall in such event furnish a new
      certificate in the event of cancellation or expiration of any insurance.

                 ARTICLE XXIV - EXPORTERS CERTIFICATE OF ORIGIN

24.1  With the assistance of NTI, VOICETEK shall initially provide and update,
      as necessary, any certificates as may be required for any PRODUCTS which
      qualify under the North American Free Trade Agreement between the United
      States, Canada, and Mexico, or to any other Free Trade Agreements of which
      the United States is or may become a party.

                      ARTICLE XXV - INDEPENDENT CONTRACTORS

25.1  VOICETEK and NTI are independent contractors in all relationships and
      actions under and contemplated by the AGREEMENT. The AGREEMENT is not to
      be construed to create, or to authorize the creation of, any employment,
      partnership, or agency relation or to authorize NTI or any NORTHERN
      TELECOM COMPANIES, MANUFACTURING LICENSEES or AUTHORIZED DISTRIBUTORS to
      enter into any commitment or agreement binding on VOICETEK or to allow one
      party to accept service of any legal process addressed to, or intended
      for, the other party. NTI and the NORTHERN TELECOM COMPANIES,
      MANUFACTURING LICENSEES and AUTHORIZED DISTRIBUTORS shall not make any
      warranties, guarantees or any other commitments on behalf of VOICETEK
      pursuant to the AGREEMENT.


                                                                         Page 28
   27
                       ARTICLE XXVI - NOTICES AND REQUESTS

26.1  All official or formal notices required or otherwise provided under the
      AGREEMENT shall be sent by certified or registered mail (return receipt
      requested), postage prepaid, or by cable, telegram, facsimile, telex or
      hand delivery to the other party at the address listed below for the other
      party and addressed as follows:

            NTI: NORTHERN TELECOM INC.
                 2305 Mission College Boulevard
                 Santa Clara, California 95054-1591

                 Attention:  Manager, Technology Acquisition
                             Dept. 0521

      VOICETEK:  VOICETEK CORPORATION
                 19 Alpha Road
                 Chelmsford, Massachusetts 01824-4175

                 Attention:  Contracts Manager

      or to such other address as the party to receive the notice so designates
      by written notice to the other party.

26.2  All other written communications required or otherwise provided hereunder
      by one party to the other shall be mailed by First Class Mail, postage
      prepaid, to the following addresses or to such changed address as either
      party entitled to notice hereunder shall have communicated in writing to
      the other party:

            NTI: NORTHERN TELECOM INC.
                 2305 Mission College Boulevard
                 Santa Clara, California 95054-1591

                 Attention:  Art Hazeldine
                             Dept. 0521

      VOICETEK:  VOICETEK CORPORATION
                 19 Alpha Road
                 Chelmsford, Massachusetts 01824-4175

                 Attention:  Contracts Manager

26.3  Except in the case of notices sent by certified or registered mail (return
      receipt requested), notices given pursuant to Article XXVI shall be deemed
      to have been received five (5) days after mailing if given by First Class
      Mail, and one (1) business day after sending if given by cable, telegram,
      facsimile, telex and upon delivery if given by hand.

                             ARTICLE XXVII - GENERAL

27.1  The interpretation of the AGREEMENT and the rights and obligations of the
      parties shall be governed by the laws of the State of California, except
      as to patent, copyright and trademark matters, which are governed by
      federal law. The parties agree that Santa Clara, California, is both the
      place of making and the place of performance of the AGREEMENT for all
      purposes.

27.2  The AGREEMENT, including all applicable Schedules constitutes the entire
      agreement between the parties and supersedes any and all prior or
      contemporaneous oral and written communications, understandings or
      agreements relating to the subject matter hereof. Any amendments, or
      alternative or supplementary provisions, must be made in writing and be
      duly executed by an authorized representative or agent of each of the
      parties hereto. The provisions of the Software License and Distribution
      Agreement dated 31 July 1992 shall not be superseded


                                                                         Page 29
   28
      in any respect by the AGREEMENT. The parties hereby agree that a
      resolution to any and all unfulfilled obligations of the parties, as set
      forth in Technology Development Agreement 2 between them, shall be
      mutually agreed upon, with the results being set forth in a Master
      Technology Development Agreement and Annexes applicable to specific
      projects, which is to be executed by NTI and VOICETEK.

27.3  The AGREEMENT shall inure to the benefit of and be binding upon the
      respective successors and assigns, if any, of the parties hereto.

27.4  The invalidity of any provision of the AGREEMENT shall not affect the
      validity of any other provision thereof.

27.5  Neither party shall, in any advertising, sales promotion materials, press
      releases or any other publicity matters use the name of the other party,
      any subsidiary or affiliate of the other party or any variation of the
      foregoing or language from which the connection of said names may be
      implied without such other party's prior written approval.

27.6  The AGREEMENT may be executed in one or more counterparts, each of which
      shall constitute one and the same instrument.

27.7  Neither party shall assign the AGREEMENT or any rights received hereunder
      without the prior written consent of the other party. Notwithstanding the
      foregoing, either party may assign the AGREEMENT or any rights received
      hereunder to a subsidiary or affiliate in which it owns at least a
      majority interest or to an affiliate that owns a majority interest in such
      party without such prior written consent, but upon notice to the other
      party. In addition, VOICETEK may assign the AGREEMENT or any rights
      received hereunder to its successor in interest by virtue of a merger or
      corporate reorganization or to the purchaser of substantially all of
      VOICETEK's assets, without prior written consent, but upon notice to NTI.
      In the event VOICETEK should merge with, or be acquired by, or sell
      substantially all its assets to, a direct competitor of NTI, NTI may
      terminate the AGREEMENT, subject only to the obligations set forth in
      those provisions of the AGREEMENT which, by their terms or clear intent,
      survive termination hereof.

27.8  No provision of the AGREEMENT shall be deemed waived, amended or modified
      by either party, unless such waiver, amendment or modification be in
      writing and signed by the party against whom enforcement of the waiver,
      amendment or modification is sought. Any such amendment or modification
      shall be binding with or without tender of any consideration.

27.9  The headings used herein are for convenience only and shall not be deemed
      to be part of the AGREEMENT or used to construe or interpret any of the
      provisions hereof.

27.10 Each party to the AGREEMENT hereby represents to the other that it has
      full power and authority to enter into and perform the AGREEMENT and that
      the person signing the AGREEMENT on its behalf has been properly
      authorized and empowered to do so. Each party further acknowledges that it
      has read the AGREEMENT, that it understands the terms and conditions
      hereof, and that it agrees to be bound by the AGREEMENT.

IN WITNESS WHEREOF, the parties hereto have, by their duly authorized
representatives, executed the AGREEMENT as of the day and year of the latter
signature set forth below.


                                                                         Page 30
   29
    NORTHERN TELECOM INC.                     VOICETEK CORPORATION

    By: /s/J. Michael Camp                    By: /s/Roger Tuttle
       _______________________________           _______________________________

    Name:  J. Michael Camp                    Name:  Roger Tuttle
         _____________________________             _____________________________
           (type/print)                                (type/print)

    Title: Vice President                     Title:  V.P. Finance
          ____________________________              ____________________________
           (type/print)                                (type/print)

    Date:  6/16/95                           Date:   16 JUNE  1995
         _____________________________            ______________________________

- ------------------------
|     APPROVED AS      |
|    TO LEGAL FORM     |
|--------------------- |
| BY: Joel M. Erickson |
- ------------------------
    15 JUNE 1995


                                                                         Page 31
   30
                                   SCHEDULE A
                              AUTHORIZED TERRITORY

    Canada                                   United States (U.S.)








    NORTHERN TELECOM INC.                    VOICETEK CORPORATION

    BY: /s/J. Michael Camp                   By:  /s/Roger Tuttle
       ____________________________             ________________________________

    Name:  J. Michael Camp                   Name:   Roger Tuttle
         __________________________               ______________________________
            (type/print)                             (type/print)

    Title: Vice President                    Title:  V.P. Finance
          _________________________                _____________________________
            (type/print)                             (type/print)

    Date:  6/16/95                           Date:   16 June  1995
         __________________________               ______________________________


- ------------------------
|     APPROVED AS      |
|    TO LEGAL FORM     |
|--------------------- |
| BY: Joel M. Erickson |
- ------------------------
    15 JUNE 1995


                                                                         Page 32
   31
                                   SCHEDULE B
                                   PRICE LIST


                                                                         PAGE 33
   32
                                   SCHEDULE C
                                      MARKS

                                   Voicetek(R)
                                     VTK(R)
                                 Generations(TM)



                                                                         Page 34
   33
                                  SCHEDULE D

                             INTERNAL USE PRICING

Under the terms of the AGREEMENT, NTI, NORTHERN TELECOM COMPANIES and
MANUFACTURING LICENSEES may purchase SYSTEMS to be used internally at the prices
enumerated in Schedule B and/or Schedule E, as qualified by the applicable
discount level set forth in Schedule 1. The prices for SYSTEMS for NTI's
internal use will include:

         -   VTK-Base System with twelve (12) ports Loopstart eight (8) ports
             ISDN/BRI, or twenty-four (24) ports T1 and forty (40) hours of 
             voice storage 
         -   GENERATIONS Development/Runtime Licenses 
         -   All optional software features enabled 
         -   Full set of USER DOCUMENTATION (including all optional features 
             USER DOCUMENTATION)
         -   Warranties as provided by VOICETEK under the AGREEMENT



Under the terms of the AGREEMENT, NTI, NORTHERN TELECOM COMPANIES and
MANUFACTURING LICENSEES may purchase GENERATIONS Development licenses for
SELF-HOSTED UNITS to be used internally at the prices set forth in Schedule B
and/or Schedule E, as qualified by the applicable discount level set forth in
Schedule 1. The price for the GENERATIONS Development license intended for use
with SELF-HOSTED UNITS to be used internally will include:

         -   GENERATIONS Development License;

         -   All Optional software features enabled; and

         -   Warranties as provided by VOICETEK under the AGREEMENT.


                                                                         Page 35
   34
                                   SCHEDULE E

                                   * PRICING



                              Order Code        Product Description                   Price

                                                                               
                              PT-04-ESC         D-41ESC 4-Port Assembly              $ *

                              PT-12-LS          Loopstart 12-Port Assembly           $ *

                              PT-08-BRI         BRI8-Port Assembly                   $ *

                              VR-02-VCS         Continuous ASR                       $ *
                                                (2-Port Assembly)

                              VR-02-VCSE        Continuous ASR Expansion             $ *
                                                (2-Port Expansion)

                              PT-24-T1          T1 24-Port Assembly                  $ *

                              PT-30-E1          E1 30-Port Assembly                  $ *

                              PT-60-E1          E1 60-Port Assembly                  $ *

                              PT-04-NS          D41 Northstar Assembly               $ *

                              TSP-SW            TSP Runtime License                  $ *

                              TTS-04-LH         TTS 4-Port Assembly                  $ *
                                                (HW & SW)

                              TTS-04-LE         TTS 4-Port Expansion                 $ *
                                                (SW only)

                              VR-04-VCS-D       Discrete ASR 4-Port Expansion        $ *
                                                (HW & SW)

                              HL-5250-HW-S      5250 Synchronous I/F                 $ *
                                                (SSI HW & SW)

                              HL-5250-HW-TR     5250 Token Ring I/F                  $ *
                                                (SSI HW & SW)

                              HL-3270-HW-S      3270 Synchronous I/F                 $ *
                                                (SSI HW & SW)

                              HL-3270-HW-TR     3270 Token Ring I/F                  $ *
                                                (SSI HW & SW)

                              HL-5250-SW        TRS 5250 Software                    $ *

                              HL-3270-SW        TRS 3270 Software                    $ *

                              HL-VT100-SW       TRS VT100 Software                   $ *

                              RED-AP-SW         Redundant AP Software                $ *



     CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES
              AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.



                                                                         Page 36
   35
                                   SCHEDULE E

                                   * PRICING
                                   (Continued)



                              Order Code        Product Description             Price


                                                                          
                              RW-OPT            Report Writer Software          *
                                                (Customized Version)

                              PBX-RM            Rolm ACD I/F                    *

                              PBX-NT            Ml ACD I/F                      *

                              PBX-C1            Customized PBX I/F              *

                              VR-04-VCS-DSO     Discrete ASR SW Only            *
                                                                                            

                              TTS-04-LHSO       TTS Software Only               *          
                                                                                            

                              FAX-02-BTSO       Fax SW Only                     *        
                                                                                             

                              RM-CAB-01         Rack Cabinet                    *           

                              PT-12-DID         12-Port Assembly                *         
                                                (D(D)

                              TBD               SMDI Software                   *     

                              TBD               UPS Software Support            *     


                              N                 Non-discountable



CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND 
EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.

                                                                         Page 37
   36


                                                                         Page 38
   37
                                  SCHEDULE G
                       REPRODUCTION SERVICES AGREEMENT

THIS REPRODUCTION SERVICES AGREEMENT (hereinafter 'Agreement") is made and
executed by and between                                                  ,
a                      corporation
with offices at                                    (hereinafter "CONTRACTOR")
                                                   and
N0RTHERN TELEC0M INC., a Delaware corporation with offices at
                                                   (hereinafter "NTI") this _
day of 199___.

                                   RECITALS

WHEREAS, NTI requires the services of a contractor to perform certain
reproduction tasks involving computer programs, user documentation and technical
documentation, among other things;

AND WHEREAS, CONTRACTOR is in the business of providing services such as volume
reproduction of an assortment of items, including computer programs and written
materials of various kinds;

NOW THEREFORE, in consideration of the mutual terms and conditions hereinafter
set forth, and for other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, THE PARTIES HERETO AGREE AS
FOLLOWS:

                             ARTICLE I - DEFINITIONS

1.1   "CAMERA-READY COPY" or "CAMERA-READY COPIES" shall mean a professional
      quality reproducible master copy of a WORK OF AUTHORSHIP other than a
      COMPUTER PROGRAM.

1.2   "COMPUTER PROGRAM" or "COMPUTER PROGRAMS" shall mean a set of statements
      or instructions to be used directly or indirectly in a computer in order
      to bring about a certain result.

1.3   "REPRODUCIBLE MASTER" or "REPRODUCIBLE MASTERS" shall mean a reproducible
      master copy of a COMPUTER PROGRAM.

1.4   "WORK OF AUTHORSHIP" or "WORKS OF AUTHORSHIP" shall mean works expressed
      in words, numbers, or other verbal or numerical symbols or indicia,
      regardless of the nature of the material objects, such as books,
      periodicals, manuscripts, tapes, disks, or cards in which they are
      embodied.

                 ARTICLE II - NTI WARRANTIES AND REPRESENTATIONS

2.1   NTI warrants and represents that, as of the date of delivery of a
      REPRODUCIBLE MASTER and/or a CAMERA-READY COPY by NTI to CONTRACTOR
      hereunder, the COMPUTER PROGRAM embodied in such REPRODUCIBLE MASTER
      and/or the WORK OF AUTHORSHIP embodied in such CAMERA-READY COPY is/are
      not known by NTI to be the subject of any claims of infringement of any
      patent, trademark, copyright and/or trade dress or of any claims of
      misappropriation of any trade secret of any third party. NTI warrants and
      represents that, to the best of its knowledge, NTI either owns or
      otherwise has been granted the necessary rights to authorize and/or grant
      all necessary rights to make reproductions of each REPRODUCIBLE MASTER
      and/or CAMERA-READY COPY provided to CONTRACTOR hereunder.

                          ARTICLE III - GRANT OF RIGHTS

3.1   In accordance with and subject to the terms and conditions of this
      Agreement, NTI hereby grants to CONTRACTOR a personal, nonexclusive,
      nontransferable license:

      (a)   to make copies from each REPRODUCIBLE MASTER delivered by NTI to
            CONTRACTOR for such purpose.


                                                                         Page 40
   38
      (b)  to make copies from each CAMERA-READY COPY delivered by NTI to
           CONTRACTOR for such purpose.

                          ARTICLE IV - DELIVERABLES

4.1  NTI shall deliver purchase orders to CONTRACTOR either accompanied by the
     REPRODUCIBLE MASTER and/or CAMERA-READY COPY of which copies are being
     ordered or referencing the appropriate REPRODUCIBLE MASTER and/or CAM-
     ERA-READY COPY already in the custody of the CONTRACTOR to the following
     address:

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


                           ARTICLE V - PRICE; PAYMENT

5.1  Upon the latter of the actual date of delivery of copies of COMPUTER
     PROGRAMS and/or WORKS OF AUTHORSHIP to NTI and the date of receipt of the
     invoice therefor by NTI, payment for such copies shall be due and payable
     by NTI to CONTRACTOR within forty-five (45) days. NTI shall make its
     payments to CONTRACTOR as provided herein, in lawful United States currency
     at the registered office of CONTRACTOR in                                 .

            ARTICLE VI - DISCLAIMER OF WARRANTY AND LIMITED WARRANTY

6.1   THE REPRODUCIBLE MASTERS AND/OR CAMERA-READY COPIES ARE PROVIDED "AS IS"
      WITHOUT WARRANTY OF ANY KIND BY NTI TO CONTRACTOR IN THE FIRST INSTANCE
      AND BY CONTRACTOR TO NTI DURING THE RETURN OF SUCH REPRODUCIBLE MASTERS
      AND/OR CAMERA-READY COPIES. NEITHER PARTY WARRANTS, GUARANTEES, OR MAKES
      ANY REPRESENTATIONS TO THE OTHER REGARDING THE USE, OR THE RESULTS OF THE
      USE, OF THE REPRODUCIBLE MASTERS AND/OR CAMERA-READY COPIES IN TERMS OF
      CORRECTNESS, ACCURACY, RELIABILITY, CURRENTNESS OR OTHERWISE.

6.2   THE ENTIRE RISK AS TO COST OF ALL REPAIR AND/OR CORRECTION OF DEFECTIVE
      COPIES OF COMPUTER PROGRAMS AND/OR WORKS OF AUTHORSHIP ASSUMED HEREUNDER
      SHALL BE ALLOCATED TO NTI IF IT CAN BE ESTABLISHED THAT THE REPRODUCIBLE
      MASTER AND/OR CAMERA-READY COPY WAS DEFECTIVE AT THE TIME OF ITS DELIVERY
      TO CONTRACTOR. THE ENTIRE RISK AS TO COST OF ALL REPAIR AND/OR CORRECTION
      OF DEFECTIVE COPIES OF COMPUTER PROGRAMS AND/OR WORKS OF AUTHORSHIP
      ASSUMED HEREUNDER SHALL BE ALLOCATED TO CONTRACTOR IF IT CAN BE
      ESTABLISHED THAT THE REPRODUCIBLE MASTER AND/OR THE CAMERA-READY COPY WAS
      NOT DEFECTIVE AS OF THE DATE OF ITS DELIVERY BY NTI TO CONTRACTOR PURSUANT
      TO SECTION 4.1 OF THIS AGREEMENT.

6.3   CONTRACTOR warrants to NTI that each unit of storage media on which a copy
      of a COMPUTER PROGRAM is recorded is free from defects in materials and
      workmanship under normal use and service for a period of ninety (90) days
      from the date of delivery of such unit of storage media to NTI, as
      evidenced by a copy of the packing slip. Further, CONTRACTOR hereby limits
      the duration of any implied warranty on each unit of storage media to the
      period stated above.

6.4   In the case where risk as to cost of all repair and/or correction of
      defective copies of COMPUTER PROGRAMS is allocated to CONTRACTOR under
      Section 6.2 of this Agreement, CONTRACTOR's entire liability and NTI's
      exclusive remedy as to the units of storage media shall be replacement of
      the units of storage media that do not meet CONTRACTOR's Limited Warranty
      as set forth in Section 6.3 and which are returned to CONTRACTOR. If
      failure of a unit of storage media has resulted from accident, abuse, or
      misapplication, CONTRACTOR shall have no responsibility to replace such
      unit of storage media. Any replacement unit of storage media will be
      warranted for the remainder of the original warranty period or thirty (30)
      days, whichever is longer.


                                                                         Page 41
   39
6.5   EXCEPT AS SET FORTH IN ARTICLE II OF THIS AGREEMENT, THE ABOVE ARE THE
      ONLY WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT
      LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
      PARTICULAR PURPOSE, THAT ARE MADE BY CONTRACTOR TO NTI AND BY NTI TO
      CONTRACTOR PURSUANT TO THIS AGREEMENT.

              ARTICLE VII - ALLEGATION OF INFRINGEMENT; LITIGATION

7.1   In the event a COMPUTER PROGRAM embodied in a REPRODUCIBLE MASTER and/or
      a WORK OF AUTHORSHIP embodied in a CAMERA-READY COPY provided by NTI to
      CONTRACTOR for reproduction under this Agreement becomes the subject of
      claims of intellectual property infringement and/or infringement
      litigation, CONTRACTOR shall have the right to cease performance of its
      obligations pursuant to this Agreement, except with respect to
      CONTRACTOR's confidentiality obligations, declare this Agreement to be
      immediately terminated and return to NTI all REPRODUCIBLE MASTERS and all
      CAMERA-READY COPIES received from NTI together with any existing inventory
      of COMPUTER PROGRAMS and/or WORKS OF AUTHORSHIP already reproduced for NTI

                    ARTICLE VIII - LIMITATION OF LIABILITY

8.1   IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER FOR ANY INDIRECT,
      SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND WHATSOEVER
      ARISING OUT OF THIS AGREEMENT, EVEN IF SUCH PARTY HAS BEEN ADVISED OF THE
      POSSIBILITY OF SUCH DAMAGES.

                                ARTICLE IX - TERM

9.1   This Agreement shall become effective on the date of signature by the
      latter of the parties to sign, and extend for a period of five (5) years,
      unless earlier terminated pursuant to the terms of Section 10.1.

                           ARTICLE X - CONFIDENTIALITY

10.1  CONTRACTOR understands that the REPRODUCIBLE MASTERS and the CAMERA-READY
      COPIES supplied by NTI to CONTRACTOR pursuant to this Agreement contain
      proprietary information of NTI and/or NTI's suppliers, and that such
      REPRODUCIBLE MASTERS and CAMERA-READY COPIES are protected by copyright.
      CONTRACTOR agrees not to use, copy and/or distribute copies made from such
      REPRODUCIBLE MASTERS and/or CAMERA-READY COPIES other than as authorized
      to do so by NTI pursuant to this Agreement.

                         ARTICLE XI - MARKING; LABELING

11.1  CONTRACTOR agrees to affix, upon each copy of each COMPUTER PROGRAM made
      from a REPRODUCIBLE MASTER delivered by NTI, the appropriate label,
      including the copyright notice, which copyright notice and/or label either
      appears on the REPRODUCIBLE MASTER of such COMPUTER PROGRAM supplied by
      NTI to CONTRACTOR or is provided to CONTRACTOR along with instructions
      regarding placement by CONTRACTOR on all copies of such COMPUTER PROGRAM
      made by CONTRACTOR for NTI.

11.2  In connection with its handling and reproduction of the COMPUTER PROGRAMS
      and/or WORKS OF AUTHORSHIP supplied to CONTRACTOR by NTI pursuant to this
      Agreement, CONTRACTOR shall not alter or modify the copyright notice
      supplied by NTI for placement by CONTRACTOR on each copy of such COMPUTER
      PROGRAMS and/or WORKS OF AUTHORSHIP made by CONTRACTOR for NTI in
      accordance with the provisions of the U.S. Copyright Act, 17 U.S.C. 101,
      et. seq., specifically 17 U.S.C. 401 through 406.

              ARTICLE XII - OWNERSHIP OF TRADEMARKS AND COPYRIGHTS

12.1  CONTRACTOR hereby acknowledges and agrees that nothing herein gives
      CONTRACTOR any right, title or interest in the trademarks and/or
      copyrights of NTI and/or NTI's suppliers pertaining to


                                                                         Page 42
   40
      the REPRODUCIBLE MASTERS and/or CAMERA-READY COPIES supplied by NTI to
      CONTRACTOR, nor in any copies of the same made by CONTRACTOR at the
      direction of NTI. Upon termination of this Agreement by expiration or for
      any other reason, CONTRACTOR shall no longer use the trademarks and
      copyrights associated with the REPRODUCIBLE MASTERS and/or CAMERA-READY
      COPIES supplied by NTI to CONTRACTOR in the making of any copies the same
      or in any other manner. Except as set forth in Section 3.1 of this
      Agreement, no license or other grant is expressed or implied to CONTRACTOR
      to produce, reproduce, copy or in any other manner use the REPRODUCIBLE
      MASTERS and/or the CAMERA-READY COPIES supplied to CONTRACTOR by NTI
      pursuant to this Agreement.

                      ARTICLE XIII - INSPECTION; ACCEPTANCE

13.1 The acceptance by NTI of copies of COMPUTER PROGRAMS and/or WORKS OF
     AUTHORSHIP reproduced by CONTRACTOR is subject to inspection at the
     delivery location and such acceptance shall be deemed to occur ten (10)
     days after receipt of such copies at the delivery location unless NTI shall
     have provided CONTRACTOR with notice of nonacceptance within such period.
     If one or more copies do not conform to the requirements of a purchase
     order issued by NTI to CONTRACTOR or, in the case of COMPUTER PROGRAMS, to
     the warranty set forth in Section 6.3, the entire quantity of copies
     delivered with the defective copy or copies may be returned to CONTRACTOR
     at CONTRACTOR's expense.

                       ARTICLE XIV - TERMINATION; REMEDIES

14.1  Except as provided to the contrary in Section 7.1, in the event either
      party fails to perform any term, condition or covenant of this Agreement
      and such failure continues uncorrected for at least fifteen (15) days
      following the date of receipt by the nonperforming party of written notice
      of the specific failure to perform from the other party, the nonperforming
      party shall be deemed to be in default of this Agreement. Upon the
      occurrence of a default of this Agreement, the party not in default shall
      have the right to and may elect to declare this Agreement to be
      immediately terminated and/or pursue each and every available remedy at
      law and in equity.

14.2  CONTRACTOR acknowledges that the COMPUTER PROGRAMS and/or WORKS OF
      AUTHORSHIP provided by NTI to CONTRACTOR hereunder are the confidential
      and proprietary property of NTI and/or NTI's suppliers, that a violation
      in any material respect of Section 10.1, 11.1 and 11.2, respectively, of
      this Agreement by CONTRACTOR would cause NTI irreparable injury for which
      NTI would have no adequate remedy at law, and that NTI shall be entitled
      to preliminary and other injunctive relief against any such violation by
      CONTRACTOR. Such injunctive relief shall be in addition to, and in no way
      in limitation of, any and all other rights and remedies which NTI may have
      at law or in equity.

                      ARTICLE XV - INDEPENDENT CONTRACTORS

15.1  CONTRACTOR and NTI are independent contractors in all relationships and
      actions under and contemplated by this Agreement. This Agreement is not to
      be construed to create, or to authorize the creation of, any employment,
      partnership, or agency relation or to authorize CONTRACTOR to enter into
      any commitment or agreement binding on NTI or to allow one party to accept
      service of any legal process addressed to, or intended for, the other
      party.

                              ARTICLE XVI - NOTICES

16.1 All notices required or provided hereunder by one party to the other party
     shall be in writing and shall be mailed by First Class United States Mail,
     postage prepaid, and in the case of a notice of default or termination also
     by Certified or Registered Mail, return receipt requested, to the following
     addresses or to such changed address as either party entitled to notice
     herein shall have communicated in writing to the other party:


                                                                         Page 43
   41
For CONTRACTOR:
                    ----------------------------------------
                    ----------------------------------------
                    ----------------------------------------
                    Attn:
                           ---------------------------------
For NTI:            Northern Telecom Inc.
                    ----------------------------------------
                    ----------------------------------------
                    Attn:
                           ---------------------------------

      All written notices, properly addressed and mailed, shall be deemed given
      when actually received by the addressee.

                             ARTICLE XVII - GENERAL

17.1  This Agreement shall inure to the benefit of and be binding upon the
      respective successors and assigns, if any, of the parties hereto.

17.2  This Agreement constitutes the entire understanding and agreement between
      the parties and supersedes any and all prior or contemporaneous oral and
      written communications, understandings or agreements relating to the
      subject matter hereof. To the extent that the terms and conditions
      appearing on any purchase order issued by NTI to CONTRACTOR or on any
      acknowledgement issued by CONTRACTOR to NTI conflict with the terms and
      conditions set forth in this Agreement, the terms and conditions of this
      Agreement shall be deemed to control and the conflicting terms appearing
      in any such purchase order or acknowledgement shall be null and void.

17.3  Neither party shall either (a) assign this Agreement or any purchase order
      or any rights under either, or (b) subcontract any of its obligations
      under this Agreement or any purchase order, without the prior written
      consent of the other party. Notwithstanding the foregoing, NTI may assign
      this Agreement or any purchase order or any rights under either to its
      parent company, Northern Telecom Limited, or to any company which is
      majority owned on a class by class basis of its voting stock by Northern
      Telecom Limited without such prior written consent but upon notice to
      CONTRACTOR.

17.4  The interpretation of this Agreement and the rights and obligations of the
      parties shall be governed by the laws of the State of California.

17.5  Each party to this Agreement hereby represents to the other that it has
      full power and authority to enter into and perform this Agreement and that
      the person signing this Agreement on its behalf has been properly
      authorized and empowered to do so. Each party further acknowledges that it
      has read this Agreement, that it understands the terms and conditions
      hereof, and that it agrees to be bound by this Agreement.

IN WITNESS WHEREOF the parties hereto have caused this Agreement to be executed
by their duly authorized corporate officers and consider this Agreement to be
effective as of the day and year first set forth above.


                                                                         Page 44
   42
  NORTHERN TELECOM INC.                    CONTRACTOR:
  By:                                      By:
     ---------------------------              --------------------------------
  Name:                                    Name:
         -----------------------                  ----------------------------
  Title:                                   Title:
         -----------------------                  ----------------------------
  Date:                                    Date:
         -----------------------                  ----------------------------


                                                                         Page 45
   43
                                   SCHEDULE H
                       END-USER SOFTWARE LICENSE AGREEMENT


                                                                         Page 46
   44
                                     ANNEX G
                            MERIDIAN SOFTWARE LICENSE
            NORTHERN TELECOM INC. ("NTI") TELECOMMUNICATIONS PRODUCTS

THIS LEGAL DOCUMENT IS A LICENSE AGREEMENT ("LICENSE") BETWEEN YOU, THE END-USER
("CUSTOMER") AND NORTHERN TELECOM INC. ("NTI"). BY OPENING THE SEALED DISK
PACKAGE WHICH CONTAINS THE SOFTWARE DISKETTE(S), OR BY EXECUTING A CONTRACT FOR
PURCHASE OF A SYSTEM WHICH INCORPORATES THIS USER SOFTWARE AGREEMENT, YOU, THE
CUSTOMER, AGREE TO BE BOUND BY THE TERMS OF THIS LICENSE.

Subject to the terms hereinafter set forth, NTI grants to CUSTOMER and/or
representatives, with a "need to know," a personal, non-exclusive license (1) to
use certain Licensed Software, proprietary to NTI or its suppliers, contained as
an integral part of the Hardware; and (2) to install and use each item of
Licensed Software not an integral part of the Hardware; and (3) to use the
associated documentation. CUSTOMER is granted no title or ownership rights, in
or to the Licensed Software, in whole or in part, and CUSTOMER acknowledges that
title to and all copyrights, patents, trade secrets and/or any other
intellectual property rights to and in all such Licensed Software and associated
documentation are and shall remain the property of NTI and/or NTI's suppliers. 
The right to use Licensed Software may be restricted by a measure of usage of
applications based upon number of lines, number of ports, number of terminal
numbers assigned, number of users, or some similar measure. Expansion beyond
the specified usage level may require payment of an incremental charge or
another license fee.

NTI considers the Licensed Software to contain "trade secrets" of NTI and/or its
suppliers. Such "trade secrets" include, without limitation thereto, the
specific design, structure and logic of individual Licensed Software programs,
their interactions with other portions of Licensed Software, both internal and
external, and the programming techniques employed therein. In order to maintain
the "trade secret" status of the information contained within the Licensed
Software, the Licensed Software is being delivered to CUSTOMER in object code
form only.

NTI or any of its suppliers holding any intellectual property rights in any
Licensed Software, and/or any third party owning any intellectual property
rights in software from which the Licensed Software was derived, are intended
third party beneficiaries of this License. All grants of rights to use
intellectual property intended to be accomplished by this License are explicitly
stated. No other grants of such rights shall be inferred or shall arise by
implication.

CUSTOMER warrants to NTI that CUSTOMER is not purchasing the rights granted by
this License in anticipation of reselling those rights.

CUSTOMER shall:

- -   Hold the Licensed Software in confidence for the benefit of NTI and/or NTI's
    suppliers using no less a degree of care than it uses to protect its own
    most confidential and valuable information; and

- -   Keep a current record of the location of each copy of Licensed Software
    made by it; and

- -   Use each copy of Licensed Software only on a single CPU at a time (for this
    purpose, single CPU shall include systems with redundant processing units);
    and

- -   Affix to each copy of Licensed Software made by it, in the same form and
    location, a reproduction of the copyright notices, trademarks, and all other
    proprietary legends and/or logos of NTI and/or NTI's suppliers, appearing on
    the original copy of such Licensed Software delivered to CUSTOMER; and
    retain the same without alteration on all original copies; and

- -   Issue instructions to each of its authorized employees, agents,. and/or
    representatives to whom Licensed Software is disclosed, advising them of
    confidential nature of such Licensed Software and to provide them with a
    summary of the requirements of this License; and

- -   Return the Licensed Software and all copies through an Authorized
    Distributor to NTI at such time as CUSTOMER chooses to permanently cease
    using it.

CUSTOMER shall not:

- -   Use licensed Software (i) for any purpose other than CUSTOMER's own internal
    business purposes and (ii) other than as provided by this License; or

- -   Allow anyone other than CUSTOMER's employees, agents and/or representatives
    with a "need to know" to have physical access to Licensed Software; or

- -   Make any copies of Licensed Software except such limited number of object
    code copies in machine readable form only, as may be reasonably necessary
    for execution or archival purposes only; or 

- -   Make any modifications, enhancements, adaptations, or translations to or 
    of Licensed Software, except as may result from those CUSTOMER interactions 
    with the Licensed Software associated with normal use and explained in the 
    associated documentation; or

- -   Attempt to reverse engineer, disassemble, reverse translate, decompile, or
    in any other manner decode Licensed Software, in order to derive the source
    code form or for any other reason; or

- -   Make full or partial copies of any documentation or other similar printed or
    machine-readable matter provided with Licensed Software unless the same has
    been supplied in a form by NTI intended for periodic reproduction of partial
    copies; or

- -   Export or re-export Licensed Software and/or associated documentation from
    the fifty states of the United States and the District of Columbia. 

- -   NOTE: notwithstanding the above restrictions, if Customer has licensed the 
    Licensed Software under a "site license" option as set forth in Customer's 
    Purchase Agreement, Customer is authorized to make a limited number of 
    copies of the Licensed Software and documentation to support additional 
    users as specified in Customer's Purchase Agreement.

CUSTOMER may assign collectively its rights under this License to any subsequent
owner of the Hardware, but not otherwise, subject to the payment of the then
current license fee for new users, if any. No such assignment shall be valid
until CUSTOMER (1) has delegated all of its obligations under this License to
the assignee; and (2) has obtained from the assignee an unconditional written
assumption of all such obligations; and (3) has provided NTI a copy of such
assignment, delegation and assumption; and (4) has transferred physical
possession of all Licensed Software and all associated documentation to the
assignee and destroyed all archival copies. Except as provided, neither this
License nor any rights acquired by CUSTOMER through this License are assignable.
Any attempted assignment of rights and/or transfer of Licensed Software not
specifically allowed shall be void and conclusively presumed a material breach
of this License.

If NTI (i) claims a material breach of this License, and (ii) provides written
notice of such claimed material breach to CUSTOMER and (iii) observes that such
claimed material breach remains uncorrected and/or unmitigated more than thirty
(30) days following CUSTOMER's receipt of written notice specifying in
reasonable detail the nature of the claimed material breach, then CUSTOMER
acknowledges that this License may be immediately terminated by NTI and CUSTOMER
further acknowledges that any such termination shall be without prejudice to any
other rights and remedies that NTI may have at law or in equity.

EXPRESS LIMITED WARRANTIES FOR ANY ITEM OF LICENSED SOFTWARE, IF ANY, WILL BE
SOLELY THOSE GRANTED DIRECTLY TO CUSTOMER BY DISTRIBUTOR AS DESCRIBED IN THE
BODY OF THE AGREEMENT TO WHICH THIS LICENSE IS ATTACHED OR, IN THE CASE OF
LICENSED SOFTWARE DISTRIBUTED IN A SEALED DISK PACKAGE, THOSE WHICH APPEAR AT
THE END OF THIS LICENSE AGREEMENT. OTHER THAN AS SET FORTH THEREIN, THIS LICENSE
DOES NOT CONFER OR GRANT ANY WARRANTY TO CUSTOMER FROM OR BY NTI; THE LICENSED
SOFTWARE IS PROVIDED BY NTI "AS IS" AND WITHOUT WARRANTY OF ANY KIND OR NATURE,
WRITTEN OR ORAL, EXPRESS OR IMPLIED, INCLUDING (WITHOUT LIMITATION) THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND OF FITNESS FOR A PARTICULAR PURPOSE. THIS
LIMITATION OF WARRANTIES WAS A MATERIAL FACTOR IN THE ESTABLISHMENT OF THE
LICENSE FEE CHARGED FOR EACH SPECIFIC ITEM OF SOFTWARE LICENSED.

IN NO EVENT WILL NTI AND/OR NTI'S SUPPLIERS AND THEIR DIRECTORS, OFFICERS,
EMPLOYEES OR AGENTS BE LIABLE TO OR THROUGH CUSTOMER FOR INCIDENTAL, INDIRECT,
SPECIAL, CONSEQUENTIAL, PUNITIVE, OR EXEMPLARY DAMAGES OF ANY KIND, INCLUDING
LOST PROFITS, LOSS OF BUSINESS OR BUSINESS INFORMATION, BUSINESS INTERRUPTION,
OR OTHER ECONOMIC DAMAGE, AND FURTHER INCLUDING INJURY TO PROPERTY, AS A RESULT
OF USE OR INABILITY TO USE THE LICENSED SOFTWARE OR


PLEASE REFER TO THE REVERSE SIDE
   45






BREACH OF ANY WARRANTY OR OTHER TERM OF THIS LICENSE, REGARDLESS OF WHETHER NTI
AND/OR NTI'S SUPPLIERS WERE ADVISED, HAD OTHER REASON TO KNOW, OR IN FACT KNEW
OF THE POSSIBILITY THEREOF, CUSTOMER ACKNOWLEDGES THAT THE FOREGOING SENTENCE
REFLECTS AN INFORMED, VOLUNTARY ALLOCATION BETWEEN THE PARTIES OF THE RISKS
(KNOWN AND UNKNOWN) THAT MAY EXIST IN CONNECTION WITH THIS LICENSE, THAT SUCH
VOLUNTARY RISK ALLOCATION WAS A MATERIAL PART OF THE BARGAIN BETWEEN THE
PARTIES, AND THAT THE ECONOMIC AND OTHER TERMS OF THIS LICENSE WERE NEGOTIATED
AND AGREED TO BY THE PARTIES IN RELIANCE ON SUCH VOLUNTARY RISK ALLOCATION.


IN THE EVENT CUSTOMER HAS NOT EXECUTED A SEPARATE PURCHASE AGREEMENT WITH A
DISTRIBUTOR, AND THIS LICENSE BECOMES EFFECTIVE BY REASON OF YOUR OPENING A
SEALED DISK PACKAGE, THE ADDITIONAL WARRANTY PROVISIONS AND LIMITATIONS LISTED
BELOW APPLY:

- -    "LICENSED SOFTWARE" SHALL MEAN THE COMPUTER PROGRAMS WHICH ARE EITHER OWNED
     BY OR LICENSED TO NTI AND WHICH ARE CONTAINED ON THE DISKS SUPPLIED TO
     CUSTOMER. "HARDWARE" SHALL MEAN EQUIPMENT ON WHICH CUSTOMER USES THE
     LICENSED SOFTWARE.

- -    NTI WARRANTS THAT THE DISKS ON WHICH THE LICENSED SOFTWARE IS RECORDED WILL
     BE FREE FROM DEFECTS IN MATERIALS AND WORKMANSHIP UNDER NORMAL USE FOR A
     PERIOD OF NINETY (90) DAYS AS EVIDENCED BY A COPY OF THE RECEIPT. NTI'S
     ENTIRE LIABILITY AND YOUR EXCLUSIVE REMEDY WILL BE REPLACEMENT OF THE DISK
     NOT MEETING NTI'S LIMITED WARRANTY AND WHICH IS RETURNED TO NTI OR AN NTI
     AUTHORIZED REPRESENTATIVE WITH A COPY OF THE RECEIPT. NTI WILL HAVE NO
     RESPONSIBILITY TO REPLACE A DISK DAMAGED BY ACCIDENT, ABUSE OR
     MISAPPLICATION.

- -    IN PARTICULAR, NO WARRANTY IS BEING PROVIDED ON SOFTWARE DEVELOPED BY THIRD
     PARTY SOFTWARE SUPPLIERS. SUCH SOFTWARE SUPPLIERS MAKE NO WARRANTIES,
     EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, REGARDING THE
     SOFTWARE. NTI'S SOFTWARE SUPPLIERS DO NOT WARRANT, GUARANTEE OR MAKE ANY
     REPRESENTATIONS REGARDING THE USE OR THE RESULTS OF THE USE OF THE SOFTWARE
     IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY, OR OTHERWISE. THE
     ENTIRE RISK AS TO THE RESULTS AND PERFORMANCE OF ANY SUCH SOFTWARE
     DEVELOPED BY SOFTWARE SUPPLIERS IS ASSUMED BY YOU. THE EXCLUSION OF IMPLIED
     WARRANTIES IS NOT PERMITTED BY SOME JURISDICTIONS. THE ABOVE EXCLUSION MAY
     NOT APPLY TO YOU.

- -    BECAUSE SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OR LIMITATION OF
     LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES, THE ABOVE LIMITATIONS
     MAY NOT APPLY TO YOU. NTI'S AND NTI'S SOFTWARE SUPPLIERS COMBINED LIABILITY
     TO YOU FOR ACTUAL DAMAGES FROM ANY CAUSE WHATSOEVER, AND REGARDLESS OF THE
     FORM OF THE ACTION (WHETHER IN CONTRACT, TORT (INCLUDING NEGLIGENCE),
     PRODUCT LIABILITY OR OTHERWISE), WILL BE LIMITED TO $50.

- -    THE RIGHTS AND OBLIGATIONS ARISING UNDER THIS LICENSE SHALL BE CONSTRUED IN
     ACCORDANCE WITH THE LAW OF THE STATE OF TEXAS.


                CUSTOMER HEREBY AGREES TO ADHERE TO THE TERMS AND
             CONDITIONS OF THIS MERIDIAN SOFTWARE LICENSE AGREEMENT:


    CUSTOMER SIGNATURE:
                        ------------------------------------
    PRINTED NAME:
                  ------------------------------------------
    DATE:
         ---------------------------------------------------


                              NORTHERN TELECOM INC.





                                 Rick P. Faletti
                   President, Multimedia Communication Systems
                              Northern Telecom Inc.



Meridian Software License                                          Version 5.00
Northern Telecom Inc. Products                                             1994
   46
                                   SCHEDULE I

                                 DISCOUNT LEVEL


                              
            *****                 Base Systems

            *****                 Discountable standard products:

                                  - including all discountable products
                                    listed in Schedule B

                                  - including all discountable products
                                    listed in Schedule F

            *****                 Discountable spares and spares kits



                                                                         Page 47


                    CONFIDENTIAL MATERIAL OMITTED AND FILED
                  SEPARATELY WITH THE SECURITIES AND EXCHANGE
                    COMMISSION. ASTERISKS DENOTE OMISSIONS.
   47
                                   SCHEDULE J

                              ESCALATION PROCEDURE


                                   
 1.     First point of contact        Voicetek Corporation Hotline
 2.     Second point of contact       Technical Support Manager
 3.     Third point of contact        Engineering Manager
 4.     Fourth point of contact       Senior Staff
 5.     Fifth point of contact        Chief Operating Officer



                                                                         Page 48
   48
                                   SCHEDULE F

                            RESELLER SUPPORT SERVICES

           PART I: SOFTWARE PRODUCTS (EXCLUDING GENERATIONS DEVELOPER)


A.       VOICETEK shall provide RESELLER SUPPORT SERVICES which shall be
         identical in scope to the software support services set forth in
         Article XIII together with the additional out-of-warranty HARDWARE
         repair services set forth in Part III of this Schedule F to SUPPORT
         ORGANIZATION(s) for each ANNUAL SUPPORT SERVICES PERIOD during the TERM
         for which NTI, or any NORTHERN TELECOM COMPANY or any MANUFACTURING
         LICENSEE, as the case may be, elects to pay the requisite annual fee(s)
         for the desired level(s) of service, the available options of which are
         enumerated for the respective calendar years as indicated in the tables
         below:

         RESELLER SUPPORT SERVICES fees for calendar year 1995 are as follows:



Service Level         Hours (EDT or                 Days                        NTI Price          Additional Northern
                      EST as applicable)            Per Week                                       Telecom Company
                                                                                                   Direct Support Price

                                                                                          
Basic                 8:00 a.m. - 6:00 p.m.            M-F                      *                      *

Optional              7:00 a.m. - 10:00 p.m.           M-F                      *                      *
Extended

Twenty-four           Twenty-four hours                M-Su                     *                      *
hour


* Not available at this price if NTI is not paying for RESELLER SUPPORT SERVICES
at the time this service is ordered.

Renewal fees for RESELLER SUPPORT SERVICES for calendar year 1996 will be as
follows:



Service Level         Hours (EDT or                   Days                    NTI Price           Additional Northern
                      EST as applicable)            Per Week                                         Telecom Company
                                                                                                  Direct Support Price
                                                                                          
Basic                 8:00 a.m. - 6:00 p.m.           M-F                      *                       *

Optional              7:00 a.m. - 10:00 p.m.          M-F                      *                       *
Extended

Twenty-four           Twenty-four hours               M-Su                     *                       *
hour


      *Not available at this price if NTI is not paying for RESELLER SUPPORT
      SERVICES at the time this service is ordered.

      Fees for RESELLER SUPPORT SERVICES can be paid to VOICETEK by NTI and/or
      NORTHERN TELECOM COMPANIES and/or MANUFACTURING LICENSEES, as the case
      may be, on a quarterly basis. In the event any entity ordering RESELLER
      SUPPORT SERVICES elects to pay the requisite fee to VOICETEK on a
      quarterly basis, then VOICETEK shall invoice such ordering entity for each
      quarterly payment forty-five (45) days prior to the start of each calendar
      quarter and such ordering entity shall pay such invoices, pursuant to the
      payment terms set forth in Section 8.7.

      Renewal fees for RESELLER SUPPORT SERVICES for calendar years 1997 and
      beyond will be based on the total software revenue to VOICETEK generated
      during the last calendar quarter immediately preceding a now ANNUAL
      SUPPORT SERVICES PERIOD. The renewal fees will be as follows:



Previous Quarter                  Service Level                  NTI Annual             Additional Northern
software revenue                                                 Renewal Fee            Telecom Company
                                                                                        Direct Support Price

                                                                                   
*                                     Basic                       $*                          $*

"    "    "    "                     Optional extended            $*                          $*



                                                                         Page 38


CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND 
EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.
   49

                                                                                   
"    "    "    "                    Twenty-four hours            *****                      *****     

      *****                         Basic                        *****                      *****     

"    "    "    "                    Optional extended            *****                      *****     

"    "    "    "                    Twenty-four hours            *****                      *****     

      *****                         Basic                        *****                      *****     

"    "    "    "                    Optional extended            *****                      *****     

"    "    "    "                    Twenty-four hours            *****                      *****     

Less than $*****                    Basic                        *****                      *****     

"    "    "    "                    Optional extended            *****                      *****     

"    "    "    "                    Twenty-four hours            *****                      *****     


      For the purpose of determining how to apply the software revenue levels
      set forth in the table above, software revenue generated will be
      calculated on all software licenses (development and runtime),
      software-only options and the software-only component of hardware/software
      packaged PRODUCTS (e.g., ASR, TTS and FAX).

B.    Under all service level options, VOICETEK shall provide unlimited
      telephone consultation on the use of PRODUCTS including, but not limited
      to, advice on use, diagnosis of user problems, diagnosis of possible
      problems in PRODUCTS and direction or remedies to be employed until
      problems are corrected. POINT RELEASES and UPDATES are to be included at
      no additional charge as part of RESELLER SUPPORT SERVICES.

                    PART II: OUT-OF-WARRANTY HARDWARE REPAIR

A.    During an ANNUAL SUPPORT SERVICES PERIOD for which NTI or any NORTHERN
      TELECOM COMPANY or MANUFACTURING LICENSEE has/have paid to VOICETEK the
      requisite annual fee for any level of RESELLER SUPPORT SERVICES, VOICETEK
      shall provide out-of-warranty repair service to such entity on any and all
      HARDWARE ordered during the TERM in accordance with the terms set forth in
      Section 11.3, provided that such entity (requesting an RMA for
      out-of-warranty repair) simultaneously issues to VOICETEK a "no charge"
      ORDER. Subsequently, VOICETEK, within three (3) business days following
      receipt of the HARDWARE for out-of-warranty repair services, shall provide
      to the requesting entity a quotation for the out-of-warranty repair of
      such HARDWARE, which quotation may either be accepted or rejected by the
      requesting entity.

      In the event the out-of-warranty repair quotation is accepted by NTI, or a
      NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE, then the requesting
      entity shall issue a change to the applicable "no charge" ORDER which sets
      forth the price quoted by VOICETEK for the out-of-warranty repair.

      In the event a requesting entity decides not to proceed with the
      out-of-warranty repair, then such entity shall direct VOICETEK to return
      the out-of-warranty HARDWARE in question to the requesting entity F.O.B.
      VOICETEK, freight colled to NTI, or the NORTHERN TELECOM COMPANY or
      MANUFACTURING LICENSEE, as the case may be.

NORTHERN TELECOM INC.                     VOICETEK CORPORATION


By:                                       By: /s/ Sheldon L. Dinkes
   ------------------------------             ----------------------------

Name:                                     Name: SHELDON L. DINKES
      ---------------------------               --------------------------
            (type/print)                             (type/print)

Title:                                    Title: President
      ---------------------------               --------------------------
            (type/print)                              (type/print)

Date:                                     Date:  June 20, 1995
      ---------------------------               --------------------------


APPROVED AS
TO LEGAL FORM
BY:  /s/ Joel M.Erickson
    -----------------------
     16 June 1995


                                                                         Page 39

                    CONFIDENTIAL MATERIAL OMITTED AND FILED
                  SEPARATELY WITH THE SECURITIES AND EXCHANGE
                    COMMISSION. ASTERISKS DENOTE OMISSIONS.
   50
                                   SCHEDULE F

                            RESELLER SUPPORT SERVICES

           PART I: SOFTWARE PRODUCTS (EXCLUDING GENERATIONS DEVELOPER)


A.       VOICETEK shall provide RESELLER SUPPORT SERVICES which shall be
         identical in scope to the software support services set forth in
         Article XIII together with the additional out-of-warranty HARDWARE
         repair services set forth in Part III of this Schedule F to SUPPORT
         ORGANIZATION(s) for each ANNUAL SUPPORT SERVICES PERIOD during the TERM
         for which NTI, or any NORTHERN TELECOM COMPANY or any MANUFACTURING
         LICENSEE, as the case may be, elects to pay the requisite annual fee(s)
         for the desired level(s) of service, the available options of which are
         enumerated for the respective calendar years as indicated in the tables
         below:

         RESELLER SUPPORT SERVICES fees for calendar year 1995 are as follows:



Service Level         Hours (EDT or                 Days                        NTI Price          Additional Northern
                      EST as applicable)            Per Week                                       Telecom Company
                                                                                                   Direct Support Price

                                                                                          
Basic                 8:00 a.m. - 6:00 p.m.            M-F                      $*********            $**********

Optional              7:00 a.m. - 10:00 p.m.           M-F                      $*********            $**********
Extended

Twenty-four           Twenty-four hours                M-Su                     $*********            $**********
hour


* Not available at this price if NTI is not paying for RESELLER SUPPORT SERVICES
at the time this service is ordered.

Renewal fees for RESELLER SUPPORT SERVICES for calendar year 1996 will be as
follows:



Service Level         Hours (EDT or                   Days                    NTI Price           Additional Northern
                      EST as applicable)            Per Week                                         Telecom Company
                                                                                                  Direct Support Price
                                                                                          
Basic                 8:00 a.m. - 6:00 p.m.           M-F                      $**********            $**********

Optional              7:00 a.m. - 10:00 p.m.          M-F                      $**********            $**********
Extended

Twenty-four           Twenty-four hours               M-Su                     $**********            $**********
hour


      *Not available at this price if NTI is not paying for RESELLER SUPPORT
      SERVICES at the time this service is ordered.

      Fees for RESELLER SUPPORT SERVICES can be paid to VOICETEK by NTI and/or
      NORTHERN TELECOM COMPANIES and/or MANUFACTURING LICENSEES, as the case
      may be, on a quarterly basis. In the event any entity ordering RESELLER
      SUPPORT SERVICES elects to pay the requisite fee to VOICETEK on a
      quarterly basis, then VOICETEK shall invoice such ordering entity for each
      quarterly payment forty-five (45) days prior to the start of each calendar
      quarter and such ordering entity shall pay such invoices, pursuant to the
      payment terms set forth in Section 8.7.

      Renewal fees for RESELLER SUPPORT SERVICES for calendar years 1997 and
      beyond will be based on the total software revenue to VOICETEK generated
      during the last calendar quarter immediately preceding a now ANNUAL
      SUPPORT SERVICES PERIOD. The renewal fees will be as follows:



Previous Quarter                  Service Level                  NTI Annual             Additional Northern
software revenue                                                 Renewal Fee            Telecom Company
                                                                                        Direct Support Price

                                                                                   
$********** or greater               Basic                       $*********                 $*********



                                                                          Page 1


                    CONFIDENTIAL MATERIAL OMITTED AND FILED
                  SEPARATELY WITH THE SECURITIES AND EXCHANGE
                     COMMISSION. ASTERISKS DENOTE OMISSIONS.
   51

                                                                                   
"    "    "    "                    Optional extended            [*]                       [*]

"    "    "    "                    Twenty-four hours            [*]                       [*]        

$[*]                                Basic                        [*]                       [*]

"    "    "    "                    Optional extended            [*]                       [*]

"    "    "    "                    Twenty-four hours            [*]                       [*]

$[*]                                Basic                        [*]                       [*]

"    "    "    "                    Optional extended            [*]                       [*]

"    "    "    "                    Twenty-four hours            [*]                       [*]

Less than $[*]                      Basic                        [*]                       [*]

"    "    "    "                    Optional extended            [*]                       [*]

"    "    "    "                    Twenty-four hours            [*]                       [*]


      For the purpose of determining how to apply the software revenue levels
      set forth in the table above, software revenue generated will be
      calculated on all software licenses (development and runtime),
      software-only options and the software-only component of hardware/software
      packaged PRODUCTS (e.g., ASR, TTS and FAX).

B.    Under all service level options, VOICETEK shall provide unlimited
      telephone consultation on the use of PRODUCTS including, but not limited
      to, advice on use, diagnosis of user problems, diagnosis of possible
      problems in PRODUCTS and direction or remedies to be employed until
      problems are corrected. POINT RELEASES and UPDATES are to be included at
      no additional charge as part of RESELLER SUPPORT SERVICES.

                    PART II: OUT-OF-WARRANTY HARDWARE REPAIR

A.    During an ANNUAL SUPPORT SERVICES PERIOD for which NTI or any NORTHERN
      TELECOM COMPANY or MANUFACTURING LICENSEE has/have paid to VOICETEK the
      requisite annual fee for any level of RESELLER SUPPORT SERVICES, VOICETEK
      shall provide out-of-warranty repair service to such entity on any and all
      HARDWARE ordered during the TERM in accordance with the terms set forth in
      Section 11.3, provided that such entity (requesting an RMA for
      out-of-warranty repair) simultaneously issues to VOICETEK a "no charge"
      ORDER. Subsequently, VOICETEK, within three (3) business days following
      receipt of the HARDWARE for out-of-warranty repair services, shall provide
      to the requesting entity a quotation for the out-of-warranty repair of
      such HARDWARE, which quotation may either be accepted or rejected by the
      requesting entity.

      In the event the out-of-warranty repair quotation is accepted by NTI, or a
      NORTHERN TELECOM COMPANY or MANUFACTURING LICENSEE, then the requesting
      entity shall issue a change to the applicable "no charge" ORDER which sets
      forth the price quoted by VOICETEK for the out-of-warranty repair.

      In the event a requesting entity decides not to proceed with the
      out-of-warranty repair, then such entity shall direct VOICETEK to return
      the out-of-warranty HARDWARE in question to the requesting entity F.O.B.
      VOICETEK, freight collect to NTI, or the NORTHERN TELECOM COMPANY or
      MANUFACTURING LICENSEE, as the case may be.

NORTHERN TELECOM INC.                     VOICETEK CORPORATION


By: /s/ J. Michael Camp                   By: /s/ Sheldon Dinkes
   ------------------------------             ----------------------------

Name: J. Michael Camp                     Name: Sheldon Dinkes
      ---------------------------               --------------------------
            (type/print)                             (type/print)

Title: Vice President, MBA                Title: President
      ---------------------------               --------------------------
            (type/print)                              (type/print)

Date:  8/31/95                            Date:  8-28-95
      ---------------------------               --------------------------


APPROVED AS
TO LEGAL FORM
BY:  /s/ Joel M.Erickson
    -----------------------
     24 August 1995


                                                                          Page 2

         CONFIDENTIAL MATERIAL OMITTED AND FILED SEPARATEY WITH THE 
       SECURITIES AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS
   52
                                   ADDENDUM

This Addendum ("ADDENDUM") to the OEM Agreement between Northern Telecom Inc.
("NTI") and Voicetek Corporation ("VOICETEK") which was executed on June 16,1995
(the "AGREEMENT") hereby adds the substantive terms of support pertaining only
to the SOFTWARE PRODUCT identified as GENERATIONS Developer and addresses an
upgrade offer pertaining to the SOFTWARE PRODUCTS identified as GENERATIONS and
VRS, respectively. The entirety of the ADDENDUM shall constitute the text of
what shall be called Schedule F-1, which shall be attached to and become a part
of the AGREEMENT as of the date of the latter signature set forth below.

                                  SCHEDULE F-1

         PART I: OPTIONAL GENERATIONS DEVELOPER SUPPORT SERVICE AND FEE

A.    VOICETEK shall provide to NTI optional support services covering
      GENERATIONS Developer which shall be equivalent in scope to RESELLER
      SUPPORT SERVICES pertaining to all other SOFTWARE PRODUCTS in
      consideration of, and in the event NTI elects to remit NTI's payment of
      the requisite annual optional support services fee ("Requisite Annual
      Fee").  The Requisite Annual Fee payable for the support of GENERATIONS
      Developer shall be calculated by determining the amount equal to seven
      percent (7%) of the total of all GENERATIONS Developer software license
      fees paid cumulatively by NTI from the EFFECTIVE DATE until the date
      upon which NTI notifies VOICETEK of its desire to have VOICETEK
      commence the provision of optional support services covering
      GENERATIONS Developer.  The Requisite Annual Fee for renewing optional
      support services covering GENERATIONS Developer shall be determined by
      establishing a total of GENERATIONS Developer licenses in place on the
      anniversary date of the commencement of optional support services for
      GENERATIONS Developer and using the seven percent (7%) multiplier with
      the new total of GENERATIONS Developer software license fees.

B.    In contrast to the arrangement for RESELLER SUPPORT SERVICES for the
      balance of SOFTWARE PRODUCTS, which expressly excludes VERSION RELEASES,
      NTI shall receive, when commercially available, a copy of all VERSION
      RELEASES for GENERATIONS Developer and for VRS, respectively, released
      during any ANNUAL SUPPORT SERVICES PERIOD for which NTI has paid the
      Requisite Annual Fee, as described in Paragraph A.

                         PART II: ONE-TIME UPGRADE OFFER

As part of the AGREEMENT, when the first VERSION RELEASE of the SOFTWARE
PRODUCTS known as GENERATIONS and VRS, respectively, (referred to as 2.1/3.0) to
be released following the EFFECTIVE DATE becomes commercially available from
VOICETEK, VOICETEK will allow NTI six (6) months from the date of NTI's receipt
of a copy of such VERSION RELEASE to migrate NTI's installed base customers to
such VERSION RELEASE at no charge to NTI.

IN WITNESS WHEREOF, the parties hereto have, by their duly authorized
representatives, executed this ADDENDUM to the AGREEMENT as of the day and year
set forth below.

NORTHERN TELECOM INC.                     VOICETEK CORPORATION


By: /s/ J. Michael Camp                   By: /s/ Sheldon Dinkes
   ------------------------------             ----------------------------

Name: J. Michael Camp                     Name: Sheldon Dinkes
      ---------------------------               --------------------------
            (type/print)                             (type/print)

Title: Vice President, MBA                Title: President
      ---------------------------               --------------------------
            (type/print)                              (type/print)

Date:  8/31/95                            Date:  8-28-95
      ---------------------------               --------------------------


APPROVED AS
TO LEGAL FORM
BY:  /s/ Joel M.Erickson
    -----------------------
     24 August 1995


                                                                          Page 1
   53
                                   SCHEDULE A

                              AUTHORIZED TERRITORY




                                                      
                             Canada                       United States (U.S.)




                             Europe Region           CALA Region                 Asia/Pacific Region
                                                                        

                             United Kingdom          Brazil                      Australia
                             France                  Mexico                      Bahrain
                             Holland                 Chile                       Hong Kong
                             Sweden                  Columbia                    India
                             Denmark                 Argentina                   Indonesia
                             Norway                  Antigua                     Japan
                             Iceland                 Bahamas                     Kuwait
                             Germany                 Barbados                    Malaysia

                             Switzerland             Br. Virgin Islands          Oman
                             Austria                 Costa Rica                  Pakistan
                             Belgium                 Dominica                    China
                             Finland                 Dominican Republic          Philippines
                             United Arab Emirates    Ecuador                     Russia
                             Greece                  El Salvador                 Saudi Arabia
                             Ireland                 Guadeloupe                  Singapore
                             Israel                  Guatemala                   South Korea
                             Italy                   Honduras                    Syria
                             Netherlands             Jamaica                     Taiwan
                             Poland                  Jordan                      Thailand
                             Portugal                Martinique                  New Zealand
                             Spain                   Netherlands Antilles
                             Turkey                  St. Kitts & Nevis
                             Trinidad                St. Lucia
                             Nicaragua               St. Vincent
                             Turks & Caicos Is.      Panama
                                                     Paraguay
                                                     Peru
                                                     Puerto Rico
                                                     Virgin Islands
                                                     U.S. Virgin Islands


NORTHERN TELECOM INC.                     VOICETEK CORPORATION


By: /s/ John A. Ryan                      By: /s/ Sheldon L. Dinkes
   ------------------------------             ----------------------------

Name: John A. Ryan                        Name: Sheldon L. Dinkes
      ---------------------------               --------------------------
            (type/print)                             (type/print)

Title: VP/GM, MBA                         Title: President
      ---------------------------               --------------------------
            (type/print)                              (type/print)

Date:  2/5/96                             Date:  January 1, 1996
      ---------------------------               --------------------------


APPROVED AS
TO LEGAL FORM
BY:  /s/ Joel M.Erickson
    -----------------------

                                                                   Page 1