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                                                                   EXHIBIT 10.12


    Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.

                           SOFTWARE LICENSE AGREEMENT
                                   (STANDARD)

This Agreement is entered into as of the 25th day of February, 1998 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation ("TRILLIUM"), having its principal office at 12100 Wilshire Blvd.,
Suite 1800, Los Angeles, California, USA 90025-7118, and facsimile number
+1-310-442-1162 and

CASTLE NETWORKS INC.

a corporation organized under the laws of Delaware

("LICENSEE"), having its principal office at:

235 Littleton Road #2
Westford, Massachusetts 01886

and facsimile number +1-978-392-9032.

TRILLIUM is in the business of developing and marketing communications software
and expertise and is willing to make available to LICENSEE, and LICENSEE desires
to obtain a license to use certain computer software and related documentation
on the terms and conditions set forth in this Agreement,

For good and valuable consideration, the receipt and adequacy of which are
hereby acknowledged, the parties hereby agree as follows:

1. DEFINITIONS

         For purposes of this Agreement:

         1.1.     "Designated Equipment" shall mean the equipment specified in
                  Exhibit A attached hereto, as amended from time to time by
                  TRILLIUM and LICENSEE ("Exhibit A"), as being the equipment
                  upon which a Licensed Program is run.

         1.2.     "Documentation" shall mean the documentation listed on Exhibit
                  A and including all Updates thereof.

         1.3.     "Licensed Program" shall mean each program in software form
                  specified in Exhibit A (collectively, the "Licensed
                  Programs"), and shall specifically include any Updates and
                  Upgrades to such program furnished to LICENSEE by TRILLIUM
                  under this Agreement for use in connection with or replacement
                  of such program.


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         1.4.     "Maintenance Service" shall mean the maintenance services
                  defined in Exhibit D attached hereto ("Exhibit D").

         1.5.     "Object Form" shall mean any machine translated version of the
                  Source Form in binary form suitable for execution by computer
                  equipment, or any intermediate binary form derived from Source
                  Form which can be made executable by computer equipment.

         1.6.     "Public Release" shall mean, in respect of a Licensed Program,
                  an Update or Upgrade of such Licensed Program that is made
                  available by TRILLIUM to its licensees generally, and shall
                  mean, in respect of Documentation, an Update of such
                  Documentation that is made available by TRILLIUM to its
                  licensees generally.

         1.7.     "Source Form" shall mean, in respect of a Licensed Program,
                  the original form on any media of such Licensed Program in the
                  language as delivered by TRILLIUM to LICENSEE, or any
                  translation or modification thereof which substantially
                  preserves its original identity.

         1.8.     "Update" shall mean, in respect of any Licensed Program, a
                  Public Release of a new version of such Licensed Program which
                  corrects errors in the previous version of such Licensed
                  Program, and shall mean, in respect of Documentation, a Public
                  Release of a new version of such Documentation.

         1.9.     "Upgrade" shall mean, in respect of a Licensed Program, a
                  Public Release of a new version of such Licensed Program which
                  adds features or functionality which differs from the
                  specifications of the previous version of such Licensed
                  Program as set forth in the Documentation relating to such
                  previous version.

         1.10.    "Use" shall mean the copying or duplicating of any portion of
                  a Licensed Program from storage units or media into equipment
                  for processing, or the utilization of any form of a Licensed
                  Program in the course of the operation of the Designated
                  Equipment.

2. LICENSE GRANT

         2.1.     Use of Source Form for Development. TRILLIUM hereby grants to
                  LICENSEE for the term of this Agreement a non-exclusive,
                  non-assignable license to copy, Use, and modify the Source
                  Form and Object Form Licensed Programs specified in Exhibit A
                  herein for the purpose of adapting or incorporating such
                  Licensed Programs for operation in connection with Designated
                  Equipment or modifying the Licensed Programs to correct errors
                  or add features or functionality. No license is granted to use
                  any Licensed Program on any configuration of equipment which
                  is different from the configuration specified in Exhibit A as
                  the "Designated Equipment". LICENSEE shall respect TRILLIUM'S
                  proprietary rights and copyrights and shall not use such
                  Licensed Program except for the purposes for which it is being
                  made available as set forth



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                  in this Agreement and shall not create similar like programs
                  based, in whole or in part, on TRILLIUM'S proprietary rights
                  and copyrights.

         2.2.     Right to Grant Sublicenses. If the license type specified in
                  Exhibit B attached hereto ("Exhibit B") is a Single Use Buyout
                  license, then TRILLIUM hereby grants LICENSEE for the term of
                  this Agreement a non-exclusive, non-assignable right to grant,
                  and to grant others (including distributors of the Designated
                  Equipment) the right to grant, non-exclusive, non-assignable,
                  sublicenses to Use the Object Form on the Designated
                  Equipment, provided that such sublicensees are bound by terms
                  and conditions that axe as protective of TRILLIUM'S rights as
                  the terms and conditions of this Agreement, including, without
                  limitation those terms and conditions set forth in Exhibit C
                  attached hereto (or, in the case of agreements with
                  distributors, terms and conditions as protective of TRILLIUM'S
                  rights as the terms and conditions of this Agreement).
                  Notwithstanding anything to the contrary contained elsewhere
                  in this Agreement, no other type of license, if any, granted
                  hereby entitles LICENSEE to grant any sublicense.

         2.3.     Right to Use Documentation. TRILLIUM hereby grants LICENSEE
                  for the term of this Agreement a non-exclusive, non-assignable
                  right to duplicate and use the Documentation, but only for
                  LICENSEE'S own internal use, subject to the restrictions
                  imposed under Paragraph 9, in connection with its Use of the
                  Licensed Programs. No other duplication or use is permitted,
                  unless expressly approved in writing by TRILLIUM prior to such
                  duplication or use. Notwithstanding the foregoing provisions
                  of this Paragraph, LICENSEE may incorporate any part of the
                  Functional Specification portion of the Documentation into its
                  own end-user documentation, provided that LICENSEE includes in
                  such documentation a valid notice to the effect that TRILLIUM
                  owns the copyright to the Functional Specification portion of
                  such documentation, with all rights reserved.

         2.4.     Sublicenses to the Government. LICENSEE represents and
                  warrants to TRILLIUM that LICENSEE is not an agency,
                  department or unit of any governmental or quasi-governmental
                  entity and is not procuring any Licensed Program as part of or
                  in connection with any government contract or subcontract. If
                  LICENSEE grants any sublicense hereunder to any agency,
                  department or unit of any government or quasi-governmental
                  authority, LICENSEE shall take whatever actions and
                  precautions are necessary in order to preserve and protect all
                  ownership and other rights of TRILLIUM in the Licensed
                  Programs, Documentation and related materials and the
                  sublicense shall contain whatever provisions, notices and,
                  legends may be necessary in order to limit the rights acquired
                  under such sublicense to rights that are no greater than those
                  permitted by Paragraph 2.2 to be granted under such
                  sublicense. In furtherance of the foregoing, if LICENSEE
                  grants any sublicense hereunder to any agency, department or
                  unit of the United States Government, such notices and legends
                  shall include without limitation the following (in respect of
                  at least the Licensed Programs):


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                           The software and related materials licensed hereby
                           are classified as "restricted computer software" as
                           defined in clause 52.227-19 of the Federal
                           Acquisition Regulation ("FAR") and were developed
                           entirely at private expense for nongovernmental
                           purposes, are commercial in nature and have been
                           regularly used for nongovernmental purposes, and, to
                           the extent not published and copyrighted, are trade
                           secrets and confidential and are provided with all
                           rights reserved under the copyright laws of the
                           United States. The Government's rights to the
                           software and related materials are limited and
                           restricted as provided in clause 52.227-19 of the
                           FAR.

                  TRILLIUM reserves the right to update the foregoing legend as
                  applicable laws and regulations change.

         2.5.     Sublicense Enforcement. LICENSEE agrees to enforce its rights
                  under any sublicense granted by LICENSEE under this Agreement
                  and, upon the request of TRILLIUM, to enforce the rights of
                  TRILLIUM with respect to any such sublicense and to cooperate
                  with TRILLIUM in any action by TRILLIUM to enforce its rights
                  (and/or by TRILLIUM in LICENSEE'S name to enforce LICENSEE'S
                  rights) with respect to any such sublicense, including without
                  limitation by providing to TRILLIUM all information and
                  assistance TRILLIUM considers reasonably useful to pursue such
                  action.

         2.6.     Territory. TRILLIUM'S grant to LICENSEE in this Paragraph 2
                  shall be worldwide, subject to the provisions of Paragraph 15.

         2.7.     No Other License. Notwithstanding any other provision of this
                  Agreement, no license or right is granted to LICENSEE by
                  implication, estoppel or otherwise, except the licenses and
                  rights expressly granted in this Paragraph 2.

3. DELIVERABLES

         3.1.     Source Form Programs. TRILLIUM shall deliver to LICENSEE,
                  effective at TRILLIUM'S shipping point by delivery to a common
                  carrier, in accordance with the delivery schedules as
                  specified in Exhibit A, one copy of the Source Form of the
                  Licensed Programs listed in Exhibit A. Such programs will be
                  in machine readable form and may be examined and/or modified
                  with any ASCII text editor.

         3.2.     Documentation. TRILLIUM shall deliver to LICENSEE, effective
                  at TRILLIUM'S shipping point by delivery to a common carrier,
                  in accordance with the delivery schedules specified in Exhibit
                  A, the Documentation. All Documentation shall be provided in
                  the English language. The Documentation is sufficient to
                  provide reasonably qualified personnel a technical
                  understanding of the Licensed Programs and to enable
                  reasonably qualified personnel to perform the portation of the
                  Licensed Programs into the Designated Equipment and to allow
                  modification and enhancement of the Licensed Programs by
                  reasonably qualified personnel who did not originally develop
                  the Licensed Programs.



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         3.3.     Training, TRILLIUM shall provide to LICENSEE, free of any
                  additional charge, training courses, for the number of hours
                  as specified in Exhibit B, at TRILLIUM'S headquarters for a
                  group of LICENSEE personnel not to exceed ten (10) persons.
                  LICENSEE shall bear the cost of travel time and travel,
                  lodging and related expenses of its staff for the period of
                  training. At LICENSEE'S option, TRILLIUM will provide training
                  at one (1) of LICENSEE'S sites at LICENSEE'S expense,
                  including but not limited to travel time and travel, lodging
                  and related expenses of TRILLIUM personnel who provide such
                  training. Such training courses, in all events, shall be on
                  such day or days as is mutually acceptable to the parties
                  hereto, but in no event shall TRILLIUM have any obligation to
                  furnish any such training courses after the date that is three
                  (3) months after the date of delivery of the Licensed
                  Programs. TRILLIUM will provide LICENSEE training course
                  materials for the Licensed Programs at no additional charge.
                  Arrangements for additional training may be provided at the
                  expense of the LICENSEE upon terms and conditions to be agreed
                  upon by TRILLIUM and LICENSEE.

         3.4.     Media. The media used for delivery of machine readable items
                  shall be the media mutually agreed upon by TRILLIUM and
                  LICENSEE prior to the time of delivery or, failing such
                  agreement, as selected by TRILLIUM. Title in and to the media
                  used for delivery of machine readable items shall be owned by
                  LICENSEE.

         3.5.     Partial Shipments. Notwithstanding any other provision of this
                  Agreement, if TRILLIUM delivers the Licensed Programs in more
                  than one shipment, the acceptance period, payment terms, and
                  warranty period applicable to a particular Licensed Program
                  shall be measured from the date of delivery of that Licensed
                  Program, provided, however, that TRILLIUM may adjust the
                  warranty period applicable to any Licensed Programs included
                  in any shipments that follow the initial shipment by giving
                  LICENSEE appropriate credits in a manner similar to the manner
                  set forth in Paragraph 7.4 (regarding Licensed Programs
                  subsequently licensed by amendment to this Agreement) so that
                  some or all Licensed Programs have warranty service and
                  Maintenance Service periods that end on the same dates.

4. ACCEPTANCE

         4.1.     Acceptance. Each Licensed Program and the related
                  Documentation shall be deemed accepted by LICENSEE thirty (30)
                  days after delivery unless, within such thirty (30) day
                  period, LICENSEE delivers to TRILLIUM a notice of rejection in
                  accordance with this Paragraph 4.1. The sole criterion for
                  rejection of any Licensed 'Program or related Documentation
                  shall be its failure to conform in all material respects to
                  the specifications referenced in paragraph 2 of Exhibit A or
                  the requirements of Paragraph 3.2. Any notice of rejection
                  shall be valid only if (i) it is delivered to TRILLIUM within
                  such thirty (30) day period and (ii) it specifies in
                  reasonable detail each of the specifications to which such
                  Licensed



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     Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.


                  Program fails to conform, or each requirement to which such
                  Documentation fails to conform, and the basis for LICENSEE'S
                  assertion of nonconformance.

         4.2.     Rejection and Cure Procedure. If LICENSEE timely and
                  rightfully rejects a delivered Licensed Program, TRILLIUM
                  shall have thirty (30) days from the date of rejection to cure
                  any nonconformance described in LICENSEE'S valid notice of
                  rejection and to deliver to LICENSEE a version of the Licensed
                  Program or Documentation that conforms in all material
                  respects to such specifications or a written statement, as
                  applicable, providing the cure after which the provisions of
                  Paragraph 4.1 shall again apply, calculated from the date of
                  delivery of the new version of the Licensed Program or
                  Documentation. If the new version of such Licensed Program is
                  again timely and rightfully rejected by LICENSEE, LICENSEE
                  may, as its sole and exclusive remedy (notwithstanding any
                  other provision of this Agreement), declare this Agreement
                  terminated, in which event the provisions of Paragraph 13.2
                  shall apply and TRILLIUM will promptly refund to LICENSEE all
                  license fees paid by LICENSEE with regard to such rejected
                  Licensed Program; otherwise, LICENSEE shall afford TRILLIUM
                  another cure period to correct the nonconformance and the
                  provisions of Paragraph 4.1 shall again apply.

5. PAYMENT

         5.1.     Payment Terms For Deliverables. As payment for the license
                  grants and deliverables specified in this Agreement for each
                  Licensed Program, LICENSEE agrees to pay TRILLIUM the license
                  fee amount specified in Exhibit B for such Licensed Program.
                  The license fees for each such Licensed Program as specified
                  in Exhibit B shall be paid:

                  5.1.1.   [**] within thirty (30) days after delivery of the
                           Licensed Program as provided in Paragraph 3.1.; and

                  5.1.2.   [**] within thirty (30) days after acceptance of the
                           Licensed Program as provided in Paragraph 4.

         5.2.     Payment Terms For Maintenance. The fees for Maintenance
                  Service specified in Exhibit B are due and payable within
                  thirty (30) days of the date of each invoice therefor.

         5.3.     Currency. Unless otherwise agreed in writing by TRILLIUM, all
                  payments under this Agreement shall be made in United States
                  Dollars at the TRILLIUM office specified in Paragraph 16 (as
                  the same may subsequently be changed in accordance with such
                  Paragraph). All payments will be made in the form of a check
                  or wire transfer.


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         5.4.     Records. LICENSEE agrees to keep all usual and proper records
                  and books of accounts and all usual and proper entries therein
                  relating to sublicense of the Licensed Programs hereunder.
                  Upon reasonable notice, TRILLIUM or its duly appointed
                  representative shall have the right to audit LICENSEE'S
                  manufacturing and shipment records related to the Licensed
                  Programs for any period of time at any time. These
                  examinations shall occur during normal business hours at
                  LICENSEE'S place of business and shall not occur more
                  frequently than two times per year.

         5.5.     Administrative Service Charge. In addition to its other rights
                  hereunder, including the right to terminate, TRILLIUM shall
                  charge, and LICENSEE agrees to pay, an administrative service
                  charge of one and one-half percent (1.5%) of the unpaid amount
                  of any invoice per month (or fraction thereof), but not to
                  exceed the maximum rate permitted by applicable law, from the
                  due date of the invoice until the deft paid for any invoice
                  not timely paid in accordance with the terms of this
                  Agreement. This administrative service charge is intended to
                  defray part of TRILLIUM'S costs in processing and handling
                  late payments.

6. WARRANTY

         6.1.     Product Warranty. TRILLIUM warrants (i) that the Licensed
                  Programs will perform substantially to the specifications
                  referenced in Paragraph 2 of Exhibit A at the time of delivery
                  and for a period of six (6) months following delivery and (ii)
                  that the media used for delivery of the Licensed Programs and
                  Documentation will be free from defects in materials and
                  workmanship at the tune of delivery and for a period of thirty
                  (30) days following delivery.

         6.2.     Remedy. During the warranty period specified in clause (i) of
                  Paragraph 6.1., TRILLIUM shall correct any errors in the
                  Licensed Programs so that the Licensed Programs perform in all
                  material respects to the specifications referenced in
                  Paragraph 2 of Exhibit A. TRILLIUM shall repair or replace, at
                  its discretion, without charge at TRILLIUM'S facility all
                  defective media used for delivery of the Licensed Programs and
                  Documentation which are returned for inspection to such
                  facility within the warranty period specified in clause (ii)
                  of Paragraph 6.1, provided that such inspection discloses that
                  the defects are not the result of misuse, improper handling,
                  negligence, accident or otherwise attributable to LICENSEE'S
                  acts or omissions.

         6.3.     Definition of Services. During the warranty period specified
                  in clause (i) of Paragraph 6.1, TRILLIUM shall provide to
                  LICENSEE the Maintenance Services defined in Exhibit D for one
                  (1) LICENSEE site in relation to one (1) type of Designated
                  Equipment.

         6.4.     Limitation. EXCEPT AS PROVIDED IN THIS PARAGRAPH 6 AND
                  PARAGRAPH 10.1, TRILLIUM MAKES NO OTHER WARRANTIES, EXPRESS OR
                  IMPLIED, INCLUDING WITHOUT LIMITATION, WARRANTIES OF
                  MERCHANTABILITY OR FITNESS FOR A




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                  PARTICULAR PURPOSE WITH REGARD TO ANY PRODUCT, SERVICE OR
                  RELATED MATERIALS PROVIDED UNDER THIS AGREEMENT.

         6.5.     Fee for Additional Sites and Equipment. Warranty service will
                  be provided for one (1) LICENSEE site in relation to one (1)
                  type of Designated Equipment without additional charge except
                  as provided in Exhibit D. Warranty service for more than one
                  (1) LICENSEE site, or in relation to additional types of
                  Designated Equipment, will be provided only upon terms and
                  conditions to be agreed upon by TRILLIUM and LICENSEE.

7. MAINTENANCE

         7.1.     Definition of Maintenance Service. During any period of
                  Maintenance Service for which LICENSEE has paid, TRILLIUM will
                  provide to LICENSEE the services defined in Exhibit D.

         7.2.     Period of Maintenance Service. By checking the applicable box
                  on Exhibit B, LICENSEE may purchase Maintenance Service for
                  the Licensed Programs for one (1) LICENSEE site in relation to
                  one (1) type of Designated Equipment for the first year
                  following the end of the warranty period specified in clause
                  (i) of Paragraph 6.1 for the fees specified in Exhibit B. If,
                  on the other hand, LICENSEE checks the box on Exhibit B to
                  decline to order the first year of Maintenance Service at the
                  time LICENSEE executes this Agreement (or otherwise fails to
                  check the applicable box to purchase such Maintenance
                  Service), then, subject to acceptance in writing by TRILLIUM,
                  LICENSEE may subsequently purchase Maintenance Service for the
                  Licensed Programs for fees to be quoted by TRILLIUM at the
                  time such Maintenance Service is ordered (which fees may vary
                  from the fees set forth in Exhibit B). The minimum period for
                  which LICENSEE may purchase Maintenance Service is one (1)
                  year for one (1) site in relation to one (1) type of
                  Designated Equipment. Maintenance Service periods greater than
                  one (1) year are available in one (1) year increments. The
                  rates shown in Exhibit B cover Maintenance Service for the
                  Licensed Programs for one (1) LICENSEE site for one (1) type
                  of Designated Equipment for the first year following the end
                  of the warranty period specified in clause (i) of
                  Paragraph 6. 1. Maintenance Service for more than one (1)
                  site, or in relation to additional types of Designated
                  Equipment, will be provided only upon terms and conditions to
                  be agreed upon by TRILLIUM and LICENSEE. If there is, at any
                  time, more than one Licensed Program under this Agreement and
                  LICENSEE desires to purchase Maintenance Service for any of
                  the Licensed Programs, TRILLIUM reserves the right to require
                  LICENSEE to purchase Maintenance Service for all Licensed
                  Programs which are variants of one another or are otherwise
                  related to one another as a condition to purchasing
                  Maintenance Service for any of such variant or otherwise
                  related Licensed Programs.

         7.3.     Renewal. Maintenance Service is renewable annually, TRILLIUM
                  will endeavor to notify LICENSEE two (2) months prior to the
                  expiration of the



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                  warranty period specified in clause (i) of Paragraph 6.1 or
                  any then-current Maintenance Service period. Whether or not
                  TRILLIUM has so notified LICENSEE, at any time prior to or
                  within thirty (30) days after the expiration date of the.
                  warranty period specified in clause (i) of Paragraph 6.1 or
                  any them-current Maintenance Service period LICENSEE may renew
                  the Maintenance Service for the ensuing year (commencing on
                  such expiration date). Any renewal order shall be subject to
                  acceptance in writing by TRILLIUM, and, if LICENSEE fails to
                  renew the Maintenance Service within such period of time,
                  LICENSEE shall pay the applicable fees for Maintenance Service
                  for the ensuing year plus, on a prorated basis, all fees that
                  would have been payable from the day following the original
                  expiration date to the date of renewal, and the renewal fees
                  shall be as quoted by TRILLIUM at the time of LICENSEE'S order
                  (and may vary from the fees specified in Exhibit B).

         7.4.     Addition of New Programs. Upon payment of the applicable
                  license fees for any new Licensed Program licensed by
                  amendment to this Agreement, LICENSEE shall be entitled to six
                  (6) months of warranty service in respect of such new Licensed
                  Program under Paragraph 6 of this Agreement. If a new Licensed
                  Program is licensed by amendment to this Agreement at a time
                  when LICENSEE is entitled to warranty service or Maintenance
                  Service from TRILLIUM for one or more Licensed Programs
                  previously licensed under this Agreement, TRILLIUM, in lieu of
                  providing the six (6) months of warranty service for the new
                  Licensed Program under Paragraph 6, may give LICENSEE credit
                  for the six (6) month warranty service period otherwise
                  applicable to such new Licensed Program in the following
                  manner, so that some or all Licensed Programs have warranty
                  service and Maintenance Service periods that end on the same
                  dates:

                  7.4.1.   If the previously-licensed Programs are still covered
                           by warranty service, LICENSEE will be entitled to
                           warranty service on the new Program for the remainder
                           of such warranty service period and, to the extent of
                           the unused portion of the credit, LICENSEE will be
                           entitled to a prorated Maintenance Service fee credit
                           which may be applied toward the ensuing year of
                           Maintenance Service.

                  7.4.2.   If the previously-licensed Programs are covered by
                           Maintenance Service, and if more than six (6) months
                           remain in the period of Maintenance Service for the
                           previously-licensed Programs, TRILLIUM will give
                           LICENSEE credit for six (6) months of Maintenance
                           Service for the new Program and may require that
                           LICENSEE pay a prorated Maintenance Service fee for
                           the new Program to cover the remainder of the
                           Maintenance Service period.

                  7.4.3.   If the previously-licensed Programs are covered by
                           Maintenance Service, and if less than six (6) months
                           remain in the period of Maintenance Service for the
                           previously-licensed Programs, LICENSEE will be
                           entitled to Maintenance Service on the new Program
                           for the remainder of such Maintenance Service period
                           and, to



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                           the extent of the unused portion of the credit,
                           LICENSEE will be entitled to a prorated Maintenance
                           Service fee credit which may be applied toward the
                           ensuing year of Maintenance Service.

8. RIGHTS OF TRILLIUM

         8.1.     Rights Retained By Trillium. Nothing in this Agreement shall
                  prohibit TRILLIUM in any manner from using, developing,
                  marketing, licensing or otherwise disposing of TRILLIUM'S
                  Licensed Programs or concepts embodied therein anywhere in the
                  world; nor shall anything herein be construed to grant to
                  LICENSEE or any sublicensee any rights in or to any other
                  present or future products of TRILLIUM whether or not similar
                  to Licensed Programs.

         8.2.     Proprietary Rights. All information and material, including
                  but not limited to the Licensed Programs and Documentation,
                  supplied by TRILLIUM hereunder is owned by TRILLIUM and/or its
                  licensors and is proprietary in nature. LICENSEE (i) shall
                  respect such claim of proprietary right, (ii) shall protect
                  such information at least to the extent that it protects its
                  own proprietary information, (iii) shall not use such
                  information except for the purposes for which it is being made
                  available under this Agreement and (iv) shall not reproduce,
                  print, disclose, or otherwise make said information available
                  to any third party, in whole or in part, in whatever form,
                  except for the purpose for which it is being made available as
                  set forth in this Agreement.

         8.3.     Preservation of Notices. TRILLIUM shall retain title and
                  copyrights to the Licensed Programs, Documentation and related
                  materials that are provided by TRILLIUM to LICENSEE. The
                  Source Form Licensed Programs and Documentation contain
                  copyright notices, proprietary notices arid restricted rights
                  legends. LICENSEE shall retain all such notices on all copies
                  thereof (whether full or partial), and LICENSEE agrees to
                  reproduce and include in all copies (whether full or partial)
                  of the Object Form Licensed Programs all such notices and
                  legends contained in the Source Form Licensed Programs.

         8.4.     Rights Retained By Licensee. Nothing in this Agreement shall
                  prohibit LICENSEE in any manner from using, developing,
                  marketing, licensing or otherwise disposing of any software
                  independently developed by LICENSEE or any third party.
                  LICENSEE shall own all modifications made by it to the
                  Licensed Programs, except for error corrections and feature
                  enhancements to any Licensed Program, Documentation or related
                  materials disclosed or suggested to TRILLIUM in the course of
                  training, warranty service or Maintenance Service provided by
                  TRILLIUM, which corrections and enhancements shall be owned by
                  TRILLIUM (unless solely specific to LICENSEE'S application).

9. CONFIDENTIALITY

         9.1.     Source Form and Documentation. THE SOURCE FORM LICENSED
                  PROGRAMS AND DOCUMENTATION THAT ARE THE SUBJECT OF THIS




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                  AGREEMENT ARE CONFIDENTIAL AND PROPRIETARY TO TRILLIUM.
                  LICENSEE shall not use, reproduce, duplicate, copy or
                  otherwise disclose, distribute or disseminate any Source Form
                  Licensed Program or Documentation or related materials or
                  information provided under this Agreement or in the course of
                  the training provided under this Agreement, in any form or
                  media, other than as expressly provided for in this Agreement.

         9.2.     Confidential Information. For purposes of this Agreement,
                  "Confidential Information" of a party (the "Discloser") shall
                  mean any information which is disclosed to the other party
                  (the "Recipient") during the term of this Agreement that
                  relates in any way to any Licensed Program and which (i) is in
                  written, recorded, electronic, graphical or other tangible
                  form and marked confidential and/or proprietary or with a
                  similar legend or other notation denoting the confidential
                  nature of the information or proprietary interest of the
                  Discloser, or (ii) is disclosed orally and is identified
                  orally as confidential and/or proprietary at the time of
                  disclosure and is identified as confidential or proprietary by
                  the Discloser in a writing delivered to the Recipient prior to
                  or within thirty (30) days after the time of disclosure; and
                  "Confidential Information" shall include all notes, memoranda,
                  analyses, compilations, studies, and other documents and
                  records prepared by or for the Recipient, which contain or
                  otherwise reflect or are generated by using any Confidential
                  Information. TRILLIUM "Confidential Information" shall in all
                  events include but not be limited to the Licensed Programs,
                  Documentation and related materials and information.
                  Notwithstanding the foregoing, "Confidential Information"
                  shall not include any information which (a) is in the public
                  domain at the time of disclosure or becomes public domain
                  information other than through a breach of this Agreement, (b)
                  has been lawfully acquired by the Recipient from an Unrelated
                  Party, (c) is already in the Recipient's possession from an
                  Unrelated Party at the time of disclosure (as evidenced by the
                  Recipient's business records), or (d) is demonstrated by the
                  Recipient to have been independently developed by the
                  Recipient. For purposes hereof, the term "Unrelated Party"
                  shall mean a person who is not the Discloser, not an
                  affiliate, employee or agent of the Discloser, and not a
                  person known by the Recipient to be prohibited from disclosing
                  the Confidential Information to the Recipient by any
                  contractual, legal or fiduciary obligation.

         9.3.     Confidentiality and Use Restrictions. The Recipient shall not
                  use any of the Discloser's Confidential Information other than
                  to carry out the purposes of this Agreement and as expressly
                  permitted by this Agreement. The Recipient (i) shall treat the
                  Discloser's Confidential Information as confidential and
                  proprietary, using at a minimum the same degree of care as it
                  uses for its own trade secrets, but in no event less than
                  reasonable care; (ii) shall not disclose or afford access to
                  any such Confidential Information to any person who has not
                  executed a confidentiality agreement with the Recipient
                  protecting such information, having terms no less stringent
                  than those in this Agreement; (iii) shall not disclose or
                  afford access to any such Confidential Information to any
                  person who does not have a specific need to know such
                  information for the purpose of this Agreement; and (iv) shall
                  use its best efforts to ensure that such persons to whom the


                                     Page 11
   12

                  Recipient discloses or affords access to any such Confidential
                  Information shall not disclose any such Confidential
                  Information to any other person or use, any such Confidential
                  Information other than to carry out the purposes of this
                  Agreement and as expressly permitted by this Agreement (and,
                  in any event, shall be liable to the Discloser for any breach
                  of the provisions of this clause (iv) of this Paragraph by any
                  person to whom the Recipient discloses or affords access to
                  any such Confidential Information); provided, however, that
                  the Recipient may disclose Confidential Information as
                  compelled by legal, judicial or administrative proceeding if
                  the Recipient gives the Discloser reasonable prior notice to
                  enable the Discloser to seek a protective order or other
                  relief to prevent or limit disclosure of such Confidential
                  Information and the Recipient cooperates with the Discloser in
                  such effort.

10. INDEMNIFICATION AGAINST INFRINGEMENT

         10.1.    Indemnity. TRILLIUM represents and warrants that it has the
                  sufficient right, title and interest in the Licensed Programs
                  to enter into this Agreement. TRILLIUM agrees, at its own
                  expense, to indemnify and defend LICENSEE and hold LICENSEE
                  harmless against any loss, suit, claim, liability, expense
                  (including without limitation reasonable attorney's fees) or
                  proceeding brought against LICENSEE alleging that any use of
                  the Licensed Programs as delivered by TRILLIUM infringes any
                  patent, copyright or trademark or any trade secrets of any
                  third parties, provided that LICENSEE (i) promptly notifies
                  TRILLIUM in writing of any such suit, claim or proceeding,
                  (ii) allows TRILLIUM at its expense, to direct the defense of
                  such suit, claim or proceeding, (iii) gives TRILLIUM all
                  information and assistance TRILLIUM considers reasonably
                  useful to defend such suit, claim or proceeding, and (iv) does
                  not enter into any settlement of any such suit, claim or
                  proceeding without TRILLIUM written consent.

         10.2.    Remedies. Following written notice of a suit, claim or
                  proceeding or a threat of suit, claim or proceeding requiring
                  indemnification under Paragraph 10.1 above, TRILLIUM shall, at
                  its sole option, either (i) procure for LICENSEE the right to
                  use the Licensed Programs as furnished hereunder, or (ii)
                  replace or modify the Licensed Programs to make the same
                  non-infringing, or (iii) return to LICENSEE the license fees
                  applicable to the infringing Licensed Program and to accept
                  return of the infringing Licensed Program and related
                  documentation without further liability of TRILLIUM. If
                  TRILLIUM elects to replace or modify the Licensed Program,
                  such replacement shall substantially meet the specifications
                  for the Licensed Program as set forth in its Documentation.

         10.3.    Limitation. TRILLIUM shall have no liability for any claim
                  that TRILLIUM lacks right, title and interest to the Licensed
                  Programs or for any claim of violation of copyright, patent,
                  trade secret or other intellectual property right, if such
                  claim is based on LICENSEE'S modification or combination of
                  the Licensed Programs with non-TRILLIUM hardware or software,
                  including without limitation the Designated Equipment, if such
                  claim would have been



                                     Page 12
   13
                  avoided had the Licensed Program not been modified, combined
                  or integrated with the Designated Equipment and/or
                  non-TRILLIUM software programs.

                  LICENSEE shall indemnify and defend TRILLIUM and its
                  affiliates and hold them harmless from and against any loss,
                  suit, claim, liability, expense (including without limitation
                  reasonable attorney's fees) or proceeding arising under this
                  Paragraph 10.3 provided that TRILLIUM (i) promptly notifies
                  LICENSEE in writing of any such loss, suit, claim, liability,
                  expense (including without limitation reasonable attorney's
                  fees) or proceeding, (ii) allows LICENSEE, at LICENSEE'S
                  expense, to direct the defense of such suit, claim or
                  proceeding, (iii) gives LICENSEE full information and
                  assistance necessary to defend such suit, claim or proceeding,
                  and (iv) does not enter into any settlement of any such suit,
                  claim or proceeding without LICENSEE'S consent.

11. LIMITATION OF LIABILITY

         TRILLIUM'S aggregate liability to LICENSEE and its sublicensees under,
         arising out of or related to any provision of this Agreement, or at law
         or in equity (including without limitation pursuant to any claim for
         indemnification), or any transaction contemplated by this Agreement,
         shall be limited to the amount of the license fees actually paid by
         LICENSEE to TRILLIUM under this Agreement. TRILLIUM'S limitation of
         liability is cumulative with all of TRILLIUM'S payments to LICENSEE in
         satisfaction of TRILLIUM'S liabilities under this Agreement being
         aggregated to determine satisfaction of the limit.

         IN NO EVENT SHALL TRILLIUM BE LIABLE FOR ANY INDIRECT, SPECIAL, OR
         CONSEQUENTIAL DAMAGES IN CONNECTION WITH OR ARISING OUT OF THIS
         AGREEMENT, WHETHER BASED ON BREACH OF CONTRACT, TORT (INCLUDING
         NEGLIGENCE), PRODUCT LIABILITY, OR OTHERWISE, AND WHETHER OR NOT IT HAS
         BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

12. INDEMNIFICATION

         LICENSEE shall indemnify and defend TRILLIUM and its affiliates and
         hold them harmless from and against any loss, suit, claim, liability,
         expense (including without limitation reasonable attorney's fees),
         proceeding or damage to persons or property arising out of or related
         to the use or possession of the Licensed Programs or any Documentation
         or related materials by LICENSEE or any of its sublicensees, provided
         that such loss, suit, claim, expense, proceeding or, damage (i) is not
         the subject of indemnity by TRILLIUM under Paragraph 10.1 or (ii) was
         not caused solely by the negligence of TRILLIUM or of TRILLIUM
         employees or representatives.

13. TERMINATION

         13.1.    Termination Events.  This Agreement shall terminate:

                  13.1.1.  Upon mutual agreement of the parties hereto; or



                                     Page 13
   14
                  13.1.2.  If either party commits a breach of any provision of
                           this Agreement, the party committing the breach (the
                           "defaulting party") shall be deemed in default and
                           the other party (the "non-defaulting party") may
                           terminate this Agreement, including all rights
                           granted herein (and without liability on the part of
                           the terminating party for terminating this Agreement,
                           and without prejudice to the terminating party's
                           other rights and remedies), upon thirty (30) days
                           written notice to the defaulting party. Such
                           termination shall become effective at the end of such
                           thirty (30) day period (or such later date, if any,
                           as may be expressly provided in such notice) unless
                           the defaulting party shall cure, all aspects of the
                           default to the reasonable satisfaction of the
                           non-defaulting party and so notify the non-defaulting
                           party of the cure in writing within such thirty (30)
                           day period; or

                  13.1.3.  Without liability on the part of the terminating
                           party for terminating this Agreement, and without
                           prejudice to the terminating party's other rights and
                           remedies, by either party by notice given at any time
                           if at any time (i) the other party commences
                           dissolution or liquidation proceedings or ceases to
                           carry on its business, (ii) a receiver or similar
                           officer is appointed for such other party and is not
                           discharged within ninety (90) days, or (iii) such
                           other party makes an. assignment for the benefit of,
                           or a composition with, its creditors, or another
                           arrangement of similar import, or if proceedings
                           under any bankruptcy or insolvency law are commenced
                           against it and are not discontinued within ninety
                           (90) days.

         13.2.    Certain Obligations Upon Termination. If this Agreement is
                  terminated, LICENSEE, on the effective date of termination,
                  shall immediately discontinue the Use of each Licensed Program
                  and Documentation and related materials, and any and all parts
                  thereof. Within five (5) days after the date of termination,
                  LICENSEE shall deliver to TRILLIUM every original copy and
                  reproduction (in any form or media) of each Licensed Program
                  and all Documentation and related materials and TRILLIUM
                  Confidential Information; provided that, notwithstanding the
                  other terms of this Paragraph 13.2, LICENSEE may retain one
                  (1) copy of the Licensed Programs for use solely in supporting
                  its then-existing sublicensees (if there are any such
                  sublicensees). In lieu of such delivery, if TRILLIUM permits,
                  every original copy and reproduction (in any form or media) of
                  each Licensed Program, and all Documentation and related
                  materials, and other Confidential Information of TRILLIUM
                  shall be destroyed by LICENSEE, who shall then provide
                  TRILLIUM with written certification that LICENSEE has complied
                  with this provision. Termination of this Agreement shall not
                  abridge the right of continued use on the part of LICENSEE'S
                  sublicensees who have rightfully received the Object Form of
                  the Licensed Programs under a sublicense granted by LICENSEE
                  as permitted by this Agreement; provided, however, that all
                  further rights on the part of LICENSEE to use Source Form or
                  Object Form, or to distribute or sublicense Licensed Programs
                  shall be canceled upon termination. Termination of this
                  Agreement shall also terminate the rights of all other
                  persons, to whom LICENSEE has


                                     Page 14
   15
                  granted any right to sublicense under Paragraph 2, to grant
                  additional sublicenses after the date of termination, and,
                  upon such termination, LICENSEE shall promptly notify each
                  such sublicensee accordingly.

         13.3.    Unpaid Amounts. Immediately upon termination of this
                  Agreement, any earned but unpaid fees shall become immediately
                  due and payable by LICENSEE to TRILLIUM.

         13.4.    Unshipped Orders. Immediately upon termination of this
                  Agreement, all unshipped orders may be canceled by either
                  party without liability to either party.

         13.5.    Survival of Provisions. The following provisions shall survive
                  any termination or expiration of this Agreement:

                           Paragraph 5    Payment
                           Paragraph 8    Rights of Trillium
                           Paragraph 9    Confidentiality
                           Paragraph 10   Indemnification Against Infringement
                           Paragraph 11   Limitations of Liability
                           Paragraph 12   Indemnification
                           Paragraph 13   Termination
                           Paragraph 14   Assignments
                           Paragraph 15   Export Controls
                           Paragraph 16   Notices
                           Paragraph 17   General Provisions

         13.6.    Term. The term of this Agreement shall be perpetual and shall
                  not terminate or expire unless and until this Agreement is
                  terminated in accordance with its provisions.

14. ASSIGNMENTS

         The rights and obligations of LICENSEE under this Agreement may not be
         assigned or delegated (by operation of law or otherwise) by LICENSEE
         without the prior written consent of TRILLIUM except for an assignment
         of this entire Agreement to an affiliate of LICENSEE that does not
         compete with TRILLIUM and only if such assignment is incident to a
         transfer of the business that includes the Designated Equipment as
         specified in Exhibit A, and in all cases, any assignment may be made
         only upon ninety (90) days prior written notice to TRILLIUM and shall
         be effective only upon the execution by the proposed assignee of an
         assignment agreement acceptable in form and substance to TRILLIUM,
         which shall include without limitation the proposed assignee's
         assumption of and agreement to be bound by all of the terms and
         conditions of this Agreement and all amendments thereto. TRILLIUM'S
         rights and obligations under this Agreement may with notice to the
         LICENSEE be assigned and/or delegated by TRILLMIM to any affiliate of
         TRILLIUM or incident to the transfer of the business of TRILLIUM to
         which this Agreement relates. TRILLIUM may upon notice given at any
         time to LICENSEE assign its rights to receive fees and other monies
         hereunder. Subject to the



                                     Page 15
   16

         limitations on assignment contained in the foregoing provisions of this
         Paragraph, this Agreement shall be binding upon and inure to the
         benefit of the successors and assigns of the parties hereto.

15. EXPORT CONTROLS

         The Licensed Programs are subject to United States Government export
         controls. LICENSEE agrees not to use, export, import, re-export,
         transfer or otherwise dispose of the Licensed Programs except in
         compliance with United States and foreign government requirements.

16. NOTICES

         Any notice required or desired to be given with respect to this
         Agreement shall be in writing and shall be deemed delivered when sent
         by registered or certified mail, return receipt requested (if being
         sent from within the USA to an address within the USA), or by confirmed
         facsimile transmission (regardless of the points of sending and
         receipt), or by overnight express courier (such as FedEx) marked for
         the earliest possible delivery (regardless of the points of sending and
         receipt), in each case addressed to the other party as set forth below,
         or to such other address as that party may have specified by prior
         notice to the other given in the manner herein provided:

                   LICENSEE:   Castle Networks Inc.
                               235 Littleton Road #2
                               Westford, Massachusetts 01886
                               Attn: Mike Regan
                               Facsimile No.: +1-978-392-9032

                   TRILLIUM:   Trillium Digital Systems, Inc.
                               12100 Wilshire Blvd., Suite 1800
                               Los Angeles, California, USA 90025-7118
                               Attn: Contract Administration
                               Facsimile No: +1-310-442-1162

         If no address is given for LICENSEE in this Paragraph, then the
         office, address of LICENSEE first set forth above shall be the address
         for notices to LICENSEE.

17. GENERAL PROVISIONS

         17.1.    Agreement Prevails. In the event that any provision of any
                  purchase order, receipt, invoice, or other document issued by
                  either party is inconsistent with the provisions of this
                  Agreement, then the terms of this Agreement will prevail. In
                  the event of a conflict in the provisions of the body of this
                  Agreement and any exhibits or other attachments hereto, the
                  provisions of the body of this Agreement shall govern.

         17.2.    Taxes. Fees shown in Exhibit B are exclusive of all sales, use
                  and other taxes and all other governmental charges and
                  assessments. Any tax TRILLIUM may be




                                     Page 16
   17
                  required to collect or pay upon the transactions contemplated
                  by this Agreement, other than taxes based on the income of
                  TRILLIUM and any foreign withholding taxes, shall be paid by
                  LICENSEE, or in lieu thereof, LICENSEE shall provide a tax
                  exemption certificate acceptable to the taxing authorities. On
                  transactions occurring outside the United States, in whole or
                  in part, all required import/export duties, license and other
                  fees shall be payable by LICENSEE in addition to the stated
                  payments to TRILLIUM. If LICENSEE is required to withhold any
                  foreign withholding taxes from amounts payable to TRILLIUM
                  under this Agreement, LICENSEE shall advise TRILLIUM of such
                  requirement at the time of signing this Agreement, shall
                  timely remit such foreign withholding taxes to the appropriate
                  taxing authority, and shall deliver to TRILLIUM proof of each
                  such remittance (in a form acceptable to the U.S. Internal
                  Revenue Service so that TRILLIUM can claim applicable U.S.
                  federal tax credits) within sixty (60) days of such
                  remittance.

         17.3.    Shipping. Shipment will be made as specified in Exhibit A. In
                  the absence of specific written instructions from LICENSEE,
                  TRILLIUM will select the carrier but shall not thereby assume
                  any liability in connection with shipment; nor shall the
                  carrier be construed to be the agent of TRILLIUM. Title to and
                  risk of loss of all physical media used for delivery of
                  machine readable items to be delivered hereunder shall pass to
                  LICENSEE at TRILLIUM'S shipping point upon delivery to the
                  carrier. All shipping and handling charges shall be paid by
                  LICENSEE.

         17.4.    Force Majeure. Neither party shall be considered in breach or
                  default under this Agreement for any delay or failure in
                  performance (other than the payment of money) resulting from
                  acts beyond the control of such party. Such acts shall include
                  but not be limited to acts of God, labor conflicts, acts of
                  war or civil disruption, act of terrorism, governmental
                  regulations imposed after the fact, public utility failures,
                  industry wide shortages of labor or material, or natural
                  disaster.

         17.5.    Complete Agreement. This Agreement (including the exhibits
                  attached hereto and referenced herein) contains the entire
                  agreement between the parties with respect to the subject
                  matter hereof. No other prior or contemporaneous agreements,
                  representations, warranties, or other matters, oral or
                  written, actually or purportedly agreed to or represented by
                  or on behalf of either party by any of its employees or
                  agents, or contained in any sales material or brochures, shall
                  be deemed to bind the parties with respect to the subject
                  matter hereof. The terms of this Agreement may be altered only
                  in a writing signed by both parties, except as otherwise
                  expressly set forth in this Agreement for changes to certain
                  exhibits to this Agreement.

         17.6.    Waivers. The failure or delay of either party at any time to
                  exercise any right under any provision of this Agreement shall
                  not limit or operate as a waiver thereof, nor shall the single
                  or partial exercise thereof preclude or limit any other or
                  further exercise thereof, nor shall the waiver of any breach
                  of any provision be



                                     Page 17
   18
                  a waiver of any other or further breach of any provision or a
                  waiver of the provision itself or of any other provision of
                  this Agreement.

         17.7.    Applicable Law and Construction. This Agreement shall be
                  governed by and construed in accordance with the laws of the
                  State of California, USA, excluding the conflict of laws
                  principles thereof. Neither this Agreement nor any provision
                  of this Agreement shall be construed against either party due
                  to the fact that this Agreement or such provision was drafted
                  by such party. In construing this Agreement, the headings
                  shall not be considered part of this Agreement, but are for
                  convenience of reference only. Wherever the context of this
                  Agreement dictates, the plural shall be read as the singular
                  and the singular as the plural.

         17.8.    Severability. If any provision of this Agreement is held by a
                  court or arbitrator of competent jurisdiction not enforceable
                  to its full extent then such provision shall be enforced to
                  the maximum extent permitted by law, and the parties hereto
                  consent and agree that such scope may be modified by such
                  court or arbitrator accordingly and that the whole of such
                  provision of this Agreement shall not thereby fail, but that
                  the scope of such provision shall be curtailed only to the
                  extent necessary to conform to the law.

         17.9.    Disputes. In the event any dispute arises under, it connection
                  with or relating to this Agreement or any transaction
                  contemplated thereby, whether to enforce any of the terms or
                  conditions of this Agreement or otherwise, the prevailing
                  party in any suit, arbitration or other proceedings shall, as
                  an additional item of damages, recover its reasonable
                  attorneys' fees and court costs, arbitration costs or costs of
                  such other proceedings as maybe fixed by any court, arbitrator
                  or other judicial or quasi-judicial body having jurisdiction
                  thereof, including without limitation any costs incurred in
                  any appeal and in any collection effort, whether or not such
                  litigation or proceedings proceed to a final judgment or
                  award.

         17.10.   Arbitration. Any claim, controversy, or dispute of whatever
                  nature arising out of or related to this Agreement or its
                  formation shall be resolved by final and binding arbitration
                  administered by the American Arbitration Association ("AAA")
                  according to the Commercial Arbitration Rules ("Rules") of the
                  AAA, except as modified herein. The arbitration shall be
                  conducted by a single arbitrator chosen from a list of
                  attorneys who are members of the AAA's large complex case
                  panel and who are also knowledgeable in the area of software
                  licensing and the software industry. If the parties cannot
                  agree on an arbitrator within thirty (30) days from the filing
                  of a demand for arbitration with the AAA, the arbitrator shall
                  be chosen pursuant to Rule 13 of the Rules. The costs and
                  administrative expenses of arbitration, including the
                  arbitrator's fees, shall be shared equally by the parties. The
                  arbitration shall be conducted in the City of Los Angeles,
                  California. In rendering any award, the arbitrator shall apply
                  and follow applicable principles of the substantive law of
                  California. The parties shall be entitled to conduct full
                  discovery as permitted by the California Discovery Act,
                  C.C.P.ss.2016 et seq., and any amendment thereto or successor
                  statutes. The period for conducting and completing discovery
                  shall be limited to three months from the date of the



                                     Page 18
   19

                  arbitrator's appointment. The arbitration shall be completed
                  within six months from the date of the arbitrator's
                  appointment. To the extent otherwise available under
                  applicable law, either party may seek provisional relief from
                  any court of competent jurisdiction as to any matter that is
                  subject to arbitration under this Agreement. Judgment on the
                  award rendered by the arbitrator may be entered in any court
                  having jurisdiction thereof. The parties consent to the
                  jurisdiction of the state and federal courts located in Los
                  Angeles County, California for all judicial proceedings.

         17.11.   Provisional Relief. The parties agree that any breach of this
                  Agreement by LICENSEE would result in irreparable harm to
                  TRILLIUM, the extent of which would be difficult and/or
                  impracticable to assess, and that money damages would not be
                  an adequate remedy for such breach. Accordingly, TRILLIUM
                  shall be entitled to immediate equitable and other provisional
                  relief, including without limitation specific performance of
                  this Agreement and a temporary restraining order and/or
                  preliminary and/or permanent injunction, as a remedy for such
                  breach in addition to all other remedies available to TRILLIUM
                  at law or in equity and without prejudice to any such other
                  remedies.

         17.12.   Further Acts. Each party to this Agreement agrees to execute
                  and deliver all documents and to perform all further acts and
                  to take any and all further steps that may be requested by the
                  other party and are reasonably necessary to carry out the
                  provisions of this Agreement and the transactions contemplated
                  hereby.

         17.13.   Counterparts. This Agreement or any amendment hereto may be
                  executed in several counterparts and, as executed, shall
                  constitute one agreement binding on all the parties hereto,
                  notwithstanding that all of the parties are not signatory to
                  the original or the same counterpart.

         17.14.   Language. All amendments of this Agreement, notices and
                  communications between the parties, and all material supplied
                  under this Agreement by either party to the other shall be in
                  the English language.

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly
executed by their respective duly authorized representative as of the date first
above written.

                LICENSEE:                        TRILLIUM:

Company:        CASTLE NETWORKS INC.             TRILLIUM DIGITAL SYSTEMS, INC.


Signature:      /s/ Michael D. Regan             /s/ Richard D. [Illegible]
                ---------------------            -------------------------
Name:           Michael D. Regan                 Richard D. [illegible]
Title:          Director - SW ENG                C.O.D.

Date:           2/25/98                          February 25, 1998


                                     Page 19
   20

Attachments:      Exhibit A - Licensed Programs
                  Exhibit B - License and Maintenance Fees
                  Exhibit C - Sample End User License Agreement
                  Exhibit D - Maintenance Service
                  Exhibit E - Trillium Action Request
                  Exhibit F - Trillium Standard Rates





                                     Page 20
   21
                                    EXHIBIT A

                                LICENSED PROGRAMS

1.       LICENSED PROGRAMS:

         The Licensed Programs are:




- -------------------------------------------------------------------------------------------------
Part No.       Options                     Name                       Version          Ship Date
- -------------------------------------------------------------------------------------------------
                                                                           

1000027           --            MTP Level 2 - CCITT 88 & 92,            Latest         1 Week ARO
                                    ANSI 88 & 92, Peoples
                                      Republic of China
- -------------------------------------------------------------------------------------------------
1000028           --             MTP Level 3 - CCITT 88 & 92            Latest         1 Week ARO
- -------------------------------------------------------------------------------------------------
1000028           12             MTP Level 3 - ANSI 88 & 92             Latest         1 Week ARO
- -------------------------------------------------------------------------------------------------
1000029           --                ISUP - CCITT 88 & 92                Latest         1 Week ARO
- -------------------------------------------------------------------------------------------------
1000029           12                 ISUP - ANSI 88 & 92                Latest         1 Week ARO
- -------------------------------------------------------------------------------------------------
1020031           21               VxWorks/Tornado System               Latest         1 Week ARO
                                     Services - General
- -------------------------------------------------------------------------------------------------
1000100           --             Motorola MPC860 SCC Driver             Latest         1 Week ARO
- -------------------------------------------------------------------------------------------------
1068001           01            MOS Binary - Microsoft Visual           Latest         1 Week ARO
                                   C++ V2.1 for WindowsNT
- -------------------------------------------------------------------------------------------------


If used above:

         "ARO" means "after receipt of order", which contemplates receipt of
         LICENSEE's purchase order and a fully-signed Software License Agreement
         acceptable to TRILLIUM.

         "Latest" means the version that is the current Public Release.

         "Beta" means a version that is not a Public Release.

2.       DOCUMENTATION:

         The following documentation shall be supplied with each Licensed
Program:

         -  Functional Specification
         -  Service Definition
         -  Portation Guide
         -  Training Manual
         -  Software Test Sample



                                     Page 21
   22
3.       OPERATING ENVIRONMENT (FOR TRILLIUM REFERENCE PURPOSES ONLY)

         Compiler:                         GNU FROM WIND RIVER SYSTEMS

         Compiler Platform:                WINDOWS NT

         Runtime Processor:                POWER PC 860/603

         Runtime Operating System:         Vx Works


4.       LICENSEE'S "DESIGNATED EQUIPMENT": LICENSEE's self contained
                                            Public Switched Telephone
                                            Network (PSTN) voice gateway
                                            product, current development
                                            codename is "Atlas," which is a
                                            23" proprietary NEBS compliant
                                            chassis with multiple shelves
                                            and proprietary busses, running
                                            VxWorks and using PowerPC and
                                            PowerQUICC processors. This
                                            definition covers versions of
                                            the "Atlas" product which vary
                                            only in their size and
                                            scalability. Prior to the first
                                            commercial sale or use of this
                                            product, LICENSEE shall notify
                                            TRILLIUM of the formal model
                                            name and/or model number of
                                            this product, which shall be
                                            then specified in this
                                            definition by an amendment to
                                            this Agreement.





                                     Page 22
   23

    Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.


                                    EXHIBIT B

                          LICENSE AND MAINTENANCE FEES

1.       LICENSE AND MAINTENANCE FEES:

         The license and maintenance fees for each of the Licensed Programs are:



- -------------------------------------------------------------------------------------------------------
Part No.   Options                 Name                 License    License   Maintenance Fee   Training
                                                         Type      Fee (1)    (Annual) (2)     (Hours)
- -------------------------------------------------------------------------------------------------------
                                                                               

1000027       --       MTP Level 2 - CCITT 88 & 92,       SUB       $[**]         $[**]          [**]
                          ANSI 88 & 92, Peoples
                            Republic of China
- -------------------------------------------------------------------------------------------------------
1000028       --       MTP Level 3 - CCITT 88 & 92        SUB       $[**]         $[**]          [**]
- -------------------------------------------------------------------------------------------------------
1000028       12        MTP Level 3 - ANSI 88 & 92        SUB       $[**]         $[**]          [**]
- -------------------------------------------------------------------------------------------------------
1000029       --           ISUP - CCITT 88 & 92           SUB       $[**]         $[**]          [**]
- -------------------------------------------------------------------------------------------------------
1000029       12           ISUP - ANSI 88 & 92            SUB       $[**]         $[**]          [**]
- -------------------------------------------------------------------------------------------------------
1020031       21          VxWorks/Tornado System          SUB       $[**]         $[**]          [**]
                            Services - General
- -------------------------------------------------------------------------------------------------------
1000100       --        Motorola MPC860 SCC Driver        SUB       $[**]         $[**]          [**]
- -------------------------------------------------------------------------------------------------------
1068001       01      MOS Binary - Microsoft Visual       UNB       $[**]         $[**]          [**]
                          C++ V2.1 for WindowsNT
- -------------------------------------------------------------------------------------------------------



         The total license and maintenance fees are:

         (1) Total License Fees:  $[**]

         (2) Total Maintenance Fees (Annual):  $[**]

         If Maintenance Services art requested for more than one (1) LICENSEE
         site, or more than one (1) type of Designated Equipment, additional
         maintenance fees may be charged.

2.       MAINTENANCE SERVICE: (check applicable box)

         [ ]      By checking this box, LICENSEE orders Maintenance Service for
                  the Licensed Programs for the first year following the end of
                  the applicable warranty period.



                                     Page 23
   24
                  TRILLIUM will invoice LICENSEE for the applicable fees for
                  such Maintenance Service (as specified above) at the
                  appropriate time.

         [ ]      By checking this box, LICENSEE declines to order Maintenance
                  Service for the Licensed Programs for the first year following
                  the end of the applicable warranty period. LICENSEE may
                  subsequently order Maintenance Service as provided in this
                  Agreement, but the fees for such Maintenance Service will be
                  as quoted by TRILLIUM at the time such Maintenance Service is
                  ordered and may vary from the fees set forth above.

3.       LICENSE TYPE DEFINITIONS:

         Single Use Buyout ("SUB") - License granted per terms of this Agreement
         to Use Source Form and sublicense an unlimited number of copies of
         Object Form with the Designated Equipment as specified in Exhibit A.
         There is a one time fee with no per Object Form royalty due.

         Unsupported Binary ("UNB") - License granted per terms of this
         Agreement to Use Object Form, but does not grant right to distribute
         copies of Object Form. Up to two (2) copies of the Object Form may be
         Used in the LICENSEE'S facilities for test purposes. No warranty,
         training, documentation, maintenance or other services will be provided
         for the Object Form. LICENSEE shall not reproduce, print, sublicense,
         duplicate, reverse engineer, decompile, distribute, disclose, or
         otherwise make the Object Form available to any third party, in whole
         or in part, in whatever form.





                                     Page 24
   25

                                    EXHIBIT C

                        SIMPLE END USER LICENSE AGREEMENT

This agreement grants a limited license to the Purchaser of Equipment ("END USER
LICENSEE") to use the object code (the "Licensed Program") embodied in the
following software or firmware (the "Designated Equipment") solely in connection
with the Designated Equipment listed. Installation and use of such Designated
Equipment constitutes END USER LICENSEE'S acceptance of the Terms and Conditions
contained herein.

1.    DEFINITIONS

      1.1   "Designated Equipment" shall refer to: [INSERT DESCRIPTION OF THE
            DESIGNATED EQUIPMENT HERE].


      1.2   "Use" shall mean the copying or duplication of any portion of a
            Licensed Program from storage units or media into the equipment for
            processing or the utilization of any Licensed Program in the course
            of the operation of the Designated Equipment.

2.    LICENSE GRANT

      Use of Object Licensed Program with Designated Equipment. LICENSOR hereby
      grants END USER LICENSEE a non-exclusive, non-transferable, except as
      provided in Paragraph 5, license to Use in machine readable form (i.e.,
      object form) the Licensed Program solely on the Designated Equipment. No
      license is granted to Use any Licensed Program on any configuration of
      equipment which is different from or less than the configuration indicated
      in Paragraph 1.1.

3.    PROPRIETARY RIGHTS

      The Licensed Program is owned by LICENSOR and/or its licensors and is
      proprietary in nature. END USER LICENSEE shall respect such proprietary
      rights and shall not use such Licensed Program except for the purposes for
      which it is being made available as set forth in this agreement and shall
      not reproduce, print, sublicense, duplicate, reverse engineer, distribute,
      disclose, or otherwise make the Licensed Program available to any third
      party, in whole or in part, in whatever form. END USER LICENSEE shall take
      all actions required to maintain control of the Licensed Program including
      securing written records, agreements, and other reasonable measures with
      its employees and agents to satisfy its obligations under this agreement.

4.    LIMITATIONS

      4.1.  No Warranty. LICENSOR AND ITS LICENSORS MAKE NO WARRANTIES, EXPRESS
            OR IMPLIED, INCLUDING WITHOUT LIMIATION, WARRANTIES OR
            MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE WITH REGARD TO
            ANY LICENSED

   26


            PROGRAM OR RELATED MATERIALS TO BE FURNISHED TO END USER LICENSEE.


      4.2.  Limitations on Liability. In no event shall LICENOSR or its
            licensors be liable for any indirect, special or consequential
            damages in connection with or arising out of the existence,
            furnishing, failure to furnish, failure to furnish, or use of any
            Licensed Program and/or related material and/or device. LICENSOR and
            its licensors shall have no liability for any claim of copyright or
            patent infringement based in (i) Use of other than a current
            unaltered release of the Licensed Program available from LICENSOR if
            such infringement would have been avoided by the use of such current
            unaltered release of the Licensed Program, or (ii) Use or
            combination of the Licensed Program with programs not supplied by
            LICENSOR and which Use or combination results in the infringement of
            any patent or copyright.

5.    TRANSFER OF LICENSE

      This license may only be transferred in connection with the transfer of
      all of the Designated Equipment; provided all copies of the Licensed
      program are delivered to the transferee and no copies or related materials
      are retained by END USER LICENSEE and provided further that the transferee
      agrees to be bound by all the Terms and Conditions of this End User
      License Agreement.

[Note: Also add any provisions required by Paragraphs 2.2 and 2.4 of the
Software License Agreement.]



   27


   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                                    EXHIBIT D

                               MAINTENANCE SERVICE

Maintenance Service with respect to Licensed Programs entitles LICENSEE to
receive Updates and Upgrades of the Licensed Programs, technical bulletins and
Documentation Updates as they become Public Releases. Maintenance Service also
entitles LICENSEE to receive telephone, FAX or e-mail technical support of
LICENSEE'S use of the Licensed Programs.

1.    Error Corrections, TRILLIUM shall use reasonable efforts to correct any
      documented reproducible program errors in a Source Form Licensed Program
      within a reasonable time, and to use due diligence to rectify such errors
      that have been notified in writing by LICENSEE; provided, however, that
      such program errors have not been introduced through modifications made by
      LICENSEE.

      Such service, with respect to a given program error, will be provided
      after TRILLIUM receives a request in writing from LICENSEE on TRILLIUM'S
      form of Action Request as set forth in Exhibit E. TRILLIUM reserves the
      right, from time to time, to modify the form utilized for this purpose as
      may be reasonable and necessary and so shall notify LICENSEE in such
      event.

      If LICENSEE reports a program error to TRILLIUM, LICENSEE shall give
      TRILLIUM reasonable access to the Designated Equipment, a copy of the
      Licensed Program as being used by LICENSEE and all relevant Documentation
      and records, and shall provide all reasonable assistance as TRILLIUM may
      request, including without limitation sample output and other diagnostic
      information to assist TRILLIUM in providing the Maintenance Service.

      Three classes of program errors are provided for, and TRILLIUM shall
      respond under this Agreement as follows:

      1.1.  CRITICAL. Program errors that cause software crashes, or similar
            events. The maximum time from notification to initiation of TRILLIUM
            response shall be [**].

      1.2.  MODERATE. Program errors that do not cause software crashes or for
            which a work-around is possible. The maximum time from notification
            to initiation of TRILLIUM response shall be less than [**].

      1.3.  NON-CRITICAL. Program Documentation errors. The maximum time from
            notification to initiation of TRILLIUM response shall be less than
            [**].

2.    Product Update. For every error found by LICENSEE, and properly reported
      to TRILLIUM, or found by TRILLIUM in a Source Form Licensed Program,
      TRILLIUM will undertake to:

   28


      2.1.  Incorporate an error correction in the next Public Release of that
            specified Licensed Program which initially contained the error; and

      2.2.  Supply LICENSEE, subject to the applicable provisions of this
            Agreement, the latest Public Release of the Licensed Program
            containing such error correction no later than four (4) calendar
            months after the program error has been reported to or by TRILLIUM.

3.    PRODUCT UPGRADE. Should TRILLIUM make any Upgrade of a Licensed Program,
      TRILLIUM will undertake to:

      3.1.  Inform LICENSEE of any such Upgrade; and

      3.2.  Supply LICENSEE, subject to the applicable provisions of this
            Agreement, the latest Public Release of the Licensed Program
            containing such Upgrade.

4.    TRILLIUM'S SUPPORT TO LICENSEE EXCLUSIVELY. LICENSEE shall be solely
      responsible for directly supporting and providing maintenance of all or
      any part of the Licensed Programs and documentation as provided to
      LICENSEE'S customers. TRILLIUM shall have no obligation to provide any
      direct consultation or warranty or maintenance support to LICENSEE'S
      customers with respect to all or any part of the Licensed Programs or
      other subject matter of this Agreement.

5.    LICENSE GRANTS TO UPDATES OR UPGRADES. Any rights and obligations of
      LICENSEE as to Source Form and Object Form of the Licensed Programs and
      Documentation shall extend to any Updates or Upgrades thereof upon
      delivery thereof by TRILLIUM to LICENSEE. TRILLIUM shall have no
      responsibility under this Agreement to correct any alleged error if
      LICENSEE fails to incorporate any Update or Upgrade of a Licensed Program
      that TRILLIUM has provided to LICENSEE.

6.    LIMITATIONS. If TRILLIUM is requested, pursuant to the applicable
      provisions of this Agreement, to correct an error and such error is found
      to be caused by LICENSEE'S negligence, modification by LICENSEE, LICENSEE
      supplied data, operator error or misuse, or any other cause not inherent
      in the Source Form Licensed Programs, LICENSEE agrees to pay for such
      support services on a time and material basis at TRILLIUM'S then
      prevailing standard rates, as specified in Exhibit F, when invoiced by
      TRILLIUM. Under no circumstances does TRILLIUM warrant or represent that
      every error can or will be corrected.


   29


                                    EXHIBIT E

                             TRILLIUM ACTION REQUEST

Licensee Name:
              ------------------------------------------------------------------

Contact Name:
             -------------------------------------------------------------------

Address:
        ------------------------------------------------------------------------

Phone:                                         Fax:
      --------------------------------------       -----------------------------

Best Time to Contact:
                     -----------------------------------------------------------

Date Problem Observed:                         Date Problem Reported:
                      ----------------------                        ------------

Requested Priority:  Critical           Moderate           Non-critical
                             ----------         ----------             ---------

Product Name:
             -------------------------------------------------------------------

Product Part No.:                           Product Version:
                 --------------------------                ---------------------

Describe Configuration:
                       ---------------------------------------------------------


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


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

Describe Problem:
                 ---------------------------------------------------------------


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


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


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

Describe Attached Materials:
                            ----------------------------------------------------


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

Date Received:              Date Closed:               Report Number:
              -------------            ----------------             ------------



   30


   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                                    EXHIBIT F

                             TRILLIUM STANDARD RATES

These rates are referenced in Paragraph 6 of Exhibit D to this Agreement.

1.    TRILLIUM'S standard rates at the date of this Agreement are:

      PERSONNEL CLASS HOURLY RATE

      Principal                  $[**]
      Senior MTS                 $[**]
      MTS                        $[**]
      Assoc. MTS                 $[**]
      Technician                 $[**]
      Clerical          $[**]

      MTS = Member of Technical Staff

2.    PERSONNEL CLASS DEFINITIONS:

      Clerical          An employee who performs mainly non-professional,
                        clerical work (e.g., documentation, filing, shipping,
                        etc.)

      Technician        An employee involved in non-professional, technical
                        activities (e.g., setting up of test equipment, repair
                        submodules, assisting in debugging and testing, creating
                        test submodules, etc.)

      Associate MTS     Typically an employee with a professional degree (e.g.,
                        BS or MS) but minimal work experience, whose work
                        requires detailed supervision.

      MTS               Typically an employee with a professional degree and 1-4
                        years of work experience who is able to produce basic
                        software modules to specifications and test them
                        independently.

      Senior            MTS An MTS with at least five years experience who is
                        able to manage a complete project from inception to
                        completion with minimal management direction.

      Principal         A senior architect who participates in the design of the
                        overall Trillium software architecture, and has a full
                        visibility of the complete product line.

   31


      In addition to payment for personnel services, TRILLIUM will be reimbursed
      for all reasonable expenses including, but not limited to: approved
      travel, shipping, supplies and rental equipment.

      These rates are subject to change at the sole option of Trillium.


   32
                                      Amendment No. 1 to Agreement dated 2/25/98


                           LICENSE AGREEMENT AMENDMENT

This License Agreement Amendment is entered into as of April 30, 1998 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation having its principal office at 12100 Wilshire Blvd., Suite 1800, Los
Angeles, California, USA 90025-7118 (hereinafter referred to as "TRILLIUM"), and
CASTLE NETWORKS INC, a Massachusetts corporation having its principal office at
235 Littleton Road #2, Westford, Massachusetts 01886 (hereinafter referred to as
"LICENSEE").

TRILLIUM and LICENSEE previously entered into that certain Software License
Agreement, dated as of February 25,1998 (the "License Agreement"), under which
TRILLIUM granted LICENSEE Single Use Buyout ("SUB") licenses for certain
TRILLIUM products and which is currently in effect between the parties. TRILLIUM
and LICENSEE now desire to modify certain terms of the License Agreement as
described below.

TRILLIUM and LICENSEE hereby amend the License Agreement as follows:

1.       The parties hereby amend Paragraph 4.1 of the License Agreement in its
         entirety to read as follows:

         4.1      Acceptance. Each Licensed Program and the related
                  Documentation shall be deemed accepted by LICENSEE thirty (30)
                  days after, delivery (or sixty (60) days with respect to Part
                  Numbers 1000027(Option --), 1000028 (Option --), 1000028
                  (Option 12), 1000029 (Option --), 1000029 (Option 12), 1020031
                  (Option 21), 1000100 (Option --) and 1068001 (Option 01))
                  unless, within such period, LICENSEE delivers to TRILLIUM a
                  notice of rejection in accordance with this Paragraph 4.1. The
                  sole criterion for rejection of any Licensed Program or
                  related Documentation shall be its failure to conform in all
                  material respects to the specifications referenced in
                  paragraph 2 of Exhibit A or the requirements of Paragraph 3.2.
                  Any notice of rejection shall be valid only if (i) it is
                  delivered to TRILLIUM within such thirty (30) day period (or
                  sixty (60) day period with respect to Part Numbers
                  1000027(Option --), 1000028 (Option --), 1000028 (Option 12),
                  1000029 (Option --, 1000029 (Option 12), 1020031 (Option 21),
                  1000100 (Option --) and 1068001 (Option 01)) and (ii) it
                  specifies in reasonable detail each of the specifications to
                  which such Licensed Program fails to conform, or each
                  requirement to which such Documentation fails to conform, and
                  the basis for LICENSEE's assertion of nonconformance.

2.       The parties hereby amend Paragraph 9.2 of the License Agreement in its
         entirety to read as follows:

         9.2      Confidential Information. For purposes of this Agreement,
                  "Confidential Information" of a party (the "Discloser") shall
                  mean any information which is disclosed to the other party
                  (the "Recipient") during the term of this Agreement that
                  relates in any way to any Licensed Program and which (i) is in
                  written,


                                      -1-
   33
                                      Amendment No. 1 to Agreement dated 2/25/98


                  recorded, electronic, graphical or other tangible form and
                  marked confidential or with a similar legend or other notation
                  denoting the confidential nature of the information or
                  proprietary interest of the Discloser, or (ii) is disclosed
                  orally and is identified orally as confidential and/or
                  proprietary at the time of disclosure and is identified as
                  confidential or proprietary by the Discloser in a writing
                  delivered to the Recipient prior to or within thirty (30) days
                  after the time of disclosure; and "Confidential Information"
                  shall include all notes, memoranda, analyses, compilations,
                  studies, and other documents and records prepared by or for
                  the Recipient, which contain any Confidential Information.
                  TRILLIUM "Confidential Information" shall in all events
                  include but not be limited to the Licensed Programs,
                  Documentation and related materials and information.
                  Notwithstanding the foregoing, "Confidential Information"
                  shall not include any information which (a) is in the public
                  domain at the time of disclosure or becomes public domain
                  information other than through a breach of this Agreement, (b)
                  has been lawfully acquired by the Recipient from an Unrelated
                  Party, (c) is already in the Recipient's possession from an
                  Unrelated Party at the time of disclosure (as evidenced by the
                  Recipient's business records), or (d) is demonstrated by the
                  Recipient to have been independently developed by the
                  Recipient. For purposes hereof, the term "Unrelated Party"
                  shall mean a person who is not the Discloser, not an
                  affiliate, employee or agent of the Discloser, and not a
                  person known by the Recipient to be prohibited from disclosing
                  the Confidential Information to the Recipient by any
                  contractual, legal or fiduciary obligation.

3.       The parties hereby amend Paragraph 10.1 of the License Agreement in its
         entirety to read as follows:

         10.1     Indemnity. TRILLIUM represents and warrants that it has the
                  sufficient right, title and interest in the Licensed Programs
                  to enter into this Agreement. TRILLIUM agrees, at its own
                  expense, to indemnify and defend LICENSEE and hold LICENSEE
                  harmless against any loss, suit, claim, liability, expense
                  (including without limitation reasonable attorney's fees) or
                  proceeding brought against LICENSEE alleging that any use of
                  the Licensed Programs as delivered by TRILLIUM infringes any
                  patent, copyright or trademark or any trade secrets of any
                  third parties, provided that LICENSEE (i) promptly notifies
                  TRILLIUM in writing of any such suit, claim or proceeding,
                  (ii) allows TRILLIUM at its expense, to direct the defense of
                  such suit, claim, or proceeding, (iii) gives TRILLIUM all
                  information and assistance TRILLIUM reasonably considers
                  useful to defend such suit, claim or proceeding, and (iv) does
                  not enter into any settlement of any such suit, claim or
                  proceeding without TRILLIUM written consent



                                      -2-
   34

                                      Amendment No. 1 to Agreement dated 2/25/98


4.       The parties hereby amend Paragraph 11 of the License Agreement in its
         entirety to read as follows:

         TRILLIUM's aggregate liability to LICENSEE and its sublicensees under,
         arising out of or related to any provision of this Agreement, or at law
         or in equity (including without limitation pursuant to any claim for
         indemnification), or any transaction contemplated by this Agreement,
         shall be limited to the amount of the license: fees actually paid by
         LICENSEE to TRILLIUM under this Agreement. TRILLIUM's limitation of
         liability is cumulative with all of TRILLIUM's payments to LICENSEE in
         satisfaction of TRILLIUM's liabilities under this Agreement being
         aggregated to determine satisfaction of the limit.

         IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY INDIRECT, SPECIAL, OR
         CONSEQUENTIAL DAMAGES IN CONNECTION WITH OR ARISING OUT OF THIS
         AGREEMENT, WHETHER BASED ON BREACH OF CONTRACT, TORT (INCLUDING
         NEGLIGENCE), PRODUCT LIABILITY, OR OTHERWISE, AND WHETHER OR NOT IT HAS
         BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

5.       The parties hereby amend Paragraph 12 of the License Agreement in its
         entirety to read as follows:

         LICENSEE shall indemnify and defend TRILLIUM and its affiliates and
         hold them harmless from and against any loss, suit, claim, liability,
         expense (including without limitation reasonable attorney's fees),
         proceeding or damage to persons or property arising out of or related
         to the use or possession of the Licensed Programs or any Documentation
         or related materials by LICENSEE or any of its sublicensees, provided
         that such loss, suit, claim, expense, proceeding or damage (I) is not
         the subject of indemnity by TRILLUM under Paragraph 10.1 and only to
         the extent (ii) that such loss, suit, claim expense, proceeding or
         damage was not caused by the negligence of TRILLIUM or of TRILLUM
         employees or representatives.

6        The parties hereby amend Paragraph 14 of the License Agreement in its
         entirety to read as follows:

         14.      Assignments

                  The rights and obligations of LICENSEE under this Agreement
                  may not be assigned or delegated (by operation of law or
                  otherwise) by LICENSEE without the prior written consent of
                  TRILLIUM (which consent shall not be unreasonably withheld)
                  except for an assignment of this entire Agreement to an
                  affiliate of LICENSEE that does not compete directly with
                  TRILLIUM and only if such assignment is incident to a transfer
                  of the business that includes the Designated Equipment as
                  specified in Exhibit A, and in all cases, any assignment may
                  be made only upon thirty (30) days prior written notice to
                  TRILLLIUM and shall be effective only upon the execution by
                  the proposed assignee of an assignment agreement acceptable in
                  form and substance to TRILLIUM, which




                                      -3-
   35

                  shall include without limitation the proposed assignee's
                  assumption of and agreement to be bound by all of the terms
                  and conditions of this Agreement and all amendments thereto.
                  TRILLIUM'S rights and obligations under this Agreement may
                  with notice to the LICENSEE be assigned and/or delegated by
                  TRILLIUM to any affiliate of TRILLIUM or incident to the
                  transfer of the business of TRILLIUM to which this Agreement
                  relates. TRILLIUM may upon notice given at any time to
                  LICENSEE assign its rights to receive fees and other monies
                  hereunder. Subject to the limitations on assignment contained
                  in the foregoing provisions of this Paragraph, this Agreement
                  shall be binding upon and inure to the benefit of the
                  successors and assigns of the parties there.

7.       General. All provisions of the License Agreement not specifically
         modified by this Amendment remain in full force and effect.

IN WITNESS THEREOF, the parties hereto have caused this Amendment to be executed
by heir respective duly authorized representative as of the date first above
written.

Company:     Castle Networks                     Trillium Digital Systems, Inc.

Signature:   /s/ Michael D. Regan                /s/ Richard O. Whalen
             --------------------------          --------------------------
Name:        Michael D. Regan                    Richard O. Whalen
             --------------------------          --------------------------
Title:       Director                            CEO
             --------------------------          --------------------------
Date:        April 24, 1998                      April 30, 1998
             --------------------------          --------------------------




                                      -4-
   36
                                      Amendment No. 2 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                           LICENSE AGREEMENT AMENDMENT

This License Agreement Amendment is entered into as of December 31, 1998 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation having its principal office at 12100 Wilshire Blvd., Suite 1800, Los
Angeles, California, USA 90025-7118 (hereinafter referred to as "TRILLIUM"), and
CASTLE NETWORKS INC., a Massachusetts corporation having its principal office at
68 Tadmuck Road, Westford, Massachusetts 01886 (hereinafter referred to as
"LICENSEE").

TRILLIUM and LICENSEE previously entered into that certain Software License
Agreement, dated as of February 25, 1998 (the "License Agreement"), under which
TRILLIUM granted LICENSEE Single Use Buyout ("SUB") licenses for certain
TRILLIUM products and which was amended by the first amendment thereto to modify
certain terms of the License Agreement. Such license is currently in effect
between the parties. TRILLIUM and LICENSEE now desire to add SUB licenses for
the additional TRILLIUM products to the License Agreement as described below.

TRILLIUM and LICENSEE hereby amend the License Agreement as follows:

1.       By this amendment, the parties hereby add to the License Agreement the
         additional TRILLIUM product described in Exhibit I of this Amendment,
         subject to the payment of the additional license fees described in
         Exhibit II of this Amendment. Exhibits I and II hereto shall be
         incorporated into and amend Exhibits A and B, respectively, to the
         License Agreement.

2.       The parties hereby amend the definition of "Designated Equipment" in
         Paragraph 4 of Exhibit A to the License Agreement, in its entirety, to
         read as the new Paragraph 4 of Exhibit I attached herein.

3.       The parties  hereby amend  Paragraph  5.4, in its entirety,  to read as
         follows:

                  5.4      Records. LICENSEE agrees to keep all usual and proper
                           records and books of accounts and all usual and
                           proper entries therein relating to sublicense of the
                           Licensed Programs hereunder. Upon reasonable notice,
                           TRILLIUM or its duly appointed representative shall
                           have the right to audit LICENSEE'S manufacturing and
                           shipment records related to the Licensed Programs for
                           any period of time at any time. These examinations
                           shall occur during normal business hours at
                           LICENSEE'S place of business and shall not occur more
                           frequently than two times per year. LICENSEE shall
                           have the right to remove customer-identifying
                           information from such records (such as customer names
                           and addresses) and all such records shall be
                           considered Confidential Information as defined in
                           Paragraph 9.


                                                                          Page 1

   37
                                      Amendment No. 2 to Agreement dated 2/25/98


4.       The parties hereby amend Paragraph 8.3, in its entirety, to read as
         follows:

                  8.3      Preservation of Notices. TRILLIUM shall retain title
                           and copyrights to the Licensed Programs,
                           Documentation and related materials that are provided
                           by TRILLIUM to LICENSEE. The Source Form Licensed
                           Programs and Documentation contain copyright notices,
                           proprietary notices and restricted rights legends.
                           LICENSEE shall retain all such notices on all copies
                           thereof (whether full or partial), and LICENSEE
                           agrees to reproduce and include in all copies
                           (whether full or partial) of the Object Form Licensed
                           Programs all such notices and legends contained in
                           the Source Form Licensed Programs.

5.       The parties hereby amend the address of LICENSEE in Paragraph 16 of the
         License Agreement to be as follows until changed in accordance with the
         provisions of that Paragraph:

                  LICENSEE:   Castle Networks, Inc.
                              68 Tadmuck Road
                              Westford, MA 01886
                              Attn: Contract Administration
                              Facsimile No.: +1-978-392-9032

6.       General. All provisions of the License Agreement not specifically
         modified by this Amendment remain in full force and effect.


IN WITNESS THEREOF, the parties hereto have caused this Amendment to be executed
by their respective duly authorized representative as of the date first above
written.

                LICENSEE:                       TRILLIUM:

Company:        CASTLE NETWORKS, INC.           TRILLIUM DIGITAL SYSTEMS, INC.


Signature:      /s/ Michael D. Regan             /s/ Richard O. Whalen
                ------------------------        -------------------------------
Name:           Michael D. Regan                Richard O. Whalen
                ------------------------        -------------------------------
Title:          VP Engineering
                ------------------------        -------------------------------
Date:           12/31/98                        December 31, 1998
                ------------------------        -------------------------------

Attachments:    Exhibit I;        Exhibit II



                                                                         Page 2

   38
                                      Amendment No. 2 to Agreement dated 2/25/98


                               AMENDMENT EXHIBIT I

                                LICENSED PROGRAMS




- --------------------------------------------------------------------------------
 Part No.    Options              Name                Version      Ship Date
- --------------------------------------------------------------------------------
                                                       

  1000133       --        Fault Tolerance/High         Latest      1 Week ARO
                              Availability
- --------------------------------------------------------------------------------
  1000145       --      PSF - MTP Level 3 (FT/HA)      Latest      1 Week ARO
- --------------------------------------------------------------------------------
  1000146       --         PSF - ISUP (FT/HA)          Latest      1 Week ARO
- --------------------------------------------------------------------------------



4.       LICENSEE'S "DESIGNATED EQUIPMENT":

LICENSEE'S C2100 Service Mediation Platform, a self-contained Public Switched
Telephone Network (PSTN) voice gateway product, which is a 23" proprietary NEBS
compliant chassis with multiple shelves and proprietary busses, running VxWorks
and using PowerPC and PowerQUICC processors however, LICENSEE may produce
versions of this product which vary only in their size and scaleability so long
as each version is substantially similar in functionality to the C2100 model.




                                                                          Page 3
   39
                                      Amendment No. 2 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                              AMENDMENT EXHIBIT II

                          LICENSE AND MAINTENANCE FEES



- ----------------------------------------------------------------------------------------------
Part No.     Options              Name             License     License      Main-     Training
                                                     Type      Fee (1)     tenance     (Hours)
                                                                             Fee
                                                                           (Annual)
                                                                             (2)
- ----------------------------------------------------------------------------------------------
                                                              

 1000133        --        Fault Tolerance/High       SUB        $[**]       $[**]       [**]
                              Availability
- ----------------------------------------------------------------------------------------------
 1000145        --     PSF - MTP Level 3 (FT/HA)     SUB        $[**]       $[**]       [**]
- ----------------------------------------------------------------------------------------------
 1000146        --         PSF - ISUP (FT/HA)        SUB        $[**]       $[**]       [**]
- ----------------------------------------------------------------------------------------------


(1)  Total License Fees:        $[**]
(2)  Annual Maintenance Fees:   $[**]




                                                                          Page 4
   40
                                      Amendment No. 3 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                           LICENSE AGREEMENT AMENDMENT

This License Agreement Amendment is entered into as of July 12, 1999 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation having its principal office at 12100 Wilshire Blvd., Suite 1800, Los
Angeles, California, USA 90025-7118 (hereinafter referred to as "TRILLIUM"), and
CASTLE NETWORKS INC., A WHOLLY-OWNED SUBSIDIARY OF SIEMENS AG, a Massachusetts
corporation having its principal office at 1 Executive Drive, Chelmsford,
Massachusetts 01824 and facsimile number +1-978-392-9632 (hereinafter referred
to as "LICENSEE").

TRILLIUM and LICENSEE previously entered into that certain Software License
Agreement, dated as of February 25, 1998 (the "License Agreement"), under which
TRILLIUM granted LICENSEE Single Use Buyout ("SUB") licenses for certain
TRILLIUM products and which was amended by the first amendment thereto to modify
certain terms of the License Agreement and, which was amended by a second
amendment thereto, dated December 31, 1998, to add SUB licenses for additional
TRILLIUM products and, which was amended by an. Such license is currently in
effect between the parties. TRILLIUM and LICENSEE now desire to add SUB licenses
for the additional TRILLIUM products to the License Agreement as described
below.

TRILLIUM and LICENSEE hereby amend the License Agreement as follows:

1.       By this amendment, the parties hereby add to the License Agreement the
         additional TRILLIUM product described in Exhibit I of this Amendment,
         subject to the payment of the additional license fees described in
         Exhibit II of this Amendment. Exhibits I and II hereto shall be
         incorporated into and amend Exhibits A and B, respectively, to the
         License Agreement.

2.       The parties hereby amend the address of LICENSEE in Paragraph 16 of the
         License Agreement to be as follows until changed in accordance with the
         provisions of that Paragraph:

             LICENSEE:   Castle Networks, Inc., a wholly-owned subsidiary of
                         Siemens AG
                         1 Executive Drive
                         Chelmsford, MA 01824
                         Attn: Contract Administration
                         Facsimile No.: +1-978-392-9632

3.       General. All provisions of the License Agreement not specifically
         modified by this Amendment remain in full force and effect.




   41



IN WITNESS THEREOF, the parties hereto have caused this Amendment to be executed
by their respective duly authorized representative as of the date first above
written.




               LICENSEE:                      TRILLIUM:

Company:       CASTLE NETWORKS, INC.          TRILLIUM DIGITAL SYSTEMS, INC.

Signature:     /s/ Michael D. Regan           /s/ Martin Kovacich
               -----------------------        -----------------------------
Name:          Michael D. Regan               Martin Kovacich
Title:         VP Engineering                 CFO
Date:          7/12/99                        7/12/99

Attachments:   Exhibit I;              Exhibit II




   42
                                      Amendment No. 3 to Agreement dated 2/25/98


                               AMENDMENT EXHIBIT I

                                LICENSED PROGRAMS



- ----------------------------------------------------------------------------------------
Part No.       Options                    Name                   Version       Ship Date
- ----------------------------------------------------------------------------------------
                                                                  

1000030           01          SCCP - Connectionless-CCITT         Latest      1 Week ARO
                                        88 & 92
- ----------------------------------------------------------------------------------------
1000030           12               SCCP - ANSI 88 &92             Latest      1 Week ARO
- ----------------------------------------------------------------------------------------
1000031           --              TCAP - CCITT 88 & 92            Latest      1 Week ARO
- ----------------------------------------------------------------------------------------
1000031           12              TCAP - ANSI 88 & 92             Latest      1 Week ARO
- ----------------------------------------------------------------------------------------
1000093           01                  INAP - Base                 Latest      1 Week ARO
- ----------------------------------------------------------------------------------------
1000093           15               INAP - AINGR - SSP             Latest      1 Week ARO
- ----------------------------------------------------------------------------------------
1000093           16               INAP - AINGR - SCP             Latest      1 Week ARO
- ----------------------------------------------------------------------------------------
1000093           17                    INAP-IP                   Latest      1 Week ARO
- ----------------------------------------------------------------------------------------
1068003           01                 MTSS-Windows NT              Latest      1 Week ARO
                                       Binary-User
                                         Space
- ----------------------------------------------------------------------------------------






   43
                                      Amendment No. 3 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                              AMENDMENT EXHIBIT II

                          LICENSE AND MAINTENANCE FEES




- -------------------------------------------------------------------------------------------------
Part No.     Options               Name            License     License    Maintenance    Training
                                                    Type       Fee (1)    Fee (Annual)   (Hours)
                                                                               (2)
- -------------------------------------------------------------------------------------------------
                                                                          

 1000030       01         SCCP - Connectionless-      SUB       $[**]         $[**]         [**]
                               CCITT 88 & 92
- -------------------------------------------------------------------------------------------------
 1000030       12           SCCP - ANSI 88 & 92       SUB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------
 1000031       --         TCAP - CCITT 88 & 92        SUB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------
 1000031       12           TCAP - ANSI 88 & 92       SUB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------
 1000093       01               INAP - Base           SUB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------
 1000093       15           INAP - AINGR - SSP        SUB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------
 1000093       16           INAP - AINGR - SCP        SUB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------
 1000093       17                 INAP-IP             SUB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------
 1068003       01             MTSS-Windows NT
                             Binary-User Space        UNB       $[**]         $[**]         [**]
- -------------------------------------------------------------------------------------------------


(1)      License Fees:              $[**]
         One-time, 10% discount     $([**])
         TOTAL LICENSE FEES:        $[**]

(2)      Annual Maintenance Fees:   $[**]







   44
                                      Amendment No. 4 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                           LICENSE AGREEMENT AMENDMENT


This License Agreement Amendment is entered into as of July 28, 1999 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation having its principal office at 12100 Wilshire Blvd., Suite 1800, Los
Angeles, California, USA 90025-7118 (hereinafter referred to as "TRILLIUM"), and
CASTLE NETWORKS INC., a wholly-owned subsidiary of Siemens AG, a Massachusetts
corporation having its principal office at 1 Executive Drive, Chelmsford,
Massachusetts 01824 and facsimile number +1-978-392-9632 (hereinafter referred
to as "LICENSEE").

TRILLIUM and LICENSEE previously entered into that certain Software License
Agreement, dated as of February 25, 1998 (the "License Agreement"), under which
TRILLIUM granted LICENSEE Single Use Buyout ("SUB") licenses for certain
TRILLIUM products and which was amended by the first amendment thereto to modify
certain terms of the License Agreement and, which was amended by a second
amendment thereto, dated December 31, 1998, to add SUB licenses for additional
TRILLIUM products and, which was amended by a third amendment, dated July 12,
1999 to add SUB and UNB licenses for additional TRILLIUM products. Such license
is currently in effect between the parties. TRILLIUM and LICENSEE now desire to
add Temporary Development Use ("TDU") licenses for additional TRILLIUM products
to the License Agreement for Use on new Designated Equipment, as described
below.

TRILLIUM and LICENSEE hereby amend the License Agreement as follows:

1.       By this amendment, the parties hereby add to the License Agreement the
         additional TRILLIUM product described in Exhibit I of this Amendment
         for Use on the certain Designated Equipment defined in Exhibit I,
         subject to the payment of the additional license fees and other terms
         described in Exhibit II of this Amendment. Exhibits I and II hereto
         shall be incorporated into and amend Exhibits A and B, respectively, to
         the License Agreement.

2.       The parties hereby acknowledge and agree that the previously existing
         Designated Equipment in the License Agreement shall henceforth be
         referred to as "Designated Equipment Number 1" and, that Designated
         Equipment No. 2 is defined and added to this Agreement as described in
         Paragraph 4 of Exhibit I.

3.       The parties hereby delete Paragraph 5.1.2. of the License Agreement
         and, amend Paragraph 5.1.1. of the License Agreement, which shall
         henceforth read as follows:

                  5.1.1    **      (**%) within thirty (30) days of delivery, as
                           described in Paragraph 3.1.

4.       The parties hereby add Paragraph 8.5 to the License Agreement, which
         shall read as follows:

   45
                                      Amendment No. 4 to Agreement dated 2/25/98


         8.5      Publicity Rights. The parties agree to work together in good
                  faith to issue a public press release related to this
                  Agreement. Such press release shall be pre-approved by both
                  parties in writing. LICENSEE agrees to include TRILLIUM in any
                  published list of telecommunications protocol providers (if
                  and when such list is published), in its public website,
                  publications (including newsletters and trade journals), press
                  releases and the like and, LICENSEE agrees that TRILLIUM shall
                  have the right to publicize its relationship with LICENSEE,
                  and reference LICENSEE as a user of TRILLIUM products, in its
                  public website, publications (including newsletters and trade
                  journals), press releases and the like.

5.       General. All provisions of the License Agreement not specifically
         modified by this Amendment remain in full force and effect.

IN WITNESS THEREOF, the parties hereto have caused this Amendment to be executed
by their respective duly authorized representative as of the date first above
written.


                LICENSEE:                       TRILLIUM:

Company:        CASTLE NETWORKS, INC.           TRILLIUM DIGITAL SYSTEMS, INC.

Signature:      /s/ Michael D. Regan            /s/ Martin Kovacich
                -----------------------         ---------------------------
Name:           Michael D. Regan                Martin Kovacich
                -----------------------         ---------------------------
Title:          VP Engineering                  CFO
                -----------------------         ---------------------------
Date:           7/28/99                         7/28/99

Attachments:    Exhibit I;        Exhibit II




                                      -2-
   46
                                      Amendment No. 4 to Agreement dated 2/25/98


                               AMENDMENT EXHIBIT I

                                LICENSED PROGRAMS



- ---------------------------------------------------------------------------------------------
Part No.    Options                    Name                      Version         Ship Date
- ---------------------------------------------------------------------------------------------
                                                                 

1000172       --           H.323 Gateway and Gatekeeper          Latest         1 Week ARO
- ---------------------------------------------------------------------------------------------
1000152       --                     RTP/RTCP                    Latest         1 Week APR
                                                                               (Scheduled for
                                                                              August 28, 1999)
- ---------------------------------------------------------------------------------------------
1068001       02        MOS Binary - Sun C for Solaris 2.X       Latest         1 Week ARO
- ---------------------------------------------------------------------------------------------


"APR" shall mean After Product Release

4.       LICENSEE'S Designated Equipment:

DESIGNATED EQUIPMENT NO. 1:

For the TRILLIUM products licensed under the original Software License
Agreement, dated February 25, 1998 and the TRILLIUM products licensed under
Amendments No. 1, 2 and 3 thereto, the "Designated Equipment" shall be defined
as follows:

LICENSEE'S C2100 Service Mediation Platform, a self-contained Public Switched
Telephone Network (PSTN) voice gateway product, which is a 23" proprietary NEBS
compliant chassis with multiple shelves and proprietary busses, running VxWorks
and using PowerPC and PowerQUICC processors however, LICENSEE may produce
versions of this product which vary only in their size and scalability so long
as each version is substantially similar in functionality to the C2100 model.

DESIGNATED EQUIPMENT NO. 2:

For the TRILLIUM products referred to as Part Nos. 1000172 (Option --) and
1000152 (Option --), and licensed under Amendment No. 4 to the License
Agreement, dated July 28, 1999, the "Designated Equipment" shall be defined as
follows:

LICENSEE'S Media Gateway controller (O/S, processor, bus, form factor, model
number and model names shall be identified in writing prior to commercialization
of this product).





                                      -3-
   47
                                      Amendment No. 4 to Agreement dated 2/25/98

          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                              AMENDMENT EXHIBIT II

                          LICENSE AND MAINTENANCE FEES


DESIGNATED EQUIPMENT NO. 2:



- -------------------------------------------------------------------------------------------------------
Part No.    Options                Name               License     License Fee    Maintenance   Training
                                                        Type         (1)             Fee        (Hours)
- -------------------------------------------------------------------------------------------------------
                                                                                

1000172       --      H.323 Gateway and Gatekeeper     TDU         $[**]*            $[**]         [**]
- -------------------------------------------------------------------------------------------------------
1000152       --                RTP/RTCP               TDU         $[**]*            $[**]         [**]
- -------------------------------------------------------------------------------------------------------
1068001       02         MOS Binary - Sun C for        UNB          $[**]            [**]          [**]
                               Solaris 2.X
- -------------------------------------------------------------------------------------------------------


* Notwithstanding anything to the contrary in this agreement, the parties agree
that the terms and pricing granted to LICENSEE under this Amendment shall be
considered Confidential Information and shall otherwise not be disclosed to any
third party without the express written permission of TRILLIUM.

(1)       Licensee Fees:                                $[**]

          One-time [**]% promotional discount on      ($[**])

          Part No. 1000172/-
          TOTAL LICENSE FEES:                           $[**]
          ---------------------------------------------------
(2)       Annual Maintenance Fees:                      $[**]

3.       LICENSE TYPE DEFINITIONS:

Temporary Development Use ("IDU") - Temporary (short-term) license granted per
terms of this Agreement to Use Source Form for the specific term set forth in
the Software License Agreement but does not grant any right to sublicense copies
of Object Form with the Designated Equipment as specified in Exhibit A. Up to
two (2) copies of the Object Form may be created and Used in LICENSEE's
facilities for test purposes. There is a one time fee with no per Object Form
royalty due.

CONVERSION AND EXPIRATION OF TDU LICENSES UNDER THIS AMENDMENT.
The TDU licenses granted under this amendment shall expire on September 26, 1999
("Expiration Date") unless the parties otherwise 1) mutually agree in writing to
extend the term



                                      -4-
   48
  Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.


                                      Amendment No. 4 to Agreement dated 2/25/98


of such licenses or, 2) LICENSEE and TRILLIUM have entered into a commercial
royalty-fee bearing license which converts the TDU License Type from TDU to
Royalty ("ROY"). LICENSEE shall receive a [**]% credit of the TDU fees payable
under this agreement towards the applicable Technology Access Fees payable under
a ROY License Type, if the conversion of the TDU licenses occurs prior to the
Expiration Date however, such credit shall be reduced by 10% for each month or
fraction thereof that the TDU licenses are extended or not otherwise converted
by LICENSEE.




                                      -5-
   49
                                      Amendment No. 5 to Agreement dated 2/25/98

   Confidential Materials omitted and filed with the Securities and Exchange
                    Commission. Asterisks denote omissions.


                           LICENSE AGREEMENT AMENDMENT

This License Agreement Amendment is entered into as of September 10, 1999 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation having its principal office at 12100 Wilshire Blvd., Suite 1800, Los
Angeles, California, USA 90025-7118 (hereinafter referred to as "TRILLIUM"), and
CASTLE NETWORKS INC., A WHOLLY-OWNED SUBSIDIARY OF SIEMENS AG, a Massachusetts
corporation having its principal office at 1 Executive Drive, Chelmsford,
Massachusetts, USA 01824 and facsimile number +1-978-392-9632 (hereinafter
referred to as "LICENSEE").

TRILLIUM and LICENSEE previously entered into that certain Software License
Agreement dated as of February 25, 1998, under which TRILLIUM granted LICENSEE
Single Use Buyout ("SUB") licenses for certain TRILLIUM products, which was
amended by a first amendment thereto, dated as of April 30,1998, to modify
certain terms of the Software License Agreement, and which was amended by a
second amendment thereto, dated as of December 31, 1998, to add SUB licenses for
additional TRILLIUM products, and which was amended by a third amendment
thereto, dated as of July 12, 1999, to add SUB and UNB licenses for additional
TRILLIUM products, and which was amended by a fourth amendment thereto, dated as
of July 28, 1999, to add Temporary Development Use ("TDU") licenses for
additional TRILLIUM products for Use on a new Designated Equipment. Such
Software License Agreement, as amended, is currently in effect between the
parties ("License Agreement"). LICENSEE now desires to acquire an additional SUB
license for an additional TRILLIUM product as described below.

TRILLIUM and LICENSEE hereby amend the License Agreement as follows:

1.       By this amendment ("Amendment"), the parties hereby add to the License
         Agreement the additional TRILLIUM product described in Exhibit I of
         this Amendment for Use on the certain Designated Equipment defined in
         Exhibit I, subject to the payment of the additional license fees and
         other terms described in Exhibit II of this Amendment. Exhibits I and
         II hereto shall be incorporated into and amend Exhibits A and B,
         respectively, to the License Agreement.

2.       The parties hereby amend Paragraph 4 of Exhibit A to the License
         Agreement in its entirety to read as set forth on the new Paragraph 4
         of Exhibit I attached hereto.

3.       General. All provisions of the License Agreement not specifically
         modified by this Amendment remain in full force and effect.




                                       1
   50
                                      Amendment No. 5 to Agreement dated 2/25/98


IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their respective duly authorized representative as of the date first above
written.


                LICENSEE:                        TRILLIUM:

Company:        CASTLE NETWORKS, INC.            TRILLIUM DIGITAL SYSTEMS, INC.

Signature:      /s/ Michael D. Regan             /s/ Martin [illegible]
                -------------------------        ------------------------------
Name:           Michael D. Regan                 Martin [illegible]
                -------------------------        ------------------------------
Title:          VP Engineering                   V.P. Finance & Administration
                -------------------------        ------------------------------
Date:           9/22/99                          9/22/99
                -------------------------        ------------------------------

Attachments:    Exhibit I; Exhibit II






                                       2
   51
                                      Amendment No. 5 to Agreement dated 2/25/98


                               AMENDMENT EXHIBIT I

                                LICENSED PROGRAMS



- --------------------------------------------------------------------------------
Part No.     Options                Name                 Version       Ship Date
- --------------------------------------------------------------------------------
                                                          

                           Multi-threaded System
1000138         --            Services - Solaris          Latest      1 Week ARO
- --------------------------------------------------------------------------------


4.        LICENSEE'S DESIGNATED EQUIPMENT:

DESIGNATED EQUIPMENT NO. 1:

For the TRILLIUM products referred to as Part Nos. 1000027 (Option --), 1000028
(Options -- and 12), 1000029 (Options -- and 12), 1020031 (Option 21), 1000100
(Option --) and 1068001 (Option 01), licensed under the original Software
License Agreement dated as of February 25, 1998, and the TRILLIUM products
referred to as Part Nos. 1000133 (Option --), 1000145 (Option --) and 1000146
(Option --), licensed under Amendment No. 2 to the License Agreement dated as of
December 31, 1998, and the TRILLIUM products referred to as Part Nos. 1000030
(Options 01 and 12), 1000031 (Options -- and 12), 1000093 (Options 01, 15, 16
and 17) and 1068003 (Option 01), licensed under Amendment No. 3 to the License
Agreement dated as of July 12, 1999, the "Designated Equipment" shall be defined
as follows:

        LICENSEE'S C2100 Service Mediation Platform, A self-contained Public
        Switched Telephone Network (PSTN) voice gateway product, which is a 23"
        proprietary NEBS compliant chassis with multiple shelves and proprietary
        busses, running VxWorks and using PowerPC and PowerQUICC processors
        however, LICENSEE may produce versions of this product which vary only
        in their size and scaleability so long as each version is substantially
        similar in functionality to the C2100 model.

DESIGNATED EQUIPMENT NO. 2:

For the TRILLIUM products referred to as Part Nos. 1000172 (Option --) and
1000152 (Option --), licensed under Amendment No. 4 to the License Agreement
dated as of July 28, 1999, and the TRILLIUM product referred to as Part No.
1000138 (Option --), licensed under Amendment No. 5 to the License Agreement
dated as of September 10, 1999, the "Designated Equipment" shall be defined as
follows:

        LICENSEE'S Media Gateway controller (O/S, processor, bus, form factor,
        model number and model names shall be identified in writing prior to
        commercialization of this product).



                                       3
   52
                                      Amendment No. 5 to Agreement dated 2/25/98


        Confidential Materials omitted and filed with the Securities and
                Exchange Commission. Asterisks denote omissions.


                              AMENDMENT EXHIBIT II

                          LICENSE AND MAINTENANCE FEES




- -----------------------------------------------------------------------------------------------
                                                                        Maintenance
Part No.   Options              Name             License      License      Fee (2)     Training
                                                   Type       Fee (1)     (Annual)     (Hours)
- -----------------------------------------------------------------------------------------------
                                                                      

                       Multi-threaded System
1000138      --          Services - Solaris         SUB       $[**]        $[**]         [**]
- -----------------------------------------------------------------------------------------------


(1)      License Fees:                 $[**]

(2)      Annual Maintenance Fees:      $[**]

         Total Current Fees Due:       $[**]













                                       4
   53
                                      Amendment No. 6 to Agreement dated 2/25/98


        Confidential Materials omitted and filed with the Securities and
                Exchange Commission. Asterisks denote omissions.


                           LICENSE AGREEMENT AMENDMENT

This License Agreement Amendment is entered into as of February 11, 2000 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation having its principal office at 12100 Wilshire Blvd., Suite 1800, Los
Angeles, California, USA 90025-7118 (hereinafter referred to as "TRILLIUM"), and
UNISPHERE SOLUTIONS, INC., A WHOLLY-OWNED SUBSIDIARY OF SIEMENS AG, a Delaware
corporation having its principal office at 1 Executive Drive, Chelmsford,
Massachusetts, USA 01824 and facsimile number +1-978-392-9632 (hereinafter
referred to as "LICENSEE").

TRILLIUM and CASTLE NETWORKS, INC. ("CASTLE") previously entered into that
certain Software License Agreement dated as of February 25, 1998, under which
TRILLIUM granted LICENSEE Single Use Buyout ("SUB") licenses and an Unsupported
Binary ("UNB") license for certain TRILLIUM products, which was amended by a
first amendment thereto, dated as of April 30, 1998, to modify certain terms of
the Software License Agreement, and which was amended by a second amendment
thereto, dated as of December 31, 1998, to add SUB licenses for additional
TRILLIUM products and to modify the definition of Designated Equipment. Such
Software License Agreement, as amended, was assigned by CASTLE to CASTLE
NETWORKS, INC., A WHOLLY OWNED SUBSIDIARY OF SIEMENS AG "CASTLE/SIEMENS") via an
Assignment and Assumption of Software License Agreement dated as of April 7,
1999. Thereafter, the Software License Agreement was amended by a third
amendment thereto, dated as of July 12, 1999, to add SUB and UNB licenses for
additional TRILLIUM products, and was amended by a fourth amendment thereto,
dated as of July 28, 1999, to add Temporary Development Use ("TDU") and UNB
licenses for additional TRILLIUM products for Use on a new Designated Equipment,
and was amended by a fifth amendment thereto, dated as of September 10, 1999, to
add a SUB license for an additional TRILLIUM product. Such Software License
Agreement, as amended, is currently in effect between the parties (the "License
Agreement"). Effective as of April 12, 1999, CASTLE/SIEMENS was acquired by
LICENSEE. The parties now wish to formalize the assignment of the License
Agreement from CASTLE/SIEMENS to LICENSEE, to modify certain terms of the
License Agreement, and to convert one of the previously acquired TDU licenses to
a Royalty ("ROY") license as described below.

TRILLIUM and LICENSEE hereby amend the License Agreement as follows:

1.       LICENSEE and TRILLIUM hereby acknowledge and agree that all of
         CASTLE/SIEMENS' right, title and interest in and to the License
         Agreement are assigned, transferred, conveyed and set over unto
         LICENSEE, and that LICENSEE hereby assumes and agrees to pay and
         perform and be bound by all of the duties and obligations of
         CASTLE/SLEMENS under the License Agreement, and TRILLIUM hereby
         consents to such assignment and assumption. LICENSEE'S representative
         executing this amendment ("Amendment") has the authority and does
         execute this Amendment on behalf of CASTLE/SIEMENS.



                                                                          Page 1
   54
                                      Amendment No. 6 to Agreement dated 2/25/98


2.       By this Amendment, the parties hereby agree that, with respect to the
         TRILLIUM product described in Exhibit I of this Amendment, and subject
         to the payment of the additional license fees described in Exhibit II
         of this Amendment, the "License Type" is hereby converted to a ROY
         license within the meaning and subject to the terms and conditions of
         the License Agreement. Exhibits I and II hereto shall be incorporated
         into and amend Exhibits A and B, respectively, to the License
         Agreement.

3.       LICENSEE represents, warrants and certifies that LICENSEE and/or its
         predecessor in interest returned and/or destroyed the original and all
         reproductions of the Licensed Program referred to as Part No. 1000152
         (--) and all Documentation and materials related thereto, licensed
         under Amendment No. 4 to the License Agreement dated as of July 28,
         1999. Accordingly, all rights and payment obligations of LICENSEE with
         respect to such Licensed Program and Documentation and materials
         related thereto are hereby terminated.

4.       The parties hereby amend Paragraph 4 of Exhibit A to the License
         Agreement in its entirety to read as set forth on the new Paragraph 4
         of Exhibit I attached hereto.

5.       The parties hereby amend Paragraphs 2.2. and 7.2. of the License
         Agreement to read as follows:

         2.2.     Right to Grant Sublicenses. If the license type specified in
                  Exhibit B attached hereto ("Exhibit B") is a Single Use Buyout
                  ("SUB") license or Royalty ("ROY") license, then TRILLIUM
                  hereby grants LICENSEE for the term of this Agreement a
                  non-exclusive, non-assignable right to grant, and to grant
                  others (including distributors of the Designated Equipment)
                  the right to grant, non exclusive, non-assignable, sublicenses
                  to Use the Object Form on the Designated Equipment, provided
                  that such sublicensees are bound by terms and conditions that
                  are as protective of TRILLIUM's rights as the terms and
                  conditions of this Agreement, including without limitation
                  those terms and conditions set forth in Exhibit C attached
                  hereto (or, in the case of agreements with distributors, terms
                  and conditions as protective of TRILLIUM's rights as the terms
                  and conditions of this Agreement). Notwithstanding anything to
                  the contrary contained elsewhere in this Agreement, no other
                  type of license, if any, granted hereby entitles LICENSEE to
                  grant any sublicense.

         7.2.     Period of Maintenance Service. If the License Type for any
                  Licensed Program in Exhibit B is identified as a ROY license,
                  LICENSEE shall purchase Maintenance Service for such Licensed
                  Program for one (1) LICENSEE site in relation to one (1) type
                  of Designated Equipment for the first year following the end
                  of the warranty period specified in clause (i) of Paragraph
                  6.1 for the fees specified in Exhibit B, and shall continue
                  Maintenance Service for so long as LICENSEE continues to
                  sublicense the Object Form of any such Licensed Program. The
                  minimum period for which LICENSEE may purchase Maintenance
                  Service is one (1) year for one (1) site in relation to one
                  (1) type of Designated Equipment. Maintenance Service periods
                  greater than one (1) year are available in one (1) year
                  increments. The rates shown in Exhibit B cover Maintenance
                  Service for the



                                                                          Page 2
   55

    Confidential Materials omitted and filed separately with the Securities
              and Exchange Commission. Asterisks denote omissions.



                                      Amendment No. 6 to Agreement dated 2/25/98


                  Licensed Program for one (1) LICENSEE site for one (1) type of
                  Designated Equipment for the first year following the end of
                  the warranty period specified in clause (i) of Paragraph 6.1.
                  Maintenance Service for more than one (1) site, or in relation
                  to additional types of Designated Equipment, will be provided
                  only upon terms and conditions to be agreed upon by TRILLIUM
                  and LICENSEE. If there is, at any time, more than one Licensed
                  Program under this Agreement and LICENSEE desires to purchase
                  Maintenance Service for any of the Licensed Programs, TRILLIUM
                  reserves the right to require LICENSEE to purchase Maintenance
                  Service for all Licensed Programs which are variants of one
                  another or are otherwise related to one another as a condition
                  to purchasing Maintenance Service for any of such variant or
                  otherwise related Licensed Programs.

6.       The parties hereby add Paragraphs 5.6., 5.7. and 5.8. to the License
         Agreement, which shall read as follows:

         5.6.     Royalty Fees. If the License Type for any Licensed Program in
                  Exhibit B is identified as a Royalty ("ROY") license, in
                  addition to the Technology Access Fees described in Exhibit B,
                  LICENSEE shall pay TRILLIUM on a    **   basis, in connection
                  with the sublicense, shipment or Use of the Object Form of any
                  Licensed Program (when included in, or distributed with, the
                  Designated Equipment) to an end user of LICENSEE (whether
                  directly from LICENSEE or through a distributor, reseller or
                  otherwise) royalty fees ("Royalty Fees") in the amount and on
                  the basis ("Royalty Basis") specified in Exhibit B. Royalty
                  Fees shall accrue upon the date of shipment of LICENSEE's
                  Designated Equipment to any third party or upon any commercial
                  use thereof (including without limitation any Use other than
                  the development and testing of the Designated Equipment itself
                  regardless of whether such Use is the result of any commercial
                  sale, trade, in-kind or other transfer from LICENSEE's place
                  of business).

         5.7.     Reports. If the License Type for any Licensed Program in
                  Exhibit B is identified as a ROY license, on a     **
                  basis during the Term (commencing with the calendar quarter in
                  which delivery of the Object Form of such Licensed Program
                  first occurs), LICENSEE shall provide to TRILLIUM a report
                  containing the type of information described in Exhibit E to
                  this Agreement, including the number of all copies of the
                  Object Form of any Licensed Program sublicensed by LICENSEE
                  and/or its distributors or resellers (or others acting under
                  its or their authority) during the preceding    **    period,
                  to which a copy was sublicensed during such    **    period.
                  Such reports shall detail each configuration of Designated
                  Equipment and the number of microprocessors present or used
                  with an Object Form on a given type of Designated Equipment.
                  Such reports shall be delivered to TRILLIUM within thirty (30)
                  days after the last day of each calendar quarter.

         5.8.     Payment. Coincident with the    **     report as provided
                  under Paragraph 5.1.4., LICENSEE shall pay to TRILLIUM the
                  amount of Royalty Fees due to TRILLIUM as shown by such
                  report. TRILLIUM's acceptance of any Royalty



                                                                          Page 3
   56

                                      Amendment No. 6 to Agreement dated 2/25/98



                  Fees shall not preclude TRILLIUM from later disputing the
                  amount of Royalty Fees owed.

7.       General. All provisions of the License Agreement not specifically
         modified by this Amendment remain in full force and effect.



IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their respective duly authorized representative as of the date first above
written.


               LICENSEE:                      TRILLIUM:

Company:       UNISPHERE SOLUTIONS, INC.      TRILLIUM DIGITAL SYSTEMS, INC.

Signature:     /s/ Michael D. Regan           /s/ Martin [Illegible]
               --------------------------     -----------------------------
Name:          Michael D. Regan               Martin [illegible]

Title:         V.P. Engineering               V.P. Finance & Administration

Date:          2/11/00                        2/23/00


Attachments:   Exhibit I
               Exhibit II





                                                                          Page 4
   57
                                      Amendment No. 6 to Agreement dated 2/25/98


                               AMENDMENT EXHIBIT I

                                LICENSED PROGRAMS



- --------------------------------------------------------------------------------
Part No.    Options           Name              Version          Ship Date
- --------------------------------------------------------------------------------
                                               

1000172       --           H.323 Gateway         Latest    Previously delivered
                           and Gatekeeper                      and accepted
- --------------------------------------------------------------------------------



4.       LICENSEE'S DESIGNATED EQUIPMENT:

DESIGNATED EQUIPMENT NO. 1:

For the TRILLIUM products referred to as Part Nos. 1000027 (Option --), 1000028
(Options --and 12), 1000029 (Options -- and 12), 1020031 (Option 21), 1000100
(Option --) and 1068001 (Option 01), licensed under the original Software
License Agreement dated as of February 25, 1998, and the TRILLIUM products
referred to as Part Nos. 1000133 (Option --), 1000145 (Option --) and 1000146
(Option --), licensed under Amendment No. 2 to the License Agreement dated as of
December 31, 1998, and the TRILLIUM products referred to as Part Nos. 1000030
(Options 01 and 12), 1000031 (Options-- and 12), 1000093 (Options 01, 15, 16 and
17) and 1068003 (Option 01), licensed under Amendment No. 3 to the License
Agreement dated as of July 12, 1999, the "Designated Equipment" shall be defined
as follows:

         LICENSEE'S SMX-2100 Service Mediation Platform, a self-contained Public
         Switched Telephone Network (PSTN) voice gateway product, which is a 23"
         proprietary NEBS compliant chassis with multiple shelves and
         proprietary busses, running VxWorks and using PowerPC and PowerQUICC
         processors however, LICENSEE may produce versions of this product which
         vary only in their size and scaleability so long as each version is
         substantially similar in functionality to the SMX-2100 model.

DESIGNATED EQUIPMENT NO. 2:

For the TRILLIUM products referred to as Part Nos. 1000172 (Option --) and
1068001 (Option 02), licensed under Amendment No. 4 to the License Agreement
dated as of July 28, 1999, and the TRILLIUM product referred to as Part No.
1000138 (Option --), licensed under Amendment No. 5 to the License Agreement
dated as of September 10, 1999, the "Designated Equipment" shall be defined as
follows:

         LICENSEE'S SRX-3000 Media Gateway Controller running on a Sun
         Microsystems Netra workstation using the Sun Solaris operating system,
         when sold in conjunction with any of LICENSEE's five (5) SRX-HS call
         metric software products.





                                                                          Page 5
   58
                                      Amendment No. 6 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                              AMENDMENT EXHIBIT II

1a.      TECHNOLOGY ACCESS, ROYALTY AND MAINTENANCE FEES:



                                                   ROYALTY FEE TABLE
- -----------------------------------------------------------------------------------------------------------------------------
                                                                                                       Maintenance
Part No.     Opt   Description   License   Technology         Royalty Fee per each Simultaneous             Fee      Training
                                   Type    Access Fee                 Multimedia Call                    (Annual)      Hours
                                                        ----------------------------------------------
                                                         Capacity    Capacity    Capacity    Capacity
                                                         of 1 to        of          of          of
                                                         100,000     100,001     200,001     400,001
                                                           calls        to          to       + calls
                                                                     200,000     400,000
                                                                      calls       calls
- -----------------------------------------------------------------------------------------------------------------------------
                                                                                       

 1000172      --     H.323         ROY      $[**]         $[**]        $[**]       $[**]       $[**]       $[**]   Previously
                    Gateway                              per call    per call     per call    per call              received
                      and
                   Gatekeeper
- -----------------------------------------------------------------------------------------------------------------------------


License/Technology Access Fees:                              $[**]

Less 30% discount (offered under Amendment No. 4):           $([**])

Less amount previously paid towards TDU being converted:     $([**])

TOTAL LICENSE FEES:                                          $[**]

TOTAL MAINTENANCE FEES:                                      $[**]

TOTAL CURRENT FEES:                                          $[**]


* Note that the conversion of the license from TDU to ROY is not effective until
payment in full is received by TRILLIUM.

ROYALTY BASIS: For purposes of determining the Royalty Fees owed, each
simultaneous multimedia IP call that can be supported by a unit of the
Designated Equipment that contains, runs or is supported by the Object Form of
any Licensed Program shall be counted. The number of simultaneous multimedia
calls supported by the Designated Equipment is the maximum number of multimedia
calls that may be supported at any one time. For example, a unit of the
Designated Equipment sold in conjunction with LICENSEE's SRX-HS-2K call metric
software




                                                                          Page 6
   59
                                      Amendment No. 6 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


product will support media gateways to a maximum of 2,000 simultaneous
multimedia calls. If the 2001st multimedia IP call is attempted, there is a busy
signal. In this case, there would be 2000 simultaneous calls capable of being
supported by the Designated Equipment and therefore the royalty fees for 2000
calls would be due, not 2001.

It is agreed that for purposes of the above, the call capacity of LICENSEE's
SRX-HS call metric software products shall be no less than:

SRX-HS-2K                           2000 simultaneous multimedia calls
SRX-HS-10K                          10,000 simultaneous multimedia calls
SRX-HS-50K                          50,000 simultaneous multimedia calls
SRX-HS-100K                         100,000 simultaneous multimedia calls
SRX-HS-500K                         500,000 simultaneous multimedia calls

In the event LICENSEE enables the end-user of the Designated Equipment to expand
the capacity of the Designated Equipment by increasing the number of
simultaneous multimedia calls capable of being supported by such Designated
Equipment, the Royalty Fees for such additional calls shall be due and payable
immediately at such time that LICENSEE enables the end-user to utilize the
additional capacity.

- - The Royalty Fees and breakpoints for the Designated Equipment have been
established based upon the definitions of the Designated Equipment and related
representations provided by LICENSEE to TRILLIUM and are intended to be
non-retroactive in the sense that once a new Royalty Fee threshold is achieved
by Object Form sublicenses, it shall only apply to additional sales beyond such
breakpoint and not to previous sales. For example, if the number of simultaneous
multimedia calls supported by units of the Designated Equipment shipped by
LICENSEE amounts to 150,000, LICENSEE shall owe TRILLIUM $[**] each for the
first 100,000 simultaneous multimedia calls and $[**] each for the remaining
50,000 simultaneous multimedia calls. For purposes of determining the applicable
royalty rate, the parties shall consider the number of simultaneous multimedia
calls over the lifetime of the Designated Equipment (i.e., the counter is not
reset each year).

LICENSEE represents that it is capable of tracking and reporting the number of
simultaneous multimedia calls that can be supported by each unit of the
Designated Equipment.

3.       LICENSE TYPE DEFINITIONS:

         Royalty ("ROY") - License granted per terms of this Agreement to Use
         Source Form and sublicense an unlimited number of copies of the Object
         Form on the Designated Equipment as specified in Exhibit A. There is a
         one-time Technology Access Fee and a Per Object Form Royalty Fee due
         for each sublicensed copy of the Object Form, the amount of which is
         set forth in Exhibit B and which is payable as set forth in Paragraph
         5.1 of this Agreement.




                                                                          page 7
   60
                                      Amendment No. 7 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                           LICENSE AGREEMENT AMENDMENT

This License Agreement Amendment is entered into as of March 20, 2000 (the
"effective date"), by and between TRILLIUM DIGITAL SYSTEMS, INC., a California
corporation having its principal office at 12100 Wilshire Blvd., Suite 1800, Los
Angeles, California, USA 90025-7118 (hereinafter referred to as "TRILLIUM"), and
UNISPHERE SOLUTIONS, INC., A WHOLLY-OWNED SUBSIDIARY OF SIEMENS AG, a Delaware,
corporation having its principal office at 1 Executive Drive, Chelmsford,
Massachusetts, USA 01824 and facsimile number +1-978-392-9632 (hereinafter
referred to as "LICENSEE").

TRILLIUM and CASTLE NETWORKS, INC. ("CASTLE") previously entered into that
certain Software License Agreement dated as of February 25,1998, under which
TRILLIUM granted LICENSEE Single Use Buyout ("SUB") licenses and an Unsupported
Binary ("UNB") license for certain TRILLIUM products, which was amended by a
first amendment thereto, dated as of April 30, 1998, to modify certain terms of
the Software License Agreement, and which was amended by a second amendment
thereto, dated as of December 31, 1998, to add SUB licenses for additional
TRILLIUM products and to modify the definition of Designated Equipment. Such
Software License Agreement, as amended, was assigned by CASTLE to CASTLE
NETWORKS, INC., A WHOLLY-OWNED SUBSIDIARY OF SIEMENS AG ("CASTLE/SIEMENS") via
an Assignment and Assumption of Software License Agreement dated as of April 7,
1999. Thereafter, the Software License Agreement was amended by a third
amendment thereto, dated as of July 12, 1999, to add SUB and UNB licenses for
additional TRILLIUM products, and was amended by a fourth amendment thereto,
dated as of July 28, 1999, to add Temporary Development Use ("TDU") and UNB
licenses for additional TRILLIUM products for Use on a new Designated Equipment,
and was amended by a fifth amendment thereto, dated as of September 10, 1999, to
add a SUB license for an additional TRILLIUM product, and was amended by a sixth
amendment thereto, dated as of February 11, 2000, to formalize the assignment of
the License Agreement from CASTLE/SIEMENS to LICENSEE, to modify certain terms
of the License Agreement, and to convert one of the previously acquired TDU
licenses to a Royalty ("ROY") license. Such Software License Agreement as
amended, is currently in effect between the parties (the "License Agreement").
LICENSEE now desires to acquire additional SUB licenses for additional TRILLIUM
products, as set forth below.

TRILLIUM and LICENSEE hereby amend the License Agreement as follows:

1.       By this amendment, the parties hereby add to the License Agreement the
         additional TRILLIUM products described in Exhibit I of this Amendment
         for Use on the certain Designated Equipment defined in Exhibit I,
         subject to the payment of the additional license fees and other terms
         described in Exhibit II of this Amendment. Exhibits I and II hereto
         shall be incorporated into and amend Exhibits A and B, respectively, to
         the License Agreement.


                                       1
   61
                                      Amendment No. 7 to Agreement dated 2/25/98


2.       General. All provisions of the License Agreement not specifically
         modified by this Amendment remain in full force and effect.



IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their respective duly authorized representative as of the date first above
written.


                LICENSEE:                      TRILLIUM:

Company:        UNISPHERE SOLUTIONS, INC.      TRILLIUM DIGITAL SYSTEMS, INC.

Signature:      /s/ Michael D. Regan           Illegible
                --------------------------     --------------------------------
Name:           Michael D. Regan               Illegible
                --------------------------     --------------------------------
Title:          VP Engineering                 Illegible
                --------------------------     --------------------------------
Date:           3/21/00                        March 27, 2000
                --------------------------     --------------------------------
Attachments:    Exhibit I
                Exhibit II





                                       2
   62
                                      Amendment No. 7 to Agreement dated 2/25/98


                               AMENDMENT EXHIBIT I

                                LICENSED PROGRAMS




- ----------------------------------------------------------------------------------------
Part No.        Options                    Name                 Version        Ship Date
- ----------------------------------------------------------------------------------------
                                                                 

1000144            -            PSF - Q.930/Q.931 (FT/HA)        Latest       1 Week ARO
- ----------------------------------------------------------------------------------------
1000009           02             Q.930/Q.931 - CCITT 88,         Latest       1 Week ARO
                                  Network Side (PRI/BRI)
- ----------------------------------------------------------------------------------------
1000009           11              Q.930/Q.931 -AT&T 4ESS         Latest       1 Week ARO
                                (User Side - PRI, Network
                                 Side - PRI) & 5ESS (User
                               Side - PRI/BRI, Network Side
                                        - PRI/BRI)
- ----------------------------------------------------------------------------------------
1000009           12              Q.930/Q.931 - Northern         Latest       1 Week ARO
                             Telecom DMS-1-- (User & Network
                                     Side - PRI/BRI)
- ----------------------------------------------------------------------------------------
1000009           28              Q.930/Q.931 -National          Latest       1 Week ARO
                                  ISDN-2 (User & Network
                                       Side - PRI)
- ----------------------------------------------------------------------------------------



4.       LICENSEE's DESIGNATED EQUIPMENT:

DESIGNATED EQUIPMENT NO. 1:

For the TRILLIUM products referred to as Part Nos. 1000027 (Option --), 1000028
(Options -- and 12), 1000029 (Options -- and 12), 1020031 (Option 2 1), 1000100
(Option --) and 1068001 (Option 01), licensed under the original Software
License Agreement dated as of February 25, 1998, and the TRILLIUM products
referred to as Part Nos. 1000133 (Option --), 1000145 (Option --) and 1000146
(Option --), licensed under Amendment No. 2 to the License Agreement dated as of
December 31, 1998, and the TRILLIUM products referred to as Part Nos. 1000030
(Options 01 and 12), 1000031 (Options -- and 12),1000093 (Options 01, 15, 16 and
17) and 1068003 (Option 01), licensed under Amendment No. 3 to the License
Agreement dated as of July 12, 1999, the "Designated Equipment" shall be defined
as follows:

         LICENSEE's SMX-2100 Service Mediation Platform, a self-contained Public
         Switched Telephone Network (PSTN) voice gateway product, which is a 23"
         proprietary NEBS compliant chassis with multiple shelves and
         proprietary busses, running VxWorks and using PowerPC and PowerQUICC
         processors however, LICENSEE may produce versions of this product which
         vary only in their size and scaleability so long as each version is
         substantially similar in functionality to the SMX-2100 model.


                                       3
   63

                                      Amendment No. 7 to Agreement dated 2/25/98


DESIGNATED EQUIPMENT NO. 2:

For the TRILLIUM products referred to as Part Nos. 1000172 (Option --) and
1068001 (Option 02), licensed under Amendment No. 4 to the License Agreement
dated as of July 28, 1999, and the TRILLIUM product referred to as Part No.
1000138 (Option --), licensed under Amendment No. 5 to the License Agreement
dated as of September 10, 1999, and the TRILLIUM products referred to as Part
Nos. 1000144 (Option --), 1000009 (Option 02), 1000009 (Option 11), 1000009
(Option 12), and 1000009 (Option 28), licensed under Amendment No. 7 to the
License Agreement dated as of March 20, 2000, the "Designated Equipment" shall
be defined as follows:

         LICENSEE's SRX-3000 Media Gateway Controller running on a Sun
         Microsystems Netra workstation using the Sun Solaris operating system,
         when sold in conjunction with any of LICENSEE'S five (5) SRX-HS call
         metric software products.




                                       4
   64

                                      Amendment No. 7 to Agreement dated 2/25/98


          Confidential Materials omitted and filed with the Securities
              and Exchange Commission. Asterisks denote omissions.


                              AMENDMENT EXHIBIT II

                          LICENSE AND MAINTENANCE FEES



- -----------------------------------------------------------------------------------------------------------
Part No.    Options                  Name                  License     License     Maintenance     Training
                                                            Type      Fee (1)    Fee (Annual)      (Hours)
                                                                                       (2)
- -----------------------------------------------------------------------------------------------------------
                                                                                    

1000144       --              PSF - Q.930/Q.931              SUB        $[**]         $[**]           [**]
                                   (FT/HA)
- -----------------------------------------------------------------------------------------------------------
1000009       02             Q.930/Q.931 - CCITT             SUB        $[**]         $[**]           [**]
                               88, Network Side
                                  (PRI/BRI)
- -----------------------------------------------------------------------------------------------------------
1000009       11        Q.930/Q.931 - AT&T 4ESS (User        SUB        $[**]         $[**]           [**]
                       Side - PRI, Network Side - PRI)
                         & 5ESS (User Side - PRI/BRI,
                           Network Side - PRI/BRI)
- -----------------------------------------------------------------------------------------------------------
1000009       12        Q.930/Q.931 - Northern Telecom       SUB        $[**]         $[**]           [**]
                                DMS-1 -- (User
                               & Network Side -
                                   PRI/BRI)
- -----------------------------------------------------------------------------------------------------------
1000009       28        Q.930/Q.931 - National ISDN-2        SUB        $[**]         $[**]           [**]
                         (User & Network Side - PRI)
- -----------------------------------------------------------------------------------------------------------



(1)      License Fees:                $[**]

(2)      Annual Maintenance Fees:     $[**]

         Total Current Fees Due:      $[**]












                                       5
   65

                          ASSIGNMENT AND ASSUMPTION OF
                           SOFTWARE LICENSE AGREEMENT

This Assignment and Assumption of Software License Agreement (this "Assignment
and Assumption") is entered into as of the 7th day of April, 1999 (the
"effective date"), by and between CASTLE NETWORKS INC., a Massachusetts
corporation having its principal office at 68 Tadmuck Road, Westford,
Massachusetts 01886 ("ASSIGNOR") and facsimile number +1-978-392-9032 and,
CASTLE NETWORKS, INC., A WHOLLY-OWNED SUBSIDIARY OF SIEMENS AG, a corporation
organized under the Federal laws of Germany (hereinafter referred to as
"ASSIGNEE"), having its principal office at Hofmannstrasse 51, 81359
Munchen, Federal Republic of Germany and facsimile number +49-89-722-33792.

WHEREAS, ASSIGNOR and TRILLIUM Digital Systems, Inc., a California corporation
having its principal office at 12100 Wilshire Blvd., Suite 1800, Los Angeles,
California 90025, USA, and facsimile number +1-310-442-9222 (hereinafter
referred to as "TRILLIUM") previously entered into that certain Software License
Agreement, dated February 25, 1998, which was amended by a first amendment
thereto, dated April 30, 1998 to modify terms and conditions and, which was
further amended by a second amendment thereto, dated December 31, 1998 to add
Single Use Buyout ("SUB") licenses and to modify the definition of Designated
Equipment. Such agreement is hereinafter referred to as the "License Agreement",
and is currently in effect between ASSIGNOR, as "LICENSEE" thereunder, and
TRILLIUM, under which ASSIGNOR has licensed a specified use of certain computer
software programs and related documentation (i.e., the "Licensed Programs") from
TRILLIUM, all as specified in the License Agreement;

WHEREAS, ASSIGNOR now desires to assign all of its rights and delegate all of
its duties under the License Agreement with respect to the Use of the Licensed
Programs to ASSIGNEE, and ASSIGNEE desires to receive such assignment of rights
and, in consideration therefor, ASSIGNEE is willing to assume all duties of
ASSIGNOR under the License Agreement with respect to the Use of the Licensed
Programs, all on the terms and conditions hereinafter set forth;

NOW, THEREFORE, for good and valuable consideration, the receipt and adequacy of
which are hereby acknowledged, the parties hereby agree as follows:

1.       Subject to the receipt of TRILLIUM'S consent hereto, as evidenced by
         TRILLIUM'S signature hereunder, and ASSIGNEE'S payment to TRILLIUM of
         the fees identified in Exhibit I to this Agreement, ASSIGNOR hereby
         assigns, transfers, conveys and sets over unto ASSIGNEE, and its
         successors and assigns, all of ASSIGNOR'S right, title and interest in
         and to the License Agreement, as it relates to the Use of the Licensed
         Programs, for the express benefit of both ASSIGNOR and TRILLIUM,
         ASSIGNEE hereby assumes and agrees to pay and perform and be bound by
         all of the duties and obligations of ASSIGNOR under the License
         Agreement as they relate to the Use of the Licensed Programs.


                                      -1-
   66
2.       ASSIGNOR represents and warrants to ASSIGNEE and TRILLIUM that the
         License Agreement is valid and binding and is in full force and effect
         and has not been assigned, transferred, conveyed, pledged or encumbered
         in any way by ASSIGNOR, and the parties agree that nothing contained
         herein constitutes a release by TRILLIUM of ASSIGNOR or ASSIGNEE from
         any duties, obligations or liabilities with respect to performance by
         any "LICENSEE" under the License Agreement or otherwise.

3.       From and after the effective date hereof, the address of the "LICENSEE"
         and "TRILLIUM" under the License Agreement, for purposes of notices
         given hereunder shall be the following address (until such address may
         be changed as provided in the License Agreement):

         LICENSEE:         Castle Networks, Inc., a wholly-owned subsidiary of
                           Siemens AG
                           68 Tadmuck Road
                           Westford, MA 01886
                           Attn:  Mike Regan
         Facsimile number (978) 392-9032

         TRILLIUM:         Trillium Digital Systems, Inc.
                           12100 Wilshire Blvd, Suite 1800
                           Los Angeles, CA 90025
                           Attn: Contracts Administration
                           Facsimile No.: 1-310-442-1162

4.       ASSIGNOR and ASSIGNEE hereby acknowledge and agree that the definition
         of Designated Equipment in Paragraph 4 of Exhibit A shall remain
         defined as follows:

         LICENSEE'S C2100 Service Mediation Platform, a self-contained Public
         Switched Telephone Network (PSTN) voice gateway product, which is a 23"
         proprietary NEBS compliant chassis with multiple shelves and
         proprietary busses, running VxWorks and using PowerPC and PowerQUICC
         processors however, LICENSEE may produce versions of this product which
         vary only in their size and scaleability so long as each version is
         substantially similar in functionality to the C2100 model.

5.       ASSIGNOR and ASSIGNEE hereby agree, for the express benefit of each
         other and TRILLIUM, to execute and deliver all documents and to perform
         all further acts and to take any and all further steps that may be
         requested by each other or TRILLIUM as reasonably necessary to
         effectuate the purpose of this Assignment and Assumption.

6.       This Assignment and Assumption or any amendment hereto may be executed
         in several counterparts and, as executed, shall constitute one
         agreement binding on all the parties hereto, notwithstanding that all
         of the parties are not signatory to the original or the same
         counterpart.

7.       All provisions of the License Agreement, which are not specifically
         modified by this Assignment and Assumption shall remain in full force
         and effect.




                                      -2-
   67

IN WITNESS WHEREOF, the parties hereto have caused this Assignment and
Assumption to be duly executed by their respective duly authorized
representative as of the effective date hereof.

                   ASSIGNOR:                   ASSIGNEE:

Company:      Castle Networks, Inc.            Castle Networks, Inc.,
                                               a wholly-owned subsidiary
                                               of Siemens AG

Signature:   /s/ Thomas M. Burkardt            /s/ Thomas M. Burkardt
             ------------------------          ----------------------
Name:        Thomas M. Burkardt                Thomas M. Burkardt
             ------------------------          ----------------------
Title:       President and CEO                 President and CEO
             ------------------------          ----------------------
Date:        March 11, 1999                    March 11, 1999


Attachment:       Exhibit I



                                      -3-
   68
                               TRILLIUM CONSENT TO
                          ASSIGNMENT AND ASSUMPTION OF
                           SOFTWARE LICENSE AGREEMENT


TRILLIUM does hereby consent to the foregoing assignment of rights and
delegation of duties under the License Agreement on the terms and conditions set
forth above. This consent shall not be deemed to be a consent to any
transactions other than those described above on the terms and conditions set
forth above or an agreement to consent to any similar or other transaction in
the future, and no provision of this consent shall be deemed to alter or modify
any term or condition of the License Agreement.

IN WITNESS WHEREOF, TRILLIUM has caused this Consent to Assignment and
Assumption of Software License Agreement to be duly executed by its duly
authorized representative as of the effective date thereof.



                                  Company: TRILLIUM DIGITAL SYSTEMS, INC.

                                  Signature:   /s/ Richard D. Cabalan
                                               -----------------------------
                                  Name:        Richard D. Cabalan
                                               -----------------------------
                                  Title        C.O.O
                                               -----------------------------
                                  Date:        March 16, 1999






                                      -4-