Document:

<PAGE>

                                                                   Exhibit 10.25

March 2, 2001

Richard J. Heaps
c/o Clarent Corporation
700 Chesapeake Drive
Redwood City, CA 94063

Dear Rich:

I am pleased that we have been able to work out a mutually beneficial
transition. This letter sets forth the substance of the separation and
consulting agreement (the "Agreement") to which you and Clarent Corporation (the
"Company") have agreed.

     1.   Resignation. You will resign from your positions as the Company's
Chief Operating Officer, Chief Financial Officer, Secretary and General Counsel,
and all positions you hold with any subsidiary or affiliate of the Company,
effective as of a date or dates specified by the Company in its sole discretion,
and you will resign from your employment with the Company (including all
subsidiaries and affiliates) effective April 30, 2001 (the "Resignation Date").

     2.   Accrued Salary and Vacation. On the Resignation Date, the Company will
pay you all accrued and unpaid salary, and all accrued and unused vacation,
earned through the Resignation Date, subject to standard payroll deductions and
withholdings. You are entitled to these payments regardless of whether you sign
this Agreement.

     3.   Bonus. The Company will pay you any bonus for the year 2000 approved
by the Company's Board of Directors (the "Board"). You will not be eligible to
receive any bonus for the year 2001 or thereafter.

     4.   Consulting Agreement. You will serve as a consultant to the Company
under the terms specified below, from May 1, 2001 until August 1, 2002 (the
"Consulting Period").

          (a)  Consulting Services. You agree to provide consulting services to
the Company in any area of your expertise (the "Consulting Services") at the
direction of the Company's Chief Executive Office or Chairman of the Board, at
the Company's sole discretion. You agree to exercise the highest degree of
professionalism and utilize your expertise and creative talents in performing
the Consulting Services. You agree to use your best efforts to provide
Consulting Services, as requested by the Company, for up to forty (40) hours per
week through August 1, 2001, and for an estimated target of fifteen (15) hours
per week (but not to exceed one hundred (100) hours per month), from August 2,
2001 through the end of the Consulting Period. The Company agrees to give you
reasonable notice of the dates and times on or by which the Consulting Services
are to be rendered, and you agree to make reasonable efforts to perform such
services on or by such requested dates and times.
<PAGE>

Richard J. Heaps
March 2, 2001
Page 2

          (b)  Consulting Fees. During the Consulting Period the Company will
pay you as consulting fees a total of two hundred and seventy-five thousand
dollars ($275,000) (the "Consulting Fees"), without withholdings or deductions,
in equal monthly installments. You agree to submit monthly invoices to the
Company stating the amount of Consulting Fees, and any expenses for which you
seek reimbursement under paragraph 9 below, due for the prior calendar month,
and such invoices shall be immediately payable. The Company will issue you 1099
forms with respect to the Consulting Fees. You shall be responsible for all
taxes with respect to the Consulting Fees, and you agree to indemnify, hold
harmless and defend the Company from any and all claims, liabilities, damages,
taxes, fines or penalties sought or recovered by any governmental entity,
including but not limited to the Internal Revenue Service or any state taxing
authority, arising out of your failure to pay federal, state or local taxes
during the term of the Consulting Period.

          (c)  Independent Contractor Status. You agree that during the
Consulting Period (i) you will be an independent contractor to the Company and
not an employee of the Company, and (ii) the Company will not withhold or make
payments for state or federal income tax or social security, make unemployment
insurance or disability insurance contributions, or obtain workers' compensation
insurance on your behalf.

          (d)  Limitations on Authority. You will have no responsibilities or
authority as a consultant to the Company other than as provided above. You agree
not to represent or purport to represent the Company in any manner whatsoever to
any third party unless authorized by the Company, in writing, to do so.

          (e)  Non-Competition. In order to protect the trade secrets and
confidential and proprietary information of the Company, you agree that, during
the Consulting Period, you will not, directly or indirectly, without the prior
written consent of the Company, own, manage, operate, join, control, finance or
participate in the ownership, management, operation, control or financing of, or
be connected as an officer, director, employee, partner, principal, agent,
representative, or consultant, in any location(s) worldwide, of any entity that
directly competes with any Company product currently available, or in
development and publicly disclosed, as of the Effective Date of this Agreement
(a "Competitor"). If you engage in any such competitive activity without the
Company's express written consent, the Company may terminate this Agreement, at
its sole election, and the Company's obligations to provide you with any and all
compensation, benefits and stock option vesting will cease effective as of the
commencement date of such competitive activity, subject to the provisions of
paragraph 22 below. The foregoing shall not be deemed to prohibit you from
holding or acquiring a passive investment of not more than 2 percent of the
capital stock of any publicly traded or privately held Competitor, and you agree
to provide prompt written notice to the Company of any such investment in any
privately held Competitor.
<PAGE>

Richard J. Heaps
March 2, 2001
Page 3

     5.   Stock Options. Your Company stock option granted on August 27, 1998
will continue to vest through the end of the Consulting Period, provided that
you have complied with the terms of this Agreement through such date. Your
Company stock options granted on March 8, 1999 and February 15, 2001, and your
Company stock option for 69,422 shares (or a greater number of shares as
described in the stock option vesting summary attached as Exhibit A hereto) to
be granted on August 17, 2001, will continue to vest through June 17, 2002,
provided that you have complied with the terms of this Agreement through such
date. You will be eligible to participate in Company stock repricing programs
through the end of your vesting periods as described in this paragraph. Your
stock options will cease vesting immediately upon your breach of this Agreement.
Except as specifically set forth in this paragraph and Exhibit A, your stock
options will continue to be governed by the applicable stock option grants,
agreements, and plan documents.

     6.   Benefits. You will continue to receive standard Company benefits
available to senior executives, including health insurance, special life and
disability insurance, and a car allowance, through June 1, 2002. The Company
will provide these continued benefits by continuing your participation in such
benefit plans and/or reimbursing you for the cost of such benefits, in the
Company's sole discretion and consistent with the terms of the applicable plans.
The Company's obligation to provide these benefits will cease immediately if you
accept employment with a new employer that provides comparable benefits for
which you are eligible. You agree to notify the Company immediately in writing
upon your acceptance of such new employment.

     7.   Secretarial Support. The Company agrees to provide you with
secretarial support through August 1, 2001, and will make reasonable efforts to
retain Sharon Fuhs to provide such support.

     8.   Other Compensation or Benefits. You acknowledge that you will not
receive from the Company any additional compensation (including but not limited
to salary, bonuses or stock option grants), severance or benefits after the
Resignation Date, except as expressly provided in this Agreement.

     9.   Expense Reimbursements. You agree that within ten (10) business days
after the Resignation Date you will submit your final documented expense
reimbursement statement reflecting all business expenses you have incurred
through the Resignation Date, if any, for which you seek reimbursement. The
Company will reimburse you for these expenses pursuant to its regular business
practice. Also pursuant to its regular business practice, the Company will
reimburse you for reasonable business expenses incurred during the Consulting
Period, provided that such expenses are routinely reimbursed for senior
executives of the Company and you comply with standard Company requirements
relating to expense reimbursement, including but not limited to requirements
regarding verification of expenses.
<PAGE>

Richard J. Heaps
March 2, 2001
Page 4

     10.  Return of Company Property. On the Resignation Date, you agree to
return to the Company all Company documents (and all copies thereof) and other
Company property that you have had in your possession at any time, including,
but not limited to, Company files, notes, drawings, records, business plans and
forecasts, financial information, specifications, training materials, computer-
recorded information, tangible property including, but not limited to,
computers, credit cards, entry cards, identification badges and keys; and any
materials of any kind that contain or embody any proprietary or confidential
information of the Company (and all reproductions thereof). You may retain such
documents, property, and materials during the Consulting Period only to the
extent approved in writing by the Company and you shall return them immediately
upon written request from the Company. The Company will continue your active
voicemail and e-mail accounts on the Company's systems through August 1, 2001.

     11.  Exit Interviews. You agree that you will participate in exit
interviews with all non-employee members of the Board at mutually agreed times
and places.

     12.  Proprietary Information and Attorney-Client Obligations. You
acknowledge your continuing obligations under your Proprietary Information and
Inventions Agreement (Exhibit B hereto) at all times hereafter, including but
not limited to all times during and after the Consulting Period. Among other
obligations in said agreement, you agree not to use or disclose, at any time,
any confidential or proprietary information of the Company without prior written
authorization from a duly authorized representative of the Company. In addition,
you acknowledge your continuing obligations to the Company arising from the
attorney-client relationship established between you and the Company.

     13.  Nonsolicitation. You agree that from the Effective Date of this
Agreement (as defined in paragraph 16 below) through the end of the Consulting
Period, you will not, either directly or through others, solicit or attempt to
solicit any employee, consultant, or independent contractor of the Company to
terminate his or her relationship with the Company in order to become an
employee, consultant or independent contractor to or for any other person or
entity; provided, however, that said restrictions shall not apply as to Sharon
Fuhs.

     14.  Nondisparagement. Both you and the Company (by its officers and
directors) agree not to disparage the other party, and the other party's
officers, directors, employees, shareholders, affiliates, and agents, in any
manner likely to be harmful to them or their business, business reputation or
personal reputation; provided, however, that both you and the Company shall
respond accurately and fully to any question, inquiry or request for information
when required by legal process.

     15.  Release of Claims. In exchange for the consulting arrangement, stock
option vesting arrangement and other consideration under this Agreement to which
you would not otherwise be entitled, you hereby release, acquit and forever
discharge the Company and its officers, directors, agents, servants, employees,
attorneys, shareholders, successors, assigns and
<PAGE>

Richard J. Heaps
March 2, 2001
Page 5

affiliates, of and from any and all claims, liabilities, demands, causes of
action, costs, expenses, attorneys fees, damages, indemnities and obligations of
every kind and nature, in law, equity, or otherwise, known and unknown,
suspected and unsuspected, disclosed and undisclosed, arising out of or in any
way related to agreements, events, acts or conduct at any time prior to and
including the date you sign this agreement, including but not limited to: any
and all such claims and demands directly or indirectly arising out of or in any
way connected with your employment with the Company or the termination of that
employment; claims or demands related to salary, bonuses, commissions, stock,
stock options, or any other ownership interests in the Company, vacation pay,
fringe benefits, expense reimbursements, sabbatical benefits, severance
benefits, or any other form of compensation; claims pursuant to any federal,
state, local law, statute or cause of action including, but not limited to, the
federal Civil Rights Act of 1964, as amended; the federal Americans with
Disabilities Act of 1990; the federal Age Discrimination in Employment Act of
1967, as amended ("ADEA"); the California Fair Employment and Housing Act, as
amended; tort law; contract law; wrongful discharge; discrimination; fraud;
defamation; harassment; emotional distress; and breach of the implied covenant
of good faith and fair dealing. The releases given herein shall not bar any
claim for breach of the terms of this Agreement.

     16.  ADEA Waiver. You acknowledge that you are knowingly and voluntarily
waiving and releasing any rights you may have under the ADEA. You also
acknowledge that the consideration given for the waiver and release in the
preceding paragraph is in addition to anything of value to which you were
already entitled. You further acknowledge that you have been advised by this
writing, as required by the ADEA, that: (a) your waiver and release do not apply
to any rights or claims that arise after the date you sign this Agreement; (b)
you should consult with an attorney prior to executing this Agreement; (c) you
have twenty-one (21) days to consider this Agreement (although you may choose to
voluntarily execute this Agreement earlier); (d) you have seven (7) days
following the date you sign this Agreement to revoke the Agreement; and (e) this
Agreement will not be effective until the date upon which the revocation period
has expired, which will be the eighth day after this Agreement is executed by
you, provided that the Company has also signed the Agreement by that date
("Effective Date").

     17.  Supplemental Release. In further consideration of the consulting
arrangement, stock option vesting arrangement and other consideration under this
Agreement to which you would not otherwise be entitled, you agree to sign and
return to the Company a supplemental release of claims (the "Supplemental
Release"), in the form attached hereto as Exhibit C, on or after April 30, 2001.

     18.  Waiver. In granting the release herein, you acknowledge that you
understand that you are waiving the benefit of California Civil Code section
1542, which states:
<PAGE>

Richard J. Heaps
March 2, 2001
Page 6

     A general release does not extend to claims which the creditor does not
     know or suspect to exist in his favor at the time of executing the release,
     which if known by him must have materially affected his settlement with the
     debtor.

You hereby expressly waive and relinquish all rights and benefits under that
section and any law or legal principle of similar effect in any jurisdiction
with respect to the release of unknown and unsuspected claims granted in this
Agreement.

     19.  Confidentiality. The provisions of this Agreement will be held in
strictest confidence by you and the Company and will not be publicized or
disclosed in any manner whatsoever; provided, however, that:  (a) you may
disclose this Agreement to your immediate family and any lender that requests
that you provide information about your income; (b) the parties may disclose
this Agreement in confidence to their respective attorneys, accountants,
auditors, tax preparers, and financial advisors; (c) the Company may disclose
this Agreement as necessary to fulfill standard or legally required corporate
reporting or disclosure requirements; and (d) the parties may disclose this
Agreement insofar as such disclosure may be necessary to enforce its terms or as
otherwise required by law.  In particular, and without limitation, you will not
disclose the provisions of this Agreement to any current or former Company
employee or any other Company personnel.

     20.  Public Statements. Notwithstanding the provisions of paragraph 18
above, the Company may issue a statement or make other public comment on your
resignation and consulting services, at its sole discretion. You agree to
refrain from making any statement to any press or media representative, or other
third party, regarding your resignation from the Company, your consulting
services arrangement, or any other matter pertaining to the Company's business
affairs, absent written authorization from the Chairman of the Board.

     21.  Indemnification. Notwithstanding your resignation from your positions
with the Company, that certain Indemnity Agreement by and between the Company
and you dated June 30, 1999 (the "Indemnity Agreement") shall continue to apply
during the term of this Agreement. A copy of the Indemnity Agreement is attached
hereto as Exhibit D.

     22.  Dispute Resolution. To ensure rapid and economical resolution of any
and all disputes that may arise in connection with this Agreement, you and the
Company agree that any and all disputes, claims, and causes of action, in law or
equity, arising from or relating to this Agreement or its enforcement,
performance, breach, or interpretation, will be resolved solely and exclusively
by final, binding, and confidential arbitration, by a single arbitrator, in San
Francisco, California, and conducted by Judicial Arbitration & Mediation
Services, Inc. ("JAMS") under its then-existing employment rules and procedures.
Nothing in this section, however, is intended to prevent either party from
obtaining injunctive relief in court to prevent irreparable harm pending the
conclusion of any such arbitration. The Company shall not terminate any
compensation or benefits provided hereunder pending the outcome of such
<PAGE>

Richard J. Heaps
March 2, 2001
Page 7

arbitration; provided, however, that in the event the Company prevails in such
arbitration on any claim resulting in the termination of such compensation
and/or benefits, you will be liable to the Company for an amount equal to the
compensation and value of benefits you received hereunder from the earliest date
of the conduct giving rise to said claim(s) until the date of the arbitration
award.

     23.  Entire Agreement. This Agreement, including all exhibits, constitutes
the complete, final and exclusive embodiment of the entire agreement between you
and the Company with regard to the subject matters hereof. It supersedes and
merges any and all agreements entered into by and between you and the Company.
It is entered into without reliance on any promise or representation, written or
oral, other than those expressly contained herein. It may not be modified except
in a writing signed by you and a duly authorized officer of the Company. Each
party has carefully read this Agreement, has been afforded the opportunity to be
advised of its meaning and consequences by his or its respective attorneys, and
signed the same of his or its own free will.

     24.  Successors and Assigns. This Agreement will bind the heirs, personal
representatives, successors, assigns, executors and administrators of each
party, and will inure to the benefit of each party, its heirs, successors and
assigns.

     25.  Warranties. You warrant and represent that there are no liens or
claims of lien or assignments in law or equity or otherwise on or against any
potential claims or causes of action released herein, and, further, that you are
fully entitled and duly authorized to give this complete and final general
release and waiver.

     26.  Applicable Law. This Agreement will be deemed to have been entered
into and will be construed and enforced in accordance with the laws of the State
of California as applied to contracts made and to be performed entirely within
California, without regard to conflicts of laws.

     27.  Severability. If a court of competent jurisdiction determines that any
term or provision of this Agreement is invalid or unenforceable, in whole or in
part, then the remaining terms and provisions hereof will be unimpaired. The
court or arbitrator will then have the authority to modify or replace the
invalid or unenforceable term or provision with a valid and enforceable term or
provision that most accurately represents the parties' intention with respect to
the invalid or unenforceable term or provision.

     28.  Counterparts. This Agreement may be executed in two counterparts, each
of which will be deemed an original, all of which together constitutes one and
the same instrument.
<PAGE>

Richard J. Heaps
March 2, 2001
Page 8

     29.  Construction. This Agreement will be deemed drafted by both parties,
and shall not be construed against either party as the drafter of the document.

If this Agreement is acceptable to you, please sign below and return the
original to me. Please sign and return the Supplemental Release (Exhibit C) to
me on or after April 30, 2001.

I wish you luck in your future endeavors.

Sincerely,

Clarent Corporation

By:  /s/ Michael F. Vargo
     --------------------
         Michael F. Vargo
         Director and Chief Technical Officer

Exhibit A  Summary of Stock Option Vesting During Term of Agreement
Exhibit B  Proprietary Information and Inventions Agreement
Exhibit C  Supplemental Release
Exhibit D  Indemnity Agreement

Understood and Agreed:

/s/ Richard J. Heaps
--------------------
Richard J. Heaps

Date:  March 2, 2001
       -------------
<PAGE>

                                   Exhibit A

           SUMMARY OF STOCK OPTION VESTING DURING CONSULTING PERIOD

<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------
       Option             Shares      Vesting          Monthly     Currently    Shares Vested on
                                   Termination         Vesting       Vested        Vesting
                                       Date                                     Termination Date
------------------------------------------------------------------------------------------------
<S>                      <C>       <C>                 <C>          <C>           <C>
August 27, 1998          400,000   August 1, 2002      8,333.33       249,999        400,000
------------------------------------------------------------------------------------------------
March 8, 1999            200,000   June 17, 2002       4,166.66        91,666        162,500
------------------------------------------------------------------------------------------------
February 15, 2001 *       41,156   June 17, 2002       6,859.33 **          0         41,156
------------------------------------------------------------------------------------------------
August 17, 2001 *         69,422+  June 17, 2002       2,892.58 ***         0         28,925+
------------------------------------------------------------------------------------------------
</TABLE>

*  Options granted pursuant to Clarent Corporation Option Cancellation and
   Regrant Program (the "Regrant Program"). As requested by Mr. Heaps, Options
   granted on February 29, 2000 for 150,000 shares and October 12, 2000 for
   30,000 shares were canceled as a condition of participation in the Regrant
   Program.

** Vests ratably over six (6) months.

*** Vests ratably over twenty-four (24) months.

+ Based on an August Option (as defined in the Regrant Program) covering the
  number of shares equal to 50% of the Unreplaced Surrendered Options (as
  defined in the Regrant Program), as specified in the Regrant Program. In the
  event that the percentage of Unreplaced Surrendered Options selected by the
  Company to calculate the August Options for the general pool of employees
  under the Regrant Program (the "August Option Percentage") is greater than
  50%, then Mr. Heaps' August Option, and the Shares Vested on Vesting
  Termination Date, will be recalculated based on the actual August Option
  Percentage.

                                      A-1
<PAGE>

                                   Exhibit B

                              CLARENT CORPORATION

                       EMPLOYEE PROPRIETARY INFORMATION
                           AND INVENTIONS AGREEMENT

          In consideration of my employment or continued employment by Clarent
Corporation (the "Company"), and the compensation now and hereafter paid to me,
I hereby agree as follows:

                               1.  Nondisclosure

     1.1  Recognition of Company's Rights; Nondisclosure. At all times during my
employment and thereafter, I will hold in strictest confidence and will not
disclose, use, lecture upon or publish any of the Company's Proprietary
Information (defined below), except as such disclosure, use or publication may
be required in connection with my work for the Company, or unless an officer of
the Company expressly authorizes such in writing. I will obtain Company's
written approval before publishing or submitting for publication any material
(written, verbal, or otherwise) that relates to my work at Company and/or
incorporates any Proprietary Information. I hereby assign to the Company any
rights I may have or acquire in such Proprietary Information and recognize that
all Proprietary Information shall be the sole property of the Company and its
assigns.

     1.2  Proprietary Information. The term "Proprietary Information" shall mean
any and all confidential and/or proprietary knowledge, data or information of
the Company. By way of illustration but not limitation, "Proprietary
Information" includes (a) trade secrets, inventions, mask works, ideas,
processes, formulas, source and object codes, data, programs, other works of
authorship, know-how, improvements, discoveries, developments, designs and
techniques (hereinafter collectively referred to as "Inventions"); and (b)
information regarding plans for research, development, new products, marketing
and selling, business plans, budgets and unpublished financial statements,
licenses, prices and costs, suppliers and customers; and (c) information
regarding the skills and compensation of other employees of the Company.
Notwithstanding the foregoing, it is understood that, at all such times, I am
free to use information which is generally known in the trade or industry, which
is not gained as result of a breach of this Agreement, and my own, skill,
knowledge, know-how and experience to whatever extent and in whichever way I
wish.

     1.3  Third Party Information. I understand, in addition, that the Company
has received and in the future will receive from third parties confidential or
proprietary information ("Third Party Information") subject to a duty on the
Company's part to maintain the confidentiality of such information and to use it
only for certain limited purposes. During the term of my employment and
thereafter, I will hold Third Party Information in the strictest confidence and
will not disclose to anyone (other than Company personnel who need to know such
information in connection with their work for the Company) or use, except in
connection with my work for the Company, Third Party Information unless
expressly authorized by an officer of the Company in writing.

     1.4  No Improper Use of Information of Prior Employers and Others. During
my employment by the Company I will not improperly use or disclose any
confidential information or trade secrets, if any, of any former employer or any
other person to whom I have an obligation of confidentiality, and I will not
bring onto the premises of the Company any unpublished documents or any property
belonging to any former employer or any other person to whom I have an
obligation of confidentiality unless consented to in writing by that former
employer or person. I will use in the performance of my duties only information
which is generally known and used by persons with training and experience
comparable to my own, which is common knowledge in the industry or otherwise
legally in the public domain, or which is otherwise provided or developed by the
Company.

2.   Assignment of Inventions.

     2.1  Proprietary Rights. The term "Proprietary Rights" shall mean all trade
secret, patent, copyright, mask work and other intellectual property rights
throughout the world.

     2.2  Prior Inventions. Inventions, if any, patented or unpatented, which I
made prior to the commencement of my employment with the Company

                                      B-1
<PAGE>

are excluded from the scope of this Agreement. To preclude any possible
uncertainty, I have set forth on Exhibit B (Previous Inventions) attached hereto
a complete list of all Inventions that I have, alone or jointly with others,
conceived, developed or reduced to practice or caused to be conceived, developed
or reduced to practice prior to the commencement of my employment with the
Company, that I consider to be my property or the property of third parties and
that I wish to have excluded from the scope of this Agreement (collectively
referred to as "Prior Inventions"). If disclosure of any such Prior Invention
would cause me to violate any prior confidentiality agreement, I understand that
I am not to list such Prior Inventions in Exhibit B but am only to disclose a
cursory name for each such invention, a listing of the party(ies) to whom it
belongs and the fact that full disclosure as to such inventions has not been
made for that reason. A space is provided on Exhibit B for such purpose. If no
such disclosure is attached, I represent that there are no Prior Inventions. If,
in the course of my employment with the Company, I incorporate a Prior Invention
into a Company product, process or machine, the Company is hereby granted and
shall have a nonexclusive, royalty-free, irrevocable, perpetual, worldwide
license (with rights to sublicense through multiple tiers of sublicensees) to
make, have made, modify, use and sell such Prior Invention. Notwithstanding the
foregoing, I agree that I will not incorporate, or permit to be incorporated,
Prior Inventions in any Company Inventions without the Company's prior written
consent.

     2.3  Assignment of Inventions. Subject to Sections 2.4, and 2.6, I hereby
assign and agree to assign in the future (when any such Inventions or
Proprietary Rights are first reduced to practice or first fixed in a tangible
medium, as applicable) to the Company all my right, title and interest in and to
any and all Inventions (and all Proprietary Rights with respect thereto) whether
or not patentable or registrable under copyright or similar statutes, made or
conceived or reduced to practice or learned by me, either alone or jointly with
others, during the period of my employment with the Company. Inventions assigned
to the Company, or to a third party as directed by the Company pursuant to this
Section 2, are hereinafter referred to as "Company Inventions."

     2.4  Nonassignable Inventions. This Agreement does not apply to an
Invention which qualifies fully as a nonassignable Invention under Section 2870
of the California Labor Code (hereinafter "Section 2870"). I have reviewed the
notification on Exhibit A (Limited Exclusion Notification) and agree that my
signature acknowledges receipt of the notification.

     2.5  Obligation to Keep Company Informed. During the period of my
employment and for six (6) months after termination of my employment with the
Company, I will promptly disclose to the Company fully and in writing all
Inventions authored, conceived or reduced to practice by me, either alone or
jointly with others. In addition, I will promptly disclose to the Company all
patent applications filed by me or on my behalf within a year after termination
of employment. At the time of each such disclosure, I will advise the Company in
writing of any Inventions that I believe fully qualify for protection under
Section 2870; and I will at that time provide to the Company in writing all
evidence necessary to substantiate that belief. The Company will keep in
confidence and will not use for any purpose or disclose to third parties without
my consent any confidential information disclosed in writing to the Company
pursuant to this Agreement relating to Inventions that qualify fully for
protection under the provisions of Section 2870. I will preserve the
confidentiality of any Invention that does not fully qualify for protection
under Section 2870.

     2.6  Government or Third Party. I also agree to assign all my right, title
and interest in and to any particular Company Invention to a third party,
including without limitation the United States, as directed by the Company.

     2.7  Works for Hire. I acknowledge that all original works of authorship
which are made by me (solely or jointly with others) within the scope of my
employment and which are protectable by copyright are "works made for hire,"
pursuant to United States Copyright Act (17 U.S.C., Section 101).

     2.8  Enforcement of Proprietary Rights. I will assist the Company in every
proper way to obtain, and from time to time enforce, United States and foreign
Proprietary Rights relating to Company Inventions in any and all countries. To
that end I will execute, verify and deliver such documents and perform such
other acts (including appearances as a witness) as the Company may reasonably
request for use in applying for, obtaining, perfecting, evidencing, sustaining
and enforcing such Proprietary Rights and the assignment thereof. In addition, I
will execute, verify and deliver assignments of such Proprietary Rights to the
Company or its designee. My obligation to assist the Company with respect to
Proprietary Rights relating to such Company Inventions in any and all countries
shall continue beyond the

                                      B-2
<PAGE>

termination of my employment, but the Company shall compensate me at a
reasonable rate after my termination for the time actually spent by me at the
Company's request on such assistance.

In the event the Company is unable for any reason, after reasonable effort, to
secure my signature on any document needed in connection with the actions
specified in the preceding paragraph, I hereby irrevocably designate and appoint
the Company and its duly authorized officers and agents as my agent and attorney
in fact, which appointment is coupled with an interest, to act for and in my
behalf to execute, verify and file any such documents and to do all other
lawfully permitted acts to further the purposes of the preceding paragraph with
the same legal force and effect as if executed by me. I hereby waive and
quitclaim to the Company any and all claims, of any nature whatsoever, which I
now or may hereafter have for infringement of any Proprietary Rights assigned
hereunder to the Company.

3.   Records. I agree to keep and maintain adequate and current records (in the
form of notes, sketches, drawings and in any other form that may be required by
the Company) of all Proprietary Information developed by me and all Inventions
made by me during the period of my employment at the Company, which records
shall be available to and remain the sole property of the Company at all times.

4.   Additional Activities. I agree that during the period of my employment by
the Company I will not, without the Company's express written consent, engage in
any employment or business activity which is competitive with, or would
otherwise conflict with, my employment by the Company. I agree further that for
the period of my employment by the Company and for one (l) year after the date
of termination of my employment by the Company, I will not directly or
indirectly, on behalf of myself or any other person or entity, solicit, call
upon, divert, take away, or recruit, or attempt to solicit, call upon, divert,
take away, or recruit, any employees, customers, licensors, or licensees of the
Company.

5.   No Conflicting Obligation. I represent that my performance of all the terms
of this Agreement and as an employee of the Company does not and will not breach
any agreement to keep in confidence information acquired by me in confidence or
in trust prior to my employment by the Company. I have not entered into, and I
agree I will not enter into, any agreement either written or oral in conflict
herewith.

6.   Return of Company Documents. When I leave the employ of the Company, I will
deliver to the Company any and all drawings, notes, memoranda, specifications,
devices, formulas, and documents, together with all copies thereof, and any
other material containing or disclosing any Company Inventions, Third Party
Information or Proprietary Information of the Company. I further agree that any
property situated on the Company's premises and owned by the Company, including
disks and other storage media, filing cabinets or other work areas, is subject
to inspection by Company personnel at any time with or without notice. Prior to
leaving, I will cooperate with the Company in completing and signing the
Company's termination statement.

7.   Legal and Equitable Remedies. Because my services are personal and unique
and because I may have access to and become acquainted with the Proprietary
Information of the Company, the Company shall have the right to enforce this
Agreement and any of its provisions by injunction, specific performance or other
equitable relief, without bond and without prejudice to any other rights and
remedies that the Company may have for a breach of this Agreement.

8.   Notices. Any notices required or permitted hereunder shall be given to the
appropriate party at the address specified below or at such other address as the
party shall specify in writing. Such notice shall be deemed given upon personal
delivery to the appropriate address or if sent by certified or registered mail,
three (3) days after the date of mailing.

9.   Notification of New Employer. In the event that I leave the employ of the
Company, I hereby consent to the notification of my new employer of my rights
and obligations under this Agreement.

10.  General Provisions.

     10.1 Governing Law; Consent to Personal Jurisdiction. This Agreement will
be governed by and construed according to the laws of the State of California,
as such laws are applied to agreements entered into and to be performed entirely
within California between California residents. I hereby expressly consent to
the personal jurisdiction of the state and federal courts located in San Mateo
County, California for any lawsuit filed there against me by Company arising
from or related to this Agreement.

     10.2 Severability. In case any one or more of the provisions contained in
this Agreement shall, for any reason, be held to be invalid, illegal or

                                      B-3
<PAGE>

unenforceable in any respect, such invalidity, illegality or unenforceability
shall not affect the other provisions of this Agreement, and this Agreement
shall be construed as if such invalid, illegal or unenforceable provision had
never been contained herein. If moreover, any one or more of the provisions
contained in this Agreement shall for any reason be held to be excessively broad
as to duration, geographical scope, activity or subject, it shall be construed
by limiting and reducing it, so as to be enforceable to the extent compatible
with the applicable law as it shall then appear.

     10.3 Successors and Assigns.  This Agreement will be binding upon my
heirs, executors, administrators and other legal representatives and will be for
the benefit of the Company, its successors, and its assigns.

     10.4 Survival. The provisions of this Agreement shall survive the
termination of my employment and the assignment of this Agreement by the Company
to any successor in interest or other assignee.

     10.5 Employment. I agree and understand that nothing in this Agreement
shall confer any right with respect to continuation of employment by the
Company, nor shall it interfere in any way with my right or the Company's right
to terminate my employment at any time, with or without cause.

     10.6 Waiver. No waiver by the Company of any breach of this Agreement shall
be a waiver of any preceding or succeeding breach. No waiver by the Company of
any right under this Agreement shall be construed as a waiver of any other
right. The Company shall not be required to give notice to enforce strict
adherence to all terms of this Agreement.

     10.7 Entire Agreement. The obligations pursuant to Sections 1 and 2 of this
Agreement shall apply to any time during which I was previously employed, or am
in the future employed, by the Company as a consultant if no other agreement
governs nondisclosure and assignment of inventions during such period. This
Agreement is the final, complete and exclusive agreement of the parties with
respect to the subject matter hereof and supersedes and merges all prior
discussions between us. No modification of or amendment to this Agreement, nor
any waiver of any rights under this Agreement, will be effective unless in
writing and signed by the party to be charged. Any subsequent change or changes
in my duties, salary or compensation will not affect the validity or scope of
this Agreement.

    This Agreement shall be effective as of the first day of my employment with
the Company, namely: August 1, 1998.

    I have read this Agreement carefully and understand its terms. I have
completely filled out Exhibit B to this Agreement.

Dated: August 1, 1998
       --------------

/s/ Richard Heaps
--------------------------------
(Signature)

Richard J. Heaps
--------------------------------
(Printed Name)

Accepted and Agreed To:

CLARENT CORPORATION

By: /s/ Lisa Gounod
   -----------------------------

Title: HR Manager
      --------------------------

700 Chesapeake Drive
--------------------------------
(Address)

Redwood City, CA 94063
--------------------------------

Dated: August 1, 1998

                                      B-4
<PAGE>

                                   Exhibit C

                             SUPPLEMENTAL RELEASE

                   (To be signed on or after April 30, 2001)

In further consideration of the consulting arrangement, stock option vesting
arrangement and other consideration under the separation and consulting
agreement between Clarent Corporation (the "Company") and me dated March 2, 2001
(the "Separation and Consulting Agreement"), I hereby release, acquit and
forever discharge the Company, its officers, directors, agents, servants,
employees, attorneys, shareholders, successors, assigns and affiliates, of and
from any and all claims, liabilities, demands, causes of action, costs,
expenses, attorneys fees, damages, indemnities and obligations of every kind and
nature, in law, equity, or otherwise, known and unknown, suspected and
unsuspected, disclosed and undisclosed, arising out of or in any way related to
agreements, events, acts or conduct at any time prior to and including the date
I sign this Supplemental Release ("Release"), including but not limited to: all
such claims and demands directly or indirectly arising out of or in any way
connected with my employment with the Company or the termination of that
employment; claims or demands related to salary, bonuses, commissions, stock,
stock options, or any other ownership interests in the Company, vacation pay,
fringe benefits, expense reimbursements, severance pay, or any other form of
compensation; claims pursuant to any federal, state or local law, statute, or
cause of action including, but not limited to, the federal Civil Rights Act of
1964, as amended; the federal Americans with Disabilities Act of 1990; the
federal Age Discrimination in Employment Act of 1967, as amended ("ADEA"); the
California Fair Employment and Housing Act, as amended; tort law; contract law;
wrongful discharge; discrimination; harassment; fraud; defamation; emotional
distress; and breach of the implied covenant of good faith and fair dealing. The
releases given herein shall not bar any claim for breach of the terms of the
Separation and Consulting Agreement.

I acknowledge that I am knowingly and voluntarily waiving and releasing any
rights I may have under the ADEA, as amended. I also acknowledge that the
consideration given for the waiver and release in the preceding paragraph hereof
is in addition to anything of value to which I was already entitled. I further
acknowledge that I have been advised by this writing, as required by the ADEA,
that: (a) my waiver and release do not apply to any rights or claims that may
arise after the date I sign this Release; (b) I have been advised hereby that I
have the right to consult with an attorney prior to executing this Release; (c)
I have had twenty-one (21) days to consider this Release; (d) I have seven (7)
days following the date I sign this Release to revoke the Release; and (e) this
Release will not be effective until the date upon which the revocation period
has expired, which will be the eighth day after this Release is executed by me
("Release Effective Date").

I UNDERSTAND THAT THIS AGREEMENT INCLUDES A RELEASE OF ALL KNOWN AND UNKNOWN
CLAIMS. In giving this release, which includes claims which may be unknown to me
at present, I acknowledge that I have read and understand Section 1542 of the
California Civil Code, which states: "A general release does not extend to
claims which the creditor does not know or suspect to exist in his favor at the
time of executing the release,

                                      C-1
<PAGE>

which if known by him must have materially affected his settlement with the
debtor." I hereby expressly waive and relinquish all rights and benefits under
that section and any law of any jurisdiction of similar effect with respect to
my release of any unknown or unsuspected claims I may have against the Company.

                                        By:  /s/ Rich Heaps
                                             -----------------------------------
                                                 Richard J. Heaps

                                        Date: April 30, 2001
                                             -----------------------------------

                                      C-2
<PAGE>

                                   Exhibit D

                              INDEMNITY AGREEMENT

     This Agreement is made and entered into this 30th day of June, 1999 by and
between Clarent Corporation, a Delaware corporation (the "Corporation"), and
Richard J. Heaps ("Agent").

                                   Recitals

     Whereas, Agent performs a valuable service to the Corporation in his/her
capacity as Chief Operating Officer, Chief Financial Officer, General Counsel
and Secretary of the Corporation;

     Whereas, the stockholders of the Corporation have adopted bylaws (the
"Bylaws") providing for the indemnification of the directors, officers,
employees and other agents of the Corporation, including persons serving at the
request of the Corporation in such capacities with other corporations or
enterprises, as authorized by the Delaware General Corporation Law, as amended
(the "Code");

     Whereas, the Bylaws and the Code, by their non-exclusive nature, permit
contracts between the Corporation and its agents, officers, employees and other
agents with respect to indemnification of such persons; and

     Whereas, in order to induce Agent to continue to serve as Chief Operating
Officer, Chief Financial Officer, General Counsel and Secretary of the
Corporation, the Corporation has determined and agreed to enter into this
Agreement with Agent;

     Now, Therefore, in consideration of Agent's continued service as Chief
Operating Officer, Chief Financial Officer, General Counsel and Secretary after
the date hereof, the parties hereto agree as follows:

                                   Agreement

     1.   Services to the Corporation. Agent will serve, at the will of the
Corporation or under separate contract, if any such contract exists, as Chief
Operating Officer, Chief Financial Officer, General Counsel and Secretary of the
Corporation or as a director, officer or other fiduciary of an affiliate of the
Corporation (including any employee benefit plan of the Corporation) faithfully
and to the best of his ability so long as he is duly elected and qualified in
accordance with the provisions of the Bylaws or other applicable charter
documents of the Corporation or such affiliate; provided, however, that Agent
may at any time and for any reason resign from such position (subject to any
contractual obligation that Agent may have assumed apart from this Agreement)
and that the Corporation or any affiliate shall have no obligation under this
Agreement to continue Agent in any such position.

     2.   Indemnity of Agent. The Corporation hereby agrees to hold harmless and
indemnify Agent to the fullest extent authorized or permitted by the provisions
of the Bylaws

                                      D-1
<PAGE>

and the Code, as the same may be amended from time to time (but, only to the
extent that such amendment permits the Corporation to provide broader
indemnification rights than the Bylaws or the Code permitted prior to adoption
of such amendment).

     3.   Additional Indemnity. In addition to and not in limitation of the
indemnification otherwise provided for herein, and subject only to the
exclusions set forth in Section 4 hereof, the Corporation hereby further agrees
to hold harmless and indemnify Agent:

          (a)  against any and all expenses (including attorneys' fees), witness
fees, damages, judgments, fines and amounts paid in settlement and any other
amounts that Agent becomes legally obligated to pay because of any claim or
claims made against or by him in connection with any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, arbitrational,
administrative or investigative (including an action by or in the right of the
Corporation) to which Agent is, was or at any time becomes a party, or is
threatened to be made a party, by reason of the fact that Agent is, was or at
any time becomes a director, officer, employee or other agent of Corporation, or
is or was serving or at any time serves at the request of the Corporation as a
director, officer, employee or other agent of another corporation, partnership,
joint venture, trust, employee benefit plan or other enterprise; and

          (b)  otherwise to the fullest extent as may be provided to Agent by
the Corporation under the non-exclusivity provisions of the Code and Section 43
of the Bylaws.

     4.   Limitations on Additional Indemnity. No indemnity pursuant to Section
3 hereof shall be paid by the Corporation:

          (a)  on account of any claim against Agent for an accounting of
profits made from the purchase or sale by Agent of securities of the Corporation
pursuant to the provisions of Section 16(b) of the Securities Exchange Act of
1934 and amendments thereto or similar provisions of any federal, state or local
statutory law;

          (b)  on account of Agent's conduct that was knowingly fraudulent or
deliberately dishonest or that constituted willful misconduct;

          (c)  on account of Agent's conduct that constituted a breach of
Agent's duty of loyalty to the Corporation or resulted in any personal profit or
advantage to which Agent was not legally entitled;

          (d)  for which payment is actually made to Agent under a valid and
collectible insurance policy or under a valid and enforceable indemnity clause,
bylaw or agreement, except in respect of any excess beyond payment under such
insurance, clause, bylaw or agreement;

          (e)  if indemnification is not lawful (and, in this respect, both the
Corporation and Agent have been advised that the Securities and Exchange
Commission believes that indemnification for liabilities arising under the
federal securities laws is against public policy and is, therefore,
unenforceable and that claims for indemnification should be submitted to
appropriate courts for adjudication); or

                                      D-2
<PAGE>

          (f)  in connection with any proceeding (or part thereof) initiated by
Agent, or any proceeding by Agent against the Corporation or its directors,
officers, employees or other agents, unless (i) such indemnification is
expressly required to be made by law, (ii) the proceeding was authorized by the
Board of Directors of the Corporation, (iii) such indemnification is provided by
the Corporation, in its sole discretion, pursuant to the powers vested in the
Corporation under the Code, or (iv) the proceeding is initiated pursuant to
Section 9 hereof.

     5.   Continuation of Indemnity. All agreements and obligations of the
Corporation contained herein shall continue during the period Agent is a
director, officer, employee or other agent of the Corporation (or is or was
serving at the request of the Corporation as a director, officer, employee or
other agent of another corporation, partnership, joint venture, trust, employee
benefit plan or other enterprise) and shall continue thereafter so long as Agent
shall be subject to any possible claim or threatened, pending or completed
action, suit or proceeding, whether civil, criminal, arbitrational,
administrative or investigative, by reason of the fact that Agent was serving in
the capacity referred to herein.

     6.   Partial Indemnification. Agent shall be entitled under this Agreement
to indemnification by the Corporation for a portion of the expenses (including
attorneys' fees), witness fees, damages, judgments, fines and amounts paid in
settlement and any other amounts that Agent becomes legally obligated to pay in
connection with any action, suit or proceeding referred to in Section 3 hereof
even if not entitled hereunder to indemnification for the total amount thereof,
and the Corporation shall indemnify Agent for the portion thereof to which Agent
is entitled.

     7.   Notification and Defense of Claim. Not later than thirty (30) days
after receipt by Agent of notice of the commencement of any action, suit or
proceeding, Agent will, if a claim in respect thereof is to be made against the
Corporation under this Agreement, notify the Corporation of the commencement
thereof; but the omission so to notify the Corporation will not relieve it from
any liability which it may have to Agent otherwise than under this Agreement.
With respect to any such action, suit or proceeding as to which Agent notifies
the Corporation of the commencement thereof:

          (a)  the Corporation will be entitled to participate therein at its
own expense;

          (b)  except as otherwise provided below, the Corporation may, at its
option and jointly with any other indemnifying party similarly notified and
electing to assume such defense, assume the defense thereof, with counsel
reasonably satisfactory to Agent. After notice from the Corporation to Agent of
its election to assume the defense thereof, the Corporation will not be liable
to Agent under this Agreement for any legal or other expenses subsequently
incurred by Agent in connection with the defense thereof except for reasonable
costs of investigation or otherwise as provided below. Agent shall have the
right to employ separate counsel in such action, suit or proceeding but the fees
and expenses of such counsel incurred after notice from the Corporation of its
assumption of the defense thereof shall be at the expense of Agent unless (i)
the employment of counsel by Agent has been authorized by the Corporation, (ii)
Agent shall have reasonably concluded that there may be a conflict of interest
between the Corporation and Agent in the conduct of the defense of such action
or (iii) the Corporation shall

                                      D-3
<PAGE>

not in fact have employed counsel to assume the defense of such action, in each
of which cases the fees and expenses of Agent's separate counsel shall be at the
expense of the Corporation. The Corporation shall not be entitled to assume the
defense of any action, suit or proceeding brought by or on behalf of the
Corporation or as to which Agent shall have made the conclusion provided for in
clause (ii) above; and

          (c)  the Corporation shall not be liable to indemnify Agent under this
Agreement for any amounts paid in settlement of any action or claim effected
without its written consent, which shall not be unreasonably withheld. The
Corporation shall be permitted to settle any action except that it shall not
settle any action or claim in any manner which would impose any penalty or
limitation on Agent without Agent's written consent, which may be given or
withheld in Agent's sole discretion.

     8.   Expenses. The Corporation shall advance, prior to the final
disposition of any proceeding, promptly following request therefor, all expenses
incurred by Agent in connection with such proceeding upon receipt of an
undertaking by or on behalf of Agent to repay said amounts if it shall be
determined ultimately that Agent is not entitled to be indemnified under the
provisions of this Agreement, the Bylaws, the Code or otherwise.

     9.   Enforcement. Any right to indemnification or advances granted by this
Agreement to Agent shall be enforceable by or on behalf of Agent in any court of
competent jurisdiction if (i) the claim for indemnification or advances is
denied, in whole or in part, or (ii) no disposition of such claim is made within
ninety (90) days of request therefor. Agent, in such enforcement action, if
successful in whole or in part, shall be entitled to be paid also the expense of
prosecuting his claim. It shall be a defense to any action for which a claim for
indemnification is made under Section 3 hereof (other than an action brought to
enforce a claim for expenses pursuant to Section 8 hereof, provided that the
required undertaking has been tendered to the Corporation) that Agent is not
entitled to indemnification because of the limitations set forth in Section 4
hereof. Neither the failure of the Corporation (including its Board of Directors
or its stockholders) to have made a determination prior to the commencement of
such enforcement action that indemnification of Agent is proper in the
circumstances, nor an actual determination by the Corporation (including its
Board of Directors or its stockholders) that such indemnification is improper
shall be a defense to the action or create a presumption that Agent is not
entitled to indemnification under this Agreement or otherwise.

     10.  Subrogation. In the event of payment under this Agreement, the
Corporation shall be subrogated to the extent of such payment to all of the
rights of recovery of Agent, who shall execute all documents required and shall
do all acts that may be necessary to secure such rights and to enable the
Corporation effectively to bring suit to enforce such rights.

     11.  Non-Exclusivity of Rights. The rights conferred on Agent by this
Agreement shall not be exclusive of any other right which Agent may have or
hereafter acquire under any statute, provision of the Corporation's Certificate
of Incorporation or Bylaws, agreement, vote of stockholders or directors, or
otherwise, both as to action in his official capacity and as to action in
another capacity while holding office.

                                      D-4
<PAGE>

     12.  Survival of Rights.

          (a)  The rights conferred on Agent by this Agreement shall continue
after Agent has ceased to be a director, officer, employee or other agent of the
Corporation or to serve at the request of the Corporation as a director,
officer, employee or other agent of another corporation, partnership, joint
venture, trust, employee benefit plan or other enterprise and shall inure to the
benefit of Agent's heirs, executors and administrators.

          (b)  The Corporation shall require any successor (whether direct or
indirect, by purchase, merger, consolidation or otherwise) to all or
substantially all of the business or assets of the Corporation, expressly to
assume and agree to perform this Agreement in the same manner and to the same
extent that the Corporation would be required to perform if no such succession
had taken place.

     13.  Separability. Each of the provisions of this Agreement is a separate
and distinct agreement and independent of the others, so that if any provision
hereof shall be held to be invalid for any reason, such invalidity or
unenforceability shall not affect the validity or enforceability of the other
provisions hereof. Furthermore, if this Agreement shall be invalidated in its
entirety on any ground, then the Corporation shall nevertheless indemnify Agent
to the fullest extent provided by the Bylaws, the Code or any other applicable
law.

     14.  Governing Law. This Agreement shall be interpreted and enforced in
accordance with the laws of the State of Delaware.

     15.  Amendment and Termination. No amendment, modification, termination or
cancellation of this Agreement shall be effective unless in writing signed by
both parties hereto.

     16.  Identical Counterparts. This Agreement may be executed in one or more
counterparts, each of which shall for all purposes be deemed to be an original
but all of which together shall constitute but one and the same Agreement. Only
one such counterpart need be produced to evidence the existence of this
Agreement.

     17.  Headings. The headings of the sections of this Agreement are inserted
for convenience only and shall not be deemed to constitute part of this
Agreement or to affect the construction hereof.

     18.  Notices. All notices, requests, demands and other communications
hereunder shall be in writing and shall be deemed to have been duly given (i)
upon delivery if delivered by hand to the party to whom such communication was
directed or (ii) upon the third business day after the date on which such
communication was mailed if mailed by certified or registered mail with postage
prepaid:

          (a)  If to Agent, at the address indicated on the signature page
hereof.

                                      D-5
<PAGE>

          (b)  If to the Corporation, to

               Clarent Corporation
               700 Chesapeake Drive
               Redwood City, CA 94063

or to such other address as may have been furnished to Agent by the Corporation.

     In Witness Whereof, the parties hereto have executed this Agreement on and
as of the day and year first above written.

                                   Clarent Corporation

                                   By:  /s/ Jerry Shaw-Yau Chang
                                        ----------------------------------------

                                   Title: President and Chief Executive Officer
                                          --------------------------------------

                                   Richard J. Heaps  ("Agent")

                                   /s/ Richard J. Heaps
                                   ---------------------------------------------

                                   Address:

                                   _____________________________________________

                                   _____________________________________________

                                      D-6<PAGE>

                                                                   Exhibit 10.26

                              CLARENT CORPORATION

           SENIOR EXECUTIVE CHANGE IN CONTROL SEVERANCE BENEFIT PLAN

Section 1.  Introduction.

     This Clarent Corporation Senior Executive Change in Control Severance
Benefit Plan (the "Plan") was established effective April 12, 2001. The purpose
of the Plan is to provide for the payment of severance benefits to certain
eligible employees of Clarent Corporation (the "Company") whose employment with
the Company is terminated following a Change in Control. This Plan shall
supersede any severance benefit plan (other than the Executive Change in Control
Severance Benefit Plan or the Employee Change in Control Severance Benefit
Plan), policy or practice previously maintained by the Company. This Plan
document also is the Summary Plan Description for the Plan.

Section 2.  Definitions.

     For purposes of the Plan, the following terms are defined as follows:

            (a)    "Base Salary" means the Eligible Employee's annual base
salary as in effect during the last regularly scheduled payroll period
immediately preceding the Change in Control or as increased thereafter.

            (b)    "Board" means the Board of Directors of the Company.

            (c)    "Change in Control" means:

                   (i)    the sale of all or substantially all of the Company's
assets to a single purchaser or a group of related purchasers;

                   (ii)   the sale, exchange or other disposition, in a single
transaction, of more than fifty percent (50%) of the Company's outstanding
capital stock; or

                   (iii)  a merger or consolidation of the Company in a
transaction following which the Company's stockholders receive less than fifty
percent (50%) of the outstanding voting shares of the surviving entity.

            (d)    "Company" means Clarent Corporation or, following a Change in
Control, the surviving entity resulting from such transaction.

            (e)    "Constructive Termination" means that the Eligible Employee
voluntarily terminates employment with the Company after:

                                       1.
<PAGE>

                   (i)    the assignment to the Eligible Employee of any duties
or responsibilities that results in a significant diminution in the Eligible
Employee's function as in effect immediately prior to the effective date of the
Change in Control;

                   (ii)   a change in the Eligible Employee's title or reporting
relationships as in effect immediately prior to the effective date of the
Change in Control;

                   (iii)  a reduction by the Company in the Eligible Employee's
Base Salary by five percent (5%) or more; provided, however, that a reduction by
the Company of the Eligible Employee's Base Salary by up to ten percent (10%)
shall not constitute a Constructive Termination for purposes of this Agreement
if it is made in connection with an across-the-board reduction by the Company of
all Eligible Employees' annual base salaries by a percentage at least equal to
the percentage by which the Eligible Employee's Base Salary is reduced;

                   (iv)   a relocation of the Eligible Employee's business
office to a location that requires the Eligible Employee to commute more than
thirty-five (35) miles each way, except for required travel by the Eligible
Employee on the Company's business to an extent substantially consistent with
the Eligible Employee's business travel obligations prior to the effective date
of a Change in Control; provided, however, that no relocation of the Eligible
Employee's business office shall constitute a Constructive Termination for
purposes of this Agreement if the Eligible Employee provides services to the
Company from a remote location (e.g., through telecommuting) at the time of the
relocation;

                   (v)    a material breach by the Company of any provision of
this Agreement; or

                   (vi)   any failure by the Company to obtain the assumption of
this Agreement by any successor or assign of the Company.

            (f)    "Continuation Period" means the period for which an Eligible
Employee is entitled to receive the benefits described in Section 4. The
Continuation Period is twenty-four (24) months.

            (g)    "Covered Termination" means an Involuntary Termination
Without Cause or a Constructive Termination, either of which occurs within
thirteen (13) months following the effective date of a Change in Control.

            (h)    "Involuntary Termination Without Cause" means the Eligible
Employee's dismissal or discharge for reasons other than Cause. For this
purpose, "Cause" means that, in the reasonable determination of the Company, the
Eligible Employee has

                   (i)    been convicted of or pleaded guilty or nolo contendere
to a felony or any crime involving moral turpitude or dishonesty;

                   (ii)   participated in a fraud or act of dishonesty against
the Company;

                   (iii)  willfully and materially breached a Company policy;

                                       2.
<PAGE>

                   (iv)   intentionally damaged the Company's property;

                   (v)    willfully and materially breached the Eligible
Employee's Proprietary Information and Inventions Agreement with the Company; or

                   (vi)   engaged in conduct that, in the reasonable
determination of the Company, demonstrates gross unfitness to serve.

     Notwithstanding the foregoing, Cause shall not exist based on conduct
described in clause (iii) or (vi) unless the conduct described in such clause
has not been cured within thirty (30) days following the Eligible Employee's
receipt of written notice from the Company specifying the particulars of the
conduct constituting Cause.

Section 3.  Eligibility For Benefits.

            (a)    General Rules. Subject to the requirements set forth in this
Section, the Company will provide the severance benefits described in Section 4
of the Plan to Eligible Employees. For purposes of this Plan, "Eligible
Employees" are all full-time and part-time regular hire employees of the Company
who hold a position of Senior Vice President, Executive Vice President, Chief
Operating Officer, Chief Financial Officer, Chief Technology Officer, President,
Chief Executive Officer or other senior executives as specified by the Board,
and whose employment with the Company terminates due to an Involuntary
Termination Without Cause or Constructive Termination, in either case within
thirteen (13) months following the effective date of a Change in Control.

                   (i)    In order to be eligible to receive benefits under the
Plan, an Eligible Employee must remain on the job until his or her date of
termination, as scheduled by the Company.

                   (ii)   In order to be eligible to receive benefits under the
Plan, an Eligible Employee also must execute a general waiver and release in
substantially the form attached hereto as Exhibit A, Exhibit B or Exhibit C, as
appropriate, and such release must become effective in accordance with its
terms.

            (b)    Exceptions to Benefit Entitlement. An employee who otherwise
is an Eligible Employee will not receive benefits under the Plan in any of the
following circumstances, as determined by the Company in its sole discretion:

                   (i)    The employee has executed an individually negotiated
employment contract or agreement with the Company relating to severance benefits
that is in effect on his or her termination date which provides severance
benefits greater than the benefits otherwise payable under this Plan.

                   (ii)   The employee is terminated for Cause, as defined in
Section 2(h).

                   (iii)  The employee voluntarily terminates employment with
the Company and such termination does not constitute a Constructive Termination.
Voluntary

                                       3.
<PAGE>

terminations include, but are not limited to, resignation, retirement or failure
to return from a leave of absence on the scheduled date.

                   (iv)   The employee voluntarily terminates employment with
the Company in order to accept employment with another entity that is wholly or
partly owned (directly or indirectly) by the Company or an affiliate of the
Company.

                   (v)    The employee continues employment, with the same title
and reporting responsibilities and no diminution in duties and responsibilities,
with a successor corporation following a Change in Control.

Section 4.  Amount Of Benefit.

            (a)    Salary Continuation. Each Eligible Employee shall continue to
receive Base Salary for the Continuation Period. Such amount shall be paid in
regular installments on the normal payroll dates of the Company and shall be
subject to all required tax withholding.

            (b)    Continued Insurance Benefits. Provided that the Eligible
Employee elects continued coverage under the Consolidated Omnibus Budget
Reconciliation Act of 1985 ("COBRA"), the Company shall pay the portion of
premiums of each Eligible Employee's group medical, dental and vision coverage,
including coverage for the Eligible Employee's eligible dependents, that the
Company paid prior to the Covered Termination for the Continuation Period or, if
shorter, for the duration of the COBRA continuation period. Such premium
payments shall continue for the duration of the Continuation Period; provided,
however, that no such premium payments shall be made following the effective
date of the Eligible Employee's coverage by a medical, dental or vision
insurance plan of a subsequent employer. Each Eligible Employee shall be
required to notify the Company immediately if the Eligible Employee becomes
covered by a medical, dental or vision insurance plan of a subsequent employer.

     No provision of this Plan will affect the continuation coverage rules under
COBRA, except that the Company's payment of any applicable insurance premiums
during the Continuation Period will be credited as payment by the Eligible
Employee for purposes of the Eligible Employee's payment required under COBRA.
Therefore, the period during which an Eligible Employee must elect to continue
the Company's group medical coverage at his or her own expense under COBRA, the
length of time during which COBRA coverage will be made available to the
Eligible Employee, and all other rights and obligations of the Eligible Employee
under COBRA (except the obligation to pay insurance premiums that the Company
pays during the Continuation Period) will be applied in the same manner that
such rules would apply in the absence of this Plan. At the conclusion of the
Continuation Period, the Eligible Employee will be responsible for the entire
payment of premiums required under COBRA for the duration of the COBRA
continuation period. For purposes of this Section 4(b), applicable premiums that
will be paid by the Company during the Continuation Period shall not include any
amounts payable by the Eligible Employee under a Section 125 health care
reimbursement plan, which amounts, if any, are the sole responsibility of the
Eligible Employee.

            (c)    Acceleration of Vesting. Effective as of the date of the
Covered Termination, each Eligible Employee shall be credited with thirty-six
(36) months of additional

                                       4.
<PAGE>

vesting under all options to purchase the Company's Common Stock that the
Eligible Employee holds on such date. Notwithstanding the foregoing, no Eligible
Employee shall be entitled to receive such additional vesting credit if the
transaction constituting the Change in Control that triggers the Eligible
Employee's entitlement to benefits under the Plan (i) occurs within six (6)
months following the effective date of the Plan and (ii) is to be accounted for
as a "pooling of interests" for financial accounting purposes.

Section 5.  Limitations on Benefits.

            (a)    Release. To receive benefits under this Plan, an Eligible
Employee must execute a release of claims in favor of the Company, in the form
attached to this Plan as Exhibit A, Exhibit B or Exhibit C, as appropriate, and
such release must become effective in accordance with its terms.

            (b)    Certain Reductions and Offsets. Notwithstanding any other
provision of the Plan to the contrary, any benefits payable to an Eligible
Employee under this Plan shall be reduced by any severance benefits payable by
the Company to such individual under any other policy, plan, program or
arrangement, including, without limitation, a contract between the Eligible
Employee and any entity, covering such individual. Furthermore, to the extent
that any federal, state or local laws, including, without limitation, so-called
"plant closing" laws, require the Company to give advance notice or make a
payment of any kind to an Eligible Employee because of that Eligible Employee's
involuntary termination due to a layoff, reduction in force, plant or facility
closing, sale of business, change of control, or any other similar event or
reason, the benefits payable under this Plan shall either be reduced or
eliminated. The benefits provided under this Plan are intended to satisfy any
and all statutory obligations that may arise out of an Eligible Employee's
involuntary termination of employment for the foregoing reasons, and the Plan
Administrator shall so construe and implement the terms of the Plan.

            (c)    Mitigation. Except as otherwise specifically provided herein,
Eligible Employees shall not be required to mitigate damages or the amount of
any payment provided under this Plan by seeking other employment or otherwise,
nor shall the amount of any payment provided for under this Plan be reduced by
any compensation earned by any Eligible Employee as a result of employment by
another employer or any retirement benefits received by such Eligible Employee
after the date of the Covered Termination.

            (d)    Termination of Benefits. Benefits under this Plan shall
terminate immediately if the Eligible Employee, at any time, violates any
proprietary information or confidentiality obligation to the Company.

            (e)    Non-Duplication of Benefits. No Eligible Employee is eligible
to receive benefits under this Plan more than one time.

            (f)    Indebtedness of Eligible Employees. If a terminating employee
is indebted to the Company or an affiliate of the Company at his or her
termination date, the Company reserves the right to offset any severance
payments under the Plan by the amount of such indebtedness.

                                       5.
<PAGE>

            (g)    Parachute Payments. If any payment or benefit the Eligible
Employee would receive in connection with a Change in Control from the Company
or otherwise ("Payment") would (i) constitute a "parachute payment" within the
meaning of Section 280G of the Internal Revenue Code of 1986, as amended (the
"Code"), and (ii) but for this sentence, be subject to the excise tax imposed by
Section 4999 of the Code (the "Excise Tax"), then such Payment shall be reduced
to the Reduced Amount. The "Reduced Amount" shall be either (x) the largest
portion of the Payment that would result in no portion of the Payment being
subject to the Excise Tax or (y) the largest portion, up to and including the
total, of the Payment, whichever amount, after taking into account all
applicable federal, state and local employment taxes, income taxes, and the
Excise Tax (all computed at the highest applicable marginal rate), results in
the Eligible Employee's receipt, on an after-tax basis, of the greater amount of
the Payment notwithstanding that all or some portion of the Payment may be
subject to the Excise Tax. If a reduction in payments or benefits constituting
"parachute payments" is necessary so that the Payment equals the Reduced Amount,
reduction shall occur in the following order unless the Eligible Employee elects
in writing a different order (provided, however, that such election shall be
subject to Company approval if made on or after the date on which the event that
triggers the Payment occurs): reduction of cash payments; cancellation of
accelerated vesting of stock awards; reduction of employee benefits. In the
event that acceleration of vesting of stock award compensation is to be reduced,
such acceleration of vesting shall be cancelled in the reverse order of the date
of grant of the Eligible Employee's stock awards unless the Eligible Employee
elects in writing a different order for cancellation.

     The accounting firm engaged by the Company for general audit purposes as of
the day prior to the effective date of the Change in Control shall perform the
foregoing calculations.  If the accounting firm so engaged by the Company is
serving as accountant or auditor for the individual, entity or group effecting
the Change in Control, the Company shall appoint a nationally recognized
accounting firm to make the determinations required hereunder.  The Company
shall bear all expenses with respect to the determinations by such accounting
firm required to be made hereunder.

     The accounting firm engaged to make the determinations hereunder shall
provide its calculations, together with detailed supporting documentation, to
the Company and the Eligible Employee within fifteen (15) calendar days after
the date on which the Eligible Employee's right to a Payment is triggered (if
requested at that time by the Company or the Eligible Employee) or such other
time as requested by the Company or the Eligible Employee. If the accounting
firm determines that no Excise Tax is payable with respect to a Payment, either
before or after the application of the Reduced Amount, it shall furnish the
Company and the Eligible Employee with an opinion reasonably acceptable to
Executive that no Excise Tax will be imposed with respect to such Payment. Any
good faith determinations of the accounting firm made hereunder shall be final,
binding and conclusive upon the Company and the Eligible Employee.

Section 6.  Right To Interpret Plan; Amendment and Termination.

            (a)    Exclusive Discretion. The Plan Administrator shall have the
exclusive discretion and authority to establish rules, forms, and procedures for
the administration of the Plan and to construe and interpret the Plan and to
decide any and all questions of fact, interpretation, definition, computation or
administration arising in connection with the operation

                                       6.
<PAGE>

of the Plan, including, but not limited to, the eligibility to participate in
the Plan and amount of benefits paid under the Plan. The rules, interpretations,
computations and other actions of the Plan Administrator shall be binding and
conclusive on all persons.

            (b)    Amendment or Termination. The Company reserves the right to
amend or terminate this Plan or the benefits provided hereunder at any time;
provided, however, that no such amendment or termination shall occur following a
Change in Control if such amendment or termination would affect the rights of
any persons who were employed by the Company prior to the Change in Control. Any
action amending or terminating the Plan shall be in writing and executed by the
chairman of the Compensation Committee of the Board of Directors of the Company.

Section 7.  Termination of Certain Employee Benefits.

     All non-health benefits (such as life insurance, disability and 401(k) plan
coverage) terminate as of the employee's termination date (except to the extent
that a conversion privilege may be available thereunder).

Section 8.  No Implied Employment Contract.

     The Plan shall not be deemed (i) to give any employee or other person any
right to be retained in the employ of the Company or (ii) to interfere with the
right of the Company to discharge any employee or other person at any time and
for any reason, which right is hereby reserved.

Section 9.  Legal Construction.

     This Plan is intended to be governed by and shall be construed in
accordance with the Employee Retirement Income Security Act of 1974 ("ERISA")
and, to the extent not preempted by ERISA, the laws of the State of California.

Section 10. Claims, Inquiries And Appeals.

            (a)    Applications for Benefits and Inquiries. Any application for
benefits, inquiries about the Plan or inquiries about present or future rights
under the Plan must be submitted to the Plan Administrator in writing. The Plan
Administrator is:

                              Clarent Corporation
                             700 Chesapeake Drive
                            Redwood City, CA 94063

            (b)    Denial of Claims. In the event that any application for
benefits is denied in whole or in part, the Plan Administrator must notify the
applicant, in writing, of the denial of the application, and of the applicant's
right to review the denial. The written notice of denial will be set forth in a
manner designed to be understood by the employee and will include specific
reasons for the denial, specific references to the Plan provision upon which the
denial is based, a description of any information or material that the Plan
Administrator needs to complete the review and an explanation of the Plan's
review procedure.

                                       7.
<PAGE>

     This written notice will be given to the employee within ninety (90) days
after the Plan Administrator receives the application, unless special
circumstances require an extension of time, in which case, the Plan
Administrator has up to an additional ninety (90) days for processing the
application. If an extension of time for processing is required, written notice
of the extension will be furnished to the applicant before the end of the
initial ninety (90) day period.

     This notice of extension will describe the special circumstances
necessitating the additional time and the date by which the Plan Administrator
is to render its decision on the application. If written notice of denial of the
application for benefits is not furnished within the specified time, the
application shall be deemed to be denied. The applicant will then be permitted
to appeal the denial in accordance with the Review Procedure described below.

            (c)    Request for a Review. Any person (or that person's authorized
representative) for whom an application for benefits is denied (or deemed
denied), in whole or in part, may appeal the denial by submitting a request for
a review to the Plan Administrator within sixty (60) days after the application
is denied (or deemed denied). The Plan Administrator will give the applicant (or
his or her representative) an opportunity to review pertinent documents in
preparing a request for a review. A request for a review shall be in writing and
shall be addressed to:

                              Clarent Corporation
                             700 Chesapeake Drive
                            Redwood City, CA 94063

A request for review must set forth all of the grounds on which it is based, all
facts in support of the request and any other matters that the applicant feels
are pertinent. The Plan Administrator may require the applicant to submit
additional facts, documents or other material as it may find necessary or
appropriate in making its review.

            (d)    Decision on Review. The Plan Administrator will act on each
request for review within sixty (60) days after receipt of the request, unless
special circumstances require an extension of time (not to exceed an additional
sixty (60) days), for processing the request for a review. If an extension for
review is required, written notice of the extension will be furnished to the
applicant within the initial sixty (60) day period. The Plan Administrator will
give prompt, written notice of its decision to the applicant. In the event that
the Plan Administrator confirms the denial of the application for benefits in
whole or in part, the notice will outline, in a manner calculated to be
understood by the applicant, the specific Plan provisions upon which the
decision is based. If written notice of the Plan Administrator's decision is not
given to the applicant within the time prescribed in this Subsection (d), the
application will be deemed denied on review.

            (e)    Rules and Procedures. The Plan Administrator will establish
rules and procedures, consistent with the Plan and with ERISA, as necessary and
appropriate in carrying out its responsibilities in reviewing benefit claims.
The Plan Administrator may require an applicant who wishes to submit additional
information in connection with an appeal from the denial (or deemed denial) of
benefits to do so at the applicant's own expense.

                                       8.
<PAGE>

            (f)    Exhaustion of Remedies. No legal action for benefits under
the Plan may be brought until the claimant (i) has submitted a written
application for benefits in accordance with the procedures described by Section
10(a) above, (ii) has been notified by the Plan Administrator that the
application is denied (or the application is deemed denied due to the Plan
Administrator's failure to act on it within the established time period), (iii)
has filed a written request for a review of the application in accordance with
the appeal procedure described in Section 10(c) above and (iv) has been notified
in writing that the Plan Administrator has denied the appeal (or the appeal is
deemed to be denied due to the Plan Administrator's failure to take any action
on the claim within the time prescribed by Section 10(d) above).

Section 11. Basis Of Payments To And From Plan.

     All benefits under the Plan shall be paid by the Company. The Plan shall be
unfunded, and benefits hereunder shall be paid only from the general assets of
the Company.

Section 12. Other Plan Information.

            (a)    Employer and Plan Identification Numbers. The Employer
Identification Number assigned to the Company (which is the "Plan Sponsor" as
that term is used in ERISA) by the Internal Revenue Service is 77-0433687. The
Plan Number assigned to the Plan by the Plan Sponsor pursuant to the
instructions of the Internal Revenue Service is 505.

            (b)    Ending Date for Plan's Fiscal Year. The date of the end of
the fiscal year for the purpose of maintaining the Plan's records is December
31.

            (c)    Agent for the Service of Legal Process. The agent for the
service of legal process with respect to the Plan is Clarent Corporation, 700
Chesapeake Drive, Redwood City, CA 94063.

            (d)    Plan Sponsor and Administrator. The "Plan Sponsor" and the
"Plan Administrator" of the Plan is Clarent Corporation, 700 Chesapeake Drive,
Redwood City, CA 94063. The Plan Sponsor's and Plan Administrator's telephone
number is (650) 306-7511. The Plan Administrator is the named fiduciary charged
with the responsibility for administering the Plan.

Section 13.  Statement Of ERISA Rights.

     Participants in this Plan (which is a welfare benefit plan sponsored by
Clarent Corporation) are entitled to certain rights and protections under ERISA.
If you are an Eligible Employee, you are considered a participant in the Plan
and, under ERISA, you are entitled to:

            (a)    Examine, without charge, at the Plan Administrator's office
and at other specified locations, such as work sites, all Plan documents and
copies of all documents filed by the Plan with the U.S. Department of Labor,
such as detailed annual reports;

            (b)    Obtain copies of all Plan documents and Plan information upon
written request to the Plan Administrator. The Administrator may make a
reasonable charge for the copies; and

                                       9.
<PAGE>

            (c)    Receive a summary of the Plan's annual financial report, in
the case of a plan that is required to file an annual financial report with the
Department of Labor. (Generally, all pension plans and welfare plans with one
hundred (100) or more participants must file these annual reports.)

     In addition to creating rights for Plan participants, ERISA imposes duties
upon the people responsible for the operation of the employee benefit plan.  The
people who operate the Plan, called "fiduciaries" of the Plan, have a duty to do
so prudently and in the interest of you and other Plan participants and
beneficiaries.

     No one, including your employer or any other person, may fire you or
otherwise discriminate against you in any way to prevent you from obtaining a
Plan benefit or exercising your rights under ERISA. If your claim for a Plan
benefit is denied in whole or in part, you must receive a written explanation of
the reason for the denial. You have the right to have the Plan review and
reconsider your claim.

     Under ERISA, there are steps you can take to enforce the above rights. For
instance, if you request materials from the Plan and do not receive them within
thirty (30) days, you may file suit in a federal court. In such a case, the
court may require the Plan Administrator to provide the materials and pay you up
to $110 a day until you receive the materials, unless the materials were not
sent because of reasons beyond the control of the Plan Administrator. If you
have a claim for benefits that is denied or ignored, in whole or in part, you
may file suit in a state or federal court. If it should happen that the Plan
fiduciaries misuse the Plan's money, or if you are discriminated against for
asserting your rights, you may seek assistance from the U.S. Department of
Labor, or you may file suit in a federal court. The court will decide who should
pay court costs and legal fees. If you are successful, the court may order the
person you have sued to pay these costs and fees. If you lose, the court may
order you to pay these costs and fees, for example, if it finds your claim is
frivolous.

     If you have any questions about the Plan, you should contact the Plan
Administrator. If you have any questions about this statement or about your
rights under ERISA, you should contact the nearest office of the Pension and
Welfare Benefits Administration, U.S. Department of Labor, listed in your
telephone directory or the Division of Technical Assistance and Inquiries,
Pension and Welfare Benefits Administration, U.S. Department of Labor, 200
Constitution Avenue N.W., Washington, D.C. 20210.

                                      10.
<PAGE>

                                   Exhibit A

                                    RELEASE
                       (Individual Termination over 40)

     Certain capitalized terms used in this Release are defined in the Change in
Control Severance Benefit Plan (the "Plan") which I have executed and of which
this Release is a part.

     I hereby confirm my obligations under the Company's proprietary information
and inventions agreement.

     I acknowledge that I have read and understand Section 1542 of the
California Civil Code which reads as follows: "A general release does not extend
to claims which the creditor does not know or suspect to exist in his favor at
the time of executing the release, which if known by him must have materially
affected his settlement with the debtor." I hereby expressly waive and
relinquish all rights and benefits under that section and any law of any
jurisdiction of similar effect with respect to my release of any claims I may
have against the Company.

     Except as otherwise set forth in this Release, I hereby release, acquit and
forever discharge the Company, its parents and subsidiaries, and their officers,
directors, agents, servants, employees, shareholders, successors, assigns and
affiliates, of and from any and all claims, liabilities, demands, causes of
action, costs, expenses, attorneys fees, damages, indemnities and obligations of
every kind and nature, in law, equity, or otherwise, known and unknown,
suspected and unsuspected, disclosed and undisclosed (other than any claim for
indemnification I may have as a result of any third party action against me
based on my employment with the Company), arising out of or in any way related
to agreements, events, acts or conduct at any time prior to the date I execute
this Release, including, but not limited to: all such claims and demands
directly or indirectly arising out of or in any way connected with my employment
with the Company or the termination of that employment, including but not
limited to, claims of intentional and negligent infliction of emotional
distress, any and all tort claims for personal injury, claims or demands related
to salary, bonuses, commissions, stock, stock options, or any other ownership
interests in the Company, vacation pay, fringe benefits, expense reimbursements,
severance pay, or any other form of compensation; claims pursuant to any
federal, state or local law or cause of action including, but not limited to,
the federal Civil Rights Act of 1964, as amended; the federal Age Discrimination
in Employment Act of 1967, as amended ("ADEA"); the federal Employee Retirement
Income Security Act of 1974, as amended; the federal Americans with Disabilities
Act of 1990; the California Fair Employment and Housing Act, as amended; tort
law; contract law; wrongful discharge; discrimination; fraud; defamation;
emotional distress; and breach of the implied covenant of good faith and fair
dealing; provided, however, that nothing in this paragraph shall be construed in
any way to release the Company from its obligation to indemnify me pursuant to
the Company's indemnification obligation pursuant to agreement or applicable
law.

     I acknowledge that I am knowingly and voluntarily waiving and releasing any
rights I may have under ADEA. I also acknowledge that the consideration given
under the Plan for the waiver and release in the preceding paragraph hereof is
in addition to anything of value to which I was already entitled. I further
acknowledge that I have been advised by this writing, as

                                      1.
<PAGE>

required by the ADEA, that: (A) my waiver and release do not apply to any rights
or claims that may arise on or after the date I execute this Release; (B) I have
the right to consult with an attorney prior to executing this Release; (C) I
have twenty-one (21) days to consider this Release (although I may choose to
voluntarily execute this Release earlier); (D) I have seven (7) days following
my execution of this Release to revoke the Release; and (E) this Release shall
not be effective until the date upon which the revocation period has expired,
which shall be the eighth (8/th/) day after I execute this Release.

                                             Employee

                                             Name:_____________________________

                                             Date:_____________________________

                                      2.
<PAGE>

                                   Exhibit B

                                    RELEASE
                       (Individual Termination under 40)

     Certain capitalized terms used in this Release are defined in the Change in
Control Severance Benefit Plan (the "Plan") which I have executed and of which
this Release is a part.

     I hereby confirm my obligations under the Company's proprietary information
and inventions agreement.

     I acknowledge that I have read and understand Section 1542 of the
California Civil Code which reads as follows: "A general release does not extend
to claims which the creditor does not know or suspect to exist in his favor at
the time of executing the release, which if known by him must have materially
affected his settlement with the debtor." I hereby expressly waive and
relinquish all rights and benefits under that section and any law of any
jurisdiction of similar effect with respect to my release of any claims I may
have against the Company.

     Except as otherwise set forth in this Release, I hereby release, acquit and
forever discharge the Company, its parents and subsidiaries, and their officers,
directors, agents, servants, employees, shareholders, successors, assigns and
affiliates, of and from any and all claims, liabilities, demands, causes of
action, costs, expenses, attorneys fees, damages, indemnities and obligations of
every kind and nature, in law, equity, or otherwise, known and unknown,
suspected and unsuspected, disclosed and undisclosed (other than any claim for
indemnification I may have as a result of any third party action against me
based on my employment with the Company), arising out of or in any way related
to agreements, events, acts or conduct at any time prior to the date I execute
this Release, including, but not limited to: all such claims and demands
directly or indirectly arising out of or in any way connected with my employment
with the Company or the termination of that employment, including but not
limited to, claims of intentional and negligent infliction of emotional
distress, any and all tort claims for personal injury, claims or demands related
to salary, bonuses, commissions, stock, stock options, or any other ownership
interests in the Company, vacation pay, fringe benefits, expense reimbursements,
severance pay, or any other form of compensation; claims pursuant to any
federal, state or local law or cause of action including, but not limited to,
the federal Civil Rights Act of 1964, as amended; the federal Age Discrimination
in Employment Act of 1967, as amended ("ADEA"); the federal Employee Retirement
Income Security Act of 1974, as amended; the federal Americans with Disabilities
Act of 1990; the California Fair Employment and Housing Act, as amended; tort
law; contract law; wrongful discharge; discrimination; fraud; defamation;
emotional distress; and breach of the implied covenant of good faith and fair
dealing; provided, however, that nothing in this paragraph shall be construed in
any way to release the Company from its obligation to indemnify me pursuant to
the Company's indemnification obligation pursuant to agreement or applicable
law.

                                             Employee

                                             Name:______________________________

                                             Date:______________________________

                                      1.
<PAGE>

                                   Exhibit C

                                    RELEASE
                              (Group Termination)

     Certain capitalized terms used in this Release are defined in the Change in
Control Severance Benefit Plan (the "Plan") which I have executed and of which
this Release is a part.

     I hereby confirm my obligations under the Company's proprietary information
and inventions agreement.

     I acknowledge that I have read and understand Section 1542 of the
California Civil Code which reads as follows: "A general release does not extend
to claims which the creditor does not know or suspect to exist in his favor at
the time of executing the release, which if known by him must have materially
affected his settlement with the debtor." I hereby expressly waive and
relinquish all rights and benefits under that section and any law of any
jurisdiction of similar effect with respect to my release of any claims I may
have against the Company.

     Except as otherwise set forth in this Release, I hereby release, acquit and
forever discharge the Company, its parents and subsidiaries, and their officers,
directors, agents, servants, employees, shareholders, successors, assigns and
affiliates, of and from any and all claims, liabilities, demands, causes of
action, costs, expenses, attorneys fees, damages, indemnities and obligations of
every kind and nature, in law, equity, or otherwise, known and unknown,
suspected and unsuspected, disclosed and undisclosed (other than any claim for
indemnification I may have as a result of any third party action against me
based on my employment with the Company), arising out of or in any way related
to agreements, events, acts or conduct at any time prior to the date I execute
this Release, including, but not limited to: all such claims and demands
directly or indirectly arising out of or in any way connected with my employment
with the Company or the termination of that employment, including but not
limited to, claims of intentional and negligent infliction of emotional
distress, any and all tort claims for personal injury, claims or demands related
to salary, bonuses, commissions, stock, stock options, or any other ownership
interests in the Company, vacation pay, fringe benefits, expense reimbursements,
severance pay, or any other form of compensation; claims pursuant to any
federal, state or local law or cause of action including, but not limited to,
the federal Civil Rights Act of 1964, as amended; the federal Age Discrimination
in Employment Act of 1967, as amended ("ADEA"); the federal Employee Retirement
Income Security Act of 1974, as amended; the federal Americans with Disabilities
Act of 1990; the California Fair Employment and Housing Act, as amended; tort
law; contract law; wrongful discharge; discrimination; fraud; defamation;
emotional distress; and breach of the implied covenant of good faith and fair
dealing; provided, however, that nothing in this paragraph shall be construed in
any way to release the Company from its obligation to indemnify me pursuant to
the Company's indemnification obligation pursuant to agreement or applicable
law.

     I acknowledge that I am knowingly and voluntarily waiving and releasing any
rights I may have under ADEA. I also acknowledge that the consideration given
under the Plan for the waiver and release in the preceding paragraph hereof is
in addition to anything of value to which I was already entitled. I further
acknowledge that I have been advised by this writing, as

                                      1.
<PAGE>

required by the ADEA, that: (A) my waiver and release do not apply to any rights
or claims that may arise on or after the date I execute this Release; (B) I have
the right to consult with an attorney prior to executing this Release; (C) I
have forty-five (45) days to consider this Release (although I may choose to
voluntarily execute this Release earlier); (D) I have seven (7) days following
my execution of this Release to revoke the Release; (E) this Release shall not
be effective until the date upon which the revocation period has expired, which
shall be the eighth day (8th) after I execute this Release; and (F) I have
received with this Release a detailed list of the job titles and ages of all
employees who were terminated in this group termination and the ages of all
employees of the Company in the same job classification or organizational unit
who were not terminated.

                                             Employee

                                             Name:______________________________

                                             Date:______________________________

                                      2.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00025-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00025-of-00352.parquet"}]]