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                                                                   EXHIBIT 10.13

                                BROOKTROUT, INC.
                      2001 STOCK OPTION AND INCENTIVE PLAN

                       NONQUALIFIED STOCK OPTION AGREEMENT

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Number of Shares                                                Date

     Pursuant to its 2001 Stock Option and Incentive Plan (the "Plan"),
Brooktrout, Inc. (the "Company") hereby grants to __________________ (the
"Optionee") an Option (the "Option") to purchase, on or prior to _____________
(the "Expiration Date"), all or any part of ________ shares (the "Option
Shares") of common stock of the Company, par value $0.01 per share ("Common
Stock"), at a price of $____ per share in accordance with the schedule set forth
in Section 1 hereof and subject to the terms and conditions set forth
hereinafter and in the Plan. Capitalized terms used herein and not otherwise
defined herein shall have the meanings given to them in the Plan.

     1. VESTING SCHEDULE. No portion of this Option may be exercised until such
portion shall have vested. Except as otherwise set forth herein, and subject to
the determination of the Committee (as defined in the Plan) in its sole
discretion to accelerate the vesting schedule hereunder, this Option shall be
vested and exercisable with respect to the following number of Option Shares and
in accordance with the timetable set forth below:

                            [INSERT VESTING SCHEDULE]

Once vested, this Option shall continue to be exercisable at any time or times
prior to the close of business on the Expiration Date, subject to the provisions
hereof and of the Plan.

     2. MANNER OF EXERCISE. The Optionee may exercise this Option only in the
following manner: from time to time on or prior to the Expiration Date of this
Option, the Optionee may give written notice to the Company of his or her
election to purchase some or all of the vested Option Shares purchasable at the
time of such notice. Said notice shall specify the number of shares to be
purchased. No portion of this Option shall be exercisable after the Expiration
Date. The exercise of this Option is subject to the Company's insider trading
policy, as in effect from time to time.

     Payment of the purchase price for the Option Shares may be made by one or
more of the following methods: (a) in cash, by certified or bank check or other
instrument acceptable by the Committee; (b) by delivery of shares of Common
Stock that the Optionee has held for at least six months and that are not then
subject to restrictions under any Company plan; (c) by the Optionee delivering
to the Company a properly executed exercise notice together with irrevocable
instructions to a broker to promptly deliver to the Company cash or a check
payable and acceptable to the Company to pay the option purchase price; provided
that in the event the Optionee chooses to pay the option purchase price as so
provided, the Optionee and the broker shall comply with such procedures and
enter into such agreements of indemnity and other agreements as the Committee
shall prescribe as a condition of such payment procedure; or (d) by the Optionee
delivering to the Company a promissory note if the Board of Directors of the
Company has expressly authorized the loan of funds to the Optionee for the
purpose of enabling or assisting the Optionee to exercise the Option. Payment
instruments will be received subject to collection.

     The delivery of certificates representing the Option Shares will be
contingent upon the Company's receipt from the Optionee of the full purchase
price therefore and the fulfillment of any other requirements contained in this
Agreement, the Plan, or applicable provisions of laws. If requested upon the
exercise of this Option, certificates for shares may be issued in the name of
the Optionee jointly with another person, in the name of the executor or
administrator of the Optionee's estate, or in the name of a designated
beneficiary.

     3. NON-TRANSFERABILITY OF OPTION. This Option shall not be transferable by
the Optionee otherwise than by will or by the laws of descent and distribution
and this Option shall be exercisable, during the Optionee's lifetime, only by
the Optionee, or by the Optionee's legal representative or guardian in the event
of the Optionee's incapacity.

     4. TERMINATION OF RELATIONSHIP WITH THE COMPANY. If the Optionee ceases to
be an employee, independent director or other key person (including a consultant
or prospective employee) of the Company or a Subsidiary (as defined in the Plan)
(an "Eligible Participant"), the period within which to exercise the Option may
be subject to earlier expiration as set forth below.

     (a)   TERMINATION BY DEATH. If the Optionee's status as an Eligible
Participant terminates by reason of death, any Option held by the Optionee may
be exercised, to the extent exercisable on the date of death, by the Optionee's
legal representative or legatee for a period of 180 days from the date of death
or until the Expiration Date, if earlier. The Optionee may designate a
beneficiary or beneficiaries to exercise this Option or receive any payment
under this Option payable on or after the Optionee's death. Any such designation
shall be on a form provided for that purpose by the Committee and shall not be
effective until received by the Committee. If no beneficiary has been
designated, or if the designated beneficiaries have predeceased the Optionee,
the beneficiary shall be the Optionee's estate.

     (b)   TERMINATION BY REASON OF DISABILITY. If the Optionee's status as an
Eligible Participant terminates by reason of Disability (as defined in Section
22(e)(3) of the Internal Revenue Code of 1986, as amended), any Option held by
the Optionee may be exercised, to the extent exercisable on the date of
termination, for a period of one (1) year from the date of termination or until
the Expiration Date, if earlier.

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     (c)   TERMINATION FOR CAUSE. If the Optionee's status as an Eligible
Participant is terminated by the Company for Cause, any Option held by the
Optionee shall immediately terminate and be of no further force and effect. For
purposes hereof, "Cause" shall mean a vote by the Board of Directors of the
Company (with respect to officers or directors of the Company) or a
determination by the chief executive officer or chief financial officer of the
Company (with respect to employees and consultants other than officers and
directors of the Company) that the Optionee shall be dismissed as a result of
(i) any material breach by the Optionee of any agreement between the Optionee
and the Company; (ii) the conviction of or plea of nolo contendere by the
Optionee to a felony or a crime involving moral turpitude; or (iii) any material
misconduct or willful and deliberate non-performance (other than by reason of
Disability) by the Optionee of the Optionee's duties to the Company.

     (d)   OTHER TERMINATION. If the Optionee's status as an Eligible
Participant terminates for any reason other than death, Disability or Cause, and
unless otherwise determined by the Committee, any Option held by the Optionee
may be exercised, to the extent exercisable on the date of termination, for a
period of ninety (90) days from the date of termination or until the Expiration
Date, if earlier. For this purpose, neither a transfer of responsibilities from
the Company to a Subsidiary (or from a Subsidiary to the Company) nor an
approved leave of absence shall be deemed a "termination of status as an
Eligible Participant."

     5. CHANGE OF CONTROL. In connection with a Sale Event (as defined below and
in Section 3(c) of the Plan), this Option shall become vested with respect
to 100% of the unvested Option Shares (and shall therefore be exercisable with
respect to such shares in addition to any unexercised Option Shares that had
previously vested) immediately before the consummation of such Sale Event,
subject to the following provisions, and shall terminate immediately thereafter.
The Optionee shall be permitted, within a specified period of time prior to the
consummation of such Sale Event as determined by the Committee, to exercise all
exercisable Options held by the Optionee, including those that will become
exercisable upon the consummation of the Sale Event; provided, however, that the
exercise of Options not exercisable prior to the Sale Event shall be subject to
the consummation of the Sale Event. Section 3(c) of the Plan defines "Sale
Event" as (i) the dissolution or liquidation of the Company, (ii) the sale of
all or substantially all of the assets of the Company on a consolidated basis to
an unrelated person or entity, (iii) a merger, reorganization or consolidation
in which the outstanding shares of Common Stock are converted into or exchanged
for a different kind of securities of the successor entity and the holders of
the Company's outstanding voting power immediately prior to such transaction do
not own a majority of the outstanding voting power of the successor entity
immediately upon completion of such transaction, or (iv) the sale of all of the
Common Stock to an unrelated person or entity.

     6. OPTION SHARES. The Option Shares are shares of the Common Stock as
constituted on the date of this Option, subject to adjustment as provided in
Section 3 of the Plan.

     7. NO SPECIAL EMPLOYMENT RIGHTS. This Option will not confer upon the
Optionee any right with respect to continuance of the Optionee's status as an
Eligible Participant, nor will it interfere in any way with the right of the
Company or a Subsidiary to terminate or discharge the Optionee at any time.

     8. RIGHTS AS A STOCKHOLDER. The Optionee shall have rights as a
stockholder, such as voting and dividend rights, only with respect to shares of
Common Stock acquired upon the exercise of this Option and not with respect to
unexercised Option Shares.

     9. TAX WITHHOLDING. No later than the date as of which part or all of the
value of any Common Stock received under the Option first becomes included in
the Optionee's gross income for federal tax purposes, the Optionee shall make
arrangements with the Company in accordance with Section 11 of the Plan
regarding the payment of any federal, state, or local taxes required to be
withheld with respect to such income.

     10. THE PLAN. In the event of any discrepancy or inconsistency between this
Agreement and the Plan, the terms and conditions of the Plan shall control.

     11. MISCELLANEOUS. Notices hereunder shall be mailed or delivered to the
Company at its principal place of business and shall be mailed or delivered to
Optionee at the address set forth below or, in either case, at such other
address as one party may subsequently furnish to the other party in writing.

                                                  BROOKTROUT, INC.


                                                  By:
                                                     ---------------------------
                                                  Name:
                                                  Title:


Receipt of the foregoing Option is acknowledged and its terms and conditions are
hereby agreed to:

                                                  --------------------------,
                                                  Optionee

Date:                                     Address:
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