Exhibit 4.2  AMENDMENT NO. 1 TO SHAREHOLDER RIGHTS
AGREEMENT  1.General Background and Appointment of Successor Rights
Agent.In accordance with
Sections 21 and 27 of the Shareholder Rights Agreement between State Street
Bank and Trust Company (the Rights Agent) and Brooktrout, Inc., f/k/a
Brooktrout Technology, Inc. (Brooktrout),dated
as of September 9, 1998 (the Agreement), the Rights Agent and Brooktrout
desire to (a) appoint EquiServe Trust Company, N.A. as the successor Rights
Agent and (b) make certain amendments to the Agreement as set forth below.  2.Effective Date and Defined Terms.This Amendment No. 1 to Rights
Agreement shall be effective as of March 1, 2002 (the Amendment) and all
defined terms and definitions in the Agreement shall have the same meanings in
the Amendment except as may otherwise be specifically set forth in the
Amendment.  3.Amendment of the Agreement.   Section 21 of the Agreement (entitled
Change of Rights Agent) is hereby deleted in its entirety and replaced with
the following:  Section 21.  Change of
Rights Agent.  The Rights Agent or
any successor Rights Agent may resign and be discharged from its duties under
this Agreement upon thirty 30 days notice in writing mailed to the Company and
to each transfer agent of the Common Stock or Preferred Stock by registered or
certified mail and to the holders of the Right Certificates by first class
mail.  The Company may remove the Rights
Agent or any successor Rights Agent (with or without cause), effective
immediately or on a specified date, by written notice given to the Rights Agent
or successor Rights Agent, as the case may be, and to each transfer agent of
the Common Stock or Preferred Stock by registered or certified mail and by
giving notice to the holders of the Right Certificates by any means reasonably
determined by the Company to inform such holders of such removal (including
without limitation, by including such information in one or more of the
Companys reports to shareholders or reports or filings with the Securities and
Exchange Commission).If the Rights Agent shall resign or be removed or shall
otherwise become incapable of acting, the Company shall appoint a successor to
the Rights Agent.  If the Company shall
fail to make such appointment within a period of thirty (30) days after giving
notice of such removal or after it has been notified in writing of such
resignation or incapacity by the resigning or incapacitated Rights Agent or by
the holder of a Right Certificate (who shall, with such notice, submit such
holders Right Certificate for inspection by the Company), then the incumbent
Rights Agent or the registered holder of any Right Certificate may apply to any
court of competent jurisdiction for the appointment of a new Rights Agent.  Any successor Rights Agent, whether
appointed by the Company or by such a court, shall be a corporation or trust
company organized and doing business under the laws of the United States or of
the Commonwealth of Massachusetts or the State of New York (or of any other state
of the United States so long as such corporation or trust company is authorized
to do business as a banking institution  
   in the
Commonwealth of Massachusetts or the State of New York), in good standing,
which is authorized under such laws to exercise corporate trust or stock
transfer powers and is subject to supervision or examination by federal or
state authority and which has individually or combined with an affiliate at the
time of its appointment as Rights Agent a combined capital and surplus of at
least $100,000,000.  After appointment,
the successor Rights Agent shall be vested with the same powers, rights, duties
and responsibilities as if it had been originally named as Rights Agent without
further act or deed; but the predecessor Rights Agent shall deliver and
transfer to the successor Rights Agent any property at the time held by it
hereunder, and execute and deliver any further assurance, conveyance, act or
deed necessary for the purpose.  Not
later than the effective date of any such appointment, the Company shall file
notice thereof in writing with the predecessor Rights Agent and each transfer
agent of the Common Stock or Preferred Stock, and mail a notice thereof in
writing to the registered holders of the Right Certificates.  Failure to give any notice provided for in
this Section 21, however, or any defect therein, shall not affect the legality
or validity of the resignation or removal of the Rights Agent or the
appointment of the successor Rights Agent, as the case may be.  4.Except
as amended hereby, the Agreement and all exhibits thereto shall remain in full
force and effect.  IN
WITNESS WHEREOF, the parties hereto have caused this
Amendment to be executed in their names and on their behalf by and through
their duly authorized officers, as of this 1st day of March, 2002.   Brooktrout, Inc.
  State Street Bank and Trust Company/s/ Robert
  C. Leahy
  
  /s/ Margaret
  PrenticeBy: Robert
  C. Leahy
  By:  Margaret PrenticeTitle:  Vice President
  Title:  Managing DirectorEquiServe Trust Company, N.A./s/ Margaret
  PrenticeBy:  Margaret PrenticeTitle:  Managing Director  2