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                                                                   EXHIBIT 10.32



                           LOAN MODIFICATION AGREEMENT


         This Agreement is made as of July 28, 1993 between Summa Four, Inc., a
Delaware corporation (the "Borrower") and Fleet Bank of Massachusetts, N.A. (the
"Bank"). For good and valuable consideration, receipt and sufficiency or which
are hereby acknowledged, the Borrower and the Bank act and agree as follows:

         1.       Reference is made to (i) that certain letter agreement dated
October 15, 1992 between the Borrower and the Bank (the "Letter Agreement"),
(ii) that certain $3,000,000 face amount Secured Time Note dated October 15,
1992 (the "1992 Revolving Note") made by the Borrower and payable to the order
of the Bank, (iii) that certain $6,000,000 face amount promissory note of even
date herewith (the "1993 Revolving Note") and (iv) that certain Inventory and
Accounts Receivable Security Agreement dated October 15, 1992 (the "Security
Agreement") given by the Borrower to the Bank. The Letter Agreement and the 1993
Revolving Note are hereinafter collectively referred to as the "Financing
Documents".

         2.       The Bank hereby releases the security interest granted by the
Security Agreement and the Bank and the Borrower agree that the Security
Agreement is terminated.

         3.       The Letter Agreement is hereby amended, effective as of the
date hereof:

         a.       By deleting in its entirety Section 1.1 of the Letter
                  Agreement and by substituting in its stead the following:

                  "1.1. REFERENCE TO NOTE. Reference is made to that certain
                  $6,000,000 face principal amount promissory note dated July
                  28, 1993 (the 'Revolving Note') made by the Borrower and
                  payable to the order of the Bank."

         b.       By deleting from clause (a) of the second paragraph of Section
                  1.5 of the Letter Agreement the words "and/or the Security
                  Agreement".

         c.       By deleting from the second sentence of Subsection 2.1(a) of
                  the Letter Agreement the words ", to grant the security
                  interests contemplated by the Security Agreement".

         d.       By deleting from the introductory paragraph of Article III of
                  the Letter Agreement the reference to the Security Agreement.




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         e.       By deleting from the second sentence of Section 3.2 of the
                  Letter Agreement the reference to the Security Agreement.

         f.       By adding to clause (ii) of Section 3.6 of the Letter
                  Agreement, at the end thereof, the following:

                  "Notwithstanding the foregoing, after the completion of a
                  public offering of the Borrower's common stock, the Borrower
                  need not furnish monthly statements in accordance with the
                  immediately preceding sentence but will be required instead to
                  furnish to the Bank, within 45 days after the end of each
                  fiscal quarter of the Borrower, financial statements for the
                  fiscal quarter then ended and for the fiscal year to date
                  containing all of the information required by Form 10-Q
                  promulgated under the Securities Exchange Act of 1934, as
                  amended. The Borrower will also provide to the Bank, promptly
                  upon filing same with the Securities and Exchange Commission,
                  the National Association of Securities Dealers, Inc. and/or
                  any securities exchange or upon furnishing same to its
                  stockholders generally, copies of all periodic reports,
                  current reports and other reports and proxy statements."

         g.       By adding to the first sentence of clause (iii) of Section
                  3.6, immediately after the words "annual statement", the
                  following:

                  "or quarterly statement"

         h.       By deleting in its entirety Section 3.8 of the Letter
                  Agreement and by substituting in its stead the following:

                           "3.8. CAPITAL BASE. The Borrower will maintain, as at
                  the end of each fiscal quarter, a consolidated Capital Base
                  which shall not be less than the then-effective Capital Base
                  Requirement. As used herein, the 'Capital Base Requirement'
                  will be deemed to have been $5,250,000 as at March 31, 1993
                  and will be deemed increased as at the end of each fiscal
                  quarter thereafter (beginning June 30, 1993) so as to equal
                  the sum of (i) the Capital Base Requirement in effect as at
                  the immediately preceding quarter-end, plus (ii) 90% of the
                  net proceeds of any equity securities sold by



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                  the Borrower during the fiscal quarter then ending or any
                  Subordinated Debt issued by the Borrower or any Subsidiary
                  during such fiscal quarter then ending (nothing contained
                  herein being deemed to authorize the incurrence of any such
                  Subordinated Debt), plus (iii) 90% of the consolidated Net
                  Income of the Borrower and Subsidiaries during such fiscal
                  quarter then ending (but without giving effect to any Net Loss
                  during such fiscal quarter)."

         i.       By deleting from the introductory paragraph of Article IV of
                  the Letter Agreement the reference to the Security Agreement.

         j.       By deleting from Section 4.5 of the Letter Agreement the
                  amount "$75,000" and by substituting in its stead the
                  following:

                  "$250,000"

         k.       By deleting from the first sentence of Section 4.11 of the
                  Letter Agreement the following words: "and providing all such
                  financing statements, certificates and other documentation as
                  the Bank may request in order to maintain the perfection and
                  priority of the security interests granted or intended to be
                  granted pursuant to the Security Agreement".

         l.       By adding to Section 4.13 of the Letter Agreement, at the end
                  thereof, the following:

                  "Notwithstanding the foregoing, the first sentence of this
                  Section 4.13 will be deemed to be of no further force or
                  effect upon the completion by the Borrower of an initial
                  public offering which generates at least $5,000,000 in net
                  proceeds to the Borrower."

         m.       By deleting from Section 5.1 of the Letter Agreement clauses
                  (k) and (l) thereof.

         n.       By relettering clause (m) of Section 5.1 of the Letter
                  Agreement so that same will become clause "(k)".

         o.       By deleting from clause (c) of Section 5.2 of the Letter
                  Agreement the reference therein to the Security Agreement.



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         p.       By deleting from Section 6.1 of the Letter Agreement all
                  references therein to the Security Agreement.

         q.       By deleting the period at the end of the first sentence of
                  Section 6.3 of the Letter Agreement and by substituting in its
                  stead the following:

                  "; provided, however, that effective as of July 28, 1993 the
                  aforesaid rate of 1/2% per annum will be deemed reduced to
                  3/8% per annum."

         r.       By changing the Bank's notice address to:

                  Fleet Bank of Massachusetts, N.A.
                  High Technology Group
                  75 State Street
                  Boston, MA 02109
                  Attention:  Thomas W. Davies, Vice President

         s.       By deleting in its entirety the definition of "Expiration
                  Date" appearing in Section 7.1 of the Letter Agreement and by
                  substituting in its stead the following:

                  "'Expiration Date' - September 1, 1994, unless extended by the
                  Bank, which extension may be given or withheld by the Bank in
                  its sole discretion."

         t.       By deleting from the definition of "Loan Documents" appearing
                  in Section 7.1 of the Letter Agreement the reference to the
                  Security Agreement.

         u.       By deleting in its entirety the definition of "Maximum
                  Revolving Amount" appearing in Section 7.1 of the Letter
                  Agreement and by substituting in its stead the following:

                  "'Maximum Revolving Amount' - Six Million ($6,000,000)
                  Dollars."

         v.       By deleting in its entirety the definition of "Obligation"
                  appearing in Section 7.1 of the Letter Agreement and by
                  substituting in its stead the following:





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                  "'Obligations' - Each and every liability, undertaking,
                  agreement, indebtedness and obligation now or hereafter owed
                  by the Borrower to the Bank or now or hereafter made by the
                  Borrower with or for the benefit of the Bank."

         w.       By deleting from the definition of "Principal Office"
                  appearing in Section 7.1 of the Letter Agreement the address
                  "28 State Street" and by substituting in its stead the
                  following:

                  "75 State Street"

         x.       By deleting in its entirety clause (i) of the second sentence
                  of the definition of "Qualified Receivables" appearing in
                  Section 7.1 of the Letter Agreement.

         y.       By deleting in its entirety Section 7.2 of the Letter
                  Agreement.

         4.       Wherever in any Financing Document, or in any certificate or
opinion to be delivered in connection therewith, reference is made to a "letter
agreement", from and after the date hereof same will be deemed to refer to the
Letter Agreement, as hereby amended.

         5.       Simultaneously with the execution and delivery of this
Agreement, the Borrower is executing and delivering to the Bank the 1993
Revolving Note in substitution for the 1992 Revolving Note. The 1993 Revolving
Note is a $6,000,000 promissory note of the Borrower, substantially in the form
attached hereto as Exhibit 1. Whenever in any Financing Document, or in any
certificate or opinion to be delivered in connection therewith, reference is
made to a "Note" or "Revolving Note", from and after the date hereof same will
be deemed to refer to the 1993 Revolving Note.

         6.       In order to induce the Bank to enter into this Agreement, the
Borrower further represents and warrants as follows:

         a.       The execution, delivery and performance of this Agreement and
                  the 1993 Revolving Note have been duly authorized by the
                  Borrower by all necessary corporate and other action, will not
                  require the consent of any third party and will not conflict
                  with, violate the provisions of, or cause a default or
                  constitute an event which, with the passage of time or giving
                  of notice or both, could cause a default on the part of the



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                  Borrower under its charter documents or by-laws or under any
                  contract, agreement, law, rule, order, ordinance, franchise,
                  instrument or other document, or result in the imposition of
                  any lien or encumbrance on any property or assets of the
                  Borrower (except lines in favor of the Bank).

         b.       The Borrower has duly executed and delivered each of this
                  Agreement and the 1993 Revolving Note.

         c.       Each of this Agreement and the 19993 Revolving Note is the
                  legal, valid and binding obligation of the Borrower,
                  enforceable against the Borrower in accordance with its
                  respective terms.

         d.       The statements, representations and warranties made in the
                  Letter Agreement continue to be correct as of the date hereof;
                  except as amended, updated and/or supplemented by the attached
                  Supplemental Schedule.

         e.       The covenants and agreements of the Borrower contained in the
                  Letter Agreement have ben complied with on and as of the date
                  hereof.

         f.       No event which constitutes or which, with notice or lapse of
                  time, or both, could constitute, an Event of Default (as
                  defined in the Letter Agreement) has occurred and is
                  continuing.

         g.       Except as heretofore disclosed to the Bank in writing, no
                  material adverse change has occurred in the financial
                  condition of the Borrower from that disclosed in the quarterly
                  financial statements of the Borrower for the fiscal year ended
                  March 31, 1993.

         7.       Except as expressly affected hereby, the Letter Agreement and
each of the other Financing Documents remains in full force and effect as
heretofore.

         8.       Except expressly set forth above, nothing contained herein
will be deemed to constitute a waiver or a release of any provision of any of
the Financing Documents. Nothing contained herein will in any event be deemed to
constitute an agreement to give a waiver or release or to agree to any amendment
or modification of any provision of any of the Financing Documents on any other
or future occasion.




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         Executed, as an instrument under seal, as of the day and year first
above written.


                               SUMMA FOUR, INC.


                               By: /s/Thomas A. St. Germain
                                   ------------------------------------------
                                    Its



                               FLEET BANK OF MASSACHUSETTS, N.A.


                               By: /s/Thomas W. Davies
                                   ------------------------------------------
                                    Its  Vice President


                               By:         [Illegible]
                                   ------------------------------------------
                                    Its  Senior Vice President





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