<PAGE>
                                                                   Exhibit 10.25
                                                                   -------------

                          GENERAL SECURITY AGREEMENT
                  (TANGIBLE AND INTANGIBLE PERSONAL PROPERTY)

This Agreement is executed on                   November 12, 1996          , by

                                DATA RACE INC.
                                                 (hereinafter called "Obligor").
In consideration of financial accommodations given, to be given or continued,
the Obligor grants to IMPERIAL BANK (hereinafter called "Bank") a security
interest in (a) all property (i) delivered to Bank by Obligor, (ii) which shall
be in Bank's possession or control in any matter or for any purpose, (iii)
described below, (iv) now owned or hereafter acquired by Obligor of the type or
class described below and/or in any supplementary schedule hereto, or in any
financing statement filed by Bank and executed by or on behalf of Obligor; (b)
the proceeds, increase and products of such property, all accessions thereto,
and all property which Obligor may receive on account of such collateral which
Obligor will immediately deliver to Bank (collectively referred to as
"Collateral") to secure payment and performance of all of Obligor's present or
future debts or obligations to Bank, whether absolute or contingent (hereafter
referred to as "Debt"). Unless otherwise defined, words used herein have the
meanings given them in the California Uniform Commercial Code.


Collateral:

<TABLE> 
<CAPTION> 

A.  VEHICLE, VESSEL, AIRCRAFT:
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                                                Identification          License or      
Year        Make/Manufacturer      Model        and Serial No.        Registration No.          New or Used        

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<S>         <C>                    <C>          <C>                   <C>                       <C>




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</TABLE>

Engine or other equipment:
                          ------------------------------------------------------
(For aircraft - original ink signature on copy to FAA)

B. DEPOSIT ACCOUNTS:

Type                    Account Number                  Amount $
    --------------------              ------------------        ----------------

In name of                              Depository
          ------------------------------          ------------------------------
AND ALL EXTENSIONS OR RENEWALS THEREOF.

C. ACCOUNTS, INTANGIBLES AND OTHER: (Describe)

        All personal property, whether presently existing or hereafter created
        or acquired, including but not limited to: All accounts, chattel paper,
        documents, instruments, money, deposit accounts and general intangibles
        including returns, repossessions, books and records relating thereto,
        and equipment containing said books and records, All goods including
        equipment and inventory. All proceeds including, without limitation,
        insurance proceeds. All guarantees and other security therefor.





The collateral not in Bank's possession will be located at: 12400 Network Blvd.,
San Antonio, TX 78249

[_] If checked, the Obligor is executing this Agreement as an Accommodation 
Debtor only and the Obligor's liability is limited to the security interest 
granted in the Collateral described herein. The party being accommodated is:

                                                                   ("Borrower").

All the terms and provisions on the reverse side hereof are incorporated herein 
as though set forth in full, and constitute a part of this Agreement.

         Name                       Signature                  Address
                        (indicate title, if applicable)


DATA RACE INC.          BY /s/ GREGORY T. SKALLA, CFO   12400 Network Blvd.
---------------------   ------------------------------  ------------------------
                                                        San Antonio, TX 78249
---------------------   ------------------------------  ------------------------

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

                                  Page 1 of 2
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                         SECURITY AGREEMENT (CONTINUED)


Obligor represents, warrants and agrees:

1.   Obligor will immediately pay (a) any Debt when due, (b) Banks reasonable 
costs of collecting the Debt, of protecting, insuring or realizing on 
Collateral, and any expenditure of Bank pursuant hereto, including attorneys' 
fees and expenses, with interest at the rate of 24% per year, or the rate 
applicable to the Debt, whichever is less, from the date of expenditure, and 
(c) any deficiency after realization of Collateral.

2.   Obligor will use the proceeds of any loan that becomes Debt hereunder for 
the purpose indicated on the application therefore, and will promptly contract 
to purchase and pay the purchase price of any property which becomes Collateral 
hereunder from the proceeds of any loan made for that purpose.

3.   As to all Collateral in Obligor's possession (unless specifically otherwise
agreed to by Bank in writing), Obligor will:
     (a)  Have, or has, possession of the Collateral at the location disclosed
     to Bank and will not remove the Collateral from the location.
     (b)  Keep the Collateral separate and identifiable.
     (c)  Maintain the Collateral in good and saleable condition, repair it if
     necessary, clean, feed, shelter, water, medicate, fertilize, cultivate,
     irrigate, prune and otherwise deal with the Collateral in all such ways as
     are considered good practice by owners of like property, use it lawfully
     and only as permitted by insurance policies, and permit Bank to inspect the
     Collateral at any reasonable time .
     (d)  Not sell, contract to sell, lease, encumber or transfer the Collateral
     (other than inventory Collateral) until the Debt has been paid, even
     though Bank has a security interest in proceed of such Collateral.

4.   As to Collateral which is inventory and accounts, Obligor:
     (a)  May, until notice from Bank, sell, lease or otherwise dispose of
     inventory Collateral in the ordinary course of business only, and
     collect the cash proceeds thereof.
     (b)  Will, upon notice from Bank, deposit all cash proceeds as received in
     a demand deposit account with Bank, containing only such proceeds and
     deliver statements identifying units of inventory disposed of, accounts
     which gave rise to proceeds, and all acquisitions and returns of inventory
     as required by Bank.
     (c)  Will receive in trust, schedule on forms satisfactory to the Bank and
     deliver to Bank all non-cash proceeds other than inventory received in
     trade.
     (d)  If not in default, may obtain release of Bank's interest in individual
     units of inventory upon request, therefore, payment to Bank of the release
     price of such units shown on any Collateral schedule supplementary hereto,
     and compliance herewith as to proceeds thereof.

5.   As to Collateral which are accounts, chattel paper, general intangibles and
proceeds described in 4(c) above, Obligor warrants, represents and agrees:
     (a)  All such Collateral is genuine, enforceable in accordance with its
     terms, free from default, prepayment, defense and conditions precedent
     (except as disclosed to and accepted by Bank in writing), and is supported
     by consecutively numbered invoices to, or rights against, the debtors
     thereon. Obligor will supply Bank with duplicate invoices or other evidence
     of Obligor's rights on Bank's request;
     (b)  To the best of Obligor's knowledge all persons appearing to be
     obligated on such Collateral have authority and capacity to contract;
     (c)  All chattel paper is in compliance with law as to form, content and
     manner of preparation and execution and has been properly registered,
     recorded,and/or filed to protect Obligor's interest thereunder.
     (d)  If an account debtor shall also be indebted to Obligor on another
     obligation, any payment made by him not specifically designated to be
     applied on any particular obligation shall be considered to be a payment on
     the account in which Bank has a security interest. Should any remittance
     include a payment not on an account, it shall be delivered to Bank and, if
     no event of default has occurred, Bank shall pay Obligor the amount of such
     payment;

     (e)  Obligor agrees not to compromise, settle or adjust any material
     account or renew or extend the time of payment thereof without Bank's
     prior written consent.

6.   Obligor owns all Collateral absolutely, and no other person has or claims
any interest in any Collateral, except as disclosed to and accepted by Bank in
writing. Obligor will defend any proceeding which may affect title to or Bank's
security interest in any Collateral, and will indemnify and hold Bank free and
harmless from all costs and expenses of Bank's defense.

7.   Obligor will pay when due all existing or future charges, liens or
encumbrances on and all taxes and assessments now or hereafter imposed on or
affecting the Collateral and, if the Collateral is in Obligor's possession, the
realty on which the Collateral is located if such realty is owned by
Obligor.

8.   Obligor will insure the Collateral with Bank as loss payee in form and
amounts with companies, and against risks and liability satisfactory to Bank,
and hereby assigns such policies to Bank, agrees to deliver them to Bank at
Bank's request, and authorizes Bank to make any claim thereunder, to cancel the
insurance on Obligor's default, and to receive payment of and endorse any
instrument in payment of any loss or return premium. If Obligor should fail to
deliver the required policy or policies to Bank, Bank may, at Obligor's cost and
expense, without any duty to do so, get and pay for insurance naming as the
Insured, at Bank's option, either both Obligor and Bank, or only Bank, and the
cost thereof shall be secured by this Security Agreement, and shall be repayable
as provided in Paragraph 1 above.

9.   Obligor will give Bank any information it reasonably requires. All
information at any time supplied to Bank by Obligor (including, but not limited
to, the value and condition of Collateral, financial statements, financing
statements, and statements made in documentary Collateral) is correct and
complete, and Obligor will notify Bank of any material adverse change in such
information. Obligor will promptly notify Bank of any change of Obligor's
residence, chief executive office or mailing address.

10.  Bank is irrevocably appointed Obligor's attorney-in-fact to do any act 
which Obligor is obligated hereby to do, to exercise such rights as Obligor may
exercise, to use such equipment as Obligor might use, to enter Obligor's
premises to give notice of Bank's security interest, and to collect Collateral
and proceeds and to execute and file in Obligor's name any financing statements
and amendments thereto required to perfect Bank's security interest hereunder,
all to protect and preserve the Collateral and Bank's rights hereunder. Bank
may:
     (a) Endorse, collect and receive delivery or payment of instruments and
     documents constituting Collateral;
     (b) Make extension agreements with respect to affecting Collateral,
     exchange it for other Collateral, release persons liable thereon or take
     security for the payment thereof, and compromise disputes in connection
     therewith;
     (c) Use or operate Collateral for the purpose of preserving Collateral or
     its value and for preserving or liquidating Collateral.

11.  If more than one Obligor signs this Agreement, their liability is joint and
several.  Any obligor who is married agrees that recourse may be had against 
separate property for the Debt.  Discharge of any Obligor except for full 
payment, or any extension, forbearance, change of rate of interest, or 
acceptance, release or substitution of Collateral or any impairment or 
suspension of Bank's rights against an Obligor, or any transfer of an Obligor's 
interest to another shall not affect the liability of any other obligor.  Until 
the Debt shall have been paid or performed in full, Bank's rights shall continue
even if the Debt is outlawed.  All Obligors waive:  (a) any right to require 
Bank to proceed against any Obligor before any other, or to pursue any other 
remedy; (b) presentment, protest and notice of protest, demand and notice of 
nonpayment, demand or performance, notice of sale, and advertisement of sale; 
(c) any right to the benefit of or to direct the application of any Collateral 
until the Debt shall have been paid; (d) and any right of subrogation to Bank 
until Debt shall have been paid or performed in full.

12.  Upon default, at Bank's option, without demand or notice, all or any part 
of the Debt, except as provided in Security and Loan Agreement, shall 
immediately become due.  Bank shall have all rights given by law, and may sell, 
in one or more sales, Collateral in any county where Bank has an office.  Bank 
may purchase at such sale.  Sales for cash or on credit to a wholesaler, 
retailer or user of the Collateral, or at public or private auction,are all to 
be considered commercially reasonable.  Bank may require Obligor to assemble the
Collateral and make it available to Bank at the entrance to the location of the 
Collateral, or a place designated by Bank.
     Defaults shall include:
     (a)  Obligor's failure to pay or perform this or any agreement with Bank or
     breach of any warranty herein, or Borrower's failure to pay or perform any
     agreement with Bank.
     (b)  Any change in Obligor's or Borrower's financial condition which in
     Bank's judgment impairs the prospect of Borrower's payment or performance.
     (c)  Any actual or reasonably anticipated deterioration of the Collateral
     or in the market price thereof which causes it, in Bank's judgment, to
     become unsatisfactory as security.
     (d)  Any levy or seizure against Borrower or any of the Collateral.
     (e)  Death, termination of business, assignment for creditors, insolvency,
     appointment of receiver, or the filing of any petition under bankruptcy or
     debtor's relief laws of, by or against Obligor or Borrower or any guarantor
     of the Debt.
     (f)  Any warranty or representation which is false or is believed in good 
     faith by Bank to be false.

13.  Bank's acceptance of partial or delinquent payments or the failure of Bank 
to exercise any right or remedy shall not waive any obligation of obligor or 
Borrower or right of Bank to modify this Agreement, waive any other similar 
default.

14.  On transfer of all or any part of the Debt, Bank may transfer all of any 
part of the Collateral.  Bank may deliver all or any part of the Collateral to 
any Obligor at any time. Any such transfer or delivery shall discharge Bank from
all liability and responsibility with respect to such Collateral transferred or
delivered. This Agreement benefits Bank's successors and assigns and binds
Obligor's heirs, legatees, personal representatives, successors, and assigns.
Obligor agrees not to assert against any assignee of Bank any claim or defense
that may exist against Bank. Time is of the essence. This Agreement and
supplementary schedules hereto contain the entire security agreement between
Bank and Obligor. Obligor will execute any additional agreements, assignments
or documents reasonably required by Bank to carry this Agreement into effect.

15.  This Agreement shall be governed by and construed in accordance with the 
laws of the State of California, to the jurisdiction of whose courts the 
Obligor hereby agrees to submit.  Obligor agrees that service of process may be 
accomplished by any means authorized by California law.  All words used herein 
in the singular shall be considered to have been used in the plural where the 
context and construction so require.

**SEE ATTACHED AMENDMENTS TO THIS AGREEMENT**