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                                                               Exhibit 10.2


                                SYNC RESEARCH, INC.
                                AMENDED AND RESTATED
                                  1991 STOCK PLAN
                               Revised: JUNE 12, 1998

     1.   PURPOSES OF THE PLAN.  The purposes of this Stock Plan are to attract
and retain the best available personnel for positions of substantial
responsibility, to provide additional incentive to Employees and Consultants of
the Company and its Subsidiaries and to promote the success of the Company's
business.  Options granted under the Plan may be incentive stock options (as
defined under Section 422 of the Code) or non-statutory stock options, as
determined by the Administrator at the time of grant of an option and subject to
the applicable provisions of Section 422 of the Code, as amended, and the
regulations promulgated thereunder.  Stock purchase rights may also be granted
under the Plan.

     2.   DEFINITIONS.  As used herein, the following definitions shall apply:

          (a)  "ADMINISTRATOR" means the Board or any of its Committees
appointed pursuant to Section 4 of the Plan.

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

          (c)  "CODE" means the Internal Revenue Code of 1986, as amended.

          (d)  "COMMITTEE"  means the Committee appointed by the Board of
Directors in accordance with paragraph (a) of Section 4 of the Plan.

          (e)  "COMMON STOCK" means the Common Stock of the Company.

          (f)  "COMPANY" means Sync Research, Inc., a Delaware corporation.

          (g)  "CONSULTANT" means any person, including an advisor, who is
engaged by the Company or any Parent or Subsidiary to render services and is
compensated for such services, and any director of the Company whether
compensated for such services or not.

          (h)  "CONTINUOUS STATUS AS AN EMPLOYEE" means the absence of any
interruption or termination of the employment relationship by the Company or any
Subsidiary.  Continuous Status as an Employee shall not be considered
interrupted in the case of:  (i) sick leave; (ii) military leave; (iii) any
other leave of absence approved by the Administrator, provided that such leave
is for a period of not more than ninety (90) days, unless reemployment upon the
expiration of such leave is guaranteed by contract or statute, or unless
provided otherwise pursuant to Company policy adopted from time to time; or
(iv) in the case of transfers between locations of the Company or between the
Company, its Subsidiaries or its successor.

(i)  "DIRECTOR" means a member of the Board.

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          (j)  "EMPLOYEE" means any person, including officers and directors,
employed by the Company or any Parent or Subsidiary of the Company.  The payment
of a director's fee by the Company to a Director shall not be sufficient to
constitute "employment" of the Director by the Company.

          (k)  "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended.

          (l)  "FAIR MARKET VALUE" means, as of any date, the value of Common
Stock determined as follows:

               (i)  If the Common Stock is listed on any established stock 
exchange or a national market system including without limitation the 
National Market System of the National Association of Securities Dealers, 
Inc. Automated Quotation ("NASDAQ") System, its Fair Market Value shall be 
the closing sales price for such stock (or the closing bid, if no sales were 
reported, as quoted on such exchange or system for the last market trading 
day prior to the time of determination) as reported in The Wall Street 
Journal or such other source as the Administrator deems reliable;

               (ii) If the Common Stock is quoted on the NASDAQ System (but 
not on the National Market System thereof) or regularly quoted by a 
recognized securities dealer but selling prices are not reported, its Fair 
Market Value shall be the mean between the high bid and low asked prices for 
the Common Stock or;

               (iii) In the absence of an established market for the Common 
Stock, the Fair Market Value thereof shall be determined in good faith by the 
Administrator.

          (m)  "INCENTIVE STOCK OPTION" means an Option intended to qualify as
an incentive stock option within the meaning of Section 422 of the Code, as
designated in the applicable written option agreement.

          (n)  "NONSTATUTORY STOCK OPTION" means an Option not intended to 
qualify as an Incentive Stock Option, as designated in the applicable written 
option agreement.

          (o)  "NAMED EXECUTIVE" shall mean any individual who, on the last day
of the Company's fiscal year, is the chief executive officer of the Company (or
is acting in such capacity) or among the four highest compensated officers of
the Company (other than the chief executive officer).  Such officer status shall
be determined pursuant to the executive compensation disclosure rules under the
Exchange Act.

          (p)  "OPTION" means a stock option granted pursuant to the Plan.

          (q)  "OPTIONED STOCK" means the Common Stock subject to an Option or a
Stock Purchase Right.

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          (r)  "OPTIONEE" means an Employee or Consultant who receives an Option
or Stock Purchase Right.

          (s)  "PARENT" means a "parent corporation", whether now or hereafter
existing, as defined in Section 424(e) of the Code.

          (t)  "PLAN" means this 1991 Stock Plan.

          (u)  "RESTRICTED STOCK" means shares of Common Stock acquired pursuant
to a grant of a Stock Purchase Right under Section 12 below.

          (v)  "SHARE" means a share of the Common Stock, as adjusted in
accordance with Section 14 below.

          (w)  "STOCK PURCHASE RIGHT" means the right to purchase Common Stock
pursuant to Section 12 below.

          (x)  "SUBSIDIARY" means a "subsidiary corporation", whether now or
hereafter existing, as defined in Section 424(f) of the Code.

     3.   STOCK SUBJECT TO THE PLAN.  Subject to the provisions of Section 14 of
the Plan, the maximum aggregate number of shares which may be optioned and sold
under the Plan is 5,058,985 shares of Common Stock..  The shares may be
authorized, but unissued, or reacquired Common Stock.

          If an Option should expire or become unexercisable for any reason
without having been exercised in full, the unpurchased Shares which were subject
thereto shall, unless the Plan shall have been terminated, become available for
future grant under the Plan.

     4.   ADMINISTRATION OF THE PLAN.

          (a)  COMPOSITION OF THE ADMINISTRATOR

               (i)  MULTIPLE ADMINISTRATIVE BODIES.  If permitted by Rule 
16b-3, and by the legal requirements relating to the administration of 
incentive stock option plans, if any, of applicable securities laws and the 
Code (collectively, the "APPLICABLE LAWS"), grants under the Plan may (but 
need not) be made by different administrative bodies with respect to 
Directors, Officers who are not directors and Employees who are neither 
Directors nor Officers.

               (ii)  ADMINISTRATION WITH RESPECT TO DIRECTORS AND OFFICERS. 
With respect to grants of Options to Employees or Consultants who are also 
Officers or Directors of the Company, grants under the Plan shall be made by 
(A) the Board, if the Board may make grants under the Plan in compliance with 
Rule 16b-3 and Section 162(m) of the Code as it applies so as to qualify 
grants of Options to Named Executives as performance-based compensation, or 
(B) a Committee designated by the Board to make grants under the Plan, which 

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Committee shall be constituted in such a manner as to permit grants under the 
Plan to comply with Rule 16b-3, to qualify grants of Options to Named 
Executives as performance-based compensation under Section 162(m) of the Code 
and otherwise so as to satisfy the Applicable Laws.

               (iii)  ADMINISTRATION WITH RESPECT TO OTHER PERSONS.  With 
respect to grants of Options to Employees or Consultants who are neither 
Directors nor Officers of the Company, the Plan shall be administered by (A) 
the Board or (B) a Committee designated by the Board, which Committee shall 
be constituted in such a manner as to satisfy the Applicable Laws.

               (iv)  GENERAL.  Once a Committee has been appointed pursuant 
to subsection (ii) or (iii) of this Section 4(a), such Committee shall 
continue to serve in its designated capacity until otherwise directed by the 
Board.  From time to time the Board may increase the size of any Committee 
and appoint additional members thereof, remove members (with or without 
cause) and appoint new members in substitution therefor, fill vacancies 
(however caused) and remove all members of a Committee and thereafter 
directly administer the Plan, all to the extent permitted by the Applicable 
Laws and, in the case of a Committee appointed under subsection (ii), to the 
extent permitted by Rule 16b-3 as it applies to a plan intended to qualify 
thereunder as a discretionary plan, and to the extent required under Section 
162(m) of the Code to qualify grants of Options to Named Executives as 
performance-based compensation.

          (b)  POWERS OF THE ADMINISTRATOR.  Subject to the provisions of the 
Plan and in the case of a Committee, the specific duties delegated by the 
Board to such Committee, and subject to the approval of any relevant 
authorities, including the approval, if required, of any stock exchange upon 
which the Common Stock is listed, the Administrator shall have the authority, 
in its discretion:

               (i)  to determine the Fair Market Value of the Common Stock, 
in accordance with Section 2(k) of the Plan;

               (ii) to select the Consultants and Employees to whom Options 
and Stock Purchase Rights may from time to time be granted hereunder;

               (iii) to determine whether and to what extent Options and 
Stock Purchase Rights or any combination thereof are granted hereunder;

               (iv) to determine the number of shares of Common Stock to be 
covered by each such award granted hereunder;

               (v) to approve forms of agreement for use under the Plan;

               (vi) to determine the terms and conditions, not inconsistent 
with the terms of the Plan, of any award granted hereunder;

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               (vii) to determine whether and under what circumstances an 
Option may be settled in cash under subsection 10(f) instead of Common Stock; 
and

               (viii) to determine the terms and restrictions applicable to 
Stock Purchase Rights and the Restricted Stock purchased by exercising such 
Stock Purchase Rights.

          (c)  EFFECT OF ADMINISTRATOR'S DECISION.  All decisions, 
determinations and interpretations of the Administrator shall be final and 
binding on all Optionees and any other holders of any Options or Stock 
Purchase Rights.

     5.   ELIGIBILITY.

          (a)  Nonstatutory Stock Options and Stock Purchase Rights may be 
granted to Employees and Consultants.  Incentive Stock Options may be granted 
only to Employees.  An Employee or Consultant who has been granted an Option 
or Stock Purchase Right may, if he is otherwise eligible, be granted 
additional Options or Stock Purchase Rights.

          (b)  Each Option shall be designated in the written option 
agreement as either an Incentive Stock Option or a Nonstatutory Stock Option. 
However, notwithstanding such designations, to the extent that the aggregate 
Fair Market Value of the Shares with respect to which Options designated as 
Incentive Stock Options are exercisable for the first time by any Optionee 
during any calendar year (under all plans of the Company or any Parent or 
Subsidiary) exceeds $100,000, such excess Options shall be treated as 
Nonstatutory Stock Options.

          (c)  For purposes of Section 5(b), Incentive Stock Options shall be 
taken into account in the order in which they were granted, and the Fair 
Market Value of the Shares shall be determined as of the time the Option with 
respect to such Shares is granted.

          (d)  The Plan shall not confer upon any Optionee any right with 
respect to continuation of employment or consulting relationship with the 
Company, nor shall it interfere in any way with his or her right or the 
Company's right to terminate his or her employment or consulting relationship 
at any time, with or without cause.

     6.   TERM OF PLAN.  The Plan shall become effective upon the earlier to 
occur of its adoption by the Board of Directors or its approval by the 
stockholders of the Company as described in Section 20 of the Plan.  It shall 
continue in effect for a term of ten (10) years unless sooner terminated 
under Section 16 of the Plan.

     7.   TERM OF OPTION.  The term of each Option shall be the term stated 
in the Option Agreement; provided, however, that the term shall be no more 
than ten (10) years from the date of grant thereof.  However, in the case of 
an Incentive Stock Option granted to an Optionee who, at the time the Option 
is granted, owns stock representing more than ten percent (10%) of the voting 
power of all classes of stock of the Company or any Parent or Subsidiary, the 
term of the 

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Option shall be five (5) years from the date of grant thereof or such shorter 
term as may be provided in the Option Agreement.

     8.   LIMITATION OF GRANTS TO EMPLOYEES. Subject to adjustment as 
provided in this Plan, the maximum number of Shares which may be subject to 
Options or Stock Purchase Rights granted to any one Employee under this Plan 
for any fiscal year of the Company shall be 525,000.

     9.   OPTION EXERCISE PRICE AND CONSIDERATION.

          (a)  The per share exercise price for the Shares to be issued 
pursuant to exercise of an Option shall be such price as is determined by the 
Board, but shall be subject to the following:

               (i)  In the case of an Incentive Stock Option

                    (A)  granted to an Employee who, at the time of the grant 
of such Incentive Stock Option, owns stock representing more than ten percent 
(10%) of the voting power of all classes of stock of the Company or any 
Parent or Subsidiary, the per Share exercise price shall be no less than 110% 
of the Fair Market Value per Share on the date of grant.

                    (B)  granted to any Employee, the per Share exercise 
price shall be no less than 100% of the Fair Market Value per Share on the 
date of grant.

               (ii) In the case of a Nonstatutory Stock Option

                    (A)  granted to a person who, at the time of the grant of
such Option, is a Named Executive of the Company, the per share Exercise Price
shall be no less than 100% of the Fair Market Value on the date of grant;

                    (B)  granted to any person other than a Named Executive, 
the per Share exercise price shall be no less than 85% of the Fair Market 
Value per Share on the date of grant.

               (iii) Notwithstanding anything to the contrary in subsections 
9(a)(i) or 9(a)(ii) above, in the case of an Option granted on or after the 
effective date of registration of any class of equity security of the Company 
pursuant to Section 12 of the Exchange Act and prior to six months after the 
termination of such registration, the per Share exercise price shall be no 
less than 100% of the Fair Market Value per Share on the date of grant.

          (b)  The consideration to be paid for the Shares to be issued upon 
exercise of an Option, including the method of payment, shall be determined 
by the Administrator (and, in the case of an Incentive Stock Option, shall be 
determined at the time of grant) and may consist entirely of (1) cash, (2) 
check, (3) promissory note, (4) other Shares which (x) in the case of Shares 
acquired upon exercise of an Option either have been owned by the Optionee 
for more 

<PAGE>

than six months on the date of surrender or were not acquired, directly or 
indirectly, from the Company, and (y) have a Fair Market Value on the date of 
surrender equal to the aggregate exercise price of the Shares as to which 
said Option shall be exercised, (5) authorization from the Company to retain 
from the total number of Shares as to which the Option is exercised that 
number of Shares having a Fair Market Value on the date of exercise equal to 
the exercise price for the total number of Shares as to which the Option is 
exercised, (6) delivery of a properly executed exercise notice together with 
such other documentation as the Administrator and the broker, if applicable, 
shall require to effect an exercise of the Option and delivery to the Company 
of the sale or loan proceeds required to pay the exercise price, (7) by 
delivering an irrevocable subscription agreement for the Shares which 
irrevocably obligates the option holder to take and pay for the Shares not 
more than twelve months after the date of delivery of the subscription 
agreement, (8) any combination of the foregoing methods of payment, (9) or 
such other consideration and method of payment for the issuance of Shares to 
the extent permitted under Applicable Laws.  In making its determination as 
to the type of consideration to accept, the Board shall consider if 
acceptance of such consideration may be reasonably expected to benefit the 
Company.

10.  EXERCISE OF OPTION.

          (a)  PROCEDURE FOR EXERCISE; RIGHTS AS A STOCKHOLDER. Any Option 
granted hereunder shall be exercisable at such times and under such 
conditions as determined by the Board, including performance criteria with 
respect to the Company and/or the Optionee, and as shall be permissible under 
the terms of the Plan.

               An Option may not be exercised for a fraction of a Share.

               An Option shall be deemed to be exercised when written notice 
of such exercise has been given to the Company in accordance with the terms 
of the Option by the person entitled to exercise the Option and full payment 
for the Shares with respect to which the Option is exercised has been 
received by the Company.  Full payment may, as authorized by the Board, 
consist of any consideration and method of payment allowable under Section 
9(b) of the Plan. Until the issuance (as evidenced by the appropriate entry 
on the books of the Company or of a duly authorized transfer agent of the 
Company) of the stock certificate evidencing such Shares, no right to vote or 
receive dividends or any other rights as a stockholder shall exist with 
respect to the Optioned Stock, notwithstanding the exercise of the Option.  
The Company shall issue (or cause to be issued) such stock certificate 
promptly upon exercise of the Option.  No adjustment will be made for a 
dividend or other right for which the record date is prior to the date the 
stock certificate is issued, except as provided in Section 14 of the Plan.

               Exercise of an Option in any manner shall result in a decrease 
in the number of Shares which thereafter may be available, both for purposes 
of the Plan and for sale under the Option, by the number of Shares as to 
which the Option is exercised.

          (b)  TERMINATION OF EMPLOYMENT. In the event of termination of an 
Optionee's consulting relationship or Continuous Status as an Employee with 
the Company (as the case may 

<PAGE>

be), such Optionee may, but only within such period of time (not less than 
thirty (30) days) as determined by the Board, with such determination in the 
case of an Incentive Stock Option being made at the time of grant of the 
Option and not exceeding three (3) months after the date of such termination 
(but in no event later than the expiration date of the term of such Option as 
set forth in the Option Agreement), exercise his Option to the extent that 
Optionee was entitled to exercise it at the date of such termination.  To the 
extent that Optionee was not entitled to exercise the Option at the date of 
such termination, or if Optionee does not exercise such Option to the extent 
so entitled within the time specified herein, the Option shall terminate.

          (c)  DISABILITY OF OPTIONEE.  Notwithstanding the provisions of 
Section 10(b) above, in the event of termination of an Optionee's consulting 
relationship or Continuous Status as an Employee as a result of his total and 
permanent disability (as defined in Section 22(e)(3) of the Code), Optionee 
may, but only within twelve (12) months from the date of such termination 
(but in no event later than the expiration date of the term of such Option as 
set forth in the Option Agreement), exercise the Option to the extent 
otherwise entitled to exercise it at the date of such termination.  To the 
extent that Optionee was not entitled to exercise the Option at the date of 
termination, or if Optionee does not exercise such Option to the extent so 
entitled within the time specified herein, the Option shall terminate.

          (d)  DEATH OF OPTIONEE.  In the event of the death of an Optionee, 
the Option may be exercised, at any time within twelve (12) months following 
the date of death (but in no event later than the expiration date of the term 
of such Option as set forth in the Option Agreement), by the Optionee's 
estate or by a person who acquired the right to exercise the Option by 
bequest or inheritance, but only to the extent the Optionee was entitled to 
exercise the Option at the date of death.  To the extent that Optionee was 
not entitled to exercise the Option at the date of termination, or if 
Optionee does not exercise such Option to the extent so entitled within the 
time specified herein, the Option shall terminate.

          (e)  RULE 16b-3.  Options granted to persons subject to Section 
16(b) of the Exchange Act must comply with Rule 16b-3 and shall contain such 
additional conditions or restrictions as may be required thereunder to 
qualify for the maximum exemption from Section 16 of the Exchange Act with 
respect to Plan transactions.

          (f)  BUYOUT PROVISIONS.  The Administrator may at any time offer to 
buy out for a payment in cash or Shares, an Option previously granted, based 
on such terms and conditions as the Administrator shall establish and 
communicate to the Optionee at the time that such offer is made.

     11.  NON-TRANSFERABILITY OF OPTIONS.  An Option or Stock Purchase Right 
may not be sold, pledged, assigned, hypothecated, transferred, or disposed of 
in any manner other than by will or by the laws of descent or distribution 
and may be exercised, during the lifetime of the Optionee, only by the 
Optionee.

     12.  STOCK PURCHASE RIGHTS.

<PAGE>

          (a)  RIGHTS TO PURCHASE.  Stock Purchase Rights may be issued 
either alone, in addition to, or in tandem with other awards granted under 
the Plan and/or cash awards made outside of the Plan.  After the 
Administrator determines that it will offer Stock Purchase Rights under the 
Plan, it shall advise the offeree in writing of the terms, conditions and 
restrictions related to the offer, including the number of Shares that such 
person shall be entitled to purchase, the price to be paid, and the time 
within which such person must accept such offer, which shall in no event 
exceed thirty (30) days from the date upon which the Administrator made the 
determination to grant the Stock Purchase Right.  The offer shall be accepted 
by execution of a Restricted Stock purchase agreement in the form determined 
by the Administrator.  Shares purchased pursuant to the grant of a Stock 
Purchase Right shall be referred to herein as "Restricted Stock."

          (b)  REPURCHASE OPTION.  Unless the Administrator determines 
otherwise, the Restricted Stock purchase agreement shall grant the Company a 
repurchase option exercisable upon the voluntary or involuntary termination 
of the purchaser's employment with the Company for any reason (including 
death or Disability).  The purchase price for Shares repurchased pursuant to 
the Restricted Stock purchase agreement shall be the original price paid by 
the purchaser and may be paid by cash or cancellation of purchase money 
indebtedness of the purchaser to the Company.  The repurchase option shall 
lapse at such rate as the Committee may determine.

          (c)  OTHER PROVISIONS.  The Restricted Stock purchase agreement 
shall contain such other terms, provisions and conditions not inconsistent 
with the Plan as may be determined by the Administrator in its sole 
discretion.  In addition, the provisions of Restricted Stock purchase 
agreements need not be the same with respect to each purchaser.

          (d)  RIGHTS AS A STOCKHOLDER.  Once the Stock Purchase Right is 
exercised, the purchaser shall have the rights equivalent to those of a 
stockholder, and shall be a stockholder when his or her purchase is entered 
upon the records of the duly authorized transfer agent of the Company.  No 
adjustment will be made for a dividend or other right for which the record 
date is prior to the date the Stock Purchase Right is exercised, except as 
provided in Section 13 of the Plan.

     13.  STOCK WITHHOLDING TO SATISFY WITHHOLDING TAX OBLIGATIONS.  At the 
discretion of the Administrator, Optionees may satisfy withholding 
obligations as provided in this paragraph.  When an Optionee incurs tax 
liability in connection with an Option or Stock Purchase Right, which tax 
liability is subject to tax withholding under applicable tax laws, and the 
Optionee is obligated to pay the Company an amount required to be withheld 
under applicable tax laws, the Optionee may satisfy the withholding tax 
obligation by electing to have the Company withhold from the Shares to be 
issued upon exercise of the Option, or the Shares to be issued in connection 
with the Stock Purchase Right, if any, that number of Shares having a Fair 
Market Value equal to the amount required to be withheld.  The Fair Market 
Value of the Shares to be withheld shall be determined on the date that the 
amount of tax to be withheld is to be determined (the "Tax Date").

<PAGE>

     All elections by an Optionee to have Shares withheld for this purpose 
shall be made in writing in a form acceptable to the Administrator and shall 
be subject to the following restrictions:

          (a)  the election must be made on or prior to the applicable Tax 
Date;

          (b)  once made, the election shall be irrevocable as to the 
particular Shares of the Option or Stock Purchase Right as to which the 
election is made; and

          (c)  all elections shall be subject to the consent or disapproval 
of the Administrator.

     In the event the election to have Shares withheld is made by an Optionee 
and the Tax Date is deferred under Section 83 of the Code because no election 
is filed under Section 83(b) of the Code, the Optionee shall receive the full 
number of Shares with respect to which the Option or Stock Purchase Right is 
exercised but such Optionee shall be unconditionally obligated to tender back 
to the Company the proper number of Shares on the Tax Date.

     14.  ADJUSTMENTS UPON CHANGES IN CAPITALIZATION OR MERGER.

          (a)  CHANGES IN CAPITALIZATION.  Subject to any required action by 
the stockholders of the Company, the number of shares of Common Stock covered 
by each outstanding Option or Stock Purchase Right, and the number of shares 
of Common Stock which have been authorized for issuance under the Plan but as 
to which no Options or Stock Purchase Rights have yet been granted or which 
have been returned to the Plan upon cancellation or expiration of an Option 
or Stock Purchase Right, the maximum number of shares of Common Stock for 
which Options may be granted to any employee under Section 8 of this plan and 
the price per share of Common Stock covered by each such outstanding Option 
or Stock Purchase Right, shall be proportionately adjusted for any increase 
or decrease in the number of issued shares of Common Stock resulting from a 
stock split, reverse stock split, stock dividend, combination or 
reclassification of the Common Stock, or any other increase or decrease in 
the number of issued shares of Common Stock effected without receipt of 
consideration by the Company; provided, however, that conversion of any 
convertible securities of the Company shall not be deemed to have been 
"effected without receipt of consideration."  Such adjustment shall be made 
by the Board, whose determination in that respect shall be final, binding and 
conclusive.  Except as expressly provided herein, no issuance by the Company 
of shares of stock of any class, or securities convertible into shares of 
stock of any class, shall affect, and no adjustment by reason thereof shall 
be made with respect to, the number or price of shares of Common Stock 
subject to an Option or Stock Purchase Right.

          (b)  CORPORATE TRANSACTIONS. In the event of the proposed 
dissolution or liquidation of the Company, the Option or Stock Purchase Right 
will terminate immediately prior to the consummation of such proposed action, 
unless otherwise provided by the Administrator.  The Administrator may, in 
the exercise of its sole discretion in such instances, declare that any 
Option or Stock Purchase Right shall terminate as of a date fixed by the 
Administrator and give 

<PAGE>

each Optionee the right to exercise his or her Option or Stock Purchase Right 
as to all or any part of the Optioned Stock, including Shares as to which the 
Option would not otherwise be exercisable.  In the event of a proposed sale 
of all or substantially all of the assets of the Company, or the merger of 
the Company with or into another corporation, the Option or Stock Purchase 
Right shall be assumed or an equivalent Option or Stock Purchase Right shall 
be substituted by such successor corporation or a parent or subsidiary of 
such successor corporation, unless the Administrator determines, in lieu of 
such assumption or substitution, that the Optionee shall have the right to 
exercise the Option or Stock Purchase Right as to some or all of the Optioned 
Stock, including Shares as to which the Option or Stock Purchase Right would 
not otherwise be exercisble.  If the Administrator makes an Option or Stock 
Purchase Right exercisable in lieu of assumption or substitution in the event 
of a merger or sale of assets, the Administrator shall notify the Optionee 
that the Option or Stock Purchase Right shall be exercisable for a period of 
fifteen (15) days from the date of such notice, and the Option or Stock 
Purchase Right will terminate upon the expiration of such period.

     15.  TIME OF GRANTING OPTIONS AND STOCK PURCHASE RIGHTS.  The date of 
grant of an Option or Stock Purchase Right shall, for all purposes, be the 
date on which the Administrator makes the determination granting such Option 
or Stock Purchase Right, or such other date as is determined by the Board.  
Notice of the determination shall be given to each Employee or Consultant to 
whom an Option or Stock Purchase Right is so granted within a reasonable time 
after the date of such grant.

     16.  AMENDMENT AND TERMINATION OF THE PLAN.

          (a)  AMENDMENT AND TERMINATION.  The Board may amend or terminate 
the Plan from time to time in such respects as the Board may deem advisable; 
provided that no amendment, alteration, suspension or discontinuation shall 
be made which would impair the rights of any optionee under any grant 
theretofore made, without his or her consent, and further that, the following 
revisions or amendments shall require approval of the stockholders of the 
Company in the manner described in Section 20 of the Plan:

               (i)  any increase in the number of Shares subject to the Plan, 
other than in connection with an adjustment under Section 14 of the Plan:

               (ii) any change in the designation of the class of persons 
eligible to be granted Options; or

               (iii) any change in the limitation on grants to employees as 
described in Section 8 of the Plan or other changes which would require 
stockholder approval to qualify options granted hereunder as 
performance-based compensation under Section 162(m) of the Code.

     In addition, to the extent necessary and desirable to comply with Rule 
16b-3 under the Exchange Act or with Sections 162(m) and 422 of the Code (or 
any other applicable law or regulation, including the requirements of the 
NASD or an established stock exchange), the 

<PAGE>

Company shall obtain stockholder approval of any Plan amendment in such a 
manner and to such a degree as required.

          (b)  EFFECT OF AMENDMENT OR TERMINATION.  Any such amendment or 
termination of the Plan shall not affect Options already granted and such 
Options shall remain in full force and effect as if this Plan had not been 
amended or terminated, unless mutually agreed otherwise between the Optionee 
and the Board, which agreement must be in writing and signed by the Optionee 
and the Company.

     17.  CONDITIONS UPON ISSUANCE OF SHARES.  Shares shall not be issued 
pursuant to the exercise of an Option unless the exercise of such Option and 
the issuance and delivery of such Shares pursuant thereto shall comply with 
all relevant provisions of law, including, without limitation, the Securities 
Act of 1933, as amended, the Exchange Act, the rules and regulations 
promulgated thereunder, and the requirements of any stock exchange upon which 
the Shares may then be listed, and shall be further subject to the approval 
of counsel for the Company with respect to such compliance.

          As a condition to the exercise of an Option, the Company may 
require the person exercising such Option to represent and warrant at the 
time of any such exercise that the Shares are being purchased only for 
investment and without any present intention to sell or distribute such 
Shares if, in the opinion of counsel for the Company, such a representation 
is required by any of the aforementioned relevant provisions of law.

     18.  RESERVATION OF SHARES.  The Company, during the term of this Plan, 
will at all times reserve and keep available such number of Shares as shall 
be sufficient to satisfy the requirements of the Plan.

          The inability of the Company to obtain authority from any 
regulatory body having jurisdiction, which authority is deemed by the 
Company's counsel to be necessary to the lawful issuance and sale of any 
Shares hereunder, shall relieve the Company of any liability in respect of 
the failure to issue or sell such Shares as to which such requisite authority 
shall not have been obtained.

     19.  AGREEMENTS.  Options and Stock Purchase Rights shall be evidenced 
by written agreements in such form as the Board shall approve from time to 
time.

     20.  STOCKHOLDER APPROVAL.  Continuance of the Plan shall be subject to 
approval by the stockholders of the Company within twelve (12) months before 
or after the date the Plan is adopted.  Such stockholder approval shall be 
obtained in the degree and manner required under applicable state and federal 
law and the rules of any stock exchange upon which the Common Stock is listed 
and, in particular, shall be solicited substantially in accordance with 
Section 14(a) of the Exchange Act and the rules and regulations promulgated 
thereunder.

     21.  INFORMATION TO OPTIONEES AND PURCHASERS.  The Company shall provide 
to each Optionee and to each individual who acquired Shares pursuant to the 
Plan, during the period such 

<PAGE>

Optionee or purchaser has one or more Options or Stock Purchase Rights 
outstanding, and, in the case of an individual who acquired Shares pursuant 
to the Plan, during the period such individual owns such Shares, copies of 
all annual reports and other information which are provided to all 
stockholders of the Company.

<PAGE>

                                 SYNC RESEARCH, INC.
                                          
                                  1991 STOCK PLAN
                                          
                            NOTICE OF STOCK OPTION GRANT

Optionee's Name and Address:

______________________________

______________________________

______________________________

               You have been granted an option to purchase Common Stock of 
Sync Research, Inc. (the "Company") as follows:

               Grant Number                         ____________________

               Date of Grant                        ____________________

               Exercise Price Per Share             $___________________

               Total Number of Shares Granted       ____________________

               Total Price of Shares Granted        ____________________

               Type of Option:                _____ Incentive Stock Option
                                              _____ Nonstatutory Stock Option

               Term/Expiration Date:                ____________________

               Vesting Commencement Date:           ____________________

Exercise Schedule:

               Subject to the terms of the attached Stock Option Agreement, 
the Option shall become exercisable cumulatively, to the extent of 25% of the 
Shares subject to the Option on the first anniversary of the Vesting 
Commencement Date, and 1/48th of the Shares at the end of each month 
thereafter.

               Termination Period:

               The option may be exercised for a period of 60 days after 
termination of employment or consulting relationship except as set out in 
Sections 7 and 8 of the Stock Option Agreement (but in no event later than 
the Expiration Date).

<PAGE>

               By your signature and the signature of the Company's 
representative below, you and the Company agree that this option is granted 
under and governed by the terms and conditions of the 1991 Stock Plan and the 
Stock Option Agreement, all of which are attached and made a part of this 
document.

Optionee:                                  SYNC RESEARCH, INC.


________________________________           By: ________________________________
Signature

                                        
________________________________           Title: _____________________________
Print Name

<PAGE>

                                 SYNC RESEARCH, INC.
                                          
                                  1991 STOCK PLAN
                                          
                              STOCK OPTION AGREEMENT


     1.   GRANT OF OPTION.  Sync Research, Inc., a Delaware corporation (the 
"Company"), hereby grants to the Optionee named in the Notice of Grant (the 
"Optionee"), an option (the "Option") to purchase a total number of shares of 
Common Stock (the "Shares") set forth in the Notice of Grant, at the exercise 
price per share set forth in the Notice of Grant (the "Exercise Price") 
subject to the terms, definitions and provisions of the Sync Research, Inc. 
1991 Stock Plan (the "Plan") adopted by the Company, which is incorporated 
herein by reference.  In the event of a conflict between the terms of the 
Plan and the terms of this agreement (the "Agreement"), the terms of the Plan 
shall govern. Unless otherwise defined herein, the terms used herein shall 
have the same meanings defined in the Plan.

     To the extent designated an Incentive Stock Option, this Option is 
intended to qualify as an Incentive Stock Option as defined in Section 422 of 
the Code, and, to the extent not so designated, this Option is intended to be 
a Nonstatutory Stock Option.

     2.   EXERCISE OF OPTION.  This Option shall be exercisable during its 
term in accordance with the Exercise Schedule set out in the Notice of Grant 
and with the provisions of Sections 9 and 10 of the Plan as follows:

          (i)  RIGHT TO EXERCISE.

               (a)  This Option may not be exercised for a fraction of a 
share.

               (b)  In the event of Optionee's death, disability or other 
termination of employment, the exercisability of the Option is governed by 
Sections 6, 7 and 8 below, subject to the limitations contained in subsection 
2(i)(c) and (d).

               (c)  In no event may this Option be exercised after the date 
of expiration of the term of this Option as set forth in the Notice of Grant.

               (d)  If designated an Incentive Stock Option in the Notice of 
Grant, in the event that the Shares subject to this Option (and all other 
Incentive Stock Options granted to Optionee by the Company or any Parent or 
Subsidiary) that vest in any calendar year have an aggregate fair market 
value (determined for each Share as of the Date of Grant of the Option 
covering such Share) in excess of $100,000, the Shares in excess of $100,000 
shall be treated as subject to a Nonstatutory Stock Option, in accordance 
with Section 5 of the Plan.  

<PAGE>

          (ii) METHOD OF EXERCISE.  

               (a)  This Option shall be exercisable by delivering to the 
Company written notice of exercise (in the form attached as Exhibit A) which 
shall state the election to exercise the Option, the number of Shares in 
respect of which the Option is being exercised, and such other 
representations and agreements as to the holder's investment intent with 
respect to such Shares of Common Stock as may be required by the Company 
pursuant to the provisions of the Plan.  Such written notice shall be signed 
by the Optionee and shall be delivered in person or by certified mail to the 
Secretary of the Company.  The written notice shall be accompanied by payment 
of the Exercise Price.  This Option shall be deemed to be exercised upon 
receipt by the Company of such written notice accompanied by the Exercise 
Price.

               (b)  As a condition to the exercise of this Option, Optionee 
agrees to make adequate provision for federal, state or other tax withholding 
obligations, if any, which arise upon the exercise of the Option or 
disposition of Shares, whether by withholding, direct payment to the Company, 
or otherwise.

               (c)  No Shares will be issued pursuant to the exercise of an 
Option unless such issuance and such exercise shall comply with all relevant 
provisions of law and the requirements of any stock exchange upon which the 
Shares may then be listed.  Assuming such compliance, for income tax purposes 
the Shares shall be considered transferred to the Optionee on the date on 
which the Option is exercised with respect to such Shares.

     3.   OPTIONEE'S REPRESENTATIONS.  In the event the Shares purchasable 
pursuant to the exercise of this Option have not been registered under the 
Securities Act of 1933, as amended (the "Securities Act"), at the time this 
Option is exercised, Optionee shall, if required by the Company, concurrently 
with the exercise of all or any portion of this Option, make the requisite 
investment representations, a copy of which is available for Optionee's 
review from the Company upon request.

     4.   METHOD OF PAYMENT.  Payment of the Exercise Price shall be by any 
of the following, or a combination thereof, at the election of the Optionee:

          (i)   cash; or

          (ii)  check; or

          (iii) surrender of other Shares of Common Stock of the Company that 
(A) either have been owned by the Optionee for more than six (6) months on 
the date of surrender or were not acquired, directly or indirectly, from the 
Company, and (B) have a Fair Market Value on the date of surrender equal to 
the aggregate exercise price of the Shares as to which the Option is being 
exercised; or

                                       2

<PAGE>

          (iv) authorization from the Company to retain from the total number 
of Shares as to which the Option is exercised that number of Shares having a 
Fair Market Value on the date of exercise equal to the exercise price for the 
total number of Shares as to which the Option is exercised; or

          (v)  if there is a public market for the Shares and they are 
registered under the Securities Act, delivery of a properly executed exercise 
notice together with such other documentation as the Administrator and the 
broker, if applicable, shall require to effect an exercise of the Option and 
delivery to the Company of the sale or loan proceeds required to pay the 
exercise price.

     5.   RESTRICTIONS ON EXERCISE.  This Option may not be exercised (i) 
until such time as the Plan has been approved by the stockholders of the 
Company, or (ii) if the issuance of such Shares upon such exercise or the 
method of payment of consideration for such shares would constitute a 
violation of any applicable federal or state securities or other law or 
regulation, including any rule under Part 207 of Title 12 of the Code of 
Federal Regulations ("Regulation G") as promulgated by the Federal Reserve 
Board.  As a condition to the exercise of this Option, the Company may 
require Optionee to make any representation and warranty to the Company as 
may be required by any applicable law or regulation.

     6.   TERMINATION OF RELATIONSHIP.  In the event of termination of 
Optionee's consulting relationship or Continuous Status as an Employee with 
the Company (as the case may be), Optionee may, to the extent otherwise so 
entitled at the date of such termination (the "Termination Date"), exercise 
this Option during the Termination Period set out in the Notice of Grant.  To 
the extent that Optionee was not entitled to exercise this Option at the date 
of such termination, or if Optionee does not exercise this Option within the 
time specified herein, the Option shall terminate.

     7.   DISABILITY OF OPTIONEE.  Notwithstanding the provisions of Section 
6 above, in the event of termination of Optionee's consulting relationship or 
Continuous Status as an Employee as a result of total and permanent 
disability (as defined in Section 22(e)(3) of the Code), Optionee may, but 
only within six (6) months from the date of such termination (but in no event 
later than the date of expiration of the term of this Option as set forth in 
Section 10 below), exercise the Option to the extent otherwise so entitled at 
the date of such termination.  To the extent that Optionee was not entitled 
to exercise the Option at the date of termination, or if Optionee does not 
exercise such Option (to the extent otherwise so entitled) within the time 
specified herein, the Option shall terminate.

     8.   DEATH OF OPTIONEE.  In the event of the death of Optionee, the 
Option may be exercised at any time within six (6) months following the date 
of death (but in no event later than the date of expiration of the term of 
this Option as set forth in Section 10 below), by Optionee's estate or by a 
person who acquired the right to exercise the Option by bequest or 
inheritance, but only to the extent the Optionee could exercise the Option at 
the date of death. To the extent that Optionee was not entitled to exercise 
the Option at the date of death, or if Optionee does not 

                                       3

<PAGE>

exercise such Option to the extent so entitled within the time specified 
herein, the Option shall terminate.

     9.   NON-TRANSFERABILITY OF OPTION.  This Option may not be transferred 
in any manner otherwise than by will or by the laws of descent or 
distribution and may be exercised during the lifetime of Optionee only by him 
or her.  The designation of a beneficiary does not constitute a transfer.  
The terms of this Option shall be binding upon the executors, administrators, 
heirs, and successors of the Optionee.

     10.  TERM OF OPTION.  This Option may be exercised only within the term 
set out in the Notice of Grant, and may be exercised during such term only in 
accordance with the Plan and the terms of this Option.  The limitations set 
out in Section 7 of the Plan regarding Options designated as Incentive Stock 
Options and Options granted to more than ten percent (10%) shareholders shall 
apply to this Option.

     11.  TAXATION UPON EXERCISE OF OPTION.  Optionee understands that, upon 
exercising a nonstatutory Option, he or she will recognize income for tax 
purposes in an amount equal to the excess of the then fair market value of 
the Shares over the exercise price.  However, the timing of this income 
recognition may be deferred for up to six months if Optionee is subject to 
Section 16 of the Securities Exchange Act of 1934, as amended (the "Exchange 
Act").  If the Optionee is an employee, the Company will be required to 
withhold from Optionee's compensation, or collect from Optionee and pay to 
the applicable taxing authorities an amount equal to a percentage of this 
compensation income. Additionally, the Optionee may at some point be required 
to satisfy tax withholding obligations with respect to the disqualifying 
disposition of an Incentive Stock Option. The Optionee shall satisfy his or 
her tax withholding obligation arising upon the exercise of this Option by 
one or some combination of the following methods: (i) by cash payment, or 
(ii) out of Optionee's current compensation, or (iii) if permitted by the 
Administrator, in its discretion, by surrendering to the Company Shares which 
(a) in the case of Shares previously acquired from the Company, have been 
owned by the Optionee for more than six months on the date of surrender, and 
(b) have a fair market value on the date of surrender equal to or less than 
Optionee's marginal tax rate times the ordinary income recognized, (iv) by 
electing to have the Company withhold from the Shares to be issued upon 
exercise of the Option that number of Shares having a fair market value equal 
to the amount required to be withheld.  For this purpose, the fair market 
value of the Shares to be withheld shall be determined on the date that the 
amount of tax to be withheld is to be determined (the "Tax Date").  

     If the Optionee is subject to Section 16 of the Exchange Act (an 
"Insider"), any surrender of previously owned Shares to satisfy tax 
withholding obligations arising upon exercise of this Option must comply with 
the applicable provisions of Rule 16b-3 promulgated under the Exchange Act 
("Rule 16b-3") and shall be subject to such additional conditions or 
restrictions as may be required thereunder to qualify for the maximum 
exemption from Section 16 of the Exchange Act with respect to Plan 
transactions.

                                       4

<PAGE>

     All elections by an Optionee to have Shares withheld to satisfy tax 
withholding obligations shall be made in writing in a form acceptable to the 
Administrator and shall be subject to the following restrictions:

          (i) the election must be made on or prior to the applicable Tax Date;

          (ii) once made, the election shall be irrevocable as to the 
particular Shares of the Option as to which the election is made;

          (iii) all elections shall be subject to the consent or disapproval 
of the Administrator;

          (iv) if the Optionee is an Insider, the election must comply with 
the applicable provisions of Rule 16b-3 and shall be subject to such 
additional conditions or restrictions as may be required thereunder to 
qualify for the maximum exemption from Section 16 of the Exchange Act with 
respect to Plan transactions.

     12.  TAX CONSEQUENCES.  Optionee acknowledges that he or she has read 
the brief summary set forth below of certain federal tax consequences of 
exercise of this Option and disposition of the Shares under the law in effect 
as of the date of grant.  THIS SUMMARY IS NECESSARILY INCOMPLETE, AND THE TAX 
LAWS AND REGULATIONS ARE SUBJECT TO CHANGE.  OPTIONEE SHOULD CONSULT HIS OR 
HER OWN TAX ADVISER BEFORE EXERCISING THIS OPTION OR DISPOSING OF THE SHARES.

          (i)  EXERCISE OF ISO.  If this Option qualifies as an ISO, there 
will be no regular federal income tax liability upon the exercise of the 
Option, although the excess, if any, of the fair market value of the Shares 
on the date of exercise over the Exercise Price will be treated as an item of 
the alternative minimum taxable income for federal tax purposes and may 
subject the Optionee to the alternative minimum tax in the year of exercise.

          (ii) EXERCISE OF NONSTATUTORY STOCK OPTION.  If this Option does 
not qualify as an ISO, Optionee may incur regular federal income tax 
liability upon the exercise of the Option.  The Optionee will be treated as 
having received compensation income (taxable at ordinary income tax rates) 
equal to the excess, if any, of the fair market value of the Shares on the 
date of exercise over the Exercise Price.  If Optionee is an employee of the 
Company, the Company will be required to withhold from Optionee's 
compensation or collect from Optionee and pay to the applicable taxing 
authorities an amount equal to a percentage of this compensation income at 
the time of exercise.

          (iii) DISPOSITION OF SHARES.  If this Option is an Incentive Stock 
Option and if Shares transferred pursuant to the Option are held for more 
than one year after exercise and more than two years after the grant date, 
any gain realized on disposition of the Shares will be treated as long-term 
capital gain for federal income tax purposes.  If Shares purchased under an 
ISO are disposed of before the end of either of such two holding periods, 
then any gain realized on such disposition will be treated as compensation 
income (taxable at ordinary income rates) to the 

                                       5

<PAGE>

extent of the excess, if any, of the lesser of (i) the fair market value of 
the Shares on the date of exercise, or (ii) the sales price over the Exercise 
Price.  If this Option is a Nonstatutory Stock Option, then gain realized on 
the disposition of Shares will be treated as long-term or short-term capital 
gain depending on whether or not the disposition occurs more than one year 
after the exercise date.

          (iv) NOTICE OF DISQUALIFYING DISPOSITION OF ISO SHARES.  If the 
Option granted to Optionee herein is an ISO, and if Optionee sells or 
otherwise disposes of any of the Shares acquired pursuant to the ISO on or 
before the later of (1) the date two years after the Date of Grant, or (2) 
the date one year after transfer of such Shares to Optionee upon exercise of 
the Incentive Stock Option,  the Optionee shall notify the Company in writing 
within thirty (30) days after the date of such disposition.  Optionee agrees 
that Optionee may be subject to income tax withholding by the Company on the 
compensation income recognized by the Optionee from the early disposition by 
payment in cash or out of the current earnings paid to the Optionee.

     13.  NO ADDITIONAL EMPLOYMENT RIGHTS.  OPTIONEE ACKNOWLEDGES AND AGREES 
THAT THE VESTING OF SHARES PURSUANT TO THE OPTION HEREOF IS EARNED ONLY BY 
CONTINUING CONSULTANCY OR EMPLOYMENT AT THE WILL OF THE COMPANY (NOT THROUGH 
THE ACT OF BEING HIRED, BEING GRANTED THIS OPTION OR ACQUIRING SHARES 
HEREUNDER). OPTIONEE FURTHER ACKNOWLEDGES AND AGREES THAT NOTHING IN THIS 
AGREEMENT, NOR IN THE COMPANY'S STOCK PLAN WHICH IS INCORPORATED HEREIN BY 
REFERENCE, SHALL CONFER UPON OPTIONEE ANY RIGHT WITH RESPECT TO CONTINUATION 
OF EMPLOYMENT OR CONSULTANCY BY THE COMPANY, NOR SHALL IT INTERFERE IN ANY 
WAY WITH HIS OR HER RIGHT OR THE COMPANY'S RIGHT TO TERMINATE HIS OR HER 
EMPLOYMENT OR CONSULTANCY AT ANY TIME, WITH OR WITHOUT CAUSE.

     Optionee acknowledges receipt of a copy of the Plan and represents that 
he or she is familiar with the terms and provisions thereof, and hereby 
accepts this Option subject to all of the terms and provisions thereof.  
Optionee has reviewed the Plan and this Option in their entirety, has had an 
opportunity to obtain the advice of counsel prior to executing this Option 
and fully understands all provisions of the Option.  Optionee hereby agrees 
to accept as binding, conclusive and final all decisions or interpretations 
of the Administrator upon any questions arising under the Plan or this Option.

     14.  SIGNATURE.  This Agreement shall be deemed executed by the Company 
and Optionee upon execution by such parties of the Notice of Grant attached 
to this Agreement.

                                       6