Document:

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                                                                     EXHIBIT 4.2

                             VINA TECHNOLOGIES, INC.

             FOURTH AMENDED AND RESTATED INVESTORS' RIGHTS AGREEMENT

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

                                JANUARY 31, 2000

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                                TABLE OF CONTENTS

<TABLE>
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                                                                            PAGE
<S> <C>                                                                     <C>
1.  Termination of Prior Agreement............................................1

2.  Registration Rights.......................................................1
        2.1  Definitions......................................................1
        2.2  Request for Registration.........................................2
        2.3  Company Registration.............................................4
        2.4  Obligations of the Company.......................................4
        2.5  Furnish Information..............................................6
        2.6  Expenses of Demand Registration..................................6
        2.7  Expenses of Company Registration.................................6
        2.8  Underwriting Requirements........................................7
        2.9  Delay of Registration............................................7
        2.10  Indemnification.................................................7
        2.11  Reports Under Securities Exchange Act of 1934..................10
        2.12  Form S-3 Registration..........................................10
        2.13  Assignment of Registration Rights..............................11
        2.14  Limitations on Subsequent Registration Rights..................11
        2.15  "Market Stand-Off" Agreement...................................12
        2.16  Termination of Registration Rights.............................12

3.  Covenants of the Company.................................................13
        3.1  Delivery of Financial Statements................................13
        3.2  Inspection......................................................14
        3.3  Termination of Information and Inspection Covenants.............14
        3.4  Right of First Offer............................................14

4.  Miscellaneous............................................................16
        4.1  Successors and Assigns..........................................16
        4.2  Governing Law...................................................16
        4.3  Counterparts....................................................16
        4.4  Titles and Subtitles............................................16
        4.5  Notices.........................................................16
        4.6  Expenses........................................................16
        4.7  Amendments and Waivers..........................................16
        4.8  Severability....................................................16
        4.9  Aggregation of Stock............................................17
        4.10  Entire Agreement; Amendment; Waiver............................17
        4.11  Additional Parties.............................................17
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Schedule A Schedule of Investors

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                           INVESTORS' RIGHTS AGREEMENT

        THIS INVESTORS' RIGHTS AGREEMENT is made as of the 31st day of January,
2000, by and between Vina Technologies, Inc., a California corporation (the
"Company"), and the investors listed on Schedule A hereto (the "Investors," each
of which is herein referred to as an "Investor").

                                    RECITALS

        WHEREAS, the Company and certain of the Investors are parties to the
Third Amended and Restated Investors' Rights Agreement, dated October 23, 1998
(the "Prior Agreement");

        WHEREAS, the Company and certain of the Investors are parties to the
Series E Preferred Stock Purchase Agreement of even date herewith (the "Series E
Agreement");

        WHEREAS, in order to induce the Company to enter into the Series E
Agreement and to induce certain of the Investors to invest funds in the Company
pursuant to the Series E Agreement, the Investors and the Company hereby agree
that this Agreement shall govern the rights of the Investors to cause the
Company to register shares of Common Stock issuable to the Investors and certain
other matters as set forth herein;

        NOW, THEREFORE, THE PARTIES HEREBY AGREE AS FOLLOWS:

        1. Termination of Prior Agreement. The parties to the Prior Agreement
(all of whom are parties to this Agreement) hereby agree that the Prior
Agreement is hereby terminated and of no further force and effect.

        2. Registration Rights. The Company covenants and agrees as follows:

            2.1 Definitions. For purposes of this Section 2:

                (a) The term "Act" means the Securities Act of 1933, as amended.

                (b) The term "Form S-3" means such form under the Act as in
effect on the date hereof or any registration form under the Act subsequently
adopted by the SEC which permits inclusion or incorporation of substantial
information by reference to other documents filed by the Company with the SEC.

                (c) The term "Holder" means any person owning or having the
right to acquire Registrable Securities or any assignee thereof in accordance
with Section 2.13 hereof.

                (d) The term "1934 Act" shall mean the Securities Exchange Act
of 1934, as amended.

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                (e) The term "register", "registered," and "registration" refer
to a registration effected by preparing and filing a registration statement or
similar document in compliance with the Act, and the declaration or ordering of
effectiveness of such registration statement or document.

                (f) The term "Registrable Securities" means (i) the Common Stock
issuable or issued upon conversion of the Series A Preferred Stock of the
Company sold pursuant to the Series A Preferred Stock Purchase Agreement, dated
August 1, 1996, between the Company and the Investors listed on Schedule A
therein (the "Series A Agreement"), (ii) the Common Stock issuable or issued
upon conversion of the Series B Preferred Stock of the Company sold pursuant to
the Series B Preferred Stock Purchase Agreement, dated December 23, 1996, as
amended, between the Company and the Investors listed on Schedule A therein (the
"Series B Agreement"), (iii) the Common Stock issuable or issued upon the
conversion of the Series C Preferred Stock of the Company sold pursuant to the
Series C Preferred Stock Purchase Agreement, dated March 3, 1998, as amended,
between the Company and the Investors listed on Schedule A therein (the "Series
C Agreement"), (iv) the Common Stock of the Company issuable or issued upon the
conversion of Series D Preferred Stock of the Company sold pursuant to the
Series D Agreement, (v) the Common Stock of the Company issuable or issued upon
the conversion of Series E Preferred Stock of the Company sold pursuant to the
Series E Agreement, and (vi) any Common Stock of the Company issued as (or
issuable upon the conversion or exercise of any warrant, right or other security
which is issued as) a dividend or other distribution with respect to, or in
exchange for or in replacement of the shares referenced in (i), (ii), (iii),
(iv) and (v) above, excluding in all cases, however, any Registrable Securities
sold by a person in a transaction in which his rights under this Section 2 are
not assigned.

                (g) The number of shares of "Registrable Securities then
outstanding" shall be determined by the number of shares of Common Stock
outstanding which are, and the number of shares of Common Stock issuable
pursuant to then exercisable or convertible securities which are, Registrable
Securities.

                (h) The term "SEC" shall mean the Securities and Exchange
Commission.

            2.2 Request for Registration.

                (a) If the Company shall receive at any time after the earlier
of (i) March 3, 2002, or (ii) six (6) months after the effective date of the
first registration statement for a public offering of securities of the Company
(other than a registration statement relating either to the sale of securities
to employees of the Company pursuant to a stock option, stock purchase or
similar plan or a SEC Rule 145 transaction), a written request from the Holders
of at least thirty percent (30%) of the Registrable Securities then outstanding
that the Company file a registration statement under the Act covering the
registration of Registrable Securities with anticipated aggregate offering
price, net of underwriting discounts and commissions, in excess of $10,000,000,
then the Company shall:

                    (i) within ten (10) days of the receipt thereof, give
written notice of such request to all Holders; and

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                    (ii) effect as soon as practicable, and in any event within
60 days of the receipt of such request, the registration under the Act of all
Registrable Securities which the Holders request to be registered, subject to
the limitations of subsection 2.2(b), within twenty (20) days of the mailing of
such notice by the Company in accordance with Section 4.5.

                (b) If the Holders initiating the registration request hereunder
("Initiating Holders") intend to distribute the Registrable Securities covered
by their request by means of an underwriting, they shall so advise the Company
as a part of their request made pursuant to subsection 2.2(a) and the Company
shall include such information in the written notice referred to in subsection
2.2(a). The underwriter will be selected by the Company and shall be reasonably
acceptable to a majority in interest of the Initiating Holders. In such event,
the right of any Holder to include his Registrable Securities in such
registration shall be conditioned upon such Holder's participation in such
underwriting and the inclusion of such Holder's Registrable Securities in the
underwriting (unless otherwise mutually agreed by a majority in interest of the
Initiating Holders and such Holder) to the extent provided herein. All Holders
proposing to distribute their securities through such underwriting shall
(together with the Company as provided in subsection 2.4(e)) enter into an
underwriting agreement in customary form with the underwriter or underwriters
selected for such underwriting. Notwithstanding any other provision of this
Section 2.2, if the underwriter advises the Initiating Holders in writing that
marketing factors require a limitation of the number of shares to be
underwritten, then the Initiating Holders shall so advise all Holders of
Registrable Securities which would otherwise be underwritten pursuant hereto,
and the number of shares of Registrable Securities that may be included in the
underwriting shall be allocated among all Holders thereof that have requested
such registration, including the Initiating Holders, in proportion (as nearly as
practicable) to the amount of Registrable Securities of the Company owned by
each such Holder; provided, however, that the number of shares of Registrable
Securities to be included in such underwriting shall not be reduced unless all
other securities are first entirely excluded from the underwriting.

                (c) Notwithstanding the foregoing, if the Company shall furnish
to Holders requesting a registration statement pursuant to this Section 2.2, a
certificate signed by the Chief Executive Officer of the Company stating that in
the good faith judgment of the Board of Directors of the Company, it would be
seriously detrimental to the Company and its shareholders for such registration
statement to be filed and it is therefore essential to defer the filing of such
registration statement, the Company shall have the right to defer taking action
with respect to such filing for a period of not more than 120 days after receipt
of the request of the Initiating Holders; provided, however, that the Company
may not utilize this right more than once in any twelve-month period.

                (d) In addition, the Company shall not be obligated to effect,
or to take any action to effect, any registration pursuant to this Section 2.2:

                    (i) After the Company has effected two registrations
pursuant to this Section 2.2 and such registrations have been declared or
ordered effective;

                    (ii) During the period starting with the date sixty (60)
days prior to the Company's good faith estimate of the date of filing of, and
ending on a date one

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hundred eighty (180) days after the effective date of, a registration subject to
Section 2.3 hereof; provided that the Company is actively employing in good
faith all reasonable efforts to cause such registration statement to become
effective; or

                    (iii) If the Initiating Holders propose to dispose of shares
of Registrable Securities that may be immediately registered on Form S-3
pursuant to a request made pursuant to Section 2.12 below.

            2.3 Company Registration. If (but without any obligation to do so)
the Company proposes to register (including for this purpose a registration
effected by the Company for shareholders other than the Holders) any of its
stock or other securities under the Act in connection with the public offering
of such securities solely for cash (other than a registration relating solely to
the sale of securities to participants in a Company stock plan, a registration
on any form which does not include substantially the same information as would
be required to be included in a registration statement covering the sale of the
Registrable Securities or a registration in which the only Common Stock being
registered is Common Stock issuable upon conversion of debt securities which are
also being registered), the Company shall, at such time, promptly give each
Holder written notice of such registration and such notice shall set forth the
basic terms of the proposed registration. Upon the written request of each
Holder given within twenty (20) days after mailing of such notice by the Company
in accordance with Section 4.5, the Company shall, subject to the provisions of
Section 2.8, cause to be registered under the Act all of the Registrable
Securities that each such Holder has requested to be registered.

            2.4 Obligations of the Company. Whenever required under this Section
2 to effect the registration of any Registrable Securities, the Company shall,
as expeditiously as is reasonably possible:

                (a) Prepare and file with the SEC a registration statement with
respect to such Registrable Securities and use its best efforts to cause such
registration statement to become effective, and, upon the request of the Holders
of a majority of the Registrable Securities registered thereunder, keep such
registration statement effective for a period of up to one hundred twenty (120)
days or until the distribution contemplated in the Registration Statement has
been completed; provided, however, that (i) such 120-day period shall be
extended for a period of time equal to the period the Holder refrains from
selling any securities included in such registration at the request of an
underwriter of Common Stock (or other securities) of the Company; and (ii) in
the case of any registration of Registrable Securities on Form S-3 which are
intended to be offered on a continuous or delayed basis, such 120-day period
shall be extended, if necessary, to keep the registration statement effective
until all such Registrable Securities are sold, provided that Rule 415, or any
successor rule under the Act, permits an offering on a continuous or delayed
basis, and provided further that applicable rules under the Act governing the
obligation to file a post-effective amendment permit, in lieu of filing a
post-effective amendment which (I) includes any prospectus required by Section
10(a)(3) of the Act or (II) reflects facts or events representing a material or
fundamental change in the information set forth in the registration statement,
the incorporation by reference of information required to be included in (I) and
(II) above to be contained in periodic reports filed pursuant to Section 13 or
15(d) of the 1934 Act in the registration statement.

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                (b) Prepare and file with the SEC such amendments and
supplements to such registration statement and the prospectus used in connection
with such registration statement as may be necessary to comply with the
provisions of the Act with respect to the disposition of all securities covered
by such registration statement.

                (c) Furnish to the Holders such numbers of copies of a
prospectus, including a preliminary prospectus, in conformity with the
requirements of the Act, and such other documents as they may reasonably request
in order to facilitate the disposition of Registrable Securities owned by them.

                (d) Use its best efforts to register and qualify the securities
covered by such registration statement under such other securities or Blue Sky
laws of such jurisdictions as shall be reasonably requested by the Holders;
provided that the Company shall not be required in connection therewith or as a
condition thereto to qualify to do business or to file a general consent to
service of process in any such states or jurisdictions, unless the Company is
already subject to service in such jurisdiction and except as may be required by
the Act.

                (e) In the event of any underwritten public offering, enter into
and perform its obligations under an underwriting agreement, in usual and
customary form, with the managing underwriter of such offering. Each Holder
participating in such underwriting shall also enter into and perform its
obligations under such an agreement.

                (f) Notify each Holder of Registrable Securities covered by such
registration statement at any time when a prospectus relating thereto is
required to be delivered under the Act of the happening of any event as a result
of which the prospectus included in such registration statement, as then in
effect, includes an untrue statement of a material fact or omits to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.

                (g) Cause all such Registrable Securities registered pursuant
hereunder to be listed on each securities exchange on which similar securities
issued by the Company are then listed.

                (h) Provide a transfer agent and registrar for all Registrable
Securities registered pursuant hereunder and a CUSIP number for all such
Registrable Securities, in each case not later than the effective date of such
registration.

                (i) Use its best efforts to furnish, at the request of any
Holder requesting registration of Registrable Securities pursuant to this
Section 2, on the date that such Registrable Securities are delivered to the
underwriters for sale in connection with a registration pursuant to this Section
2, if such securities are being sold through underwriters, or, if such
securities are not being sold through underwriters, on the date that the
registration statement with respect to such securities becomes effective, (i) an
opinion, dated such date, of the counsel representing the Company for the
purposes of such registration, in form and substance as is customarily given to
underwriters in an underwritten public offering, addressed to the underwriters,
if any, and to the Holders requesting registration of Registrable Securities and
(ii) a

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letter dated such date, from the independent certified public accountants of the
Company, in form and substance as is customarily given by independent certified
public accountants to underwriters in an underwritten public offering, addressed
to the underwriters, if any, and to the Holders requesting registration of
Registrable Securities.

            2.5 Furnish Information.

                (a) It shall be a condition precedent to the obligations of the
Company to take any action pursuant to this Section 2 with respect to the
Registrable Securities of any selling Holder that such Holder shall furnish to
the Company such information regarding itself, the Registrable Securities held
by it, and the intended method of disposition of such securities as shall be
required to effect the registration of such Holder's Registrable Securities.

                (b) The Company shall have no obligation with respect to any
registration requested pursuant to Section 2.2 or Section 2.12 if, the number of
shares or the anticipated aggregate offering price of the Registrable Securities
to be included in the registration does not equal or exceed the number of shares
or the anticipated aggregate offering price required to originally trigger the
Company's obligation to initiate such registration as specified in subsection
2.2(a) or subsection 2.12(b)(2), whichever is applicable.

            2.6 Expenses of Demand Registration. All expenses other than
underwriting discounts and commissions incurred in connection with
registrations, filings or qualifications pursuant to Section 2.2, including
(without limitation) all registration, filing and qualification fees, printers'
and accounting fees, fees and disbursements of counsel for the Company
(including fees and disbursements of counsel for the Company in its capacity as
counsel to the selling Holders hereunder; if Company counsel does not make
itself available for this purpose, the Company will pay the reasonable fees and
disbursements of one counsel for the selling Holders) shall be borne by the
Company; provided, however, that the Company shall not be required to pay for
any expenses of any registration proceeding begun pursuant to Section 2.2 if the
registration request is subsequently withdrawn at the request of the Holders of
a majority of the Registrable Securities to be registered (in which case all
participating holders shall bear such expenses), unless the Holders of a
majority of the Registrable Securities agree to forfeit their right to one
demand registration pursuant to Section 2.2; provided further, however, that if
at the time of such withdrawal, the Holders have learned of a material adverse
change in the condition, business, or prospects of the Company from that known
to the Holders at the time of their request and have withdrawn the request with
reasonable promptness following disclosure by the Company of such material
adverse change, then the Holders shall not be required to pay any of such
expenses and shall retain their rights pursuant to Section 2.2.

            2.7 Expenses of Company Registration. The Company shall bear and pay
all expenses incurred in connection with any registration, filing or
qualification of Registrable Securities with respect to the registrations
pursuant to Section 2.3 for each Holder (which right may be assigned as provided
in Section 2.13), including (without limitation) all registration, filing, and
qualification fees, printers and accounting fees relating or apportionable
thereto and the fees and disbursements of counsel for the Company in its
capacity as counsel to the selling Holders hereunder; if Company counsel does
not make itself available for this purpose, the Company will pay the reasonable
fees and disbursements of one counsel for the

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selling Holders selected by them, but excluding underwriting discounts and
commissions relating to Registrable Securities.

            2.8 Underwriting Requirements. In connection with any offering
involving an underwriting of shares of the Company's capital stock, the Company
shall not be required under Section 2.3 to include any of the Holders'
securities in such underwriting unless they accept the terms of the underwriting
as agreed upon between the Company and the underwriters selected by it (or by
other persons entitled to select the underwriters), and then only in such
quantity as the underwriters determine in their sole discretion will not
jeopardize the success of the offering by the Company. If the total amount of
securities, including Registrable Securities, requested by shareholders to be
included in such offering exceeds the amount of securities sold other than by
the Company that the underwriters determine in their sole discretion is
compatible with the success of the offering, then the Company shall be required
to include in the offering only that number of such securities, including
Registrable Securities, which the underwriters determine in their sole
discretion will not jeopardize the success of the offering (the securities so
included to be apportioned pro rata among the selling shareholders according to
the total amount of securities entitled to be included therein owned by each
selling shareholder or in such other proportions as shall mutually be agreed to
by such selling shareholders) but in no event shall (i) the amount of securities
of the selling Holders included in the offering be reduced below thirty percent
(30%) of the total amount of securities included in such offering, unless such
offering is the initial public offering of the Company's securities in which
case the selling shareholders may be excluded if the underwriters make the
determination described above and no other shareholder's securities are included
or (ii) notwithstanding (i) above, any shares being sold by a shareholder
exercising a demand registration right similar to that granted in Section 2.2 be
excluded from such offering. For purposes of the preceding parenthetical
concerning apportionment, for any selling shareholder which is a holder of
Registrable Securities and which is a partnership or corporation, the partners,
retired partners and shareholders of such holder, or the estates and family
members of any such partners and retired partners and any trusts for the benefit
of any of the foregoing persons shall be deemed to be a single "selling
shareholder", and any pro-rata reduction with respect to such "selling
shareholder" shall be based upon the aggregate amount of shares carrying
registration rights owned by all entities and individuals included in such
"selling shareholder", as defined in this sentence.

            2.9 Delay of Registration. No Holder shall have any right to obtain
or seek an injunction restraining or otherwise delaying any such registration as
the result of any controversy that might arise with respect to the
interpretation or implementation of this Section 2.

            2.10 Indemnification. In the event any Registrable Securities are
included in a registration statement under this Section 2:

                (a) To the extent permitted by law, the Company will indemnify
and hold harmless each Holder, the executive officers, directors and partners of
each Holder, any underwriter (as defined in the Act) for such Holder and each
person, if any, who controls such Holder or underwriter within the meaning of
the Act or the 1934 Act, against any losses, claims, damages, or liabilities
(joint or several) to which they may become subject under the Act, or the 1934
Act or other federal or state law or otherwise, insofar as such losses, claims,

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damages, or liabilities (or actions in respect thereof) arise out of or are
based upon any of the following statements, omissions or violations
(collectively a "Violation"): (i) any untrue statement or alleged untrue
statement of a material fact contained in such registration statement, including
any preliminary prospectus or final prospectus contained therein or any
amendments or supplements thereto, (ii) the omission or alleged omission to
state therein a material fact required to be stated therein, or necessary to
make the statements therein not misleading, or (iii) any violation or alleged
violation by the Company of the Act, the 1934 Act, any state securities law or
any rule or regulation promulgated under the Act, or the 1934 Act or any state
securities law; and the Company will pay to each such Holder, underwriter or
controlling person, as incurred, any legal or other expenses reasonably incurred
by them in connection with investigating or defending any such loss, claim,
damage, liability, or action; provided, however, that the indemnity agreement
contained in this subsection 2.10(a) shall not apply to amounts paid in
settlement of any such loss, claim, damage, liability, or action if such
settlement is effected without the consent of the Company (which consent shall
not be unreasonably withheld), nor shall the Company be liable in any such case
for any such loss, claim, damage, liability, or action to the extent that it
arises out of or is based upon a Violation which occurs in reliance upon and in
conformity with written information furnished expressly for use in connection
with such registration by any such Holder, underwriter or controlling person.
Except as set forth herein, the indemnified party and any party cooperating in
the defense of such claim shall not settle or compromise any such claim or admit
liability without the express written consent of the indemnifying party. The
indemnified party shall have the right to be represented by an advisory counsel
and accountants, at its own expense, and the indemnified party shall be kept
fully informed of such action, suit or proceeding at all stages thereof whether
or not the indemnified party is so represented. After a period of thirty days
following the date the written notice of such claim was given to the
indemnifying party the indemnified party may settle any such claim (and the
amount of any such settlement shall be subject to indemnification hereunder)
unless within such thirty-day period the indemnifying party shall have provided
the indemnified party with notice and evidence to the indemnified party's
satisfaction that the indemnifying party reasonably disputes such claim and has
the financial ability to meet its indemnification obligations hereunder.
Notwithstanding the foregoing, the indemnified party may immediately cause to be
paid or discharged any asserted claim the non-payment of which would have an
immediate substantial adverse impact on the indemnified party and any claim
which the indemnifying party has not disputed within thirty days of notice as
provided above.

                (b) To the extent permitted by law, each selling Holder will
indemnify and hold harmless the Company, each of its directors, each of its
officers who has signed the registration statement, each person, if any, who
controls the Company within the meaning of the Act, any underwriter, any other
Holder selling securities in such registration statement and any controlling
person of any such underwriter or other Holder, against any losses, claims,
damages, or liabilities (joint or several) to which any of the foregoing persons
may become subject, under the Act, or the 1934 Act or other federal or state law
or otherwise, insofar as such losses, claims, damages, or liabilities (or
actions in respect thereto) arise out of or are based upon any Violation, in
each case to the extent (and only to the extent) that such Violation occurs in
reliance upon and in conformity with written information furnished by such
Holder expressly for use in connection with such registration; and each such
Holder will pay, as incurred, any legal or other expenses reasonably incurred by
any person intended to be indemnified pursuant to this subsection 2.10(b), in
connection with investigating or defending

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any such loss, claim, damage, liability, or action; provided, however, that the
indemnity agreement contained in this subsection 2.10(b) shall not apply to
amounts paid in settlement of any such loss, claim, damage, liability or action
if such settlement is effected without the consent of the Holder, which consent
shall not be unreasonably withheld; provided, that, in no event shall any
indemnity under this subsection 2.10(b) exceed the gross proceeds from the
offering received by such Holder.

                (c) Promptly after receipt by an indemnified party under this
Section 2.10 of notice of the commencement of any action (including any
governmental action), such indemnified party will, if a claim in respect thereof
is to be made against any indemnifying party under this Section 2.10, deliver to
the indemnifying party a written notice of the commencement thereof and the
indemnifying party shall have the right to participate in, and, to the extent
the indemnifying party so desires, jointly with any other indemnifying party
similarly noticed, to assume the defense thereof with counsel mutually
satisfactory to the parties; provided, however, that an indemnified party
(together with all other indemnified parties which may be represented without
conflict by one counsel) shall have the right to retain one separate counsel,
with the fees and expenses to be paid by the indemnifying party, if
representation of such indemnified party by the counsel retained by the
indemnifying party would be inappropriate due to actual or potential differing
interests between such indemnified party and any other party represented by such
counsel in such proceeding. The failure to deliver written notice to the
indemnifying party within a reasonable time of the commencement of any such
action, if prejudicial to its ability to defend such action, shall relieve such
indemnifying party of any liability to the indemnified party under this Section
2.10, but the omission so to deliver written notice to the indemnifying party
will not relieve it of any liability that it may have to any indemnified party
otherwise than under this Section 2.10.

                (d) If the indemnification provided for in this Section 2.10 is
held by a court of competent jurisdiction to be unavailable to an indemnified
party with respect to any loss, liability, claim, damage, or expense referred to
therein, then the indemnifying party, in lieu of indemnifying such indemnified
party hereunder, shall contribute to the amount paid or payable by such
indemnified party as a result of such loss, liability, claim, damage, or expense
in such proportion as is appropriate to reflect the relative fault of the
indemnifying party on the one hand and of the indemnified party on the other in
connection with the statements or omissions that resulted in such loss,
liability, claim, damage, or expense as well as any other relevant equitable
considerations. The relative fault of the indemnifying party and of the
indemnified party shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission to state a material fact relates to information supplied by the
indemnifying party or by the indemnified party and the parties' relative intent,
knowledge, access to information, and opportunity to correct or prevent such
statement or omission.

                (e) Notwithstanding the foregoing, to the extent that the
provisions on indemnification and contribution contained in the underwriting
agreement entered into in connection with the underwritten public offering are
in conflict with the foregoing provisions, the provisions in the underwriting
agreement shall control.

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                (f) The obligations of the Company and Holders under this
Section 2.10 shall survive the completion of any offering of Registrable
Securities in a registration statement under this Section 2, and otherwise.

                (g) The rights of indemnification contained in this Section 2
shall not be deemed to be the exclusive remedy of the parties hereto and such
rights shall be in addition to any other rights or remedies which any party
hereto may have at law or equity.

            2.11 Reports Under Securities Exchange Act of 1934. With a view to
making available to the Holders the benefits of Rule 144 promulgated under the
Act ("Rule 144") and any other rule or regulation of the SEC that may at any
time permit a Holder to sell securities of the Company to the public without
registration or pursuant to a registration on Form S-3, the Company agrees to:

                (a) make and keep public information available, as those terms
are understood and defined in Rule 144, at all times after ninety (90) days
after the effective date of the first registration statement filed by the
Company for the offering of its securities to the general public;

                (b) take such action, including the voluntary registration of
its Common Stock under Section 12 of the 1934 Act, as is necessary to enable the
Holders to utilize Form S-3 for the sale of their Registrable Securities, such
action to be taken concurrently with the first registration statement filed by
the Company for the offering of its securities to the general public is declared
effective;

                (c) file with the SEC in a timely manner all reports and other
documents required of the Company under the Act and the 1934 Act; and

                (d) furnish to any Holder, so long as the Holder owns any
Registrable Securities, forthwith upon request (i) a written statement by the
Company that it has complied with the reporting requirements of Rule 144 (at any
time after ninety (90) days after the effective date of the first registration
statement filed by the Company), the Act and the 1934 Act (at any time after it
has become subject to such reporting requirements), or that it qualifies as a
registrant whose securities may be resold pursuant to Form S-3 (at any time
after it so qualifies), (ii) a copy of the most recent annual or quarterly
report of the Company and such other reports and documents so filed by the
Company, and (iii) such other information as may be reasonably requested in
availing any Holder of any rule or regulation of the SEC which permits the
selling of any such securities without registration or pursuant to such form.

            2.12 Form S-3 Registration. In case the Company shall receive from
any Holder or Holders of at least twenty percent (20%) of the Registrable
Securities then outstanding a written request or requests that the Company
effect a registration on Form S-3 and any related qualification or compliance
with respect to all or a part of the Registrable Securities owned by such Holder
or Holders, the Company will:

                (a) promptly give written notice of the proposed registration,
and any related qualification or compliance, to all other Holders; and

                                       10
<PAGE>   13

                (b) as soon as practicable, effect such registration and all
such qualifications and compliances as may be so requested and as would permit
or facilitate the sale and distribution of all or such portion of such Holder's
or Holders' Registrable Securities as are specified in such request, together
with all or such portion of the Registrable Securities of any other Holder or
Holders joining in such request as are specified in a written request given
within 15 days after receipt of such written notice from the Company; provided,
however, that the Company shall not be obligated to effect any such
registration, qualification or compliance, pursuant to this Section 2.12: (1) if
Form S-3 is not available for such offering by the Holders; (2) if the Holders,
together with the holders of any other securities of the Company entitled to
inclusion in such registration, propose to sell Registrable Securities and such
other securities (if any) at an aggregate price to the public (net of any
underwriters' discounts or commissions) of less than $1,000,000; (3) if the
Company shall furnish to the Holders a certificate signed by the President of
the Company stating that in the good faith judgment of the Board of Directors of
the Company, it would be seriously detrimental to the Company and its
shareholders for such Form S-3 Registration to be effected at such time, in
which event the Company shall have the right to defer the filing of the Form S-3
registration statement for a period of not more than 60 days after receipt of
the request of the Holder or Holders under this Section 2.12; provided, however,
that the Company shall not utilize this right more than once in any twelve month
period; (4) if the Company has, within the twelve (12) month period preceding
the date of such request, already effected two registrations on Form S-3 for the
Holders pursuant to this Section 2.12; or (5) in any particular jurisdiction in
which the Company would be required to qualify to do business or to execute a
general consent to service of process in effecting such registration,
qualification or compliance.

                (c) Subject to the foregoing, the Company shall file a
registration statement covering the Registrable Securities and other securities
so requested to be registered as soon as practicable after receipt of the
request or requests of the Holders. All expenses incurred in connection with a
registration requested pursuant to Section 2.12, including (without limitation)
all registration, filing, qualification, printer's and accounting fees and the
reasonable fees and disbursements of counsel for the Company, but excluding any
underwriters' discounts or commissions associated with Registrable Securities,
shall be borne by the Company. Registrations effected pursuant to this Section
2.12 shall not be counted as demands for registration or registrations effected
pursuant to Sections 2.2 or 2.3, respectively.

            2.13 Assignment of Registration Rights. The rights to cause the
Company to register Registrable Securities pursuant to this Section 2 may be
assigned (but only with all related obligations) by a Holder to a transferee or
assignee of such securities, provided: (a) the Company is, within a reasonable
time after such transfer, furnished with written notice of the name and address
of such transferee or assignee and the securities with respect to which such
registration rights are being assigned; (b) such transferee or assignee agrees
in writing to be bound by and subject to the terms and conditions of this
Agreement, including without limitation the provisions of Section 2.15 below;
and (c) such assignment shall be effective only if immediately following such
transfer the further disposition of such securities by the transferee or
assignee is restricted under the Act.

            2.14 Limitations on Subsequent Registration Rights. From and after
the date of this Agreement, the Company shall not, without the prior written
consent of the Holders

                                       11
<PAGE>   14

of a majority of the outstanding Registrable Securities, enter into any
agreement with any holder or prospective holder of any securities of the Company
which would allow such holder or prospective holder (a) to include such
securities in any registration filed under Section 2.2 hereof, unless under the
terms of such agreement, such holder or prospective holder may include such
securities in any such registration only to the extent that the inclusion of his
securities will not reduce the amount of the Registrable Securities of the
Holders which is included or (b) to make a demand registration which could
result in such registration statement being declared effective prior to the
earlier of either of the dates set forth in subsection 2.2(a) or within one
hundred twenty (120) days of the effective date of any registration effected
pursuant to Section 2.2.

            2.15 "Market Stand-Off" Agreement. Each Investor hereby agrees that,
during the period of duration specified by the Company and an underwriter of
Common Stock or other securities of the Company, following the date of the first
sale to the public pursuant to a registration statement of the Company filed
under the Act, it shall not, to the extent requested by the Company and such
underwriter, directly or indirectly sell, offer to sell, contract to sell
(including, without limitation, any short sale), grant any option to purchase or
otherwise transfer or dispose of (other than to donees who agree to be similarly
bound) any securities of the Company held by it at any time during such period
except Common Stock included in such registration; provided, however, that:

                (a) such agreement shall be applicable only to the first such
registration statement of the Company which covers Common Stock (or other
securities) to be sold on its behalf to the public in an underwritten offering;
and

                (b) all officers and directors of the Company and all other
persons with registration rights (whether or not pursuant to this Agreement)
enter into similar agreements; and

                (c) such market stand-off time period shall not exceed 180 days.

        In order to enforce the foregoing covenant, the Company may impose
stop-transfer instructions with respect to the Registrable Securities of each
Investor (and the shares or securities of every other person subject to the
foregoing restriction) until the end of such period.

        Notwithstanding the foregoing, the obligations described in this Section
2.15 shall not apply to a registration relating solely to employee benefit plans
on Form S-l or Form S-8 or similar forms which may be promulgated in the future,
or a registration relating solely to a Commission Rule 145 transaction on Form
S-14 or Form S-15 or similar forms which may be promulgated in the future.

            2.16 Termination of Registration Rights.

                (a) No Holder shall be entitled to exercise any right provided
for in this Section 2 after five (5) years following the consummation of the
sale of securities

                                       12
<PAGE>   15

pursuant to a registration statement filed by the Company under the Act in
connection with the initial firm commitment underwritten offering of its
securities to the general public.

                (b) In addition, the right of any Holder to request registration
or inclusion in any registration pursuant to Section 2.3 shall terminate on the
closing of the first Company-initiated registered public offering of Common
Stock of the Company if all shares of Registrable Securities held or entitled to
be held upon conversion by such Holder may immediately be sold under Rule 144
during any 90-day period, or on such date after the closing of the first
Company-initiated registered public offering of Common Stock of the Company as
all shares of Registrable Securities held or entitled to be held upon conversion
by such Holder may immediately be sold under Rule 144 during any 90-day period;
provided, however, that the provisions of this Section 2.16(b) shall not apply
to any Holder who owns more than two percent (2%) of the Company's outstanding
stock until such time as such Holder owns less than two percent (2%) of the
outstanding stock of the Company.

        3. Covenants of the Company.

            3.1 Delivery of Financial Statements. The Company shall deliver to
each Investor:

                (a) as soon as practicable, but in any event within ninety (90)
days after the end of each fiscal year of the Company, an income statement for
such fiscal year, a balance sheet of the Company and statement of shareholder's
equity as of the end of such year, and a schedule as to the sources and
applications of funds for such year, such year-end financial reports to be in
reasonable detail, prepared in accordance with generally accepted accounting
principles ("gaap"), and audited and certified by independent public accountants
of nationally recognized standing selected by the Company;

                (b) as soon as practicable, but in any event within forty-five
(45) days after the end of each of the first three (3) quarters of each fiscal
year of the Company, an unaudited profit or loss statement, schedule as to the
sources and application of funds for such fiscal quarter and an unaudited
balance sheet as of the end of such fiscal quarter;

                (c) within thirty (30) days of the end of each month, an
unaudited income statement and schedule as to the sources and application of
funds and balance sheet for and as of the end of such month, in reasonable
detail;

                (d) as soon as practicable, but in any event thirty (30) days
prior to the end of each fiscal year, a budget and business plan for the next
fiscal year, prepared on a monthly basis, including balance sheets and sources
and applications of funds statements for such months and, as soon as prepared,
any other budgets or revised budgets prepared by the Company;

                (e) with respect to the financial statements called for in
subsections (b) and (c) of this Section 3.1, an instrument executed by the Chief
Financial Officer or President of the Company and certifying that such
financials were prepared in accordance with gaap consistently applied with prior
practice for earlier periods (with the exception of footnotes that may be
required by gaap) and fairly present the financial condition of the

                                       13
<PAGE>   16

Company and its results of operation for the period specified, subject to
year-end audit adjustment;

                (f) such other information relating to the financial condition,
business, prospects or corporate affairs of the Company as the Investor or any
assignee of the Investor may from time to time request, provided, however, that
the Company shall not be obligated under this subsection (f) or any other
subsection of Section 3.1 to provide information which it deems in good faith to
be a trade secret or similar confidential information.

            3.2 Inspection. The Company shall permit each Investor, at such
Investor's expense, to visit and inspect the Company's properties, to examine
its books of account and records and to discuss the Company's affairs, finances
and accounts with its officers, all at such reasonable times as may be requested
by the Investor; provided, however, that the Company shall not be obligated
pursuant to this Section 3.2 to provide access to any information which it
reasonably considers to be a trade secret or similar confidential information.

            3.3 Termination of Information and Inspection Covenants. The
covenants set forth in subsections 3.1(c), (d) and (f) and Section 3.2 shall
terminate as to Investors and be of no further force or effect when the sale of
securities pursuant to a registration statement filed by the Company under the
Act in connection with the firm commitment underwritten offering of its
securities to the general public is consummated or when the Company first
becomes subject to the periodic reporting requirements of Sections 12(g) or
15(d) of the 1934 Act, whichever event shall first occur.

            3.4 Right of First Offer. Subject to the terms and conditions
specified in this paragraph 3.4, the Company hereby grants to each Major
Investor (as hereinafter defined) a right of first offer with respect to future
sales by the Company of its Shares (as hereinafter defined). For purposes of
this Section 3.4, a Major Investor shall mean (i) any Investor who holds at
least 10% of the original investment such Investor makes in the Company pursuant
to the Series A Agreement, Series B Agreement, Series C Agreement, Series D
Agreement or Series E Agreement and (ii) any person who acquires at least 10% of
the Series A Preferred Stock, Series B Preferred Stock, Series C Preferred
Stock, Series D Preferred Stock or Series E Preferred Stock (or the Common Stock
issued upon conversion thereof) issued pursuant to the Series A Agreement,
Series B Agreement, Series C Agreement, Series D Agreement or Series E
Agreement. For purposes of this Section 3.4, the term Investor includes any
general partners and affiliates of an Investor. An Investor shall be entitled to
apportion the right of first offer hereby granted it among itself and its
partners and affiliates in such proportions as it deems appropriate.

        Each time the Company proposes to offer any shares of, or securities
convertible into or exercisable for any shares of, any class of its capital
stock ("Shares"), the Company shall first make an offering of such Shares to
each Major Investor in accordance with the following provisions:

                (a) The Company shall deliver a notice by certified mail
("Notice") to the Major Investors stating (i) its bona fide intention to offer
such Shares, (ii) the number of such Shares to be offered, and (iii) the price
and terms, if any, upon which it proposes to offer such Shares.

                                       14
<PAGE>   17

                (b) Within 20 calendar days after giving of the Notice, the
Major Investor may elect to purchase or obtain, at the price and on the terms
specified in the Notice, up to that portion of such Shares which equals the
proportion that the number of shares of Common Stock issued and held, or
issuable upon conversion of the Series A Preferred Stock, Series B Preferred
Stock, Series C Preferred Stock, Series D Preferred Stock or Series E Preferred
Stock then held, by such Major Investor bears to the total number of shares of
Common Stock of the Company then outstanding (assuming full conversion and
exercise of all convertible or exercisable securities). The Company shall
promptly, in writing, inform each Major Investor which purchases all the shares
available to it ("Fully-Exercising Investor") of any other Major Investor's
failure to do likewise. During the ten-day period commencing after such
information is given, each Fully-Exercising Investor shall be entitled to obtain
that portion of the Shares for which Major Investors were entitled to subscribe
but which were not subscribed for by the Major Investors which is equal to the
proportion that the number of shares of Common Stock issued and held, or
issuable upon conversion of Series A Preferred Stock, Series B Preferred Stock,
Series C Preferred Stock, Series D Preferred Stock or Series E Preferred Stock
then held, by such Fully-Exercising Investor bears to the total number of shares
of Common Stock issued and held, or issuable upon conversion of the Series A
Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D
Preferred Stock or Series E Preferred Stock then held, by all Fully-Exercising
Investors who wish to purchase some of the unsubscribed shares.

                (c) If all Shares which Investors are entitled to obtain
pursuant to subsection 3.4(b) are not elected to be obtained as provided in
subsection 3.4(b) hereof, the Company may, during the 30-day period following
the expiration of the period provided in subsection 3.4(b) hereof, offer the
remaining unsubscribed portion of such Shares to any person or persons at a
price not less than, and upon terms no more favorable to the offeree than those
specified in the Notice. If the Company does not enter into an agreement for the
sale of the Shares within such period, or if such agreement is not consummated
within 30 days of the execution thereof, the right provided hereunder shall be
deemed to be revived and such Shares shall not be offered unless first reoffered
to the Major Investors in accordance herewith.

                (d) The right of first offer in this paragraph 3.4 shall not be
applicable (i) to the issuance or sale of shares of Common Stock (or options
therefor) to employees for the primary purpose of soliciting or retaining their
employment, (ii) to or after consummation of a bona fide, firmly underwritten
public offering of shares of Common Stock, registered under the Act, at an
offering price of at least $7.00 per share (appropriately adjusted for any stock
split, dividend, combination or other recapitalization) and $7,500,000 in the
aggregate, (iii) the issuance of securities pursuant to the conversion or
exercise of convertible or exercisable securities, (iv) the issuance of
securities in connection with a bona fide business acquisition of or by the
Company, whether by merger, consolidation, sale of assets, sale or exchange of
stock or otherwise or (v) the issuance of stock, warrants or other securities or
rights to persons or entities with which the Company has business relationships,
provided such issuances are for other than primarily equity financing purposes.

                (e) The right of first refusal set forth in this Section 3.4 may
not be assigned or transferred, except that (i) such right is assignable by each
Holder to any wholly owned subsidiary or parent of, or to any corporation or
entity that is, within the meaning

                                       15
<PAGE>   18

of the Act, controlling, controlled by or under common control with, any such
Holder, and (ii) such right is assignable between and among any of the Holders.

        4. Miscellaneous.

            4.1 Successors and Assigns. Except as otherwise provided herein, the
terms and conditions of this Agreement shall inure to the benefit of and be
binding upon the respective successors and assigns of the parties (including
transferees of any shares of Registrable Securities). Nothing in this Agreement,
express or implied, is intended to confer upon any party other than the parties
hereto or their respective successors and assigns any rights, remedies,
obligations, or liabilities under or by reason of this Agreement, except as
expressly provided in this Agreement.

            4.2 Governing Law. This Agreement shall be governed by and construed
under the laws of the State of California as applied to agreements among
California residents entered into and to be performed entirely within
California.

            4.3 Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

            4.4 Titles and Subtitles. The titles and subtitles used in this
Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

            4.5 Notices. Unless otherwise provided, any notice required or
permitted under this Agreement shall be given in writing and shall be deemed
effectively given upon personal delivery to the party to be notified or upon
deposit with the United States Post Office, by registered or certified mail,
postage prepaid and addressed to the party to be notified at the address as set
forth for such party in the records of the Company, or at such other address as
such party may designate by ten (10) days' advance written notice to the other
parties.

            4.6 Expenses. If any action at law or in equity is necessary to
enforce or interpret the terms of this Agreement, the prevailing party shall be
entitled to reasonable attorneys' fees, costs and necessary disbursements in
addition to any other relief to which such party may be entitled.

            4.7 Amendments and Waivers. Any term of this Agreement may be
amended and the observance of any term of this Agreement may be waived (either
generally or in a particular instance and either retroactively or
prospectively), only with the written consent of the Company and the holders of
a majority of the Registrable Securities then outstanding. Any amendment or
waiver effected in accordance with this paragraph shall be binding upon each
holder of any Registrable Securities then outstanding, each future holder of all
such Registrable Securities, and the Company.

            4.8 Severability. If one or more provisions of this Agreement are
held to be unenforceable under applicable law, such provision shall be excluded
from this Agreement

                                       16
<PAGE>   19

and the balance of the Agreement shall be interpreted as if such provision were
so excluded and shall be enforceable in accordance with its terms.

            4.9 Aggregation of Stock. All shares of Registrable Securities held
or acquired by affiliated entities or persons shall be aggregated together for
the purpose of determining the availability of any rights under this Agreement.

            4.10 Entire Agreement; Amendment; Waiver. This Agreement (including
the Exhibits hereto, if any) constitutes the full and entire understanding and
agreement between the parties with regard to the subjects hereof and thereof.

            4.11 Additional Parties. In the event of a subsequent closing with
an investor as provided for in Section 1.2(c) of the Series E Agreement, such
investor shall become a party to this Agreement as an "Investor" upon receipt
from such investor of a fully executed signature page.

                                       17
<PAGE>   20

            IN WITNESS WHEREOF, the parties have executed this Agreement as of
the date first above written.

                                     VINA TECHNOLOGIES, INC.

                                     By:  /s/ Stan Kazmierczak
                                          --------------------------------------
                                          Stan Kazmierczak
                                          Secretary

                                     INVESTORS:

                                     LONDON PACIFIC LIFE & ANNUITY
                                     COMPANY, a North Carolina Joint Stock
                                     Life Insurer

                                     By:  /s/ Susan Y. Gressel
                                          --------------------------------------
                                          Susan Y. Gressel
                                          V.P. & Treasurer

                                     SEQUOIA CAPITAL VII,
                                     a California Limited Partnership

                                     SEQUOIA TECHNOLOGY PARTNERS VII,
                                     a California Limited Partnership

                                     SQP 1997

                                     SEQUOIA 1997

                                     SEQUOIA INTERNATIONAL PARTNERS

                                     By:    SC VII-A Management, LLC
                                     a California Limited Liability Company, its
                                     General Partner

                                     By:
                                         ---------------------------------------
                                            Managing Member

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   21

                                     VICTORY VENTURES

                                     By:
                                        ----------------------------------------

                                     MIII PARTNERS

                                     By:
                                        ----------------------------------------

                                     BERT L. ZACCARIA

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

                                     TELESOFT PARTNERS IA, L.P.

                                     By:    TeleSoft IA-GP, Inc.
                                            General Partner

                                     By:    /s/ Arjun Gupta
                                            ------------------------------------
                                            Arjun Gupta
                                            President and Chairman

                                     TELESOFT STRATEGIC SIDE FUND I, L.L.C.

                                     By:    /s/ Arjun Gupta
                                            ------------------------------------
                                            Arjun Gupta

                                     TIMARK L.P.

                                     By:
                                         ---------------------------------------
                                         Frank Marshall

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   22

                                     KEVIN J. McQUILLAN

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

                                     QUIGLEY, PHILIP J. AND TERESA LYNNE CARSS
                                     QUIGLEY 1997 FAMILY TRUST

                                     -------------------------------------------
                                     By:
                                        ----------------------------------------

                                     SIERRA VENTURES VI

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

                                     SV ASSOCIATES VI

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

                                     EQUITIES HOLDINGS LLC

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

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   23

                                     SUMITOMO CORPORATION

                                     -------------------------------------------
                                     By:
                                        ----------------------------------------

                                     SUMITOMO CORPORATION OF AMERICA

                                     -------------------------------------------
                                     By:
                                        ----------------------------------------

                                     EAST RIVER VENTURES

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

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   24

                                     NORTH AMERICA VENTURE FUND, L.P.,
                                     a Cayman Islands Limited Partnership

                                     By:  CDIB North America Venture Management,
                                          L.D.C., a Cayman Islands Limited
                                          Duration Company
                                          General Partner

                                     By:    /s/ Emily Chen
                                          --------------------------------------
                                     Name:  Emily Chen
                                     Title:   Member

                                     By:    /s/ Charles Lau
                                          --------------------------------------
                                     Name:  Charles Lau
                                     Title:   Member

                                     SEQUOIA CAPITAL VII
                                     A CALIFORNIA LIMITED PARTNERSHIP

                                     SEQUOIA TECHNOLOGY PARTNERS VII
                                     A CALIFORNIA LIMITED PARTNERSHIP

                                     SQP 1997

                                     SEQUOIA INTERNATIONAL PARTNERS

                                     By:  SC VII-A Management, LLC
                                     A California Limited Liability Company,
                                     its General Partner

                                     By: /s/ Doug Lyon
                                         ---------------------------------------
                                         Managing Member

                                     GERALD SHALTZ

                                     /s/ Gerald Shaltz
                                     /s/ Sharon A. Shaltz, Trustee
                                     -------------------------------------------

                                     STANLEY L. AND CAROL J. GOODSTEIN

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   25

                                     /s/ Stanley L. Goodstein Trustee
                                     /s/ Carol L. Goodstein Trustee
                                     -------------------------------------------

                                     WILLIAM M. McCORMICK, Jr.

                                     /s/    William M. McCormick, Jr.
                                     -------------------------------------------

                                     ADAM McNICOL

                                     /s/ Adam McNicol
                                     -------------------------------------------

                                     JEFF AND STACEY REITMEIR

                                     /s/ Jeff & Stacey Reitmeir
                                     -------------------------------------------

                                     WM. MICHAEL WEST, SANDRA K. WEST

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

                                     PRAVEEN GUPTA

                                            /s/ Praveen Gupta
                                     -------------------------------------------

                                     CHARLES AND MEHRI LAU

                                            /s/ Charles Lau & /s/ Mehri Lau
                                     -------------------------------------------

                                     YEE CHUEN CHEN YANG

                                            /s/ Yee Chuen Chen Yang
                                     -------------------------------------------
                                     By:  Emily Chen

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   26

                                     CARMEN CHANG

                                            /s/ Carmen Chang
                                     -------------------------------------------

                                     HAROLD NEWMAN

                                            /s/ Harold Newman
                                     -------------------------------------------

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   27

                                     OTHER SHAREHOLDERS:

                                     Frank Walters
                                     -------------------------------------------

                                     /s/ Frank Walters
                                     -------------------------------------------

                                     Michael D. Maher
                                     -------------------------------------------

                                     /s/ Michael D. Maher
                                     -------------------------------------------

                                     Max Straube
                                     -------------------------------------------

                                     /s/ Max Straube
                                     -------------------------------------------

                                     W.R. Hambrecht/ Vina LLC
                                     -------------------------------------------

                                     /s/ Brian Frank
                                     -------------------------------------------

                                     Patricia Ng
                                     -------------------------------------------

                                     /s/ Patricia Ng
                                     -------------------------------------------

                                     Greenacre Venture LLC
                                     -------------------------------------------

                                     /s/ John Murray
                                     -------------------------------------------

                                     Charter Growth Capital II, L.P.
                                     -------------------------------------------

                                     /s/ Kevin J. McQuillan
                                     -------------------------------------------

                  SIGNATURE PAGE TO INVESTORS' RIGHTS AGREEMENT

<PAGE>   28

                                   SCHEDULE A<PAGE>   1

                                                                    EXHIBIT 10.1

                            VINA TECHNOLOGIES, INC.
                      1996 STOCK OPTION/STOCK ISSUANCE PLAN

                                   ARTICLE ONE

                               GENERAL PROVISIONS

        I. PURPOSE OF THE PLAN

        This 1996 Stock Option/Stock Issuance Plan is intended to promote the
interests of Vina Technologies, Inc., a California corporation, by providing
eligible persons with the opportunity to acquire a proprietary interest, or
otherwise increase their proprietary interest, in the Corporation as an
incentive for them to remain in the service of the Corporation.

        Capitalized terms herein shall have the meanings assigned to such terms
in the attached Appendix.

        II. STRUCTURE OF THE PLAN

        A. The Plan shall be divided into two (2) separate equity programs:

                (i) the Option Grant Program under which eligible persons may,
        at the discretion of the Plan Administrator, be granted options to
        purchase shares of Common Stock, and

                (ii) the Stock Issuance Program under which eligible persons
        may, at the discretion of the Plan Administrator, be issued shares of
        Common Stock directly, either through the immediate purchase of such
        shares or as a bonus for services rendered the Corporation (or any
        Parent or Subsidiary).

        B. The provisions of Articles One and Four shall apply to both equity
programs under the Plan and shall accordingly govern the interests of all
persons under the Plan.

<PAGE>   2

        III. ADMINISTRATION OF THE PLAN

        A. The Plan shall be administered by the Board. However, any or all
administrative functions otherwise exercisable by the Board may be delegated to
the Committee. Members of the Committee shall serve for such period of time as
the Board may determine and shall be subject to removal by the Board at any
time. The Board may also at any time terminate the functions of the Committee
and reassume all powers and authority previously delegated to the Committee.

        B. The Plan Administrator shall have full power and authority (subject
to the provisions of the Plan) to establish such rules and regulations as it may
deem appropriate for proper administration of the Plan and to make such
determinations under, and issue such interpretations of, the Plan and any
outstanding options or stock issuances thereunder as it may deem necessary or
advisable. Decisions of the Plan Administrator shall be final and binding on all
parties who have an interest in the Plan or any option or stock issuance
thereunder.

        IV. ELIGIBILITY

        A. The persons eligible to participate in the Plan are as follows:

                (i) Employees,

                (ii) non-employee members of the Board or the non-employee
        members of the board of directors of any Parent or Subsidiary, and

                (iii) consultants and other independent advisors who provide
        services to the Corporation (or any Parent or Subsidiary).

        B. The Plan Administrator shall have full authority to determine, (i)
with respect to the option grants under the Option Grant Program, which eligible
persons are to receive option grants, the time or times when such option grants
are to be made, the number of shares to be covered by each such grant, the
status of the granted option as either an Incentive Option or a Non-Statutory
Option, the time or times at which each option is to become exercisable, the
vesting schedule (if any) applicable to the option shares and the maximum term
for which the option is to remain outstanding, and (ii) with respect to stock
issuances under the Stock Issuance Program, which eligible persons are to
receive stock issuances, the time or times when such issuances are to be made,
the number of shares to be issued to each Participant, the vesting schedule (if
any) applicable to the issued shares and the consideration to be paid by the
Participant for such shares.

        C. The Plan Administrator shall have the absolute discretion either to
grant options in accordance with the Option Grant Program or to effect stock
issuances in accordance with the Stock Issuance Program.

                                      -2-
<PAGE>   3

        V. STOCK SUBJECT TO THE PLAN

        A. The stock issuable under the Plan shall be shares of authorized but
unissued or reacquired Common Stock. The maximum number of shares of Common
Stock which may be issued over the term of the Plan shall not exceed 2,307,400
shares.

        B. Shares of Common Stock subject to outstanding options shall be
available for subsequent issuance under the Plan to the extent (i) the options
expire or terminate for any reason prior to exercise in full or (ii) the options
are cancelled in accordance with the cancellation-regrant provisions of Article
Two. Unvested shares issued under the Plan and subsequently repurchased by the
Corporation, at the option exercise price paid per share, pursuant to the
Corporation's repurchase rights under the Plan shall be added back to the number
of shares of Common Stock reserved for issuance under the Plan and shall
accordingly be available for re-issuance through one or more subsequent option
grants or direct stock issuances under the Plan.

        C. Should any change be made to the Common Stock by reason of any stock
split, stock dividend, recapitalization, combination of shares, exchange of
shares or other change affecting the outstanding Common Stock as a class without
the Corporation's receipt of consideration, appropriate adjustments shall be
made to (i) the maximum number and/or class of securities issuable under the
Plan and (ii) the number and/or class of securities and the exercise price per
share in effect under each outstanding option in order to prevent the dilution
or enlargement of benefits thereunder. The adjustments determined by the Plan
Administrator shall be final, binding and conclusive. In no event shall any such
adjustments be made in connection with the conversion of one or more outstanding
shares of the Corporation's preferred stock into shares of Common Stock.

                                      -3-
<PAGE>   4

                                   ARTICLE TWO

                              OPTION GRANT PROGRAM

        I. OPTION TERMS

        Each option shall be evidenced by one or more documents in the form
approved by the Plan Administrator; provided, however, that each such document
shall comply with the terms specified below. Each document evidencing an
Incentive Option shall, in addition, be subject to the provisions of the Plan
applicable to such options.

        A. Exercise Price.

                1. The exercise price per share shall be fixed by the Plan
Administrator in accordance with the following provisions:

                (i) The exercise price per share shall not be less than
        eighty-five percent (85%) of the Fair Market Value per share of Common
        Stock on the option grant date.

                (ii) If the person to whom the option is granted is a 10%
        Shareholder, then the exercise price per share shall not be less than
        one hundred ten percent (110%) of the Fair Market Value per share of
        Common Stock on the option grant date.

                2. The exercise price shall become immediately due upon exercise
of the option and shall, subject to the provisions of Section I of Article Four
and the documents evidencing the option, be payable in cash or check made
payable to the Corporation. Should the Common Stock be registered under Section
12(g) of the 1934 Act at the time the option is exercised, then the exercise
price may also be paid as follows:

                (i) in shares of Common Stock held for the requisite period
        necessary to avoid a charge to the Corporation's earnings for financial
        reporting purposes and valued at Fair Market Value on the Exercise Date,
        or

                (ii) to the extent the option is exercised for vested shares,
        through a special sale and remittance procedure pursuant to which the
        Optionee shall concurrently provide irrevocable written instructions (A)
        to a Corporation-designated brokerage firm to effect the immediate sale
        of the purchased shares and remit to the Corporation, out of the sale
        proceeds available on the settlement date, sufficient funds to cover the
        aggregate exercise price payable for the purchased shares plus all
        applicable

                                      -4-
<PAGE>   5

        Federal, state and local income and employment taxes required to be
        withheld by the Corporation by reason of such exercise and (B) to the
        Corporation to deliver the certificates for the purchased shares
        directly to such brokerage firm in order to complete the sale.

        Except to the extent such sale and remittance procedure is utilized,
payment of the exercise price for the purchased shares must be made on the
Exercise Date.

        B. EXERCISE AND TERM OF OPTIONS. Each option shall be exercisable at
such time or times, during such period and for such number of shares as shall be
determined by the Plan Administrator and set forth in the documents evidencing
the option grant. However, no option shall have a term in excess of ten (10)
years measured from the option grant date.

        C. EFFECT OF TERMINATION OF SERVICE.

                1. The following provisions shall govern the exercise of any
options held by the Optionee at the time of cessation of Service or death:

                (i) Should the Optionee cease to remain in Service for any
        reason other than Disability or death, then the Optionee shall have a
        period of three (3) months following the date of such cessation of
        Service during which to exercise each outstanding option held by such
        Optionee.

                (ii) Should Optionee's Service terminate by reason of
        Disability, then the Optionee shall have a period of twelve (12) months
        following the date of such cessation of Service during which to exercise
        each outstanding option held by such Optionee.

                (iii) If the Optionee dies while holding an outstanding option,
        then the personal representative of his or her estate or the person or
        persons to whom the option is transferred pursuant to the Optionee's
        will or the laws of inheritance shall have a twelve (12)-month period
        following the date of the Optionee's death to exercise such option.

                (iv) Under no circumstances, however, shall any such option be
        exercisable after the specified expiration of the option term.

                (v) During the applicable post-Service exercise period, the
        option may not be exercised in the aggregate for more than the number of
        vested shares for which the option is exercisable on the date of the
        Optionee's cessation of Service. Upon the expiration of the applicable
        exercise period or (if earlier) upon the expiration of the option term,
        the

                                      -5-
<PAGE>   6

        option shall terminate and cease to be outstanding for any vested shares
        for which the option has not been exercised. However, the option shall,
        immediately upon the Optionee's cessation of Service, terminate and
        cease to be outstanding with respect to any and all option shares for
        which the option is not otherwise at the time exercisable or in which
        the Optionee is not otherwise at that time vested.

        2. The Plan Administrator shall have the discretion, exercisable either
at the time an option is granted or at any time while the option remains
outstanding, to:

                (i) extend the period of time for which the option is to remain
        exercisable following Optionee's cessation of Service or death from the
        limited period otherwise in effect for that option to such greater
        period of time as the Plan Administrator shall deem appropriate, but in
        no event beyond the expiration of the option term, and/or

                (ii) permit the option to become vested not only with respect to
        the number of shares of Common Stock in accordance with the Optionee's
        vesting schedule but also with respect to one or more additional
        installments.

        D. SHAREHOLDER RIGHTS. The holder of an option shall have no shareholder
rights with respect to the shares subject to the option until such person shall
have exercised the option, paid the exercise price and become a holder of record
of the purchased shares.

        E. UNVESTED SHARES. The Plan Administrator shall have the discretion to
grant options which are exercisable for unvested shares of Common Stock. Should
the Optionee cease Service while holding such unvested shares, the Corporation
shall have the right to repurchase, at the exercise price paid per share, all or
(at the discretion of the Corporation and with the consent of the Optionee) any
of those unvested shares. The terms upon which such repurchase right shall be
exercisable (including the period and procedure for exercise and the appropriate
vesting schedule for the purchased shares) shall be established by the Plan
Administrator and set forth in the document evidencing such repurchase right.
The Plan Administrator may not impose a vesting schedule upon any option grant
or any shares of Common Stock subject to the option which is more restrictive
than twenty percent (20%) per year vesting, with the initial vesting to occur
not later than one (1) year after the option grant date.

        F. FIRST REFUSAL RIGHTS. Until such time as the Common Stock is first
registered under Section 12(g) of the 1934 Act, the Corporation shall have the
right of first refusal with respect to any proposed disposition by the Optionee
(or any successor in interest) of any shares of Common Stock issued under the
Plan. Such right of first refusal

                                      -6-
<PAGE>   7

shall be exercisable in accordance with the terms established by the Plan
Administrator and set forth in the document evidencing such right.

        G. LIMITED TRANSFERABILITY OF OPTIONS. During the lifetime of the
Optionee, the option shall be exercisable only by the Optionee and shall not be
assignable or transferable other than by will or by the laws of descent and
distribution following the Optionee's death.

        H. WITHHOLDING. The Corporation's obligation to deliver shares of Common
Stock upon the exercise of any options granted under the Plan shall be subject
to the satisfaction of all applicable Federal, state and local income and
employment tax withholding requirements.

        II. INCENTIVE OPTIONS

        The terms specified below shall be applicable to all Incentive Options.
Except as modified by the provisions of this Section II, all the provisions of
the Plan shall be applicable to Incentive Options. Options which are
specifically designated as Non-Statutory Options shall not be subject to the
terms of this Section II.

        A. ELIGIBILITY. Incentive Options may only be granted to Employees.

        B. EXERCISE PRICE. The exercise price per share shall not be less than
one hundred percent (100%) of the Fair Market Value per share of Common Stock on
the option grant date.

        C. DOLLAR LIMITATION. The aggregate Fair Market Value of the shares of
Common Stock (determined as of the respective date or dates of grant) for which
one or more options granted to any Employee under the Plan (or any other option
plan of the Corporation or any Parent or Subsidiary) may for the first time
become exercisable as Incentive Options during any one (1) calendar year shall
not exceed the sum of One Hundred Thousand Dollars ($100,000). To the extent the
Employee holds two (2) or more such options which become exercisable for the
first time in the same calendar year, the foregoing limitation on the
exercisability of such options as Incentive Options shall be applied on the
basis of the order in which such options are granted.

        D. 10% SHAREHOLDER. If any Employee to whom an Incentive Option is
granted is a 10% Shareholder, then the option term shall not exceed five (5)
years measured from the option grant date.

                                      -7-
<PAGE>   8

        III. CORPORATE TRANSACTION

        A. The shares subject to each option outstanding under the Plan at the
time of a Corporate Transaction shall automatically vest in full so that each
such option shall, immediately prior to the effective date of the Corporate
Transaction, become fully exercisable for all of the shares of Common Stock at
the time subject to that option and may be exercised for any or all of those
shares as fully-vested shares of Common Stock. However, the shares subject to an
outstanding option shall not vest on such an accelerated basis if and to the
extent: (i) such option is assumed by the successor corporation (or parent
thereof) in the Corporate Transaction and the Corporation's repurchase rights
with respect to the unvested option shares are concurrently assigned to such
successor corporation (or parent thereof) or (ii) such option is to be replaced
with a cash incentive program of the successor corporation which preserves the
spread existing on the unvested option shares at the time of the Corporate
Transaction and provides for subsequent payout in accordance with the same
vesting schedule applicable to those unvested option shares or (iii) the
acceleration of such option is subject to other limitations imposed by the Plan
Administrator at the time of the option grant.

        B. All outstanding repurchase rights shall also terminate automatically,
and the shares of Common Stock subject to those terminated rights shall
immediately vest in full, in the event of any Corporate Transaction, except to
the extent: (i) those repurchase rights are assigned to the successor
corporation (or parent thereof) in connection with such Corporate Transaction or
(ii) such accelerated vesting is precluded by other limitations imposed by the
Plan Administrator at the time the repurchase right is issued.

        C. Immediately following the consummation of the Corporate Transaction,
all outstanding options shall terminate and cease to be outstanding, except to
the extent assumed by the successor corporation (or parent thereof).

        D. Each option which is assumed in connection with a Corporate
Transaction shall be appropriately adjusted, immediately after such Corporate
Transaction, to apply to the number and class of securities which would have
been issuable to the Optionee in consummation of such Corporate Transaction, had
the option been exercised immediately prior to such Corporate Transaction.
Appropriate adjustments shall also be made to (i) the number and class of
securities available for issuance under the Plan following the consummation of
such Corporate Transaction and (ii) the exercise price payable per share under
each outstanding option, provided the aggregate exercise price payable for such
securities shall remain the same.

        E. The portion of any Incentive Option accelerated in connection with a
Corporate Transaction shall remain exercisable as an Incentive Option only to
the extent the applicable One Hundred Thousand Dollar limitation is not
exceeded. To the extent such dollar limitation is exceeded, the accelerated
portion of such option shall be exercisable as a Non-Statutory Option under the
Federal tax laws.

                                      -8-
<PAGE>   9

        F. The grant of options under the Plan shall in no way affect the right
of the Corporation to adjust, reclassify, reorganize or otherwise change its
capital or business structure or to merge, consolidate, dissolve, liquidate or
sell or transfer all or any part of its business or assets.

        IV. CANCELLATION AND REGRANT OF OPTIONS

        The Plan Administrator shall have the authority to effect, at any time
and from time to time, with the consent of the affected option holders, the
cancellation of any or all outstanding options under the Plan and to grant in
substitution therefor new options covering the same or different number of
shares of Common Stock but with an exercise price per share based on the Fair
Market Value per share of Common Stock on the new option grant date.

                                      -9-
<PAGE>   10

                                  ARTICLE THREE

                             STOCK ISSUANCE PROGRAM

        I. STOCK ISSUANCE TERMS

        Shares of Common Stock may be issued under the Stock Issuance Program
through direct and immediate issuances without any intervening option grants.
Each such stock issuance shall be evidenced by a Stock Issuance Agreement which
complies with the terms specified below.

        A. PURCHASE PRICE.

                1. The purchase price per share shall be fixed by the Plan
Administrator but shall not be less than eighty-five percent (85%) of the Fair
Market Value per share of Common Stock on the issue date. However, the purchase
price per share of Common Stock issued to a 10% Shareholder shall not be less
than one hundred and ten percent (110%) of such Fair Market Value.

                2. Subject to the provisions of Section I of Article Four,
shares of Common Stock may be issued under the Stock Issuance Program for any of
the following items of consideration which the Plan Administrator may deem
appropriate in each individual instance:

                (i) cash or check made payable to the Corporation, or

                (ii) past services rendered to the Corporation (or any Parent or
        Subsidiary).

        B. VESTING PROVISIONS.

                1. Shares of Common Stock issued under the Stock Issuance
Program may, in the discretion of the Plan Administrator, be fully and
immediately vested upon issuance or may vest in one or more installments over
the Participant's period of Service or upon attainment of specified performance
objectives. However, the Plan Administrator may not impose a vesting schedule
upon any stock issuance effected under the Stock Issuance Program which is more
restrictive than twenty percent (20%) per year vesting, with initial vesting to
occur not later than one (1) year after the issuance date.

                                      -10-
<PAGE>   11

                2. Any new, substituted or additional securities or other
property (including money paid other than as a regular cash dividend) which the
Participant may have the right to receive with respect to the Participant's
unvested shares of Common Stock by reason of any stock dividend, stock split
recapitalization, combination of shares, exchange of shares or other change
affecting the outstanding Common Stock as a class without the Corporation's
receipt of consideration shall be issued subject to (i) the same vesting
requirements applicable to the Participant's unvested shares of Common Stock and
(ii) such escrow arrangements as the Plan Administrator shall deem appropriate.

                3. The Participant shall have full shareholder rights with
respect to any shares of Common Stock issued to the Participant under the Stock
Issuance Program, whether or not the Participant's interest in those shares is
vested. Accordingly, the Participant shall have the right to vote such shares
and to receive any regular cash dividends paid on such shares.

                4. Should the Participant cease to remain in Service while
holding one or more unvested shares of Common Stock issued under the Stock
Issuance Program or should the performance objectives not be attained with
respect to one or more such unvested shares of Common Stock, then those shares
shall be immediately surrendered to the Corporation for cancellation, and the
Participant shall have no further shareholder rights with respect to those
shares. To the extent the surrendered shares were previously issued to the
Participant for consideration paid in cash or cash equivalent (including the
Participant's purchase-money indebtedness), the Corporation shall repay to the
Participant the cash consideration paid for the surrendered shares and shall
cancel the unpaid principal balance of any outstanding purchase-money note of
the Participant attributable to such surrendered shares.

                5. The Plan Administrator may in its discretion waive the
surrender and cancellation of one or more unvested shares of Common Stock (or
other assets attributable thereto) which would otherwise occur upon the
non-completion of the vesting schedule applicable to such shares. Such waiver
shall result in the immediate vesting of the Participant's interest in the
shares of Common Stock as to which the waiver applies. Such waiver may be
effected at any time, whether before or after the Participant's cessation of
Service or the attainment or non-attainment of the applicable performance
objectives.

        C. FIRST REFUSAL RIGHTS. Until such time as the Common Stock is first
registered under Section 12(g) of the 1934 Act, the Corporation shall have the
right of first refusal with respect to any proposed disposition by the
Participant (or any successor in interest) of any shares of Common Stock issued
under the Stock Issuance Program. Such right of first refusal shall be
exercisable in accordance with the terms established by the Plan Administrator
and set forth in the document evidencing such right.

                                      -11-
<PAGE>   12

        II. CORPORATE TRANSACTION

        A. Upon the occurrence of a Corporate Transaction, all outstanding
repurchase rights under the Stock Issuance Program shall terminate
automatically, and the shares of Common Stock subject to those terminated rights
shall immediately vest in full, except to the extent: (i) those repurchase
rights are assigned to the successor corporation (or parent thereof) in
connection with such Corporate Transaction or (ii) such accelerated vesting is
precluded by other limitations imposed by the Plan Administrator at the time the
repurchase right is issued.

        III. SHARE ESCROW/LEGENDS

        Unvested shares may, in the Plan Administrator's discretion, be held in
escrow by the Corporation until the Participant's interest in such shares vests
or may be issued directly to the Participant with restrictive legends on the
certificates evidencing those unvested shares.

                                      -12-
<PAGE>   13

                                  ARTICLE FOUR

                                  MISCELLANEOUS

        I. FINANCING

        The Plan Administrator may permit any Optionee or Participant to pay the
option exercise price or the purchase price for shares issued to such person
under the Plan by delivering a full-recourse, interest-bearing promissory note
payable in one or more installments and secured by the purchased shares.
However, any promissory note delivered by a consultant must be secured by
property in addition to the purchased shares of Common Stock. In no event shall
the maximum credit available to the Optionee or Participant exceed the sum of
(i) the aggregate option exercise price or purchase price payable for the
purchased shares plus (ii) any Federal, state and local income and employment
tax liability incurred by the Optionee or the Participant in connection with the
option exercise or share purchase.

        II. EFFECTIVE DATE AND TERM OF PLAN

        A. The Plan shall become effective when adopted by the Board, but no
option granted under the Plan may be exercised, and no shares shall be issued
under the Plan, until the Plan is approved by the Corporation's shareholders. If
such shareholder approval is not obtained within twelve (12) months after the
date of the Board's adoption of the Plan, then all options previously granted
under the Plan shall terminate and cease to be outstanding, and no further
options shall be granted and no shares shall be issued under the Plan. Subject
to such limitation, the Plan Administrator may grant options and issue shares
under the Plan at any time after the effective date of the Plan and before the
date fixed herein for termination of the Plan.

        B. The Plan shall terminate upon the earliest of (i) the expiration of
the ten (10)-year period measured from the date the Plan is adopted by the
Board, (ii) the date on which all shares available for issuance under the Plan
shall have been issued or (iii) the termination of all outstanding options in
connection with a Corporate Transaction. All options and unvested stock
issuances outstanding at that time under the Plan shall continue to have full
force and effect in accordance with the provisions of the documents evidencing
such options or issuances.

        III. AMENDMENT OF THE PLAN

        A. The Board shall have complete and exclusive power and authority to
amend or modify the Plan in any or all respects. However, no such amendment or
modification shall adversely affect the rights and obligations with respect to
options or unvested stock issuances at the time outstanding under the Plan
unless the Optionee or the

                                      -13-
<PAGE>   14

Participant consents to such amendment or modification. In addition, certain
amendments may require shareholder approval pursuant to applicable laws and
regulations.

        B. Options may be granted under the Option Grant Program and shares may
be issued under the Stock Issuance Program which are in each instance in excess
of the number of shares of Common Stock then available for issuance under the
Plan, provided any excess shares actually issued under those programs shall be
held in escrow until there is obtained shareholder approval of an amendment
sufficiently increasing the number of shares of Common Stock available for
issuance under the Plan. If such shareholder approval is not obtained within
twelve (12) months after the date the first such excess issuances are made, then
(i) any unexercised options granted on the basis of such excess shares shall
terminate and cease to be outstanding and (ii) the Corporation shall promptly
refund to the Optionees and the Participants the exercise or purchase price paid
for any excess shares issued under the Plan and held in escrow, together with
interest (at the applicable Short Term Federal Rate) for the period the shares
were held in escrow, and such shares shall thereupon be automatically cancelled
and cease to be outstanding.

        IV. USE OF PROCEEDS

        Any cash proceeds received by the Corporation from the sale of shares of
Common Stock under the Plan shall be used for general corporate purposes.

        V. WITHHOLDING

        The Corporation's obligation to deliver shares of Common Stock upon the
exercise of any options or upon the issuance or vesting of any shares issued
under the Plan shall be subject to the satisfaction of all applicable Federal,
state and local income and employment tax withholding requirements.

        VI. REGULATORY APPROVALS

        The implementation of the Plan, the granting of any options under the
Plan and the issuance of any shares of Common Stock (i) upon the exercise of any
option or (ii) under the Stock Issuance Program shall be subject to the
Corporation's procurement of all approvals and permits required by regulatory
authorities having jurisdiction over the Plan, the options granted under it and
the shares of Common Stock issued pursuant to it.

        VII. NO EMPLOYMENT OR SERVICE RIGHTS

        Nothing in the Plan shall confer upon the Optionee or the Participant
any right to continue in Service for any period of specific duration or
interfere with or otherwise restrict in any way the rights of the Corporation
(or any Parent or Subsidiary employing or retaining such person) or of the
Optionee or the Participant, which rights are hereby

                                      -14-
<PAGE>   15

expressly reserved by each, to terminate such person's Service at any time for
any reason, with or without cause.

        VIII. FINANCIAL REPORTS

        The Corporation shall deliver a balance sheet and an income statement at
least annually to each individual holding an outstanding option under the Plan,
unless such individual is a key Employee whose duties in connection with the
Corporation (or any Parent or Subsidiary) assure such individual access to
equivalent information.

                                      -15-
<PAGE>   16

                                    APPENDIX

        The following definitions shall be in effect under the Plan:

        A. BOARD shall mean the Corporation's Board of Directors.

        B. CODE shall mean the Internal Revenue Code of 1986, as amended.

        C. COMMITTEE shall mean a committee of two (2) or more Board members
appointed by the Board to exercise one or more administrative functions under
the Plan.

        D. COMMON STOCK shall mean the Corporation's common stock.

        E. CORPORATE TRANSACTION shall mean either of the following
shareholder-approved transactions to which the Corporation is a party:

                (i) a merger or consolidation in which securities possessing
        more than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

                (ii) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. CORPORATION shall mean Vina Technologies, Inc., a California
corporation.

        G. DISABILITY shall mean the inability of the Optionee or the
Participant to engage in any substantial gainful activity by reason of any
medically determinable physical or mental impairment and shall be determined by
the Plan Administrator on the basis of such medical evidence as the Plan
Administrator deems warranted under the circumstances.

        H. EMPLOYEE shall mean an individual who is in the employ of the
Corporation (or any Parent or Subsidiary), subject to the control and direction
of the employer entity as to both the work to be performed and the manner and
method of performance.

        I. EXERCISE DATE shall mean the date on which the Corporation shall have
received written notice of the option exercise.

        J. FAIR MARKET VALUE per share of Common Stock on any relevant date
shall be determined in accordance with the following provisions:

                                       A-1
<PAGE>   17

                (i) If the Common Stock is at the time traded on the Nasdaq
        National Market, then the Fair Market Value shall be the closing selling
        price per share of Common Stock on the date in question, as such price
        is reported by the National Association of Securities Dealers on the
        Nasdaq National Market or any successor system. If there is no closing
        selling price for the Common Stock on the date in question, then the
        Fair Market Value shall be the closing selling price on the last
        preceding date for which such quotation exists.

                (ii) If the Common Stock is at the time listed on any Stock
        Exchange, then the Fair Market Value shall be the closing selling price
        per share of Common Stock on the date in question on the Stock Exchange
        determined by the Plan Administrator to be the primary market for the
        Common Stock, as such price is officially quoted in the composite tape
        of transactions on such exchange. If there is no closing selling price
        for the Common Stock on the date in question, then the Fair Market Value
        shall be the closing selling price on the last preceding date for which
        such quotation exists.

                (iii) If the Common Stock is at the time neither listed on any
        Stock Exchange nor traded on the Nasdaq National Market, then the Fair
        Market Value shall be determined by the Plan Administrator after taking
        into account such factors as the Plan Administrator shall deem
        appropriate.

        K. INCENTIVE OPTION shall mean an option which satisfies the
requirements of Code Section 422.

        L. MISCONDUCT shall mean the commission of any act of fraud,
embezzlement or dishonesty by the Optionee or Participant, any unauthorized use
or disclosure by such person of confidential information or trade secrets of the
Corporation (or any Parent or Subsidiary), or any other intentional misconduct
by such person adversely affecting the business or affairs of the Corporation
(or any Parent or Subsidiary) in a material manner. The foregoing definition
shall not be deemed to be inclusive of all the acts or omissions which the
Corporation (or any Parent or Subsidiary) may consider as grounds for the
dismissal or discharge of any Optionee, Participant or other person in the
Service of the Corporation (or any Parent or Subsidiary).

        M. 1934 ACT shall mean the Securities Exchange Act of 1934, as amended.

        N. NON-STATUTORY OPTION shall mean an option not intended to satisfy the
requirements of Code Section 422.

        O. OPTION GRANT PROGRAM shall mean the option grant program in effect
under the Plan.

                                      A-2

<PAGE>   18

        P. OPTIONEE shall mean any person to whom an option is granted under the
Plan.

        Q. PARENT shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, stock possessing fifty percent (50%) or more of the total
combined voting power of all classes of stock in one of the other corporations
in such chain.

        R. PARTICIPANT shall mean any person who is issued shares of Common
Stock under the Stock Issuance Program.

        S. PLAN shall mean the Corporation's 1996 Stock Option/Stock Issuance
Plan, as set forth in this document.

        T. PLAN ADMINISTRATOR shall mean either the Board or the Committee
acting in its capacity as administrator of the Plan.

        U. SERVICE shall mean the provision of services to the Corporation (or
any Parent or Subsidiary) by a person in the capacity of an Employee, a
non-employee member of the board of directors or a consultant or independent
advisor, except to the extent otherwise specifically provided in the documents
evidencing the option grant.

        V. STOCK EXCHANGE shall mean either the American Stock Exchange or the
New York Stock Exchange.

        W. STOCK ISSUANCE AGREEMENT shall mean the agreement entered into by the
Corporation and the Participant at the time of issuance of shares of Common
Stock under the Stock Issuance Program.

        X. STOCK ISSUANCE PROGRAM shall mean the stock issuance program in
effect under the Plan.

        Y. SUBSIDIARY shall mean any corporation (other than the Corporation) in
an unbroken chain of corporations beginning with the Corporation, provided each
corporation (other than the last corporation) in the unbroken chain owns, at the
time of the determination, stock possessing fifty percent (50%) or more of the
total combined voting power of all classes of stock in one of the other
corporations in such chain.

        Z. 10% SHAREHOLDER shall mean the owner of stock (as determined under
Code Section 424(d)) possessing more than ten percent (10%) of the total
combined voting power of all classes of stock of the Corporation (or any Parent
or Subsidiary).

                                      A-3
<PAGE>   19

                            VINA TECHNOLOGIES, INC.
                            STOCK PURCHASE AGREEMENT

        AGREEMENT made this _____ day of 199__, by and between Vina
Technologies, Inc., a California corporation, and _________________________,
Optionee under the Corporation's 1996 Stock Option/Stock Issuance Plan.

        All capitalized terms in this Agreement shall have the meaning assigned
to them in this Agreement or in the attached Appendix.

        A.     EXERCISE OF OPTION

        1. Exercise. Optionee hereby purchases ______ shares of Common Stock
(the "Purchased Shares") pursuant to that certain option (the "Option") granted
Optionee on __________, 199__ (the "Grant Date") to purchase up to _________
shares of Common Stock (the "Option Shares") under the Plan at the exercise
price of $ ___ per share (the "Exercise Price").

        2. Payment. Concurrently with the delivery of this Agreement to the
Corporation, Optionee shall pay the Exercise Price for the Purchased Shares in
accordance with the provisions of the Option Agreement and shall deliver
whatever additional documents may be required by the Option Agreement as a
condition for exercise, together with a duly-executed blank Assignment Separate
from Certificate (in the form attached hereto as Exhibit I) with respect to the
Purchased Shares.

        3. Shareholder Rights. Until such time as the Corporation exercises the
Repurchase Right or the First Refusal Right, Optionee (or any successor in
interest) shall have all the rights of a shareholder (including voting, dividend
and liquidation rights) with respect to the Purchased Shares, subject, however,
to the transfer restrictions of Articles B and C.

        B.     SECURITIES LAW COMPLIANCE

        1. Restricted Securities. The Purchased Shares have not been registered
under the 1933 Act and are being issued to Optionee in reliance upon the
exemption from such registration provided by SEC Rule 701 for stock issuances
under compensatory benefit plans such as the Plan. Optionee hereby confirms that
Optionee has been informed that the Purchased Shares are restricted securities
under the 1933 Act and may not be resold or transferred unless the Purchased
Shares are first registered under the Federal securities laws

                                     - 1 -
<PAGE>   20

or unless an exemption from such registration is available. Accordingly,
Optionee hereby acknowledges that Optionee is prepared to hold the Purchased
Shares for an indefinite period and that Optionee is aware that SEC Rule 144
issued under the 1933 Act which exempts certain resales of unrestricted
securities is not presently available to exempt the resale of the Purchased
Shares from the registration requirements of the 1933 Act.

        2. Restrictions on Disposition of Purchased Shares. Optionee shall make
no disposition of the Purchased Shares (other than a Permitted Transfer) unless
and until there is compliance with all of the following requirements:

               (i) Optionee shall have provided the Corporation with a written
        summary of the terms and conditions of the proposed disposition.

               (ii) Optionee shall have complied with all requirements of this
        Agreement applicable to the disposition of the Purchased Shares.

               (iii) Optionee shall have provided the Corporation with written
        assurances, in form and substance satisfactory to the Corporation, that
        (a) the proposed disposition does not require registration of the
        Purchased Shares under the 1933 Act or (b) all appropriate action
        necessary for compliance with the registration requirements of the 1933
        Act or any exemption from registration available under the 1933 Act
        (including Rule 144) has been taken.

        The Corporation shall not be required (i) to transfer on its books any
Purchased Shares which have been sold or transferred in violation of the
provisions of this Agreement or (ii) to treat as the owner of the Purchased
Shares, or otherwise to accord voting, dividend or liquidation rights to, any
transferee to whom the Purchased Shares have been transferred in contravention
of this Agreement.

        3. Restrictive Legends. The stock certificates for the Purchased Shares
shall be endorsed with one or more of the following restrictive legends:

        "The shares represented by this certificate have not been registered
        under the Securities Act of 1933. The shares may not be sold or offered
        for sale in the absence of (a) an effective registration statement for
        the shares under such Act, (b) a "no action" letter of the Securities
        and Exchange Commission with respect to such sale or offer or (c)
        satisfactory assurances to the Corporation that registration under such
        Act is not required with respect to such sale or offer."

                                     - 2 -
<PAGE>   21

        "The shares represented by this certificate are subject to certain
        repurchase rights and rights of first refusal granted to the Corporation
        and accordingly may not be sold, assigned, transferred, encumbered, or
        in any manner disposed of except in conformity with the terms of a
        written agreement dated _________, 19__ between the Corporation and the
        registered holder of the shares (or the predecessor in interest to the
        shares). A copy of such agreement is maintained at the Corporation's
        principal corporate offices."

        C.     TRANSFER RESTRICTIONS

        1. Restriction on Transfer. Except for any Permitted Transfer, Optionee
shall not transfer, assign, encumber or otherwise dispose of any of the
Purchased Shares which are subject to the Repurchase Right. In addition,
Purchased Shares which are released from the Repurchase Right shall not be
transferred, assigned, encumbered or otherwise disposed of in contravention of
the First Refusal Right or the Market Stand-Off.

        2. Transferee Obligations. Each person (other than the Corporation) to
whom the Purchased Shares are transferred by means of a Permitted Transfer must,
as a condition precedent to the validity of such transfer, acknowledge in
writing to the Corporation that such person is bound by the provisions of this
Agreement and that the transferred shares are subject to (i) the Repurchase
Right, (ii) the First Refusal Right and (iii) the Market Stand-Off, to the same
extent such shares would be so subject if retained by Optionee.

        3. Market Stand-Off.

        (a) In connection with any underwritten public offering by the
Corporation of its equity securities pursuant to an effective registration
statement filed under the 1933 Act, including the Corporation's initial public
offering, Owner shall not sell, make any short sale of, loan, hypothecate,
pledge, grant any option for the purchase of, or otherwise dispose or transfer
for value or otherwise agree to engage in any of the foregoing transactions with
respect to, any Purchased Shares without the prior written consent of the
Corporation or its underwriters. Such restriction (the "Market Stand-Off") shall
be in effect for such period of time from and after the effective date of the
final prospectus for the offering as may be requested by the Corporation or such
underwriters. In no event, however, shall such period exceed one hundred eighty
(180) days and the Market Stand-Off shall in all events terminate two (2) years
after the effective date of the Corporation's initial public offering.

        (b) Owner shall be subject to the Market Stand-Off provided and only if
the officers and directors of the Corporation are also subject to similar
restrictions.

                                     - 3 -
<PAGE>   22

        (c) Any new, substituted or additional securities which are by reason of
any Recapitalization or Reorganization distributed with respect to the Purchased
Shares shall be immediately subject to the Market Stand-Off, to the same extent
the Purchased Shares are at such time covered by such provisions.

        (d) In order to enforce the Market Stand-Off, the Corporation may impose
stop-transfer instructions with respect to the Purchased Shares until the end of
the applicable stand-off period.

        D.     REPURCHASE RIGHT

        1. Grant. The Corporation is hereby granted the right (the "Repurchase
Right"), exercisable at any time during the sixty (60)-day period following the
date Optionee ceases for any reason to remain in Service or (if later) during
the sixty (60)-day period following the execution date of this Agreement, to
repurchase at the Exercise Price all or (at the discretion of the Corporation
and with the consent of Optionee) any portion of the Purchased Shares in which
Optionee is not at the time of his or her cessation of Service, vested in
accordance with the Vesting Schedule (such shares to be hereinafter referred to
as the "Unvested Shares").

        2. Exercise of the Repurchase Right. The Repurchase Right shall be
exercisable by written notice delivered to each Owner of the Unvested Shares
prior to the expiration of the sixty (60)-day exercise period. The notice shall
indicate the number of Unvested Shares to be repurchased and the date on which
the repurchase is to be effected, such date to be not more than thirty (30) days
after the date of such notice. The certificates representing the Unvested Shares
to be repurchased shall be delivered to the Corporation on or before the close
of business on the date specified for the repurchase. Concurrently with the
receipt of such stock certificates, the Corporation shall pay to Owner, in cash
or cash equivalents (including the cancellation of any purchase-money
indebtedness), an amount equal to the Exercise Price previously paid for the
Unvested Shares which are to be repurchased from Owner.

        3. Termination of the Repurchase Right. The Repurchase Right shall
terminate with respect to any Unvested Shares for which it is not timely
exercised under Paragraph D.2. In addition, the Repurchase Right shall terminate
and cease to be exercisable with respect to any and all Purchased Shares in
which Optionee vests in accordance with the Vesting Schedule. All Purchased
Shares as to which the Repurchase Right lapses shall, however, remain subject to
(i) the First Refusal Right and (ii) the Market Stand-Off.

        4. Aggregate Vesting Limitation. If the Option is exercised in more than
one increment so that Optionee is a party to one or more other Stock Purchase
Agreements (the "Prior Purchase Agreements") which are executed prior to the
date of this Agreement, then the total number of Purchased Shares as to which
Optionee shall be deemed to have

                                     - 4 -
<PAGE>   23

a fully-vested interest under this Agreement and all Prior Purchase Agreements
shall not exceed in the aggregate the number of Purchased Shares in which
Optionee would otherwise at the time be vested, in accordance with the Vesting
Schedule, had all the Purchased Shares (including those acquired under the Prior
Purchase Agreements) been acquired exclusively under this Agreement.

        5. Recapitalization. Any new, substituted or additional securities or
other property (including cash paid other than as a regular cash dividend) which
is by reason of any Recapitalization distributed with respect to the Purchased
Shares shall be immediately subject to the Repurchase Right and any escrow
requirements hereunder, but only to the extent the Purchased Shares are at the
time covered by such right or escrow requirements. Appropriate adjustments to
reflect such distribution shall be made to the number and/or class of Purchased
Shares subject to this Agreement and to the price per share to be paid upon the
exercise of the Repurchase Right in order to reflect the effect of any such
Recapitalization upon the Corporation's capital structure; provided, however,
that the aggregate purchase price shall remain the same.

        6. Corporate Transaction.

        (a) The Repurchase Right shall automatically terminate in its entirety,
and all the Purchased Shares shall vest in full, immediately prior to the
consummation of any Corporate Transaction, except to the extent the Repurchase
Right is to be assigned to the successor entity in such Corporate Transaction.

        (b) To the extent the Repurchase Right remains in effect following a
Corporate Transaction, such right shall apply to any new securities or other
property (including any cash payments) received in exchange for the Purchased
Shares in consummation of the Corporate Transaction, but only to the extent the
Purchased Shares are at the time covered by such right. Appropriate adjustments
shall be made to the price per share payable upon exercise of the Repurchase
Right to reflect the effect of the Corporate Transaction upon the Corporation's
capital structure; provided, however, that the aggregate purchase price shall
remain the same. The new securities or other property (including any cash
payments) issued or distributed with respect to the Purchased Shares in
consummation of the Corporate Transaction shall be immediately deposited in
escrow with the Corporation (or the successor entity) and shall not be released
from escrow until Optionee vests in such securities or other property in
accordance with the same Vesting Schedule in effect for the Purchased Shares.

        E. RIGHT OF FIRST REFUSAL

        1. Grant. The Corporation is hereby granted the right of first refusal
(the "First Refusal Right"), exercisable in connection with any proposed
transfer of the Purchased Shares in which Optionee has vested in accordance with
the provisions of Article D. For purposes of this Article E, the term "transfer"
shall include any sale, assignment, pledge,

                                     - 5 -
<PAGE>   24

encumbrance or other disposition of the Purchased Shares intended to be made by
Owner, but shall not include any Permitted Transfer.

        2. Notice of Intended Disposition. In the event any Owner of Purchased
Shares in which Optionee has vested desires to accept a bona fide third-party
offer for the transfer of any or all of such shares (the Purchased Shares
subject to such offer to be hereinafter referred to as the "Target Shares"),
Owner shall promptly (i) deliver to the Corporation written notice (the
"Disposition Notice") of the terms of the offer, including the purchase price
and the identity of the third-party offeror, and (ii) provide satisfactory proof
that the disposition of the Target Shares to such third-party offeror would not
be in contravention of the provisions set forth in Articles B and C.

        3. Exercise of the First Refusal Right. The Corporation shall, for a
period of twenty-five (25) days following receipt of the Disposition Notice,
have the right to repurchase any or all of the Target Shares subject to the
Disposition Notice upon the same terms as those specified therein or upon such
other terms (not materially different from those specified in the Disposition
Notice) to which Owner consents. Such right shall be exercisable by delivery of
written notice (the "Exercise Notice") to Owner prior to the expiration of the
twenty-five (25)-day exercise period. If such right is exercised with respect to
all the Target Shares, then the Corporation shall effect the repurchase of such
shares, including payment of the purchase price, not more than five (5) business
days after delivery of the Exercise Notice; and at such time the certificates
representing the Target Shares shall be delivered to the Corporation.

        Should the purchase price specified in the Disposition Notice be payable
in property other than cash or evidences of indebtedness, the Corporation shall
have the right to pay the purchase price in the form of cash equal in amount to
the value of such property. If Owner and the Corporation cannot agree on such
cash value within ten (10) days after the Corporation's receipt of the
Disposition Notice, the valuation shall be made by an appraiser of recognized
standing selected by Owner and the Corporation or, if they cannot agree on an
appraiser within twenty (20) days after the Corporation's receipt of the
Disposition Notice, each shall select an appraiser of recognized standing and
the two (2) appraisers shall designate a third appraiser of recognized standing,
whose appraisal shall be determinative of such value. The cost of such appraisal
shall be shared equally by Owner and the Corporation. The closing shall then be
held on the later of (i) the fifth (5th) business day following delivery of the
Exercise Notice or (ii) the fifth (5th) business day after such valuation shall
have been made.

        4. Non-Exercise of the First Refusal Right. In the event the Exercise
Notice is not given to Owner prior to the expiration of the twenty-five (25)-day
exercise period, Owner shall have a period of thirty (30) days thereafter in
which to sell or otherwise dispose of the Target Shares to the third-party
offeror identified in the Disposition Notice upon terms (including the purchase
price) no more favorable to such third-party offeror than those specified in the
Disposition Notice; provided, however, that any such sale or

                                     - 6 -
<PAGE>   25

disposition must not be effected in contravention of the provisions of Articles
B and C. The third-party offeror shall acquire the Target Shares free and clear
of the Repurchase Right and the First Refusal Right, but the acquired shares
shall remain subject to the provisions of Article B and Paragraph C.3. In the
event Owner does not effect such sale or disposition of the Target Shares within
the specified thirty (30)-day period, the First Refusal Right shall continue to
be applicable to any subsequent disposition of the Target Shares by Owner until
such right lapses.

        5. Partial Exercise of the First Refusal Right. In the event the
Corporation makes a timely exercise of the First Refusal Right with respect to a
portion, but not all, of the Target Shares specified in the Disposition Notice,
Owner shall have the option, exercisable by written notice to the Corporation
delivered within five (5) business days after Owner's receipt of the Exercise
Notice, to effect the sale of the Target Shares pursuant to either of the
following alternatives:

               (i) sale or other disposition of all the Target Shares to the
        third-party offeror identified in the Disposition Notice, but in full
        compliance with the requirements of Paragraph E.4, as if the Corporation
        did not exercise the First Refusal Right; or

               (ii) sale to the Corporation of the portion of the Target Shares
        which the Corporation has elected to purchase, such sale to be effected
        in substantial conformity with the provisions of Paragraph E.3. The
        First Refusal Right shall continue to be applicable to any subsequent
        disposition of the remaining Target Shares until such right lapses.

        Owner's failure to deliver timely notification to the Corporation shall
be deemed to be an election by Owner to sell the Target Shares pursuant to
alternative (i) above.

        6. Recapitalization/Reorganization.

        (a) Any new, substituted or additional securities or other property
which is by reason of any Recapitalization distributed with respect to the
Purchased Shares shall be immediately subject to the First Refusal Right, but
only to the extent the Purchased Shares are at the time covered by such right.

        (b) In the event of a Reorganization, the First Refusal Right shall
remain in full force and effect and shall apply to the new capital stock or
other property received in exchange for the Purchased Shares in consummation of
the Reorganization, but only to the extent the Purchased Shares are at the time
covered by such right.

        7. Lapse. The First Refusal Right shall lapse upon the earliest to occur
of (i) the first date on which shares of the Common Stock are held of record by
more than

                                     - 7 -
<PAGE>   26

five hundred (500) persons, (ii) a determination is made by the Board that a
public market exists for the outstanding shares of Common Stock or (iii) a firm
commitment underwritten public offering, pursuant to an effective registration
statement under the 1933 Act, covering the offer and sale of the Common Stock in
the aggregate amount of at least ten million dollars ($10,000,000). However, the
Market Stand-Off shall continue to remain in full force and effect following the
lapse of the First Refusal Right.

        F.     SPECIAL TAX ELECTION

        The acquisition of the Purchased Shares may result in adverse tax
consequences which may be avoided or mitigated by filing an election under Code
Section 83(b). Such election must be filed within thirty (30) days after the
date of this Agreement. A description of the tax consequences applicable to the
acquisition of the Purchased Shares and the form for making the Code Section
83(b) election are set forth in Exhibit II. OPTIONEE SHOULD CONSULT WITH HIS OR
HER TAX ADVISOR TO DETERMINE THE TAX CONSEQUENCES OF ACQUIRING THE PURCHASED
SHARES AND THE ADVANTAGES AND DISADVANTAGES OF FILING THE CODE SECTION 83(b)
ELECTION. OPTIONEE ACKNOWLEDGES THAT IT IS OPTIONEE'S SOLE RESPONSIBILITY, AND
NOT THE CORPORATION'S, TO FILE A TIMELY ELECTION UNDER CODE SECTION 83(b), EVEN
IF OPTIONEE REQUESTS THE CORPORATION OR ITS REPRESENTATIVES TO MAKE THIS FILING
ON HIS OR HER BEHALF.

        G.     GENERAL PROVISIONS

        1. Assignment. The Corporation may assign the Repurchase Right and/or
the First Refusal Right to any person or entity selected by the Board, including
(without limitation) one or more shareholders of the Corporation. If the
assignee of the Repurchase Right is other than (i) a wholly owned subsidiary of
the Corporation or (ii) the parent corporation owning one hundred percent (100%)
of the Corporation's outstanding capital stock, then such assignee must make a
cash payment to the Corporation, upon the assignment of the Repurchase Right, in
an amount equal to the excess (if any) of (i) the Fair Market Value of the
Purchased Shares at the time subject to the assigned Repurchase Right over (ii)
the aggregate repurchase price payable for the Purchased Shares.

        2. No Employment or Service Contract. Nothing in this Agreement or in
the Plan shall confer upon Optionee any right to continue in Service for any
period of specific duration or interfere with or otherwise restrict in any way
the rights of the Corporation (or any Parent or Subsidiary employing or
retaining Optionee) or of Optionee, which rights are hereby expressly reserved
by each, to terminate Optionee's Service at any time for any reason, with or
without cause.

        3. Notices. Any notice required to be given under this Agreement shall
be in writing and shall be deemed effective upon personal delivery or upon
deposit in the U.S. mail, registered or certified, postage prepaid and properly
addressed to the party

                                     - 8 -
<PAGE>   27

entitled to such notice at the address indicated below such party's signature
line on this Agreement or at such other address as such party may designate by
ten (10) days advance written notice under this paragraph to all other parties
to this Agreement.

        4. No Waiver. The failure of the Corporation in any instance to exercise
the Repurchase Right or the First Refusal Right shall not constitute a waiver of
any other repurchase rights and/or rights of first refusal that may subsequently
arise under the provisions of this Agreement or any other agreement between the
Corporation and Optionee. No waiver of any breach or condition of this Agreement
shall be deemed to be a waiver of any other or subsequent breach or condition,
whether of like or different nature.

        5. Cancellation of Shares. If the Corporation shall make available, at
the time and place and in the amount and form provided in this Agreement, the
consideration for the Purchased Shares to be repurchased in accordance with the
provisions of this Agreement, then from and after such time, the person from
whom such shares are to be repurchased shall no longer have any rights as a
holder of such shares (other than the right to receive payment of such
consideration in accordance with this Agreement). Such shares shall be deemed
purchased in accordance with the applicable provisions hereof, and the
Corporation shall be deemed the owner and holder of such shares, whether or not
the certificates therefor have been delivered as required by this Agreement.

        H.     MISCELLANEOUS PROVISIONS

        1. Optionee Undertaking. Optionee hereby agrees to take whatever
additional action and execute whatever additional documents the Corporation may
deem necessary or advisable in order to carry out or effect one or more of the
obligations or restrictions imposed on either Optionee or the Purchased Shares
pursuant to the provisions of this Agreement.

        2. Agreement is Entire Contract. This Agreement constitutes the entire
contract between the parties hereto with regard to the subject matter hereof.
This Agreement is made pursuant to the provisions of the Plan and shall in all
respects be construed in conformity with the terms of the Plan.

        3. Governing Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of California without resort to that
State's conflict-of-laws rules.

        4. Counterparts. This Agreement may be executed in counterparts, each of
which shall be deemed to be an original, but all of which together shall
constitute one and the same instrument.

        5. Successors and Assigns. The provisions of this Agreement shall inure
to the benefit of, and be binding upon, the Corporation and its successors and
assigns and

                                     - 9 -
<PAGE>   28

upon Optionee, optionee's permitted assigns and the legal representatives, heirs
and legatees of Optionee's estate, whether or not any such person shall have
become a party to this Agreement and have agreed in writing to join herein and
be bound by the terms hereof.

        IN WITNESS WHEREOF, the parties have executed this Agreement on the day
and year first indicated above.

                                        VINA TECHNOLOGIES, INC.

                                        By:
                                            ------------------------------------

                                        Title:
                                                --------------------------------

                                        Address:
                                                 -------------------------------

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

                                        ----------------------------------------
                                        OPTIONEE

                                        Address:
                                                 -------------------------------

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

                                     - 10 -
<PAGE>   29

                             SPOUSAL ACKNOWLEDGMENT

        The undersigned spouse of Optionee has read and hereby approves the
foregoing Stock Purchase Agreement. In consideration of the Corporation's
granting Optionee the right to acquire the Purchased Shares in accordance with
the terms of such Agreement, the undersigned hereby agrees to be irrevocably
bound by all the terms of such Agreement, including (without limitation) the
right of the Corporation (or its assigns) to purchase any Purchased Shares in
which Optionee is not vested at time of his or her cessation of Service.

                                        ----------------------------------------
                                        OPTIONEE'S SPOUSE

                                        Address:
                                                 -------------------------------

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

                                     - 11 -
<PAGE>   30

                                    EXHIBIT I

                      ASSIGNMENT SEPARATE FROM CERTIFICATE

        FOR VALUE RECEIVED ___________ hereby sell(s), assign(s) and transfer(s)
unto Vina Technologies, Inc. (the "Corporation"), _____________ (_____) shares
of the Common Stock of the Corporation standing in his or her name on the books
of the Corporation represented by Certificate No. ___________ herewith and
do(es) hereby irrevocably constitute and appoint _____________ Attorney to
transfer the said stock on the books of the Corporation with full power of
substitution in the premises.

        Dated:
               ------------------

                                        Signature
                                                 -------------------------------

INSTRUCTION: Please do not fill in any blanks other than the signature line.
Please sip exactly as you would like your name to appear on the issued stock
certificate. The purpose of this assignment is to enable the Corporation to
exercise the Repurchase Right without requiring additional signatures on the
part of Optionee.

                                       I
<PAGE>   31

                                   EXHIBIT II

                       FEDERAL INCOME TAX CONSEQUENCES AND
                           SECTION 83(b) TAX ELECTION

        I. Federal Income Tax Consequences and Section 83(b) Election For
Exercise of Non-Statutory Option. If the Purchased Shares are acquired pursuant
to the exercise of a Non-Statutory Option, as specified in the Grant Notice,
then under Code Section 83, the excess of the Fair Market Value of the Purchased
Shares on the date any forfeiture restrictions applicable to such shares lapse
over the Exercise Price paid for such shares will be reportable as ordinary
income on the lapse date. For this purpose, the term "forfeiture restrictions"
includes the right of the Corporation to repurchase the Purchased Shares
pursuant to the Repurchase Right. However, Optionee may elect under Code Section
83(b) to be taxed at the time the Purchased Shares are acquired, rather than
when and as such Purchased Shares cease to be subject to such forfeiture
restrictions. Such election must be filed with the Internal Revenue Service
within thirty (30) days after the date of the Agreement. Even if the Fair Market
Value of the Purchased Shares on the date of the Agreement equals the Exercise
Price paid (and thus no tax is payable), the election must be made to avoid
adverse tax consequences in the future. The form for making this election is
attached as part of this exhibit. FAILURE TO MAKE THIS FILING WITHIN THE
APPLICABLE THIRTY (30)-DAY PERIOD WILL RESULT IN THE RECOGNITION OF ORDINARY
INCOME BY OPTIONEE AS THE FORFEITURE RESTRICTIONS LAPSE.

        II. Federal Income Tax Consequences and Conditional Section 83(b)
Election For Exercise of Incentive Option. If the Purchased Shares are acquired
pursuant to the exercise of an Incentive Option, as specified in the Grant
Notice, then the following tax principles shall be applicable to the Purchased
Shares:

               (i) For regular tax purposes, no taxable income will be
        recognized at the time the Option is exercised.

               (ii) The excess of (a) the Fair Market Value of the Purchased
        Shares on the date the Option is exercised or (if later) on the date any
        forfeiture restrictions applicable to the Purchased Shares lapse over
        (b) the Exercise Price paid for the Purchased Shares will be includible
        in Optionee's taxable income for alternative minimum tax purposes.

               (iii) If Optionee makes a disqualifying disposition of the
        Purchased Shares, then Optionee will recognize ordinary income in the
        year of such disposition equal in amount to the excess of (a) the Fair
        Market Value of the Purchased Shares on the date the Option is exercised
        or (if later) on the date any forfeiture restrictions applicable to the
        Purchased Shares lapse over (b) the Exercise Price paid for the
        Purchased Shares. Any additional gain recognized upon the disqualifying
        disposition will be either

                                      II-1
<PAGE>   32

        short-term or long-term capital gain depending upon the period for which
        the Purchased Shares are held prior to the disposition.

               (iv) For purposes of the foregoing, the term "forfeiture
        restrictions" will include the right of the Corporation to repurchase
        the Purchased Shares pursuant to the Repurchase Right. The term
        "disqualifying disposition" means any sale or other disposition(1) of
        the Purchased Shares within two (2) years after the Grant Date or within
        one (1) year after the exercise date of the Option.

               (v) In the absence of final Treasury Regulations relating to
        Incentive Options, it is not certain whether Optionee may, in connection
        with the exercise of the Option for any Purchased Shares at the time
        subject to forfeiture restrictions, file a protective election under
        Code Section 83(b) which would limit (a) Optionee's alternative minimum
        taxable income upon exercise and (b) Optionee's ordinary income upon a
        disqualifying disposition to the excess of the Fair Market Value of the
        Purchased Shares on the date the Option is exercised over the Exercise
        Price paid for the Purchased Shares. Accordingly, such election if
        properly filed will only be allowed to the extent the final Treasury
        Regulations permit such a protective election. Page 2 of the attached
        form for making the election should be filed with any election made in
        connection with the exercise of an Incentive Option.

--------

(1) Generally, a disposition of shares purchased under an Incentive Option
    includes any transfer of legal title, including a transfer by sale, exchange
    or gift, but does not include a transfer to the Optionee's spouse, a
    transfer into joint ownership with right of survivorship if Optionee remains
    one of the joint owners, a pledge, a transfer by bequest or inheritance or
    certain tax free exchanges permitted under the Code.

                                      II-2

<PAGE>   33

                             SECTION 83(b) ELECTION

        This statement is being made under Section 83(b) f the Internal Revenue
Code, pursuant to Treas. Reg. Section 1.83-2.

(1)     The taxpayer who performed the services is:

        Name:
        Address:
        Taxpayer Ident. No.:

(2)     The property with respect to which the election is being made is
        ________ shares of the common stock of Vina Technologies, Inc.

(3)     The property was issued on ________, 199_.

(4)     The taxable year in which the election is being made is the calendar
        year 199_.

(5)     The property is subject to a repurchase right pursuant to which the
        issuer has the right to acquire the property at the original purchase
        price if for any reason taxpayer's employment with the issuer is
        terminated. The issuer's repurchase right lapses in a series of
        installments over a four (4)-year period ending on ___________, 200_.

(6)     The fair market value at the time of transfer (determined without regard
        to any restriction other than a restriction which by its terms will
        never lapse) is $_________ per share.

(7)     The amount paid for such property is $__________ per share.

(8)     A copy of this statement was furnished to Vina Technologies, Inc. for
        whom taxpayer rendered the services underlying the transfer of property.

(9)     This statement is executed on ______________, 199_.

-----------------------------------          -----------------------------------
(              )                             (                 )
 --------------                               -----------------
Spouse (if any)                              Taxpayer

This election must be filed with the Internal Revenue Service Center with which
taxpayer files his or her Federal income tax returns and must be made within
thirty (30) days after the execution date of the Stock Purchase Agreement. This
filing should be made by registered or certified mail, return receipt requested.
Optionee must retain two (2) copies of the completed form for filing with his or
her Federal and state tax returns for the current tax year and an additional
copy for his or her records.

<PAGE>   34

The property described in the above Section 83(b) election is comprised of
shares of common stock acquired pursuant to the exercise of an incentive stock
option under Section 422 of the Internal Revenue Code (the "Code"). Accordingly,
it is the intent of the Taxpayer to utilize this election to achieve the
following tax results:

        1. The purpose of this election is to have the alternative minimum
taxable income attributable to the purchased shares measured by the amount by
which the fair market value of such shares at the time of their transfer to the
Taxpayer exceeds the purchase price paid for the shares. In the absence of this
election, such alternative minimum taxable income would be measured by the
spread between the fair market value of the purchased shares and the purchase
price which exists on the various lapse dates in effect for the forfeiture
restrictions applicable to such shares. The election is to be effective to the
full extent permitted under the Code.

        2. Section 421(a)(1) of the Code expressly excludes from income any
excess of the fair market value of the purchased shares over the amount paid for
such shares. Accordingly, this election is also intended to be effective in the
event there is a "disqualifying disposition" of the shares, within the meaning
of Section 421(b) of the Code, which would otherwise render the provisions of
Section 83(a) of the Code applicable at that time. Consequently, the Taxpayer
hereby elects to have the amount of disqualifying disposition income measured by
the excess of the fair market value of the purchased shares on the date of
transfer to the Taxpayer over the amount paid for such shares. Since Section
421(a) presently applies to the shares which are the subject of this Section
83(b) election, no taxable income is actually recognized for regular tax
purposes at this time, and no income taxes are payable, by the Taxpayer as a
result of this election.

THIS PAGE 2 IS TO BE ATTACHED TO ANY SECTION 83(b) ELECTION FILED IN CONNECTION
WITH THE EXERCISE OF AN INCENTIVE STOCK OPTION UNDER THE FEDERAL TAX LAWS.

<PAGE>   35

                                    APPENDIX

        The following definitions shall be in effect under the Agreement:

        A. AGREEMENT shall mean this Stock Purchase Agreement.

        B. BOARD shall mean the Corporation's Board of Directors.

        C. CODE shall mean the Internal Revenue Code of 1986, as amended.

        D. COMMON STOCK shall mean the Corporation's common stock.

        E. CORPORATE TRANSACTION shall mean either of the following
shareholder-approved transactions:

               (i) a merger or consolidation in which securities possessing more
        than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

               (ii) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. CORPORATION shall mean Vina Technologies, Inc., a California
corporation.

        G. DISPOSITION NOTICE shall have the meaning assigned to such term in
Paragraph E.2.

        H. EXERCISE NOTICE shall have the meaning assigned to such term in
Paragraph E.3.

        I. EXERCISE PRICE shall have the meaning assigned to such term in
Paragraph A.1.

        J. FAIR MARKET VALUE of a share of Common Stock on any relevant date,
prior to the initial public offering of the Common Stock, shall be determined by
the Plan Administrator after taking into account such factors as it shall deem
appropriate.

        K. FIRST REFUSAL RIGHT shall mean the right granted to the Corporation
in accordance with Article E.

        L. GRANT DATE shall have the meaning assigned to such term in Paragraph
A.1.

                                       A-1

<PAGE>   36

        M. GRANT NOTICE shall mean the Notice of Grant of Stock Option pursuant
to which Optionee has been informed of the basic terms of the Option.

        N. INCENTIVE OPTION shall mean an option which satisfies the
requirements of Code Section 422.

        O. MARKET STAND-OFF shall mean the market stand-off restriction
specified in Paragraph C.3.

        P. MISCONDUCT shall mean the commission of any act of fraud,
embezzlement or dishonesty by Optionee, any unauthorized use or disclosure by
Optionee of confidential information or trade secrets of the Corporation (or any
Parent or Subsidiary), or any other intentional misconduct by Optionee adversely
affecting the business or affairs of the Corporation (or any Parent or
Subsidiary) in a material manner. The foregoing definition shall not be deemed
to be inclusive of all the acts or omissions which the Corporation (or any
Parent or Subsidiary) may consider as grounds for the dismissal or discharge of
Optionee or any other individual in the Service of the Corporation (or any
Parent or Subsidiary).

        Q. 1933 ACT shall mean the Securities Act of 1933, as amended.

        R. 1934 ACT shall mean the Securities Exchange Act of 1934, as amended.

        S. NON-STATUTORY OPTION shall mean an option not intended to satisfy the
requirements of Code Section 422.

        T. OPTION shall have the meaning assigned to such term in Paragraph A.1.

        U. OPTION AGREEMENT shall mean all agreements and other documents
evidencing the Option.

        V. OPTIONEE shall mean the person to whom the Option is granted under
the Plan.

        W. OWNER shall mean Optionee and all subsequent holders of the Purchased
Shares who derive their chain of ownership through a Permitted Transfer from
Optionee.

        X. PARENT shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, stock possessing fifty percent (50%) or more of the total
combined voting power of all classes of stock in one of the other corporations
in such chain.

                                       A-2

<PAGE>   37

        Y. PERMITTED TRANSFER shall mean (i) a gratuitous transfer of the
Purchased Shares, provided and only if Optionee obtains the Corporation's prior
written consent to such transfer, (ii) a transfer of title to the Purchased
Shares effected pursuant to Optionee's will or the laws of intestate succession
following Optionee's death or (iii) a transfer to the Corporation in pledge as
security for any purchase-money indebtedness incurred by Optionee in connection
with the acquisition of the Purchased Shares.

        Z. PLAN shall mean the Corporation's 1996 Stock Option Plan.

        AA. PLAN ADMINISTRATOR shall mean either the Board or a committee of the
Board acting in its capacity as administrator of the Plan.

        AB. PRIOR PURCHASE AGREEMENT shall have the meaning assigned to such
term in Paragraph D.4.

        AC. PURCHASED SHARES shall have the meaning assigned to such term in
Paragraph A.1.

        AD. RECAPITALIZATION shall mean any stock split, stock dividend,
recapitalization, combination of shares, exchange of shares or other change
affecting the Corporation's outstanding Common Stock as a class without the
Corporation's receipt of consideration.

        AE. ORGANIZATION shall mean any of the following transactions:

               (i) a merger or consolidation in which the Corporation is not the
        surviving entity,

               (ii) a sale, transfer or other disposition of all or
        substantially all of the Corporation's assets,

               (iii) a reverse merger in which the Corporation is the surviving
        entity but in which the Corporation's outstanding voting securities are
        transferred in whole or in part to a person or persons different from
        the persons holding those securities immediately prior to the merger, or

               (iv) any transaction effected primarily to change the state in
        which the Corporation is incorporated or to create a holding company
        structure.

        AF. REPURCHASE RIGHT shall mean the right granted to the Corporation in
accordance with Article D.

        AG. SEC shall mean the Securities and Exchange Commission.

                                       A-3

<PAGE>   38

        AH. SERVICE shall mean the Optionee's performance of services for the
Corporation (or any Parent or Subsidiary) in the capacity of an employee,
subject to the control and direction of the employer entity as to both the work
to be performed and the manner and method of performance, a non-employee member
of the board of directors or an independent consultant.

        AI. SUBSIDIARY shall mean any corporation (other than the Corporation)
in an unbroken chain of corporations beginning with the Corporation, provided
each corporation (other than the last corporation) in the unbroken chain owns,
at the time of the determination, stock possessing fifty percent (50%) or more
of the total combined voting power of all classes of stock in one of the other
corporations in such chain.

        AJ. TARGET SHARES shall have the meaning assigned to such term in
Paragraph E.2.

        AK. VESTING SCHEDULE shall mean the vesting schedule specified in the
Grant Notice pursuant to which the Optionee is to vest in the Option Shares in a
series of installments over his or her period of Service.

        AL. UNVESTED SHARES shall have the meaning assigned to such term in
Paragraph D.1.

                                       A-4
<PAGE>   39

                                    ADDENDUM
                                       TO
                            STOCK PURCHASE AGREEMENT

        The following provisions are hereby incorporated into, and are hereby
made a part of, that certain Stock Purchase Agreement ( the "Purchase
Agreement") by and between Vina Technologies, Inc. (the "Corporation") and 1
("Optionee") evidencing the Optionee's purchase of shares of the Corporation's
common stock (the "Purchased Shares") pursuant to that certain option granted on
2 to Optionee under the Corporation's 1996 Stock Option/Stock Issuance Plan, and
such provisions shall be effective as of the Effective Date specified below. All
capitalized terms in this Addendum, to the extent not otherwise defined herein,
shall have the meanings assigned to them in the Purchase Agreement.

                        INVOLUNTARY TERMINATION FOLLOWING
                              CORPORATE TRANSACTION

        1. To the extent the Repurchase Right is assigned to the successor
corporation (or parent thereof) in connection with a Corporate Transaction, no
accelerated vesting of the Purchased Shares shall occur upon such Corporate
Transaction, and the Repurchase Right shall continue to remain in full force and
effect in accordance with the provisions of the Purchase Agreement. Accordingly,
the Optionee shall, over Optionee's continued period of Service after the
Corporate Transaction, continue to vest in the Purchased Shares pursuant to the
provisions of the Vesting Schedule in effect under the Purchase Agreement.
However, immediately upon an Involuntary Termination of Optionee's Service
within twelve (12) months after the effective date of the Corporate Transaction,
the Repurchase Right shall automatically terminate in its entirety and all the
Purchased Shares shall vest in full.

        2. For purposes of this Addendum, the following definitions shall be in
effect:

        An INVOLUNTARY TERMINATION shall mean the termination of Optionee's
Service by reason of:

             (i) Optionee's involuntary dismissal or discharge by the
        Corporation for reasons other than Misconduct, or

             (ii) Optionee's voluntary resignation following (A) a change in
        Optionee's position with the Corporation (or Parent or Subsidiary
        employing Optionee) which materially reduces Optionee's level of
        responsibility, (B) a reduction in Optionee's level of compensation
        (including base salary, fringe benefits and participation in any
        corporate-performance based bonus or incentive programs) by more than
        fifteen percent (15%) or

<PAGE>   40

        (C) a relocation of Optionee's place of employment by more than fifty
        (50) miles, provided and only if such change, reduction or relocation is
        effected by the Corporation without Optionee's consent.

        MISCONDUCT shall mean the commission of any act of fraud, embezzlement
or dishonesty by Optionee, any unauthorized use or disclosure by Optionee of
confidential information or trade secrets of the Corporation (or any Parent or
Subsidiary), or any other intentional misconduct by Optionee adversely affecting
the business or affairs of the Corporation (or any Parent or Subsidiary) in a
material manner. The foregoing definition shall not be deemed to be inclusive of
all the acts or omissions which the Corporation (or any Parent or Subsidiary)
may consider as grounds for the dismissal or discharge of Optionee or other
person in the Service of the Corporation (or any Parent or Subsidiary).

        IN WITNESS WHEREOF, Vina Technologies, Inc. has caused this Addendum to
be executed by its duly-authorized officer, and Optionee has executed this
Addendum, all as of the Effective Date specified below.

                                       VINA TECHNOLOGIES, INC.

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

                                       ---------------------------------------
                                       1 ~, OPTIONEE

EFFECTIVE DATE:     ___________,199__

                                      -2-

<PAGE>   41

                             VINA TECHNOLOGIES, INC.
                             STOCK OPTION AGREEMENT

RECITALS

        A. The Board has adopted the Plan for the purpose of retaining the
services of selected Employees, non-employee members of the Board or the board
of directors of any Parent or Subsidiary and consultants and other independent
advisors in the service of the Corporation (or any Parent or Subsidiary).

        B. Optionee is to render valuable services to the Corporation (or a
Parent or Subsidiary), and this Agreement is executed pursuant to, and is
intended to carry out the purposes of, the Plan in connection with the
Corporation's grant of an option to Optionee.

        C. All capitalized terms in this Agreement shall have the meaning
assigned to them in the attached Appendix.

        NOW, THEREFORE, it is hereby agreed as follows:

                1. GRANT OF OPTION. The Corporation hereby grants to Optionee,
as of the Grant Date, an option to purchase up to the number of Option Shares
specified in the Grant Notice. The Option Shares shall be purchasable from time
to time during the option term specified in Paragraph 2 at the Exercise Price.

                2. OPTION TERM. This option shall have a term of ten (10) years
measured from the Grant Date and shall accordingly expire at the close of
business on the Expiration Date, unless sooner terminated in accordance with
Paragraph 5 or 6.

                3. LIMITED TRANSFERABILITY. During Optionee's lifetime, this
option shall be exercisable only by Optionee and shall not be assignable or
transferable other than by will or by the laws of descent and distribution
following Optionee's death.

                4. DATES OF EXERCISE. This option shall become exercisable for
the Option Shares in one or more installments as specified in the Grant Notice.
As the option becomes exercisable for such installments, those installments
shall accumulate and the option shall remain exercisable for the accumulated
installments until the Expiration Date or sooner termination of the option term
under Paragraph 5 or 6.

<PAGE>   42

        5. CESSATION OF SERVICE. The option term specified in Paragraph 2 shall
terminate (and this option shall cease to be outstanding) prior to the
Expiration Date should any of the following provisions become applicable:

                (a) Should Optionee cease to remain in Service for any reason
(other than death or Disability) while this option is outstanding, then Optionee
shall have a period of three (3) months (commencing with the date of such
cessation of Service) during which to exercise this option, but in no event
shall this option be exercisable at any time after the Expiration Date.

                (b) Should Optionee die while this option is outstanding, then
the personal representative of Optionee's estate or the person or persons to
whom the option is transferred pursuant to Optionee's will or in accordance with
the laws of inheritance shall have the right to exercise this option. Such right
shall lapse, and this option shall cease to be outstanding, upon the earlier of
(i) the expiration of the twelve (12)- month period measured from the date of
Optionee's death or (ii) the Expiration Date.

                (c) Should Optionee cease Service by reason of Disability while
this option is outstanding, then Optionee shall have a period of twelve (12)
months (commencing with the date of such cessation of Service) during which to
exercise this option. In no event shall this option be exercisable at any time
after the Expiration Date.

        Note: Exercise of this option on a date later than three (3) months
        following cessation of Service due to Disability will result in loss of
        favorable Incentive Option treatment, unless such Disability constitutes
        Permanent Disability. In the event that Incentive Option treatment is
        not available, this option will be taxed as a Non-Statutory Option upon
        exercise.

                (d) During the limited period of post-Service exercisability,
this option may not be exercised in the aggregate for more than the number of
Option Shares in which Optionee is, at the time of Optionee's cessation of
Service, vested pursuant to the Vesting Schedule specified in the Grant Notice
or the special vesting acceleration provisions of Paragraph 6. Upon the
expiration of such limited exercise period or (if earlier) upon the Expiration
Date, this option shall terminate and cease to be outstanding for any vested
Option Shares for which the option has not been exercised. To the extent
Optionee is not vested in the Option Shares at the time of Optionee's cessation
of Service, this option shall immediately terminate and cease to be outstanding
with respect to those shares.

                (e) In the event of a Corporate Transaction, the provisions of
Paragraph 6 shall govern the period for which this option is to remain
exercisable following Optionee's cessation of Service and shall supersede any
provisions to the contrary in this paragraph.

                                      -2-
<PAGE>   43

        6. ACCELERATED VESTING.

                (a) In the event of any Corporate Transaction, the Option Shares
at the time subject to this option but not otherwise vested shall automatically
vest in full so that this option shall, immediately prior to the effective date
of the Corporate Transaction, become fully exercisable for all of those Option
Shares and may be exercised for any or all of those Option Shares as
fully-vested shares of Common Stock. However, the Option Shares shall not vest
on such an accelerated basis if and to the extent: (i) this option is assumed by
the successor corporation (or parent thereof) in the Corporate Transaction and
the Corporation's repurchase rights with respect to the unvested Option Shares
are assigned to such successor corporation (or parent thereof) or (ii) this
option is to be replaced with a cash incentive program of the successor
corporation which preserves the spread existing on the unvested Option Shares at
the time of the Corporate Transaction (the excess of the Fair Market Value of
those Option Shares over the Exercise Price payable for such shares) and
provides for subsequent payout in accordance with the same Vesting Schedule
applicable to those unvested Option Shares as set forth in the Grant Notice.

                (b) Immediately following the Corporate Transaction, this option
shall terminate and cease to be outstanding, except to the extent assumed by the
successor corporation (or parent thereof) in connection with the Corporate
Transaction.

                (c) If this option is assumed in connection with a Corporate
Transaction, then this option shall be appropriately adjusted, immediately after
such Corporate Transaction, to apply to the number and class of securities which
would have been issuable to Optionee in consummation of such Corporate
Transaction had the option been exercised immediately prior to such Corporate
Transaction, and appropriate adjustments shall also be made to the Exercise
Price, provided the aggregate Exercise Price shall remain the same.

                (d) This Agreement shall not in any way affect the right of the
Corporation to adjust, reclassify, reorganize or otherwise change its capital or
business structure or to merge, consolidate, dissolve, liquidate or sell or
transfer all or any part of its business or assets.

        7. ADJUSTMENT IN OPTION SHARES. Should any change be made to the Common
Stock by reason of any stock split, stock dividend, recapitalization,
combination of shares, exchange of shares or other change affecting the
outstanding Common Stock as a class without the Corporation's receipt of
consideration, appropriate adjustments shall be made to (i) the total number
and/or class of securities subject to this option and (ii) the Exercise Price in
order to reflect such change and thereby preclude a dilution or enlargement of
benefits hereunder.

                                      -3-
<PAGE>   44

        8. SHAREHOLDER RIGHTS. The holder of this option shall not have any
shareholder rights with respect to the Option Shares until such person shall
have exercised the option, paid the Exercise Price and become a holder of record
of the purchased shares.

        9. MANNER OF EXERCISING OPTION.

                (a) In order to exercise this option with respect to all or any
part of the Option Shares for which this option is at the time exercisable,
Optionee (or any other person or persons exercising the option) must take the
following actions:

                (i) Execute and deliver to the Corporation a Purchase Agreement
        for the Option Shares for which the option is exercised.

                (ii) Pay the aggregate Exercise Price for the purchased shares
        in one or more of the following forms:

                        (A) cash or check made payable to the Corporation; or

                        (B) a promissory note payable to the Corporation, but
        only to the extent authorized by the Plan Administrator in accordance
        with Paragraph 14.

                Should the Common Stock be registered under Section 12(g) of the
        1934 Act at the time the option is exercised, then the Exercise Price
        may also be paid as follows:

                        (C) in shares of Common Stock held by Optionee (or any
        other person or persons exercising the option) for the requisite period
        necessary to avoid a charge to the Corporation's earnings for financial
        reporting purposes and valued at Fair Market Value on the Exercise Date;
        or

                        (D) to the extent the option is exercised for vested
        Option Shares, through a special sale and remittance procedure pursuant
        to which Optionee (or any other person or persons exercising the option)
        shall concurrently provide irrevocable written instructions (a) to a
        Corporation-designated brokerage firm to effect the immediate sale of
        the purchased shares and remit to the Corporation, out of the sale
        proceeds available on the settlement date, sufficient funds to cover the
        aggregate Exercise Price payable for the purchased shares plus all
        applicable Federal, state and local income and employment taxes required
        to be withheld by the Corporation by reason of such exercise

                                      -4-
<PAGE>   45

        and (b) to the Corporation to deliver the certificates for the Purchased
        shares directly to such brokerage firm in order to complete the sale.

                Except to the extent the sale and remittance procedure is
        utilized in connection with the option exercise, payment of the Exercise
        Price must accompany the Purchase Agreement delivered to the Corporation
        in connection with the option exercise.

                              (iii) Furnish to the Corporation appropriate
        documentation that the person or persons exercising the option (if other
        than Optionee) have the right to exercise this option.

                              (iv) Execute and deliver to the Corporation such
        written representations as may be requested by the Corporation in Order
        for it to comply with the applicable requirements of Federal and state
        securities laws.

                              (v) Make appropriate arrangements with the
        Corporation (or Parent or Subsidiary employing or retaining Optionee)
        for the satisfaction of all Federal, state and local income and
        employment tax withholding requirements applicable to the option
        exercise.

                        (b) As soon as practical after the Exercise Date, the
        Corporation shall issue to or on behalf of Optionee (or any other person
        or persons exercising this option) a certificate for the purchased
        Option Shares, with the appropriate legends affixed thereto.

                        (c) In no event may this option be exercised for any
        fractional shares.

        10. REPURCHASE RIGHTS. ALL OPTION SHARES ACQUIRED UPON THE EXERCISE OF
THIS OPTION SHALL BE SUBJECT TO CERTAIN RIGHTS OF THE CORPORATION AND ITS
ASSIGNS TO REPURCHASE THOSE SHARES IN ACCORDANCE WITH THE TERMS SPECIFIED IN THE
PURCHASE AGREEMENT.

        11. COMPLIANCE WITH LAWS AND REGULATIONS.

                (a) The exercise of this option and the issuance of the Option
Shares upon such exercise shall be subject to compliance by the Corporation and
Optionee with all applicable requirements of law relating thereto and with all
applicable regulations of any stock exchange (or the Nasdaq National Market, if
applicable) on which the Common Stock may be listed for trading at the time of
such exercise and issuance.

                                      -5-
<PAGE>   46

                (b) The inability of the Corporation to obtain approval from any
regulatory body having authority deemed by the Corporation to be necessary to
the lawful issuance and sale of any Common Stock pursuant to this option shall
relieve the Corporation of any liability with respect to the non-issuance or
sale of the Common Stock as to which such approval shall not have been obtained.
The Corporation, however, shall use its best efforts to obtain all such
approvals.

        12. SUCCESSORS AND ASSIGNS. Except to the extent otherwise provided in
Paragraphs 3 and 6, the provisions of this Agreement shall inure to the benefit
of, and be binding upon, the Corporation and its successors and assigns and
Optionee, Optionee's assigns and the legal representatives, heirs and legatees
of Optionee's estate.

        13. NOTICES. Any notice required to be given or delivered to the
Corporation under the terms of this Agreement shall be in writing and addressed
to the Corporation at its principal corporate offices. Any notice required to be
given or delivered to Optionee shall be in writing and addressed to Optionee at
the address indicated below Optionee's signature line on the Grant Notice. All
notices shall be deemed effective upon personal delivery or upon deposit in the
U.S. mail, postage prepaid and properly addressed to the party to be notified.

        14. FINANCING. The Plan Administrator may, in its absolute discretion
and without any obligation to do so, permit Optionee to pay the Exercise Price
for the purchased Option Shares by delivering a full-recourse, interest-bearing
promissory note secured by those Option Shares. The payment schedule in effect
for any such promissory note shall be established by the Plan Administrator in
its sole discretion.

        15. CONSTRUCTION. This Agreement and the option evidenced hereby are
made and granted pursuant to the Plan and are in all respects limited by and
subject to the terms of the Plan. All decisions of the Plan Administrator with
respect to any question or issue arising under the Plan or this Agreement shall
be conclusive and binding on all persons having an interest in this option.

        16. GOVERNING LAW. The interpretation, performance and enforcement of
this Agreement shall be governed by the laws of the State of California without
resort to that State's conflict-of-laws rules.

        17. SHAREHOLDER APPROVAL. If the Option Shares covered by this Agreement
exceed, as of the Grant Date, the number of shares of Common Stock which may be
issued under the Plan as last approved by the shareholders, then this option
shall be void with respect to such excess shares, unless shareholder approval of
an amendment sufficiently increasing the number of shares of Common Stock
issuable under the Plan is obtained in accordance with the provisions of the
Plan.

                                      -6-
<PAGE>   47

        18. ADDITIONAL TERMS APPLICABLE TO AN INCENTIVE OPTION. In the event
this option is designated an Incentive Option in the Grant Notice, the following
terms and conditions shall also apply to the grant:

                (a) This option shall cease to qualify for favorable tax
treatment as an Incentive Option if (and to the extent) this option is exercised
for one or more Option Shares: (i) more than three (3) months after the date
Optionee ceases to be an Employee for any reason other than death or Permanent
Disability or (ii) more than twelve (12) months after the date Optionee ceases
to be an Employee by reason of Permanent Disability.

                (b) This option shall not become exercisable in the calendar
year in which granted if (and to the extent) the aggregate Fair Market Value
(determined at the Grant Date) of the Common Stock for which this option would
otherwise first become exercisable in such calendar year would, when added to
the aggregate value (determined as of the respective date or dates of grant) of
the Common Stock and any other securities for which one or more other Incentive
Options granted to Optionee prior to the Grant Date (whether under the Plan or
any other option plan of the Corporation or any Parent or Subsidiary) first
become exercisable during the same calendar year, exceed One Hundred Thousand
Dollars ($100,000) in the aggregate. To the extent the exercisability of this
option is deferred by reason of the foregoing limitation, the deferred portion
shall become exercisable in the first calendar year or years thereafter in which
the One Hundred Thousand Dollar ($100,000) limitation of this Paragraph 18(b)
would not be contravened, but such deferral shall in all events end immediately
prior to the effective date of a Corporate Transaction in which this option is
not to be assumed, whereupon the option shall become immediately exercisable as
a Non-Statutory Option for the deferred portion of the Option Shares.

                (c) Should Optionee hold, in addition to this option, one or
more other options to purchase Common Stock which become exercisable for the
first time in the same calendar year as this option, then the foregoing
limitations on the exercisability of such options as Incentive Options shall be
applied on the basis of the order in which such options are granted.

                                      -7-
<PAGE>   48

                                    APPENDIX

        The following definitions shall be in effect under the Agreement:

        A. AGREEMENT shall mean this Stock Option Agreement.

        B. BOARD shall mean the Corporation's Board of Directors.

        C. CODE shall mean the Internal Revenue Code of 1986, as amended.

        D. COMMON STOCK shall mean the Corporation's common stock.

        E. CORPORATE TRANSACTION shall mean either of the following
shareholder-approved transactions to which the Corporation is a party:

                (i) a merger or consolidation in which securities possessing
        more than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

                (ii) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. CORPORATION shall mean Vina Technologies, Inc., a California
corporation.

        G. DISABILITY shall mean the inability of Optionee to engage in any
substantial gainful activity by reason of any medically determinable physical or
mental impairment and shall be determined by the Plan Administrator on the basis
of such medical evidence as the Plan Administrator deems warranted under the
circumstances. Disability shall be deemed to constitute Permanent Disability in
the event that such Disability is expected to result in death or has lasted or
can be expected to last for a continuous period of twelve (12) months or more.

        H. EMPLOYEE shall mean an individual who is in the employ of the
Corporation (or any Parent or Subsidiary), subject to the control and direction
of the employer entity as to both the work to be performed and the manner and
method of performance.

        I. EXERCISE DATE shall mean the date on which the option shall have been
exercised in accordance with Paragraph 9 of the Agreement.

                                      A-1.
<PAGE>   49

        J. EXERCISE PRICE shall mean the exercise price payable per Option Share
as specified in the Grant Notice.

        K. EXPIRATION DATE shall mean the date on which the option expires as
specified in the Grant Notice.

        L. FAIR MARKET VALUE per share of Common Stock on any relevant date
shall be determined in accordance with the following provisions:

                (i) If the Common Stock is at the time traded on the Nasdaq
        National Market, then the Fair Market Value shall be the closing selling
        price per share of Common Stock on the date in question, as the price is
        reported by the National Association of Securities Dealers on the Nasdaq
        National Market or any successor system. If there is no closing selling
        price for the Common Stock on the date in question, then the Fair Market
        Value shall be the closing selling price on the last preceding date for
        which such quotation exists.

                (ii) If the Common Stock is at the time listed on any Stock
        Exchange, then the Fair Market Value shall be the closing selling price
        per share of Common Stock on the date in question on the Stock Exchange
        determined by the Plan Administrator to be the primary market for the
        Common Stock, as such price is officially quoted in the composite tape
        of transactions on such exchange. If there is no closing selling price
        for the Common Stock on the date in question, then the Fair Market Value
        shall be the closing selling price on the last preceding date for which
        such quotation exists.

                (iii) If the Common Stock is at the time neither listed on any
        Stock Exchange nor traded on the Nasdaq National Market, then the Fair
        Market Value shall be determined by the Plan Administrator after taking
        into account such factors as the Plan Administrator shall deem
        appropriate.

        M. GRANT DATE shall mean the date of grant of the option as specified in
the Grant Notice.

        N. GRANT NOTICE shall mean the Notice of Grant of Stock Option
accompanying the Agreement, pursuant to which Optionee has been informed of the
basic terms of the option evidenced hereby.

        O. INCENTIVE OPTION shall mean an option which satisfies the
requirements of Code Section 422.

                                      A-2.
<PAGE>   50

        P. MISCONDUCT shall mean the commission of any act of fraud,
embezzlement or dishonesty by Optionee, any unauthorized use or disclosure by
Optionee of confidential information or trade secrets of the Corporation (or any
Parent or Subsidiary), or any other intentional misconduct by Optionee adversely
affecting the business or affairs of the Corporation (or any Parent or
Subsidiary) in a material manner. The foregoing definition shall not be deemed
to be inclusive of all the acts or omissions which the Corporation (or any
Parent or Subsidiary) may consider as grounds for the dismissal or discharge of
Optionee or any other individual in the Service of the Corporation (or any
Parent or Subsidiary).

        Q. 1934 ACT shall mean the Securities Exchange Act of 1934, as amended.

        R. NON-STATUTORY OPTION shall mean an option not intended to satisfy the
requirements of Code Section 422.

        S. OPTION SHARES shall mean the number of shares of Common Stock subject
to the option.

        T. OPTIONEE shall mean the person to whom the option is granted as
specified in the Grant Notice.

        U. PARENT shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, stock possessing fifty percent (50%) or more of the total
combined voting power of all classes of stock in one of the other corporations
in such chain.

        V. PLAN shall mean the Corporation's 1996 Stock Option/Stock Issuance
Plan.

        W. PLAN ADMINISTRATOR shall mean either the Board or a committee of the
Board acting in its capacity as administrator of the Plan.

        X. PURCHASE AGREEMENT shall mean the stock purchase agreement in
substantially the form of Exhibit B to the Grant Notice.

        Y. SERVICE shall mean the Optionee's performance of services for the
Corporation (or any Parent or Subsidiary) in the capacity of an Employee, a
non-employee member of the board of directors or an independent consultant.

        Z. STOCK EXCHANGE shall mean the American Stock Exchange or the New York
Stock Exchange.

        AA. SUBSIDIARY shall mean any corporation (other than the Corporation)
in an unbroken chain of corporations beginning with the Corporation, provided
each corporation

                                      A-3.
<PAGE>   51

(other than the last corporation) in the unbroken chain owns, at the time of the
determination, stock possessing fifty percent (50%) or More of the total
combined voting power of all classes of stock in one of the other corporations
in such chain.

        AB. VESTING SCHEDULE shall mean the vesting schedule specified in the
Grant Notice pursuant to which the Optionee is to vest in the Option Shares in a
series of installments over his or her period of Service.

                                      A-4.
<PAGE>   52

                                    ADDENDUM
                                       TO
                             STOCK OPTION AGREEMENT

             The following provisions are hereby incorporated into, and are
hereby made a part of, that certain Stock Option Agreement (the "Option
Agreement") by and between Vina Technologies, Inc. (the "Corporation") and 1
("Optionee") evidencing the stock option (the "Option") granted on 2 (the
"Option Grant Date") to Optionee under the Corporation's 1996 Stock Option/Stock
Issuance Plan, and such provisions shall be effective as of the Option Grant
Date. All capitalized terms in this Addendum, to the extent not otherwise
defined herein, shall have the meanings assigned to them in the Option
Agreement.

                        INVOLUNTARY TERMINATION FOLLOWING
                              CORPORATE TRANSACTION

        1. To the extent the Option is assumed by the successor corporation (or
parent thereof) in connection with a Corporate Transaction, the vesting of the
Option Shares shall be accelerated in an amount equal to twenty-four (24) months
of vesting upon such Corporate Transaction. In addition, immediately upon an
Involuntary Termination of Optionee's Service within twelve (12) months after
the effective date of the Corporate Transaction, the vesting of the Option
Shares at the time subject to the Option but not otherwise vested at that time
shall automatically be accelerated in an amount equal to an additional twelve
(12) months of vesting. The Option shall remain exercisable for such
fully-vested shares until the earlier of (i) the Expiration Date of the option
term or (ii) the expiration of the one (l)-year period measured from the date of
such Involuntary Termination.

        2. For purposes of this Addendum, the following definitions shall be in
effect:

             An INVOLUNTARY TERMINATION shall mean the termination of Optionee's
Service by reason of:

             (i) Optionee's involuntary dismissal or discharge by the
        Corporation for reasons other than Misconduct, or

<PAGE>   53

             (ii) Optionee's voluntary resignation following (A) a change in
        Optionee's position with the Corporation (or Parent or Subsidiary
        employing Optionee) which materially reduces Optionee's level of
        responsibility, (B) a reduction in Optionee's level of compensation
        (including base salary, fringe benefits and participation in any
        corporate-performance based bonus or incentive programs) by more than
        fifteen percent (15%) or (C) a relocation of Optionee's place of
        employment by more than fifty (50) miles, provided and only if such
        change, reduction or relocation is effected by the Corporation without
        Optionee's consent.

        MISCONDUCT shall mean the commission of any act of fraud, embezzlement
or dishonesty by Optionee, any unauthorized use or disclosure by Optionee of
confidential information or trade secrets of the Corporation (or any Parent or
Subsidiary), or any other intentional misconduct by Optionee adversely affecting
the business or affairs of the Corporation (or any Parent or Subsidiary) in a
material manner. The foregoing definition shall not be deemed to be inclusive of
all the acts or omissions which the Corporation (or any Parent or Subsidiary)
may consider as grounds for the dismissal or discharge of Optionee or other
person in the Service of the Corporation (or any Parent or Subsidiary).

        3. The provisions of Paragraph 1 of this Addendum shall govern the
period for which the Option is to remain exercisable following the Involuntary
Termination of Optionee's Service within twelve (12) months after the Corporate
Transaction in which the Option is assumed or replaced and shall supersede any
provisions to the contrary in Paragraph 5 of the Option Agreement. The
provisions of this Addendum shall also supersede any provisions to the contrary
in Paragraph 18 of the Option Agreement concerning the deferred exercisability
of the Option.

        IN WITNESS WHEREOF, Vina Technologies, Inc. has caused this Addendum to
be executed by its duly-authorized officer, and Optionee has executed this
Addendum, all as of the Option Grant Date.

                                       VINA TECHNOLOGIES, INC.

                                       By:
                                          ------------------------------------

                                       Title:
                                             ---------------------------------

                                       ---------------------------------------
                                       1~, OPTIONEE

                                      -2-

<PAGE>   54
                            VINA TECHNOLOGIES, INC.

                            STOCK ISSUANCE AGREEMENT

        AGREEMENT made as of this ____ day of _______________, 19___, by and
between Vina Technologies, Inc., a California corporation, and
_________________________, Participant in the Corporation's 1996 Stock
Option/Stock Issuance Plan.

        All capitalized terms in this Agreement shall have the meaning assigned
to them in this Agreement or in the attached Appendix.

        A.     PURCHASE OF SHARES

        1. Purchase. Participant hereby purchases ________ shares of Common
Stock (the "Purchased Shares") pursuant to the provisions of the Stock Issuance
Program at the purchase price of $____ per share (the "Purchase Price").

        2. Payment. Concurrently with the delivery of this Agreement to the
Corporation, Participant shall pay the Purchase Price for the Purchased Shares
in cash or check payable to the Corporation and shall deliver a duly-executed
blank Assignment Separate from Certificate (in the form attached hereto as
Exhibit I) with respect to the Purchased Shares.

        3. Shareholder Rights. Until such time as the Corporation exercises the
Repurchase Right or the First Refusal Right, Participant (or any successor in
interest) shall have all the rights of a shareholder (including voting, dividend
and liquidation rights) with respect to the Purchased Shares, subject, however,
to the transfer restrictions of Articles B and C.

        B.     SECURITIES LAW COMPLIANCE

        1. Restricted Securities. The Purchased Shares have not been registered
under the 1933 Act and are being issued to Participant in reliance upon the
exemption from such registration provided by SEC Rule 701 for stock issuances
under compensatory benefit plans such as the Plan. Participant hereby confirms
that Participant has been informed that the Purchased Shares are restricted
securities under the 1933 Act and may not be resold or transferred unless the
Purchased Shares are first registered under the Federal securities laws or
unless an exemption from such registration is available. Accordingly,
Participant hereby acknowledges that Participant is prepared to hold the
Purchased Shares for an indefinite period and that Participant is aware that SEC
Rule 144 issued under the 1933 Act which exempts certain resales of unrestricted
securities is not presently available to exempt the resale of the Purchased
Shares from the registration requirements of the 1933 Act.

                                      -1-
<PAGE>   55

        2. Disposition of Purchased Shares. Participant shall make no
disposition of the Purchased Shares (other than a Permitted Transfer) unless and
until there is compliance with all of the following requirements:

               (i) Participant shall have provided the Corporation with a
        written summary of the terms and conditions of the proposed disposition.

               (ii) Participant shall have complied with all requirements of
        this Agreement applicable to the disposition of the Purchased Shares.

               (iii) Participant shall have provided the Corporation with
        written assurances, in form and substance satisfactory to the
        Corporation, that (a) the proposed disposition does not require
        registration of the Purchased Shares under the 1933 Act or (b) all
        appropriate action necessary for compliance with the registration
        requirements of the 1933 Act or any exemption from registration
        available under the 1933 Act (including Rule 144) has been taken.

        The Corporation shall not be required (i) to transfer on its books any
Purchased Shares which have been sold or transferred in violation of the
provisions of this Agreement or (ii) to treat as the owner of the Purchased
Shares, or otherwise to accord voting, dividend or liquidation rights to, any
transferee to whom the Purchased Shares have been transferred in contravention
of this Agreement.

        3. Restrictive Legends. The stock certificates for the Purchased Shares
shall be endorsed with one or more of the following restrictive legends:

               "The shares represented by this certificate have not been
        registered under the Securities Act of 1933. The shares may not be sold
        or offered for sale in the absence of (a) an effective registration
        statement for the shares under such Act, (b) a "no action" letter of the
        Securities and Exchange Commission with respect to such sale or offer or
        (c) satisfactory assurances to the Corporation that registration under
        such Act is not required with respect to such sale or offer."

               "The shares represented by this certificate are subject to
        certain repurchase rights and rights of first refusal granted to the
        Corporation and accordingly may not be sold, assigned, transferred,
        encumbered, or in any manner disposed of except in conformity with the
        terms of a written agreement dated ___________, 199_ between the
        Corporation and the registered holder of the shares (or the predecessor
        in interest to the shares). A copy of such agreement is maintained at
        the Corporation's principal corporate offices."

                                      -2-
<PAGE>   56

        C.     TRANSFER RESTRICTIONS

        1. Restriction on Transfer. Except for any Permitted Transfer,
Participant shall not transfer, assign, encumber or otherwise dispose of any of
the Purchased Shares which are subject to the Repurchase Right. In addition,
Purchased Shares which are released from the Repurchase Right shall not be
transferred, assigned, encumbered or otherwise disposed of in contravention of
the First Refusal Right or the Market Stand-Off.

        2. Transferee Obligations. Each person (other than the Corporation) to
whom the Purchased Shares are transferred by means of a Permitted Transfer must,
as a condition precedent to the validity of such transfer, acknowledge in
writing to the Corporation that such person is bound by the provisions of this
Agreement and that the transferred shares are subject to (i) the Repurchase
Right, (ii) the First Refusal Right and (iii) the Market Stand-Off, to the same
extent such shares would be so subject if retained by Participant.

        3. Market Stand-Off.

        (a) In connection with any underwritten public offering by the
Corporation of its equity securities pursuant to an effective registration
statement filed under the 1933 Act, including the Corporation's initial public
offering, Owner shall not sell, make any short sale of, loan, hypothecate,
pledge, grant any option for the purchase of, or otherwise dispose or transfer
for value or otherwise agree to engage in any of the foregoing transactions with
respect to, any Purchased Shares without the prior written consent of the
Corporation or its underwriters. Such restriction (the "Market Stand-Off") shall
be in effect for such period of time from and after the effective date of the
final prospectus for the offering as may be requested by the Corporation or such
underwriters. In no event, however, shall such period exceed one hundred eighty
(180) days and the Market Stand-Off shall in all events terminate two (2) years
after the effective date of the Corporation's initial public offering.

        (b) Owner shall be subject to the Market Stand-Off provided and only if
the officers and directors of the Corporation are also subject to similar
restrictions.

        (c) Any new, substituted or additional securities which are by reason of
any Recapitalization or Reorganization distributed with respect to the Purchased
Shares shall be immediately subject to the Market Stand-Off, to the same extent
the Purchased Shares are at such time covered by such provisions.

        (d) In order to enforce the Market Stand-Off, the Corporation may impose
stop-transfer instructions with respect to the Purchased Shares until the end of
the applicable stand-off period.

                                      -3-
<PAGE>   57

        D.     REPURCHASE RIGHT

        1. Grant. The Corporation is hereby granted the right (the "Repurchase
Right"), exercisable at any time during the sixty (60)-day period following the
date Participant ceases for any reason to remain in Service, to repurchase at
the Purchase Price all or (at the discretion of the Corporation and with the
consent of Participant) any portion of the Purchased Shares in which Participant
is not, at the time of his or her cessation of Service, vested in accordance
with the Vesting Schedule (such shares to be hereinafter referred to as the
"Unvested Shares").

        2. Exercise of the Repurchase Right. The Repurchase Right shall be
exercisable by written notice delivered to each Owner of the Unvested Shares
prior to the expiration of the sixty (60)-day exercise period. The notice shall
indicate the number of Unvested Shares to be repurchased and the date on which
the repurchase is to be effected, such date to be not more than thirty (30) days
after the date of such notice. The certificates representing the Unvested Shares
to be repurchased shall be delivered to the Corporation on or before the close
of business on the date specified for the repurchase. Concurrently with the
receipt of such stock certificates, the Corporation shall pay to Owner, in cash
or cash equivalents (including the cancellation of any purchase-money
indebtedness), an amount equal to the Purchase Price previously paid for the
Unvested Shares which are to be repurchased from Owner.

        3. Termination of the Repurchase Right. The Repurchase Right shall
terminate with respect to any Unvested Shares for which it is not timely
exercised under Paragraph D.2. In addition, the Repurchase Right shall terminate
and cease to be exercisable with respect to any and all Purchased Shares in
which Participant vests in accordance with the following Vesting Schedule:

               (i) Upon Participant's completion of one (1) year of Service
        measured from __________, 19_, Participant shall acquire a vested
        interest in, and the Repurchase Right shall lapse with respect to,
        twenty-five percent (25%) of the Purchased Shares.

               (ii) Participant shall acquire a vested interest in, and the
        Repurchase Right shall lapse with respect to, the remaining Purchased
        Shares in a series of thirty-six (36) successive equal monthly
        installments upon Participant's completion of each additional month of
        Service over the thirty-six (36)-month period measured from the initial
        vesting date under subparagraph (i) above.

        All Purchased Shares as to which the Repurchase Right lapses shall,
however, remain subject to (i) the First Refusal Right and (ii) the Market
Stand-Off.

                                      -4-
<PAGE>   58

        4. Recapitalization. Any new, substituted or additional securities or
other property (including cash paid other than as a regular cash dividend) which
is by reason of any Recapitalization distributed with respect to the Purchased
Shares shall be immediately subject to the Repurchase Right and any escrow
requirements hereunder, but only to the extent the Purchased Shares are at the
time covered by such right or escrow requirements. Appropriate adjustments to
reflect such distribution shall be made to the number and/or class of Purchased
Shares subject to this Agreement and to the price per share to be paid upon the
exercise of the Repurchase Right in order to reflect the effect of any such
Recapitalization upon the Corporation's capital structure; provided, however,
that the aggregate purchase price shall remain the same.

        5. Corporate Transaction.

        (a) The Repurchase Right shall automatically terminate in its entirety,
and all the Purchased Shares shall vest in full, immediately prior to the
consummation of any Corporate Transaction, except to the extent the Repurchase
Right is to be assigned to the successor entity in such Corporate Transaction.

        (b) To the extent the Repurchase Right remains in effect following a
Corporate Transaction, such right shall apply to any new securities or other
property (including any cash payments) received in exchange for the Purchased
Shares in consummation of the Corporate Transaction, but only to the extent the
Purchased Shares are at the time covered by such right. Appropriate adjustments
shall be made to the price per share payable upon exercise of the Repurchase
Right to reflect the effect of the Corporate Transaction upon the Corporation's
capital structure; provided, however, that the aggregate purchase price shall
remain the same. The new securities or other property (including any cash
payments) issued or distributed with respect to the Purchased Shares in
consummation of the Corporate Transaction shall be immediately deposited in
escrow with the Corporation (or the successor entity) and shall not be released
from escrow until Optionee vests in such securities or other property in
accordance with the same Vesting Schedule in effect for the Purchased Shares.

        E.     RIGHT OF FIRST REFUSAL

        1. Grant. The Corporation is hereby granted the right of first refusal
(the "First Refusal Right"), exercisable in connection with any proposed
transfer of the Purchased Shares in which Participant has vested in accordance
with the provisions of Article D. For purposes of this Article E, the term
"transfer" shall include any sale, assignment, pledge, encumbrance or other
disposition of the Purchased Shares intended to be made by Owner, but shall not
include any Permitted Transfer.

        2. Notice of Intended Disposition. In the event any Owner of Purchased
Shares in which Participant has vested desires to accept a bona fide third-party
offer for the transfer of any or all of such shares (the Purchased Shares
subject to such offer to be

                                      -5-
<PAGE>   59

hereinafter referred to as -the "Target Shares"), Owner shall promptly (i)
deliver to the Corporation written notice (the "Disposition Notice") of the
terms of the offer, including the purchase price and the identity of the
third-party offeror, and (ii) provide satisfactory proof that the disposition of
the Target Shares to such third-party offeror would not be in contravention of
the provisions set forth in Articles B and C.

        3. Exercise of the First Refusal Right. The Corporation shall, for a
period of twenty-five (25) days following receipt of the Disposition Notice,
have the right to repurchase any or all of the Target Shares subject to the
Disposition Notice upon the same terms as those specified therein or upon such
other terms (not materially different from those specified in the Disposition
Notice) to which Owner consents. Such right shall be exercisable by delivery of
written notice (the "Exercise Notice") to Owner prior to the expiration of the
twenty-five (25)-day exercise period. If such right is exercised with respect to
all the Target Shares, then the Corporation shall effect the repurchase of such
shares, including payment of the purchase price, not more than five (5) business
days after delivery of the Exercise Notice; and at such time the certificates
representing the Target Shares shall be delivered to the Corporation.

        Should the purchase price specified in the Disposition Notice be payable
in property other than cash or evidences of indebtedness; the Corporation shall
have the right to pay the purchase price in the form of cash equal in amount to
the value of such property. If Owner and the Corporation cannot agree on such
cash value within ten (10) days after the Corporation's receipt of the
Disposition Notice, the valuation shall be made by an appraiser of recognized
standing selected by Owner and the Corporation or, if they cannot agree on an
appraiser within twenty (20) days after the Corporation's receipt of the
Disposition Notice, each shall select an appraiser of recognized standing and
the two (2) appraisers shall designate a third appraiser of recognized standing,
whose appraisal shall be determinative of such value. The cost of such appraisal
shall be shared equally by Owner and the Corporation. The closing shall then be
held on the later of (i) the fifth (5th) business day following delivery of the
Exercise Notice or (ii) the fifth (5th) business day after such valuation shall
have been made.

        4. Non-Exercise of the First Refusal Right. In the event the Exercise
Notice is not given to Owner prior to the expiration of the twenty-five (25)-day
exercise period, Owner shall have a period of thirty (30) days thereafter in
which to sell or otherwise dispose of the Target Shares to the third-party
offeror identified in the Disposition Notice upon terms (including the purchase
price) no more favorable to such third-party offeror than those specified in the
Disposition Notice; provided, however, that any such sale or disposition must
not be effected in contravention of the provisions of Articles B and C. The
third-party offeror shall acquire the Target Shares free and clear of the
Repurchase Right and the First Refusal Right, but the acquired shares shall
remain subject to the provisions of Article B and Paragraph C.3. In the event
Owner does not effect such sale or disposition of the Target Shares within the
specified thirty (30)-day period, the First Refusal Right shall

                                      -6-
<PAGE>   60

continue to be applicable to any subsequent disposition of the Target Shares by
Owner until such right lapses.

        5. Partial Exercise of the First Refusal Right. In the event the
Corporation makes a timely exercise of the First Refusal Right with respect to a
portion, but not all, of the Target Shares specified in the Disposition Notice,
Owner shall have the option, exercisable by written notice to the Corporation
delivered within five (5) business days after Owner's receipt of the Exercise
Notice, to effect the sale of the Target Shares pursuant to either of the
following alternatives:

               (i) sale or other disposition of all the Target Shares to the
        third-party offeror identified in the Disposition Notice, but in full
        compliance with the requirements of Paragraph E.4, as if the Corporation
        did not exercise the First Refusal Right; or

               (ii) sale to the Corporation of the portion of the Target Shares
        which the Corporation has elected to purchase, such sale to be effected
        in substantial conformity with the provisions of Paragraph E.3. The
        First Refusal Right shall continue to be applicable to any subsequent
        disposition of the remaining Target Shares until such right lapses.

        Owner's failure to deliver timely notification to the Corporation shall
be deemed an election by Owner to sell the Target Shares pursuant to alternative
(i) above.

        6. Recapitalization/Reorganization.

        (a) Any new, substituted or additional securities or other property
which is by reason of any Recapitalization distributed with respect to the
Purchased Shares shall be immediately subject to the First Refusal Right, but
only to the extent the Purchased Shares are at the time covered by such right.

        (b) In the event of a Reorganization, the First Refusal Right shall
remain in full force and effect and shall apply to the new capital stock or
other property received in exchange for the Purchased Shares in consummation of
the Reorganization, but only to the extent the Purchased Shares are at the time
covered by such right.

        7. Lapse. The First Refusal Right shall lapse upon the earliest to occur
of (i) the first date on which shares of the Common Stock are held of record by
more than five hundred (500) persons, (ii) a determination is made by the Board
that a public market exists for the outstanding shares of Common Stock or (iii)
a firm commitment underwritten public offering, pursuant to an effective
registration statement under the 1933 Act, covering the offer and sale of the
Common Stock in the aggregate amount of at least ten million dollars
($10,000,000). However, the Market Stand-Off shall continue to remain in full
force and effect following the lapse of the First Refusal Right.

                                      -7-
<PAGE>   61

        SPECIAL TAX ELECTION

        8. Section 83(b) Election. Under Code Section 83, the excess of the Fair
Market Value of the Purchased Shares on the date any forfeiture restrictions
applicable to such shares lapse over the Purchase Price paid for such shares
will be reportable as ordinary income on the lapse date. For this purpose, the
term "forfeiture restrictions" includes the right of the Corporation to
repurchase the Purchased Shares pursuant to the Repurchase Right. Participant
may elect under Code Section 83(b) to be taxed at the time the Purchased Shares
are acquired, rather than when and as such Purchased Shares cease to be subject
to such forfeiture restrictions. Such election must be filed with the Internal
Revenue Service within thirty (30) days after the date of this Agreement. Even
if the Fair Market Value of the Purchased Shares on the date of this Agreement
equals the Purchase Price paid (and thus no tax is payable), the election must
be made to avoid adverse tax consequences in the future. THE FORM FOR MAKING
THIS ELECTION IS ATTACHED AS EXHIBIT II HERETO. PARTICIPANT UNDERSTANDS THAT
FAILURE TO MAKE THIS FILING WITHIN THE APPLICABLE THIRTY (30)-DAY PERIOD WILL
RESULT IN THE RECOGNITION OF ORDINARY INCOME AS THE FORFEITURE RESTRICTIONS
LAPSE.

        9. FILING RESPONSIBILITY. PARTICIPANT ACKNOWLEDGES THAT IT IS
PARTICIPANT'S SOLE RESPONSIBILITY, AND NOT THE CORPORATION'S, TO FILE A TIMELY
ELECTION UNDER CODE SECTION 83(b), EVEN IF PARTICIPANT REQUESTS THE CORPORATION
OR ITS REPRESENTATIVES TO MAKE THIS FILING ON HIS OR HER BEHALF.

        F.     GENERAL PROVISIONS

        1. Assignment. The Corporation may assign the Repurchase Right and/or
the First Refusal Right to any person or entity selected by the Board, including
(without limitation) one or more shareholders of the Corporation. If the
assignee of the Repurchase Right is other than (i) a wholly owned subsidiary of
the Corporation or (ii) the parent corporation owning one hundred percent (100%)
of the Corporation's outstanding capital stock, then such assignee must make a
cash payment to the Corporation, upon the assignment of the Repurchase Right, in
an amount equal to the excess (if any) of (i) the Fair Market Value of the
Purchased Shares at the time subject to the assigned Repurchase Right over (ii)
the aggregate repurchase price payable for the Purchased Shares.

        2. No Employment or Service Contract. Nothing in this Agreement or in
the Plan shall confer upon Participant any right to continue in Service for any
period of specific duration or interfere with or otherwise restrict in any way
the rights of the Corporation (or any Parent or Subsidiary employing or
retaining Participant) or of Participant, which rights are hereby expressly
reserved by each, to terminate Participant's Service at any time for any reason,
with or without cause.

                                      -8-
<PAGE>   62

        3. Notices. Any notice required to be given under this Agreement shall
be in writing and shall be deemed effective upon personal delivery or upon
deposit in the U.S. mail, registered or certified, postage prepaid and properly
addressed to the party entitled to such notice at the address indicated below
such party's signature line on this Agreement or at such other address as such
party may designate by ten (10) days advance written notice under this paragraph
to all other parties to this Agreement.

        4. No Waiver. The failure of the Corporation in any instance to exercise
the Repurchase Right or the First Refusal Right shall not constitute a waiver of
any other repurchase rights and/or rights of first refusal that may subsequently
arise under the provisions of this Agreement or any other agreement between the
Corporation and Participant. No waiver of any breach or condition of this
Agreement shall be deemed to be a waiver of any other or subsequent breach or
condition, whether of like or different nature.

        5. Cancellation of Shares. If the Corporation shall make available, at
the time and place and in the amount and form provided in this Agreement, the
consideration for the Purchased Shares to be repurchased in accordance with the
provisions of this Agreement, then from and after such time, the person from
whom such shares are to be repurchased shall no longer have any rights as a
holder of such shares (other than the right to receive payment of such
consideration in accordance with this Agreement). Such shares shall be deemed
purchased in accordance with the applicable provisions hereof, and the
Corporation shall be deemed the owner and holder of such shares, whether or not
the certificates therefor have been delivered as required by this Agreement.

        G.     MISCELLANEOUS PROVISIONS

        1. Participant Undertaking. Participant hereby agrees to take whatever
additional action and execute whatever additional documents the Corporation may
deem necessary or advisable in order to carry out or effect one or more of the
obligations or restrictions imposed on either Participant or the Purchased
Shares pursuant to the provisions of this Agreement.

        2. Agreement is Entire Contract. This Agreement constitutes the entire
contract between the parties hereto with regard to the subject matter hereof.
This Agreement is made pursuant to the provisions of the Plan and shall in all
respects be construed in conformity with the terms of the Plan.

        3. Governing Law. This Agreement shall be governed by, and construed in
accordance with, the laws of the State of California without resort to that
State's conflict-of-laws rules.

                                      -9-
<PAGE>   63

        4. Counterparts. This Agreement may be executed in counterparts, each of
which shall be deemed to be an original, but all of which together shall
constitute one and the same instrument.

        5. Successors and Assigns. The provisions of this Agreement shall inure
to the benefit of, and be binding upon, the Corporation and its successors and
assigns and upon Participant, Participant's assigns and the legal
representatives, heirs and legatees of Participant's estate, whether or not any
such person shall have become a party to this Agreement and have agreed in
writing to join herein and be bound by the terms hereof.

        IN WITNESS WHEREOF, the parties have executed this Agreement on the day
and year first indicated above.

                                        VINA TECHNOLOGIES, INC.

                                        By:
                                            ------------------------------------

                                        Title:
                                              ----------------------------------

                                        Address:
                                                --------------------------------

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

                                        ----------------------------------------
                                                      PARTICIPANT

                                        Address:
                                                --------------------------------

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

                                      -10-
<PAGE>   64

                             SPOUSAL ACKNOWLEDGMENT

        The undersigned spouse of Participant has read and hereby approves the
foregoing Stock Issuance Agreement. In consideration of the Corporation's
granting Participant the right to acquire the Purchased Shares in accordance
with the terms of such Agreement, the undersigned hereby agrees to be
irrevocably bound by all the terms of such Agreement, including (without
limitation) the right of the Corporation (or its assigns) to purchase any
Purchased Shares in which Participant is not vested at the time of his or her
cessation of Service.

                                        ----------------------------------------
                                                 PARTICIPANT'S SPOUSE

                                        Address:
                                                --------------------------------

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

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

                                      -11-
<PAGE>   65

                                    EXHIBIT I

                      ASSIGNMENT SEPARATE FROM CERTIFICATE

        FOR VALUE RECEIVED ____________________ hereby sell(s), assign(s) and
transfer(s) unto Vina Technologies, Inc. (the "Corporation"), ______ (________)
shares of the Common Stock of the Corporation standing in his or her name on the
books of the Corporation represented by Certificate No. ________ herewith and do
hereby irrevocably constitute and appoint _________ Attorney to transfer the
said stock on the books of the Corporation with full power of substitution in
the premises.

        Dated:
              ---------------------

                                    Signature
                                             -----------------------------------

INSTRUCTION: PLEASE DO NOT FILL IN ANY BLANKS OTHER THAN THE SIGNATURE LINE.
PLEASE SIGN EXACTLY AS YOU WOULD LIKE YOUR NAME TO APPEAR ON THE ISSUED STOCK
CERTIFICATE. THE PURPOSE OF THIS ASSIGNMENT IS TO ENABLE THE CORPORATION TO
EXERCISE THE REPURCHASE RIGHT WITHOUT REQUIRING ADDITIONAL SIGNATURES ON THE
PART OF PARTICIPANT.

<PAGE>   66

                                   EXHIBIT II

                           SECTION 83(b) TAX ELECTION

        This statement is being made under Section 83(b) of the Internal Revenue
Code, pursuant to Treas. Reg. Section 1.83-2.

(1)     The taxpayer who performed the services is:

        Name:

        Address:

        Taxpayer Ident. No.:

(2)     The property with respect to which the election is being made is ______
        shares of the common stock of Vina Technologies, Inc.

(3)     The property was issued on __________, 199_.

(4)     The taxable year in which the election is being made is the calendar
        year 199_.

(5)     The property is subject to a repurchase right pursuant to which the
        issuer has the right to acquire the property at the original purchase
        price if for any reason taxpayer's employment with the issuer is
        terminated. The issuer's repurchase right lapses in a series of
        installments over a four (4)-year period ending on ______________, 200_.

(6)     The fair market value at the time of transfer (determined without regard
        to any restriction other than a restriction which by its terms will
        never lapse) is $________ per share.

(7)     The amount paid for such property is $_______ per share.

(8)     A copy of this statement was furnished to Vina Technologies, Inc. for
        whom taxpayer rendered the services underlying the transfer of property.

(9)     This statement is executed on __________, 199_.

-----------------------------------          -----------------------------------
Spouse (if any)                              Taxpayer

This election must be filed with the Internal Revenue Service Center with which
taxpayer files his or her Federal Income tax returns and must be made within
thirty (30) days after the execution date of the Stock Issuance Agreement. This
filing should be made by registered or certified mail, return receipt requested.
Participant must retain two (2) copies of the completed form for filing with his
or her Federal and state tax returns for the current tax year and an additional
copy for his or her records.

<PAGE>   67

                                   EXHIBIT III

                     1996 STOCK OPTION/STOCK ISSUANCE PLAN

<PAGE>   68

                                    APPENDIX

        The following definitions shall be in effect under the Agreement:

        A. Agreement shall mean this Stock Issuance Agreement.

        B. Board shall mean the Corporation's Board of Directors.

        C. Code shall mean the Internal Revenue Code of 1986, as amended.

        D. Common Stock shall mean the Corporation's common stock.

        E. Corporate Transaction shall mean either of the following
shareholder-approved transactions:

               (i) a merger or consolidation in which securities possessing more
        than fifty percent (50%) of the total combined voting power of the
        Corporation's outstanding securities are transferred to a person or
        persons different from the persons holding those securities immediately
        prior to such transaction, or

               (ii) the sale, transfer or other disposition of all or
        substantially all of the Corporation's assets in complete liquidation or
        dissolution of the Corporation.

        F. Corporation shall mean Vina Technologies, Inc., a California
corporation.

        G. Disposition Notice shall have the meaning assigned to such term in
Paragraph E.2.

        H. Exercise Notice shall have the meaning assigned to such term in
Paragraph E.3.

        I. Fair Market Value of a share of Common Stock on any relevant date,
prior to the initial public offering of the Common Stock, shall be determined by
the Plan Administrator after taking into account such factors as it shall deem
appropriate.

        J. First Refusal Right shall mean the right granted to the Corporation
in accordance with Article E.

                                      A-1
<PAGE>   69

        K. Market Stand-Off shall mean the market stand-off restriction
specified in Paragraph C-3.

        L. Misconduct shall mean the commission of any act of fraud,
embezzlement or dishonesty by Participant, any unauthorized use or disclosure by
Participant of confidential information or trade secrets of the Corporation (or
any Parent or Subsidiary), or any other intentional misconduct by Participant
adversely affecting the business or affairs of the Corporation (or any Parent or
Subsidiary) in a material manner. The foregoing definition shall not be deemed
to be inclusive of all the acts or omissions which the Corporation (or any
Parent or Subsidiary) may consider as grounds for the dismissal or discharge of
Participant or any other individual in the Service of the Corporation (or any
Parent or Subsidiary).

        M. 1933 Act shall mean the Securities Act of 1933, as amended.

        N. Owner shall mean Participant and all subsequent holders of the
Purchased Shares who derive their chain of ownership through a Permitted
Transfer from Participant.

        O. Parent shall mean any corporation (other than the Corporation) in an
unbroken chain of corporations ending with the Corporation, provided each
corporation in the unbroken chain (other than the Corporation) owns, at the time
of the determination, stock possessing fifty percent (50%) or more of the total
combined voting power of all classes of stock in one of the other corporations
in such chain.

        P. Participant shall mean the person to whom shares are issued under the
Stock Issuance Program.

        Q. Permitted Transfer shall mean (i) a gratuitous transfer of the
Purchased Shares, provided and only if Participant obtains the Corporation's
prior written consent to such transfer, (ii) a transfer of title to the
Purchased Shares effected pursuant to Participant's will or the laws of
intestate succession following Participant's death or (iii) a transfer to the
Corporation in pledge as security for any purchase-money indebtedness incurred
by Participant in connection with the acquisition of the Purchased Shares.

        R. Plan shall mean the Corporation's 1996 Stock Option/Stock Issuance
Plan attached hereto as Exhibit III.

        S. Plan Administrator shall mean either the Board or a committee of the
Board acting in its capacity as administrator of the Plan.

        T. Purchase Price shall have the meaning assigned to such term in
Paragraph A.1.

                                      A-2
<PAGE>   70

        U. Purchased Shares shall have the meaning assigned to such term in
Paragraph A.1.

        V. Recapitalization shall mean any stock split, stock dividend,
recapitalization, combination of shares, exchange of shares or other change
affecting the Corporation's outstanding Common Stock as a class without the
Corporation's receipt of consideration.

        W.     Reorganization shall mean any of the following transactions:

               (i) a merger or consolidation in which the Corporation is not the
        surviving entity,

               (ii) a sale, transfer or other disposition of all or
        substantially all of the Corporation's assets,

               (iii) a reverse merger in which the Corporation is the surviving
        entity but in which the Corporation's outstanding voting securities are
        transferred in whole or in part to a person or persons different from
        the persons holding those securities immediately prior to the merger, or

               (iv) any transaction effected primarily to change the state in
        which the Corporation is incorporated or to create a holding company
        structure.

        X. Repurchase Right shall mean the right granted to the Corporation in
accordance with Article D.

        Y. SEC shall mean the Securities and Exchange Commission.

        Z. Service shall mean the provision of services to the Corporation (or
any Parent or Subsidiary) by an individual in the capacity of an employee,
subject to the control and direction of the employer entity as to both the work
to be performed and the manner and method of performance, a non-employee member
of the board of directors or an independent consultant.

        AA. Stock Issuance Program shall mean the Stock Issuance Program under
the Plan.

        AB. Subsidiary shall mean any corporation (other than the Corporation)
in an unbroken chain of corporations beginning with the Corporation, provided
each corporation (other than the last corporation) in the unbroken chain owns,
at the time of the determination, stock possessing fifty percent (50%) or more
of the total combined voting power of all classes of stock in one of the other
corporations in such chain.

                                      A-3
<PAGE>   71

        AC. Target Shares shall have the meaning assigned to such term in
Paragraph E.2.

        AD. Vesting Schedule shall mean the vesting schedule specified in
Paragraph D.3 pursuant to which Participant is to vest in the Purchased Shares
in a series of installments over the Participant's period of Service.

        AE. Unvested Shares shall have the meaning assigned to such term in
Paragraph D.1.

                                      A-4

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