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                                                                    Exhibit 4.3
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                           RIVERSTONE NETWORKS, INC.
                          EMPLOYEE STOCK PURCHASE PLAN

   SECTION 1. PURPOSE OF PLAN

   The Riverstone Networks, Inc. Employee Stock Purchase Plan (the "Plan") is
intended to provide a method by which eligible employees of Riverstone
Networks, Inc. ("Riverstone") and such of its Subsidiaries as the Board of
Directors of Riverstone (the "Board") may from time to time designate
(Riverstone and such Subsidiaries being hereinafter referred to as the
"Company") may use voluntary, systematic payroll deductions to purchase shares
of common stock, $.01 par value of Riverstone (such common stock being
hereafter referred to as "Stock") and thereby acquire an interest in the future
of Riverstone. For purposes of the Plan, a "Subsidiary" is any corporation that
would be treated as a subsidiary of Riverstone under Section 424(f) of the
Internal Revenue Code of 1986, as amended (the "Code"). The Plan is intended to
qualify under Section 423 of the Code and shall be construed accordingly.

   SECTION 2. OPTIONS TO PURCHASE STOCK

   Subject to adjustment as provided in Section 14, the maximum number of
shares of Stock that may be delivered under the Plan pursuant to the exercise
of options ("Options") granted hereunder is 1,000,000 shares plus an additional
500,000 shares effective as of the first day of Riverstone's fiscal year ending
in each of 2003, 2004, 2005 and 2006. Options shall be granted under the Plan
to employees of the Company ("Employees") who meet the eligibility requirements
set forth in Section 3 hereof ("Eligible Employees"). The Stock to be delivered
upon exercise of Options under the Plan may be either shares of authorized but
unissued Stock or shares of reacquired Stock, as the Board may determine.

   SECTION 3. ELIGIBLE EMPLOYEES

   Subject to the exceptions and limitations set forth below, all Employees are
eligible to participate in the Plan.

    (a) Any Employee who immediately after the grant of an Option would own (or
pursuant to Section 423(b)(3) of the Code would be deemed to own) stock
possessing 5% or more of the total combined voting power or value of all
classes of stock of the employer corporation or of its parent or subsidiary
corporations, as defined in Section 424 of the Code, will not be eligible to
receive an Option to purchase Stock pursuant to the Plan.

    (b) No Employee will be granted an Option under the Plan that would permit
his or her rights to purchase shares of stock under all employee stock purchase
plans of the employer corporation and parent and subsidiary corporations to
accrue at a rate which exceeds $25,000 in fair market value of such stock
(determined at the time the Option is granted) for each calendar year during
which any such Option granted to such Employee is outstanding at any time, as
provided in Section 423 of the Code.

   SECTION 4. METHOD OF PARTICIPATION

   Each person who will be an Eligible Employee on the first day of an Option
Period may elect to participate in the Plan for that Option Period by executing
and delivering, by such deadline prior thereto as the Board may specify, such
enrollment forms, including a payroll deduction authorization in accordance
with Section 5, as the Board may determine. An Eligible Employee who elects to
participate in the Plan for an Option Period in accordance with the foregoing
will thereby become a participant ("Participant") on the first day of the
Option Period and will remain a Participant until his or her participation is
terminated as provided in the Plan.

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   The Plan shall operate on the basis of consecutive six-month Option Periods
commencing January 1 or July 1 and ending (unless abbreviated pursuant to
Section 16) on the next following June 30 or December 31; provided, that the
first Option Period shall be a short period commencing on the first day of the
month coinciding with or next following the date on which Cabletron Systems,
Inc. ("Cabletron") distributes to its shareholders the stock of Riverstone held
by Cabletron and ending on the next following December 31 or, if earlier, the
next following June 30.

   SECTION 5. PAYROLL DEDUCTION

   Each payroll deduction authorization will request withholding at a rate (in
whole percentages) of not less than 1% nor more than 10% of Compensation per
payroll period, to be accomplished by means of payroll deductions over each
Option Period (as defined in Section 8 below) with respect to payroll dates
within the Option Period. "Compensation" for this purpose shall include and be
limited to base salary and sales commissions. A Participant may (i) change the
withholding rate of his or her payroll deduction authorization by written
notice delivered to the Company on or before the deadline specified by the
Board for the Option Period as to which the change is to be effective, and (ii)
not more than once during an Option Period may reduce (but not increase) his or
her payroll withholding percentage (within the limits described in the first
sentence of this Section 5) with respect to the remainder of such Option
Period. All amounts withheld in accordance with a Participant's payroll
deduction authorization will be credited to a withholding account maintained in
the Participant's name on the books of the Company. Amounts credited to the
withholding account shall not be required to be set aside in trust or otherwise
segregated from the Company's general assets, and shall not bear interest.

   SECTION 6. GRANT OF OPTIONS

   Subject to Section 3(b), each person who is a Participant on the first day
of an Option Period (the "applicable Period") will be granted, as of such day
and for the applicable Period, an Option entitling the Participant to purchase
up to, and the right to purchase Stock under the Option will be deemed to
accrue for the number of shares equal to, the lesser of (i) and (ii), where

(i)  is the remainder obtained by subtracting (A) the number of shares of
     Stock, if any, purchased for any earlier Option Period ending in the same
     calendar year, from (B) the number of shares of Stock obtained by dividing
     $25,000 by the fair market value of one share of Stock on the first day of
     the applicable Period, rounded down to the nearest whole share, and

(ii) is the number of shares of Stock obtained by dividing the balance of the
     Participant's withholding account on the last day of the applicable Period
     by the per-share exercise price for such Period, and rounding down to the
     nearest whole share;

provided, that the Board in its discretion may further limit the number of
shares of Stock subject to Options for any Option Period. Option grants under
this Section 6 shall be automatic and need not be separately documented.

   SECTION 7. PURCHASE PRICE

   The purchase price of Stock issued pursuant to the exercise of an Option
will be 85% of the fair market value of the Stock on (a) the date of grant of
the Option or (b) the date on which the Option is deemed exercised, whichever
is less. Fair market value for any day will mean the Closing Price of the Stock
for such day; provided, that if such day is not a trading day, fair market
value shall mean the Closing Price of the Stock for the next preceding day
which is a trading day. The "Closing Price" of the Stock on any trading day
will be the last sale price, regular way, with respect to such Stock, or, in
case no such sale takes place on such day, the average of the closing bid and
asked prices, regular way, with respect to such Stock, in either case as
reported in the principal consolidated transaction reporting system with
respect to securities listed or admitted to trading

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on the New York Stock Exchange; or, if such Stock is not listed or admitted to
trading on the New York Stock Exchange, as reported in the principal
consolidated transaction reporting system with respect to securities listed on
the principal national securities exchange on which such Stock is listed or
admitted to trading; or, if such Stock is not listed or admitted to trading,
the last quoted price with respect to such Stock, or, if not so quoted, the
average of the high bid and low asked prices in the over-the-counter market
with respect to such Stock, as reported by the National Association of
Securities Dealers, Inc. Automated Quotation System or such other similar
system then in use; or, if on any such date such Stock is not quoted by any
such organization, the average of the closing bid and asked prices with respect
to such Stock, as furnished by a professional market maker making a market in
such Stock selected by the Board in good faith; or, if no such market maker is
available, the fair market value of such Stock as of such day as determined in
good faith by the Board.

   SECTION 8. EXERCISE OF OPTIONS

   If an Employee is a Participant in the Plan on the last day of an Option
Period, he or she will be deemed to have exercise the Option granted to him or
her for that Period, unless such Option shall earlier have been canceled
pursuant to Section 9. Upon such exercise, Riverstone will apply the balance of
the Participant's withholding account to the purchase of the maximum whole
number of shares of Stock available for purchase therewith under the Option (as
determined pursuant to Section 6) and as soon as practicable thereafter will
issue and deliver a certificate or certificates for the purchased shares (or
will otherwise evidence the transfer of ownership of said shares) to the
Participant and will return to him or her the balance, if any, of his or her
withholding account in excess of the total purchase price of the shares so
issued; provided, that if the balance left in the account consists solely of an
amount equal to the value of a fractional share it will be retained in the
Account and carried over to the next Option Period.

   Notwithstanding anything herein to the contrary, Riverstone's obligation to
issue and deliver shares of Stock under the Plan will be subject to the
approval required of any governmental authority in connection with the
authorization, issuance, sale or transfer of said shares, to any requirements
of any national securities exchange applicable thereto, and to compliance by
Riverstone with other applicable legal requirements in effect from time to
time.

   SECTION 9. CANCELLATION AND WITHDRAWAL

   A Participant who holds an Option under the Plan may at any time prior to
exercise thereof under Section 8 cancel all (but not less than all) of his or
her Options by written notice delivered to the Company. Upon such cancellation,
the balance in the Participant's withholding account will be returned to the
Participant.

   A Participant may terminate his or her payroll deduction authorization as of
any date by written notice delivered to the Company prior to such date. A
Participant who voluntarily terminates his or her payroll deduction
authorization prior to the last day of an Option Period will be deemed to have
canceled all of his or her Options then outstanding.

   SECTION 10. TERMINATION OF EMPLOYMENT

   Except as otherwise provided in Section 11, upon the termination of a
Participant's employment with the Company for any reason, he or she will cease
to be a Participant, any Option held by him or her under the Plan will be
deemed canceled, the balance of his or her withholding account will be
returned, and he or she will have no further rights under the Plan.

   SECTION 11. DEATH OF PARTICIPANT

   A Participant may elect that if death should occur during an Option Period
the balance, if any, of the Participant's withholding account at the time of
death will be applied at the end of the Period to the exercise of the
Participant's Option and the shares thereby purchased under the Option (plus
any balance remaining in the

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Participant's withholding account) will be delivered to the Participant's
beneficiary or beneficiaries. If the Participant has more than one beneficiary,
the Company will determine the allocation among them and its determination will
be final and binding on all persons. Except as otherwise determined by the
Board (which may establish a procedure for the designation of beneficiaries
under the Plan), a Participant's beneficiary(ies) for purposes of the Plan
shall be (i) such person or persons as are treated as the Participant's
beneficiary(ies) for purposes of the Company group life insurance plan
applicable to the Participant, or (ii) in the absence of any beneficiary
determined under clause (i) or other designated beneficiary, the Participant's
estate.

   SECTION 12. EQUAL RIGHTS; PARTICIPANT'S RIGHTS NOT TRANSFERABLE

   All Participants granted Options under the Plan with respect to any Option
Period will have the same rights and privileges. Each Participant's rights and
privileges under any Option granted under the Plan will be exercisable during
the Participant's lifetime only by him or her and except as provided at Section
11 above may not be sold, pledged, assigned, or transferred in any manner. In
the event any Participant violates or attempts to violate the terms of this
Section, any Options held by him or her may be terminated by the Company and,
upon return to the Participant of the balance of his or her withholding
account, all of the Participant's rights under the Plan will terminate.

   SECTION 13. EMPLOYMENT RIGHTS

   Nothing contained in the provisions of the Plan will be construed as giving
to any Employee any right of employment or as interfering with the right of the
Company to discharge any Employee at any time.

   SECTION 14. CHANGE IN CAPITALIZATION

   In the event of any change in the outstanding Stock of Riverstone by reason
of a stock dividend, split-up, recapitalization, merger, consolidation,
reorganization, or other capital change, the aggregate number and type of
shares available under the Plan, the number and type of shares under Options
granted but not exercised, the maximum number and type of shares purchasable
under an Option, and the Option price will be appropriately adjusted.

   SECTION 15. ADMINISTRATION OF PLAN

   The Plan will be administered by the Board, which will have the right to
determine any matters which may arise regarding the interpretation and
application of the provisions of the Plan and to make, administer, and
interpret such rules and regulations as it deems necessary or advisable.
References in the Plan to the Board shall include the Board's delegates to the
extent of any delegation by the Board to such delegates of administrative
responsibilities hereunder.

   SECTION 16. AMENDMENT AND TERMINATION OF PLAN

   Riverstone reserves the right at any time to amend the Plan in any manner it
may deem advisable, by vote of the Board; provided, that any amendment that
would be treated as the adoption of a new plan for purposes of Section 423 of
the Code will have no effect unless approved by the shareholders of Riverstone
within twelve months before or after its adoption.

   The Plan may be suspended or terminated at any time by the Board. In
connection therewith, the Board may either cancel outstanding Options or
continue them and provide that they will be exercisable either at the end of
the Option Period or on such earlier date as the Board may specify (in which
case such earlier date shall be treated as the last day of the applicable
Option Period).

   SECTION 17. APPROVAL OF SHAREHOLDERS

   The Plan and the exercisability of Options granted hereunder will be subject
to the approval of the shareholders of Riverstone obtained within twelve months
before or after the date the Plan is adopted by the Board.

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