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                                                                  EXHIBIT 10.20

               REDBACK NETWORKS INC. 1999 STOCK INCENTIVE PLAN:
                       NOTICE OF RESTRICTED STOCK AWARD

     You have been granted restricted shares of Common Stock of Redback Networks
Inc. (the "Company") on the following terms:

     Name of Recipient:                 Kevin DeNuccio

     Total Number of Shares Granted:    500,000

     Fair Market Value per Share:       $4.17

     Total Fair Market Value of Award:  $2,085,000.00

     Date of Grant:                     August 29, 2001

     Vesting Commencement Date:         August 29, 2001

     Vesting Schedule:                  The right of forfeiture shall lapse and
                                        the shares shall become unrestricted at
                                        the rate of 8.333% once a month when you
                                        complete each month of continuous
                                        service as an employee, consultant or
                                        director of the Company or a subsidiary
                                        of the Company ("Service") from the
                                        Vesting Commencement Date.
                                        Notwithstanding the forgoing, your
                                        shares will not vest and shall not
                                        become unrestricted during any period
                                        where the Company's then current Insider
                                        Trading Policy would not allow you to
                                        immediately sell the shares on the open
                                        market. No shares shall vest hereunder
                                        until the day this agreement is executed
                                        by both parties. The shares may become
                                        exercisable on an accelerated basis, as
                                        described in the Restricted Stock
                                        Agreement.

                                        The Pro Rata Return Portion (as defined
                                        in your letter agreement dated August
                                        17, 2001 "Letter Agreement") of the
                                        shares will revert back to the Company
                                        if, before you complete 12 months of
                                        continuous service with the Company,
                                        your employment ends due to a Pay-back
                                        Event (as defined in the Letter
                                        Agreement).

By your signature and the signature of the Company's representative below, you
and the Company agree that these shares are granted under and governed by the
terms and conditions of the Redback Networks Inc. 1999 Stock Incentive Plan (the
"Plan") and the Restricted Stock Agreement, which is attached to and made a part
of this document.

RECIPIENT:                              REDBACK NETWORKS INC.


/s/ Kevin A. DeNuccio                   By: /s/ Thomas C. Cronan
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               REDBACK NETWORKS INC. 1999 STOCK INCENTIVE PLAN:
                          RESTRICTED STOCK AGREEMENT

Payment for Shares      No payment is required for the shares that you are
                        receiving.

Vesting                 The shares that you are receiving will vest in
                        installments, as shown in the Notice of Restricted Stock
                        Award. Except as set forth herein no additional shares
                        will vest after your Service has terminated for any
                        reason. Vesting may accelerate, as provided below.

Vesting Following       If the Company is subject to a "Change in Control" (as
Change in Control       defined in the Plan) before  your Service terminates,
                        then all of your restricted shares will immediately vest
                        in full.

Shares Restricted       Unvested shares will be considered  "Restricted  Shares"
                        and will be maintained in a Company escrow account. You
                        may not sell,  transfer,  pledge or otherwise dispose of
                        any  Restricted  Shares  without  the  written  consent
                        of the  Company,  except as provided in the next
                        sentence.  You may transfer  Restricted  Shares to your
                        spouse, children  or  grandchildren  or to a trust
                        established  by you for the  benefit  of yourself or
                        your  spouse,  children  or  grandchildren.  However,  a
                        transferee  of Restricted  Shares must agree in writing
                        on a form  prescribed  by the Company to be bound by all
                        provisions  of this  Agreement  and the shares will be
                        maintained in a Company escrow account.

  Forfeiture            If for any reason, under this agreement your shares are
                        forfeited the Restricted Shares will immediately revert
                        to the Company. You receive no payment for Restricted
                        Shares that are forfeited.

  Leaves of Absence     For  purposes  of this  award,  your  Service  does not
                        terminate  when you go on a military  leave,  a sick
                        leave or another  bona fide leave of absence,  if the
                        leave was  approved  by the Company in writing and if
                        continued  crediting  of Service is required by
                        applicable  law, the Company's  leave of absence
                        policy or the terms of your leave.  But your Service
                        terminates  when the approved leave ends,  unless you
                        immediately return to active work.

  Voting Rights         You may vote your shares even before they vest.









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  Withholding Taxes    No stock certificates or electronic transfer of shares
                       will be released to you unless you have made acceptable
                       arrangements to pay any withholding, including taxes,
                       that may be due as a result of this award or the vesting
                       of the shares. These arrangements may include withholding
                       shares of Company stock that otherwise would be released
                       to you when they vest. These arrangements may also
                       include surrendering shares of Company stock that you
                       already own. The fair market value of the shares you
                       surrender, determined as of the date when taxes otherwise
                       would have been withheld in cash, will be applied as a
                       credit against the withholding. The amount of withholding
                       will be determined by the Company in its sole discretion.

  Restrictions         By signing this Agreement, you agree not to sell any
  on Resale            shares at a time when applicable laws or Company policies
                       prohibit a sale. This restriction will apply as long as
                       you are an employee, consultant or director of the
                       Company or a subsidiary of the Company.

  No Retention         Your award or this Agreement does not give you the right
  Rights               to be employed or retained by the Company or a subsidiary
                       of the Company in any capacity. The Company and its
                       subsidiaries reserve the right to terminate your Service
                       at any time, with or without cause.

  Adjustments          In the event of a stock split, a stock dividend or a
                       similar change in Company stock, the number of Restricted
                       Shares that remain subject to forfeiture will be adjusted
                       accordingly.

  Applicable Law       This Agreement will be interpreted and enforced under the
                       laws of the State of Delaware (without regard to their
                       choice-of-law provisions).

  The Plan and         The text of the 1999 Stock  Incentive  Plan is
  Other Agreements     incorporated in this Agreement by reference.

                       This Agreement and the Plan constitute the entire
                       understanding between you and the Company regarding this
                       award. Any prior agreements, commitments or negotiations
                       concerning this award are superseded. This Agreement may
                       be amended only by another written agreement, signed by
                       both parties.

BY SIGNING THE COVER SHEET OF THIS AGREEMENT, YOU AGREE TO ALL OF THE TERMS AND
                  CONDITIONS DESCRIBED ABOVE AND IN THE PLAN.

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