POLYCOM, INC.

Exhibit 10.21

POLYCOM, INC.

MANAGEMENT BONUS PLAN

SECTION 1

BACKGROUND AND PURPOSE

1.1 Effective Date. This amendment and restatement of this Plan is effective as of November 6, 2007.

1.2 Purpose of the Plan. The Plan is intended to motivate Participants to achieve excellent short and long term financial performance for the Company and its business units. The Plan’s goals are to be achieved by providing Participants with the opportunity to earn incentive awards for the achievement of goals relating to the performance of the Company.

SECTION 2

DEFINITIONS

The following words and phrases shall have the following meanings unless a different meaning is plainly required by the context:

2.1 “Actual Award” means as to any Performance Period, the actual award (if any) payable to a Participant for the Performance Period. Each Actual Award is determined by the Payout Formula for the Performance Period, subject to the Committee’s authority under Section 3.6 to increase, eliminate or reduce the award otherwise indicated by the Payout Formula.

2.2 “Affiliate” means any corporation or other entity (including, but not limited to, partnerships and joint ventures) controlled by the Company.

2.3 “Base Salary” means as to any Performance Period, the Participant’s earned salary during the Performance Period. Such Base Salary shall be before both (a) deductions for taxes or benefits, and (b) deferrals of compensation pursuant to Company-sponsored plans and Affiliate-sponsored plans.

2.4 “Board” means the Board of Directors of the Company.

2.5 “Committee” means the committee appointed by the Board (pursuant to Section 5.1) to administer the Plan.

2.6 “Company” means Polycom, Inc., a Delaware corporation, or any successor thereto.

2.7 “Disability” means a permanent disability in accordance with a policy or policies established by the Committee (in its discretion) from time to time.

2.8 “Employee” means any employee of the Company or of an Affiliate, whether such employee is so employed at the time the Plan is adopted or becomes so employed subsequent to the adoption of the Plan.

2.9 “Fiscal Quarter” means a fiscal quarter within a Fiscal Year of the Company.

2.10 “Fiscal Year” means the fiscal year of the Company.

2.11 “Participant” means as to any Performance Period, an Employee who has been selected by the Committee for participation in the Plan for that Performance Period.

2.12 “Payout Formula” means as to any Performance Period, the formula or payout matrix established by the Committee pursuant to Section 3.4 in order to determine the Actual Awards (if any) to be paid to Participants. The formula or matrix may differ from Participant to Participant.

2.13 “Performance Period” means any Fiscal Year or such other period longer or shorter than a Fiscal Year but not shorter than a Fiscal Quarter or longer than three Fiscal Years, as determined by the Committee in its sole discretion.

2.14 “Performance Goals” means the goal(s) (or combined goal(s)) determined by the Committee (in its discretion) to be applicable to a Participant for a Target Award for a Performance Period. As determined by the Committee, the Performance Goal(s) may provide for a targeted level or levels of achievement using the performance criteria specified by the Committee. Any criteria used may be measured, as applicable, (i) in absolute terms, (ii) in relative terms (including, but not limited, the passage of time and/or against other companies or metrics), (iii) on a per share and/or share per capita basis, (iv) against the performance of the Company as a whole or against particular segments or products of the Company, and/or (v) on a pre-tax or after-tax basis. The Committee (in its discretion) shall determine whether any element(s) (for example, but not by way of limitation, the effect of mergers or acquisitions) shall be included in or excluded from the calculation of any Performance Goal with respect to any Participants (whether or not such determinations result in any Performance Goal being measured on a basis other than generally accepted accounting principles).

2.15 “Plan” means the Polycom, Inc. Management Bonus Plan, as set forth in this instrument and as hereafter amended from time to time.

2.16 “Progress Payment” means a portion of the Target Award or Actual Award for which the Committee has determined in accordance with Section 3.6 has been earned by the Participant as of the end of the Progress Period based on achievement of the applicable Performance Goals and thereby that may be paid to the Participant during the Performance Period.

2.17 “Progress Period” means a period shorter than and within the Performance Period for which a Progress Payment may be made.

2.18 “Retirement” means with respect to any Participant, a Termination of Employment occurring in accordance with a policy or policies established by the Committee (in its discretion) from time to time.

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2.19 “Target Award” means the target award payable under the Plan to a Participant for the Performance Period, expressed as a percentage of his or her Base Salary or a specific dollar amount, as determined by the Committee in accordance with Section 3.3.

2.20 “Termination of Employment” means a cessation of the employee-employer relationship between an Employee and the Company or an Affiliate for any reason, including, but not by way of limitation, a termination by resignation, discharge, death, Disability, Retirement, or the disaffiliation of an Affiliate, but excluding any such termination where there is a simultaneous reemployment by the Company or an Affiliate.

SECTION 3

SELECTION OF PARTICIPANTS AND DETERMINATION OF AWARDS

3.1 Selection of Participants. The Committee, in its sole discretion, shall select the Employees who shall be Participants for any Performance Period. The Committee, in its sole discretion, also may designate as Participants one or more individuals (by name or position) who are expected to become Employees during a Performance Period. Participation in the Plan is in the sole discretion of the Committee, and shall be determined on a Performance Period by Performance Period basis. Accordingly, an Employee who is a Participant for a given Performance Period in no way is guaranteed or assured of being selected for participation in any subsequent Performance Period.

3.2 Determination of Performance Goals. The Committee, in its sole discretion, shall establish the Performance Goals for each Participant for the Performance Period. Such Performance Goals shall be set forth in writing.

3.3 Determination of Target Awards. The Committee, in its sole discretion, shall establish a Target Award for each Participant. Each Participant’s Target Award shall be determined by the Committee in its sole discretion, and each Target Award shall be set forth in writing.

3.4 Determination of Payout Formula or Formulae. The Committee, in its sole discretion, shall establish a Payout Formula or Formulae for purposes of determining the Actual Award (if any) payable to each Participant. Each Payout Formula shall (a) be in writing, (b) be based on a comparison of actual performance to the Performance Goals, (c) provide for the payment of a Participant’s Target Award if the Performance Goals for the Performance Period are achieved at the predetermined level, and (d) provide for the payment of an Actual Award greater than or less than the Participant’s Target Award, depending upon the extent to which actual performance exceeds or falls below the Performance Goals.

3.5 Determination of Actual Awards. After the end of each Performance Period or, to the extent Progress Payments will be made, after the end of the Progress Period, the Committee shall certify the extent to which the Performance Goals applicable to each Participant for the Performance Period or Progress Period, as applicable, were achieved or exceeded, as determined by the Committee. The Actual Award for each Participant shall be determined by applying the Payout Formula to the level of actual performance that has been certified by the Committee. Notwithstanding any contrary provision of the Plan, the Committee, in its sole discretion, may

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(a) increase, eliminate or reduce the Actual Award that otherwise would be payable under the Payout Formula, and (b) determine whether or not any Participant will receive an Actual Award in the event the Participant incurs a Termination of Employment prior to the date the Actual Award is to be paid pursuant Section 4.2 below.

SECTION 4

PAYMENT OF AWARDS

4.1 Right to Receive Payment. Each Actual Award that may become payable under the Plan shall be paid solely from the general assets of the Company or the Affiliate that employs the Participant (as the case may be), as determined by the Committee. Nothing in this Plan shall be construed to create a trust or to establish or evidence any Participant’s claim of any right to payment of an Actual Award other than as an unsecured general creditor with respect to any payment to which he or she may be entitled.

4.2 Timing of Payment. Subject to Section 3.6, payment of each Actual Award shall be made as soon as administratively practicable, but in no event later than two and one-half months after the end of the applicable Performance Period or Progress Period.

4.3 Form of Payment. Each Actual Award shall be paid in cash (or its equivalent) in a single lump sum.

4.4 Payment in the Event of Death. If a Participant dies prior to the payment of an Actual Award (determined under Section 3.6) that was scheduled to be paid to him or her prior to death for a prior Performance Period, the Award shall be paid to his or her designated beneficiary or, if no beneficiary has been designated, to the administrator or representative of his or her estate.

SECTION 5

ADMINISTRATION

5.1 Committee is the Administrator. The Plan shall be administered by the Committee. The Committee shall consist of not less than two (2) members of the Board. Any member of the Committee may resign at any time by notice in writing mailed or delivered to the Secretary of the Company. As of the Effective Date of the Plan, the Plan shall be administered by the Compensation Committee of the Board.

5.2 Committee Authority. It shall be the duty of the Committee to administer the Plan in accordance with the Plan’s provisions. The Committee shall have all powers and discretion necessary or appropriate to administer the Plan and to control its operation, including, but not limited to, the power to (a) determine which Employees shall be granted awards, (b) prescribe the terms and conditions of awards, (c) interpret the Plan and the awards, (d) adopt such procedures and subplans as are necessary or appropriate to permit participation in the Plan by Employees who are foreign nationals or employed outside of the United States, (e) adopt rules for the administration, interpretation and application of the Plan as are consistent therewith, and (f) interpret, amend or revoke any such rules.

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5.3 Decisions Binding. All determinations and decisions made by the Committee, the Board, and any delegate of the Committee pursuant to the provisions of the Plan shall be final, conclusive, and binding on all persons, and shall be given the maximum deference permitted by law.

5.4 Delegation by the Committee. The Committee, in its sole discretion and on such terms and conditions as it may provide, may delegate all or part of its authority and powers under the Plan to one or more directors and/or employees of the Company.

SECTION 6

GENERAL PROVISIONS

6.1 Tax Withholding. The Company or an Affiliate, as determined by the Committee, shall withhold all applicable taxes from any Actual Award, including any federal, state, local and other taxes.

6.2 No Effect on Employment. Nothing in the Plan shall interfere with or limit in any way the right of the Company or an Affiliate, as applicable, to terminate any Participant’s employment or service at any time, with or without cause. For purposes of the Plan, transfer of employment of a Participant between the Company and any one of its Affiliates (or between Affiliates) shall not be deemed a Termination of Employment. Employment with the Company and its Affiliates is on an at-will basis only. The Company expressly reserves the right, which may be exercised at any time and without regard to when during or after a Performance Period such exercise occurs, to terminate any individual’s employment with or without cause, and to treat him or her without regard to the effect which such treatment might have upon him or her as a Participant.

6.3 Participation. No Employee shall have the right to be selected to receive an award under this Plan, or, having been so selected, to be selected to receive a future award.

6.4 Indemnification. Each person who is or shall have been a member of the Committee, or of the Board, shall be indemnified and held harmless by the Company against and from (a) any loss, cost, liability, or expense that may be imposed upon or reasonably incurred by him or her in connection with or resulting from any claim, action, suit, or proceeding to which he or she may be a party or in which he or she may be involved by reason of any action taken or failure to act under the Plan or any award, and (b) from any and all amounts paid by him or her in settlement thereof, with the Company’s approval, or paid by him or her in satisfaction of any judgment in any such claim, action, suit, or proceeding against him or her, provided he or she shall give the Company an opportunity, at its own expense, to handle and defend the same before he or she undertakes to handle and defend it on his or her own behalf. The foregoing right of indemnification shall not be exclusive of any other rights of indemnification to which such persons may be entitled under the Company’s Certificate of Incorporation or Bylaws, by contract, as a matter of law, or otherwise, or under any power that the Company may have to indemnify them or hold them harmless.

6.5 Successors. All obligations of the Company and any Affiliate under the Plan, with respect to awards granted hereunder, shall be binding on any successor to the Company and/or such Affiliate, whether the existence of such successor is the result of a direct or indirect purchase, merger, consolidation, or otherwise, of all or substantially all of the business or assets of the Company or such Affiliate.

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6.6 Beneficiary Designations.

(a) Designation. Each Participant may, pursuant to such uniform and nondiscriminatory procedures as the Committee may specify from time to time, designate one or more Beneficiaries to receive any Actual Award payable to the Participant at the time of his or her death. Notwithstanding any contrary provision of this Section 6.6 shall be operative only after (and for so long as) the Committee determines (on a uniform and nondiscriminatory basis) to permit the designation of Beneficiaries.

(b) Changes. A Participant may designate different Beneficiaries (or may revoke a prior Beneficiary designation) at any time by delivering a new designation (or revocation of a prior designation) in like manner. Any designation or revocation shall be effective only if it is received by the Committee. However, when so received, the designation or revocation shall be effective as of the date the designation or revocation is executed (whether or not the Participant still is living), but without prejudice to the Committee on account of any payment made before the change is recorded. The last effective designation received by the Committee shall supersede all prior designations.

(c) Failed Designation. If the Committee (in its discretion) does not make this Section 6.6 operative or if Participant dies without having effectively designated a Beneficiary, the Participant’s Account shall be payable to the administrator or representative of his or her estate.

6.7 Nontransferability of Awards. No award granted under the Plan may be sold, transferred, pledged, assigned, or otherwise alienated or hypothecated, other than by will, by the laws of descent and distribution, or to the limited extent provided in Section 6.6. All rights with respect to an award granted to a Participant shall be available during his or her lifetime only to the Participant.

6.8 Deferrals. The Committee, in its sole discretion, may permit a Participant to defer receipt of the payment of cash that would otherwise be delivered to a Participant under the Plan. Any such deferral elections shall be subject to such rules and procedures as shall be determined by the Committee in its sole discretion. Unless otherwise expressly determined by the Committee, the rules and procedures for any deferral elections and deferrals shall be designed to comply with Section 409A of the Code.

SECTION 7

AMENDMENT, TERMINATION AND DURATION

7.1 Amendment, Suspension or Termination. The Board or the Committee, each in its sole discretion, may amend or terminate the Plan, or any part thereof, at any time and for any reason. No award may be granted during any period of suspension or after termination of the Plan.

7.2 Duration of the Plan. The Plan shall commence on the date specified herein, and subject to Section 7.1 (regarding the Board or the Committee’s right to amend or terminate the Plan), shall remain in effect thereafter.

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SECTION 8

LEGAL CONSTRUCTION

8.1 Gender and Number. Except where otherwise indicated by the context, any masculine term used herein also shall include the feminine; the plural shall include the singular and the singular shall include the plural.

8.2 Severability. In the event any provision of the Plan shall be held illegal or invalid for any reason, the illegality or invalidity shall not affect the remaining parts of the Plan, and the Plan shall be construed and enforced as if the illegal or invalid provision had not been included.

8.3 Requirements of Law. The granting of awards under the Plan shall be subject to all applicable laws, rules and regulations, and to such approvals by any governmental agencies or national securities exchanges as may be required.

8.4 Governing Law. The Plan and all awards shall be construed in accordance with and governed by the laws of the State of California, but without regard to its conflict of law provisions.

8.5 Captions. Captions are provided herein for convenience only, and shall not serve as a basis for interpretation or construction of the Plan.

EXECUTION

IN WITNESS WHEREOF, Polycom, Inc., by its duly authorized officer, has executed the amended and restated Plan on the date indicated below.

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