Exhibit
10.6


ACME
PACKET, INC.


NON-STATUTORY
STOCK OPTION AGREEMENT

(Form of Non-Statutory Stock Option Agreement for Directors)


This NON-STATUTORY
STOCK OPTION AGREEMENT, dated as of <date> (this “Agreement”), is
between ACME PACKET, INC., a Delaware corporation (the “Company”), and
<Optionee Name> (the “Optionee”). 
Capitalized terms used herein without definition shall have the meaning
ascribed to such terms in the Company’s 2006 Equity Incentive Plan, a copy of
which is attached hereto as Exhibit A (the “Plan”).


1.             Grant  of  Option.  Pursuant to the Plan, the Company grants to
the Optionee an option (the “Option”) to purchase from the Company all
or any number of an aggregate of <Number of Shares> shares, subject to
adjustment pursuant to Section 8 of the Plan (the “Option  Shares”),
of the Company’s common stock, $.001 par value per share, at a price of
$<price> per share.  The Option is
granted as of <Date of Grant> (the “Grant  Date”).


2.             Character  of  Option.  The Option is not intended to be treated as an
“incentive stock option” within the meaning of Section 422 of the Internal
Revenue Code of 1986, as amended (the “Code”).


3.             Duration  of  Option.  Unless subject to earlier expiration or
termination pursuant to the terms of the Plan, the Option shall expire on the
ten year anniversary of the Grant Date.


4.             Exercise  of  Option.


(a)           Vesting Schedule.  The
Option may be exercised, at any time and from time to time until its expiration
or termination, for any or all of those Option Shares in respect of which the
Option shall have become exercisable, in accordance with the provisions set
forth below in this Section 4, on or at any time prior to the date of any such
exercise.  Subject to the provisions of
the Plan (including, without limitation, the provisions of Section 7.1(e) of
the Plan), the Option shall become exercisable in a series of four (4)
quarterly installments, with each installment being as nearly equal as
practicable (as determined by the Company in its reasonable discretion), with
the first of such quarterly installments becoming exercisable on [___________]
and an additional of such quarterly installments becoming exercisable on the
first day of each calendar quarter thereafter until the Option shall have
become exercisable for all of the Option Shares(1).






(1)             The
specific vesting schedule of each option granted under the Plan is determined
at the discretion of the Committee on a case-by-case basis at the time of
grant.









 



 


Notwithstanding anything
expressed or implied to the contrary in the foregoing provisions of this
Section 4(a), (A) the exercisability of the Option shall, as provided in
Section 4(b) below, be automatically Accelerated under certain circumstances
and (B) the exercisability of the Option may, as provided in Section 7.1(d) of
the Plan, at any time be Accelerated in the discretion of the Committee.


(b)           Acceleration of Vesting.  Notwithstanding
anything in Section 4(a) above to the contrary, in the event that a Change of
Control occurs prior to the time that the Option is exercisable in full for all
of the Option Shares and that the Optionee is a member of the Board of
Directors of the Company immediately prior to such Change of Control, then the
exercisability of the Option shall be automatically Accelerated such that the
Option shall become exercisable for an additional number of Option Shares equal
to one hundred percent (100%) of the then Unvested Option Shares (as defined
below in Section 4(c) below).


(c)           Definitions.


 “Unvested  Option  Shares”
shall mean, at the relevant time of reference thereto, those Option Shares for
which the Option has not yet become exercisable at such time pursuant to
Section 4(a) and without giving effect to the provisions of Section 4(b) above.


5.             Transfer  of  Option.  Other than as expressly permitted by the
provisions of Section 7.1(f) of the Plan, the Option may not be transferred
except by will or the laws of descent and distribution and, during the lifetime
of the Optionee, may be exercised only by the Optionee.


6.             Incorporation  of  Plan
Terms.  The Option is granted
subject to all of the applicable terms and provisions of the Plan, including,
but not limited to, the limitations on the Company’s obligation to deliver
Option Shares upon exercise set forth in Section 9.1 (Violation of Law),
Section 9.2 (Corporate Restrictions on Rights in Stock), Section 9.3
(Investment Representations) and Section 9.7 (Tax Withholding).


7.             Miscellaneous.  This Agreement shall be construed and
enforced in accordance with the internal, substantive laws of The Commonwealth
of Massachusetts and shall be binding upon and inure to the benefit of any
successor or assign of the Company and any executor, administrator, trustee,
guardian, or other legal representative of the Optionee.


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IN WITNESS
WHEREOF, the parties have executed this Non-Statutory Stock Option Agreement as
a sealed instrument as of the date first above written.


	
  ACME PACKET, INC.

  	
   

  	
  OPTIONEE

  
	
   

  	
   

  	
   

  	
   

  
	
  By:

  	
   

  	
   

  	
   

  
	
   

  	
  Name:

  	
   

  	
   

  
	
   

  	
  Title

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  Optionee’s Address:

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  



 



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Exhibit A


2006 EQUITY INCENTIVE
PLAN