Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
BARROWS TIMOTHY A
   2. Issuer Name and Ticker or Trading Symbol
Starent Networks, Corp. [STAR] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O MATRIX PARTNERS, 1000 WINTER STREET, SUITE 4500		 3. Date of Earliest Transaction (Month/Day/Year)
05/12/2009
(Street)

WALTHAM, MA 02451		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock               3,297,920 I See Footnote (1)
Common Stock 05/12/2009   S   20,633 D $ 19.3087 (2) 1,100,230 I See Footnote (3)
Common Stock               397,472 I See Footnote (4)
Common Stock               775,977 I See Footnote (5)
Common Stock               204,822 D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BARROWS TIMOTHY A
C/O MATRIX PARTNERS
1000 WINTER STREET, SUITE 4500
WALTHAM, MA 02451		   X      

Signatures

 /s/ Timothy A. Barrows   05/13/2009
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Represents securities held by Matrix Partners VI, LP. Matrix VI Management Co., L.L.C. ("Matrix VI LLC") is the general partner of Matrix Partners VI, L.P. Timothy Barrows, as a Managing Member of Matrix VI LLC, has sole voting and dispostive power with respect to the shares held by those entities. Mr. Barrows disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein.
(2) Represents average sale price per share. Sales were made at prices between $19.01 and $19.77. Upon request, the reporting person will provide to the Securities and Exchange Commission staff, Starent Networks, Corp. or its securityholders full information regarding the number of shares sold at each separate price.
(3) Represents securities held by Matrix VI Parallel Partnership-A, L.P. Matrix VI LLC is the general partner of Matrix VI Parallel Partnership-A, L.P. Timothy Barrows, as a Managing Member of Matrix VI LLC, has sole voting and dispostive power with respect to the shares held by those entities. Mr. Barrows disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein.
(4) Represents securities held by Matrix VI Parallel Partnership-B, L.P. Matrix VI LLC is the general partner of Matrix VI Parallel Partnership-B, L.P. Timothy Barrows, as a Managing Member of Matrix VI LLC, has sole voting and dispostive power with respect to the shares held by those entities. Mr. Barrows disclaims beneficial ownership of such shares, except to the extent of his pecuniary interest therein.
(5) Represents securities held by Weston & Co. VI LLC. Mr. Barrows is authorized by the sole member of Weston & Co. VI LLC to take any action as directed by the underlying beneficial owners with respect to the shares held by this entity. Mr. Barrows disclaims beneficial ownership of such shares, except for those shares held by Weston & Co. VI LLC as nominee for him personally. Mr. Barrows has sole voting and/or investment control over only said shares held by Weston & Co. VI LLC as nominee for him personally. Mr. Barrows does not have sole or shared voting and/or investment control with respect to the other shares held by Weston & Co. VI LLC.

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