QuickLinks -- Click here to rapidly navigate through this document

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

        We hereby consent to the use in this Amendment No. 2 to Registration Statement on Form S-1 of our report dated March 5, 2007 except for Note 15, as to which the date is May 1, 2007 relating to the financial statements of Starent Networks, Corp., which appears in such Registration Statement. We also consent to the reference to us under the heading "Experts" in such Registration Statement.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts
October 29, 2007

QuickLinks

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM