EXHIBIT B

Agreement of Joint Filing

The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock of Infinera Corporation shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13D.

Date: February 12, 2009


	BENCHMARK CAPITAL PARTNERS IV, L.P., a Delaware Limited Partnership BENCHMARK CAPITAL MANAGEMENT CO. IV, L.L.C., a Delaware Limited Liability Company
	By:	/s/ Steven M. Spurlock
		Steven M. Spurlock
		Managing Member

	BENCHMARK CAPITAL PARTNERS VI, L.P., a Delaware Limited Partnership BENCHMARK CAPITAL MANAGEMENT CO. VI, L.L.C., a Delaware Limited Liability Company

	By:	/s/ Steven M. Spurlock
		Steven M. Spurlock
		Managing Member

	ALEXANDRE BALKANSKI MATTHEW R. COHLER BRUCE W. DUNLEVIE PETER H. FENTON J. WILLIAM GURLEY KEVIN R. HARVEY ROBERT C. KAGLE MITCHELL H. LASKY ANDREW S. RACHLEFF STEVEN M. SPURLOCK
	By:	/s/ Steven M. Spurlock
		Steven M. Spurlock
		Attorney-in-Fact


*		Signed pursuant to a Power of Attorney already on file with the appropriate agencies.

BENCHMARK CAPITAL PARTNERS IV LP SC 13D