EXHIBIT A

Joint Filing Statement

Pursuant to Rule 13d-1(k)(1), the undersigned hereby express their agreement that the attached Schedule 13G is filed on each of their behalf.

Dated:  February 4, 2002

By:       /s/ R. David Spreng		By:       /s/ R. David Spreng		By:       /s/ R. David Spreng
R. David Spreng		R. David Spreng		R. David Spreng
CRESCENDO WORLD FUND, LLC		CRESCENDO III, LP		CRESCENDO III, GbR
By:  Crescendo Ventures - World        Fund, LLC		By:  Crescendo Ventures III, LLC		By:  Crescendo Ventures III, LLC and        Verbier Ventures, LLC
Its:  Managing Member		Its:  General Partner		Its:  Managing Partners

By:       /s/ R. David Spreng		By:       /s/ R. David Spreng		By:       /s/ R. David Spreng
R. David Spreng		R. David Spreng        Managing Member		R. David Spreng        Chief Manager
CRESCENDO VENTURES III, LLC		EAGLE VENTURES WF, LLC		CRESCENDO III EXECUTIVE FUND, LP
				By:  Crescendo Ventures III, LLC
				Its:  General Partner

By:       /s/ R. David Spreng		By:       /s/ R. David Spreng		By:       /s/ R. David Spreng
R. David Spreng		R. David Spreng        Managing Member		R. David Spreng        Manager Member
CRESCENDO VENTURES - WORLD FUND, LLC		VERBIER VENTURES, LLC