This document describes the Onboard High Rate/Capacity Data System Enhanced Test Bed (ETC) performance requirements (ETB). The ETB requirements will be used to trade studies and design efforts to implement ETB with resulting specifications. Only primary performance requirements are given. There is an overview of the ETB and identifying Engineering Development Modules (EDM's) provided in the ETB facility. Capabilities of the EDM's that drive ETB performance requirements are also summarized. Possible evolution of the ETB and EDM are discussed.