We are investigating alternative transport protocol strategies for realizing large scale dissemination services across a wide area network. Communication requirements of such applications are distinct from those based on conventional client-server interactions. Conventional flow and error control methods based on the retransmissions-with-timeout paradigm are not appropriate for such applications. Instead, we are interested in using optimistic flow and error control strategies that take into account application-specific error tolerance and media rates of multimedia applications. This paper describes transport level policies that use a combination of redundant transmissions, rate-based flow control, and selective feedback from receivers. A simulation-based performance evaluation demonstrates that relatively simple techniques succeed well in meeting the QOS requirements of a multimedia multicast and in scaling to hundreds of recipients. 1 Introduction Our research is motivated by the co...