Some Design Issues of SRMTP, a Scalable Reliable Multicast Transport Protocol

In this paper, we propose a transport layer protocol for one-to-many multicast that is designed to have good scalability properties in large receiver groups and provides reliable transmission. Reliability is achieved using forward error correction (FEC) in combination with selective repeat NAK-based ARQ. Using FEC can signiicantly reduce the necessity for retransmission requests or make them totally unnecessary, which is important in wireless and satellite communicaton environments, as well as for delay-sensitive multimedia applications. The protocol uses one multicast group address for the original transmission and a second group address for the handling of retransmissions, which helps in signii-cantly reducing the network load on branches with low loss and facilitates usage in the context of satellite communications. We hope that our work will be useful and encouraging for the development of group communication applications.