A Delay Analysis of Reliable Multicast Protocols

We present a delay analysis of one senderand two receiver-initiated classes of reliable multicast protoco ls. Besides the average delivery delay we consider the delay to reliably del iver all packets and the round trip delay. The former two examines the delay between generation of a packet at the sender and correct rece ption at a randomly chosen receiver or all receivers, respectively. The latter is the delay between generation of a packet at the sender and rec eption of all acknowledgment packets at the sender. Our numerical results show that receiver-initiated protoc ls provide significantly better scalability for large receiver groups and transmission rates compared to the sender-initiated protocol. Howe ver, the delay of the sender-initiated protocol within its scalabilit y range is substantially lower compared to the receiver-initiated proto cols. To assess the quality of our analytical model we have compare d the analytical results with a SRM-like protocol simulation . We show that the analytical and simulation results are strongly cor related, which demonstrates the appropriateness of our analytical model.