An analysis of retransmission strategies for reliable multicast protocols
Marko Schuba, Peter Reichl · 1998
In this paper we present an analytical comparison of retransmission strategies for three types of reliable multicast protocols. In the first protocol (called sender-originated) it is the task of the source to guarantee reliable delivery of data to all receivers. The other two approaches additionally allow either receivers or routers to retransmit packets (these protocols are termed receiver-originated and router-originated, resp.). Thus the load on the sender is relieved while at the same time transmission cost decreases since packets can be retransmitted with a limited scope. We determine the retransmission cost of all three protocol types based on discrete-time Markov chains. In contrast to other analytical models this approach does not require loss events to be independent for different receivers. Numerical results show that the cost for sender-originated protocols may become unacceptable even if loss probabilities within the network are small. In larger networks with widely spread groups the performance of receiver-originated protocols is also very limited. In such scenarios only router-originated protocols yield acceptable cost.