Optimizing buffer management for reliable multicast

Reliable multicast delivery requires that a multicast message be received by all members in a group. Hence certain or all members need to buffer messages for possible retransmissions. Designing an efficient buffer management algorithm is challenging in large multicast groups where no member has complete group membership information and the delivery latency to different members could differ by orders of magnitude. We propose an innovative two-phase buffering algorithm, which explicitly addresses variations in delivery latency seen in large multicast groups. The algorithm effectively reduces buffer requirements by adaptively allocating buffer space to messages most needed in the system and by spreading the load of buffering among all members in the group. Simulation and experimental results demonstrate that the algorithm has good performance.