Router-assisted layered multicast

Several layered multicast protocols have been proposed for congestion control in real-time multicast applications. Most of them are pure end-to-end protocols, thus having difficulty in coordinating receivers and coping with traffic variations. We propose RALM, a new receiver-driven router-assisted layered multicast protocol. RALM achieves much better performance at the expense of moderate additional complexity in the network. RALM is incrementally deployable. We evaluate RALM through simulations, and compare its performance with RLM, the well known layered multicast protocol.