Aggregated Multicast: A Scheme to Reduce Multicast States
In this document, we present a novel scheme, called aggregated multicast, to reduce multicast states ([FeiGI01] and [FeiNGC01]). The key idea is that multiple groups are forced to share one distribution tree, which we call aggregated tree. In our scheme, core routers need to keep states only per aggregated tree instead of per group. This can significantly reduce the total number of trees in the network and thus reduce forwarding states. We investigate the implementation issues of aggregated multicast in different network scenarios. We also discuss the effects of aggregated multicast on some important issues, such as QoS multicast provisioning, mobility support and fault tolerance. The scope of this paper is not to propose a detailed protocol, but present the idea of aggregated multicast at high level and show its merits.