AMBTS: A Scheme of Aggregated Multicast Based on Tree Splitting

As the number of simultaneously active groups increases, IP multicast suffers from scalability problem. In backbone networks, the state scalability problem is even more serious. In this paper, we propose a novel scheme, called AMBTS, which uses the concept of aggregated multicast, and employs tree splitting before aggregating. We design an algorithm to divide the leaf nodes of backbone into different sub-groups, and then splitting the native multicast spanning tree. We propose a scheme to assign a set of aggregated multicast trees to deliver packets for a group. Analyses and simulations show that AMBTS can greatly improve state scalability: the number of aggregated trees is bounded in a small fixed number, and the multicast routing entries in transit nodes decreased dramatically.