Traffic-volume-based forwarding table reducing method for multicast traffic

In the Internet, the explosive increase of the number of users requires one-to-many information distribution tools. Multicast is one of the most promising ways. One of the most important technical problems of multicast communications in the Internet is the increase of forwarding table entries with the increase of multicast groups. CIDR (classless interdomain routing), effectively used for unicast communications, cannot be applied to multicast communications because a multicast address is a virtual address. We propose a new multicast group aggregation technique where a shared tree aggregates several multicast groups by taking account of redundant traffic volumes in a shared tree. Simulation results show that our proposed scheme can effectively reduce multicast forwarding table entries in a backbone router with small overhead of redundant data transmission in a shared tree.