An architecture for wide-area multicast routing

The Protocol Independent Multicast (PIM) architecture maintains the traditional IP multicast service model of receiver-initiated membership and uses soft-state mechanisms to adapt to underlying network conditions and group dynamics, which make it well suited to large heterogeneous inter-networks.

Abstract

Existing multicast routing mechanisms were intended for use within regions where a group is widely represented or bandwidth is universally plentiful. When group members, and senders to those group members, are distributed sparsely across a wide area, these schemes are not efficient; data packets or membership report information are occasionally sent over many links that do not lead to receivers or senders, respectively. We have developed a multicast routing architecture that efficiently establishes distribution trees across wide area internets, where many groups will be sparsely represented. Efficiency is measured in terms of the state, control message processing, and data packet processing, required across the entire network in order to deliver data packets to the members of the group.