A session tree creation mechanism with router assist for reliable multicast

For reliable multicast service, the hierarchical control tree based mechanism can be a promising solution to avoid the well-known feedback implosion. To configure a logical tree is difficult because IP multicast does not provide explicit membership and routing topology information to upper layer protocols. Because of this problem, the transport layer tree may not be congruent with the underlying routing tree, and in this case, reliable multicast services may incur a large cost. This problem can be solved if the router that knows that the routing topology can support configuration of a control tree and reliable delivery. Thus, this paper proposes a router-assist mechanism which uses very simple methods to allow the routers to assist in providing a reliable multicast transport service.