Overlay Construction within Diffserv Domains for QoS-Aware Multicasting

We propose DIRA as an overlay multicast routing algorithm to support QoS-aware multicast applications. Its basic idea is to construct overlay multicast trees within Diffserv domains and try to find an overlay tree spanning all member nodes at a cost as low as possible. The proposed algorithm exploits the special relationship between the edge routers and the core routers in the Diffserv domain to adapt its overlay tree topology for a least cost gain when accepting a new node. Through a large amount of simulations, we have shown that DIRA has a superior performance in terms of tree cost and flexibility.