End System Multicast routing for multi-party videoconferencing applications

Inspired by the success of peer-to-peer file sharing, End System Multicasting promises immediate deployment of many-to-many multimedia applications such as videoconferencing and web-casting, without requiring the underlying inter-network infrastructure to support IP Multicasting capability. By sharing the responsibility of forwarding media streams, peers in a many-to-many conferencing application can alleviate the bandwidth limitations of a source transmitting to several receivers. Current approaches to End System Multicasting however focus on single source applications and do not consider multicasting for multiple simultaneous sources in their group management mechanisms. In this paper, we examine the shortcomings of current End System Multicast routing schemes for supporting small-group multi-party media conferencing applications and propose our own heuristic routing algorithms. The contributions of the paper include two heuristic algorithms called MOTOR and MOTOR-Dynamic that perform significantly better than similar algorithms for creation of minimum-cost degree-constrained trees for each multicasting source. Through simulations, we show that our heuristics find a greater percentage of solutions than existing approaches while constructing video distribution overlay trees with low delay, comparable to existing approaches.