Achieving bounded fairness for multicast and TCP traffic in the Internet

There is an urgent need for effective multicast congestion control algorithms which enable reasonably fair share of network resources between multicast and unicast TCP traffic under the current Internet infrastructure. In this paper, we propose a quantitative definition of a type of bounded fairness between multicast and unicast best-effort traffic, termed "essentially fair". We also propose a window-based Random Listening Algorithm (RLA) for multicast congestion control. The algorithm is proven to be essentially fair to TCP connections under a restricted topology with equal round-trip times and with phase effects eliminated. The algorithm is also fair to multiple multicast sessions. This paper provides the theoretical proofs and some simulation results to demonstrate that the RLA achieves good performance under various network topologies. These include the performance of a generalization of the RLA algorithm for topologies with different round-trip times.