A distributed max-min flow control algorithm for multi-rate multicast flows

Abstract

We present a distributed algorithm to compute the bandwidth max-min fair rates in a multi-rate multicast network. The significance of the algorithm, compared to previous algorithms (Sakar, S. and Tassiulas L., 1999, 2000; Kar, K. et al., 2001), is that it is more scalable (it does not require each link to maintain the saturation status of all sessions and virtual sessions travelling through it) it is more stable (it converges asymptotically to the desired equilibrium, satisfying the minimum plus max-min fairness, even in the presence of heterogeneous round-trip delays) and it has explicit link buffer control (the buffer occupancy of every bottlenecked link in the network asymptotically converges to the pre-defined value). In addition, we propose an efficient feedback consolidation algorithm which is computationally simpler than its hard-synchronization based counterpart and eliminates unnecessary consolidation delay by preventing it from awaiting backward control packets (BCPs) that do not directly contribute to the session rate. Through simulations, we verify the performance of the proposed multi-rate multicast flow control scheme based on these two algorithms.