We present a distributed algorithm to compute bandwidth max-min fair rates in a multi-rate multicast network.
The significance of the algorithm, compared to previous algorithms [1–3], is that it is more scalable in that it does
not require each link to maintain the saturation status of all sessions and virtual sessions travelling through it, more
stable in that it converges asymptotically to the desired equilibrium satisfying the minimum plus max-min fairness
even in presence of heterogeneous round-trip delays, and has explicit link buffer control in that the buffer occupancy
of every bottlenecked link in the network asymptotically converges to the pre-defined value. The algorithm is based
on PI (proportional integral) control in the feedback control theory and by appealing to the Nyquist stability
criterion, an usable stability condition is derived in presence of sources with heterogeneous round-trip delays. In
addition, we propose an efficient feedback consolidation algorithm which is computationally simpler than its hardsynchronization
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 further
verify the analytical results and the performance of the proposed multi-rate multicast flow control scheme based
on these two algorithms in a multiple-link network configuration.