A TCP friendly, rate-based mechanism for NACK-oriented reliable multicast congestion control

We describe ongoing work in adding congestion control extensions to an existing negative acknowledgement (NACK) oriented reliable multicast protocol. Our previous work adopted and used the concept of a dynamic worst path representative (WPR) receiver for equation-based rate adaptation at the multicast source. We have further refined this approach. We present a design overview and simulation results of these extensions within a working reliable multicast protocol (MDP-CC, multicast dissemination protocol congestion control). Our analysis of interflow fairness with steady state TCP unicast sessions demonstrates friendly behavior across a set of scenarios. Testing with more dynamic TCP flows and more complex topologies demonstrates the WPR approach adapts well to changing congestion conditions.