Congestion Control Performance of a Reliable Multicast Protocol

This paper evaluates the congestion control performance of Pseudofed, a congestion-controlled, reliable multicast transport protocol for bulk data transfer. Pseudofed’s congestion control mechanism is based on the concept of representatives, a small, dynamic set of multicast group members. By reducing the congestion control problem to a bounded set of receivers, representatives allow the pointto-point congestion control model used by unicast protocols like TCP to scale to larger multicast groups. Other features that contribute to the scalability of Pseudofed’s congestion control algorithm are: (1) attempting to distinguish between correlated and uncorrelated packet losses, (2) not requiring complete knowledge of the multicast group, and (3) not exchanging control communication with congestionfree subtrees.