pgmcc: a TCP-friendly single-rate multicast congestion control scheme

We present a single rate multicast congestion control scheme (pgmcc) which is TCP-friendly and achieves scalability, stability and fast response to va riations in network conditions. pgmcc is suitable for both non-reliable and reliable data transfers; it uses a window-based TCP-like controller based on positive ACKs and run between the sender and a group's representative, t he acker. The innovative part of pgmcc is a fast and low-overhead procedure to select (and track changes of) the acker, which permits us to consider t he acker as a moving receiver rather than a changing one. As such, the sche me is robust to measurement errors, and supports fast response to changes i n the receiver set and/or network conditions. The scheme has been implement ed in the PCM protocol, and the paper presents a number of experimental res ults on its performance.