Fair link sharing with layered multicast videoconferencing

Some type of transmission rate control protocol is required in order to support multicast video applications over the Internet. Previously, we proposed a protocol, the layered multicast control protocol (LMCP), which utilizes both the sender and receiver to control the rate of the video transmission. The sender stripes the video signal across multiple multicast channels, and each receiver selectively adds and drops channels to meet their individual needs. The receivers also send feedback to the sender, and the sender uses this feedback to adjust the transmission rate for each channel. One weakness of this approach is that it did not share the available bandwidth fairly among multiple video applications. In this paper we introduce a new router based approach for determining a video applications fair share of the available network bandwidth. This approach builds on the strengths of the LMCP approach while allowing multiple video applications to share the available bandwidth. This approach requires low overhead on the network routers, scales well to hundreds of video sources and is independent of the number of video receivers. We show through our simulation results that this approach allows the network to be shared fairly among video applications and adjusts gracefully to fluctuations in available bandwidth