TCP-friendly video transfer

When both TCP and UDP connections co-exist in the Internet environment, the performance of TCP connections is heavily affected by the behavior of "greedy" UDP connections of real-time multimedia applications. In this paper, we propose a new TCP-friendly rate control protocol for video connections, called MPEG-TFRCP, to fairly share the link with TCP connections. To achieve fairness among TCP and UDP connections while performing high quality video transmission, we argue that (1) the interval of rate control must be appropriately determined, (2) the network condition must be accurately predicted, (3) the TCP throughput must be precisely estimated and (4) the video rate must be effectively adjusted. Although our algorithm is based on the existing proposals which do not satisfy all of those conditions, through careful considerations on the applicability of TFRCP to the actual video applications ours can achieve the high-quality MPEG-2 video transfer while satisfying the TCP-friendliness. Through simulation experiments, we show that the TCP throughput estimation based on pseudo-TCP feedback collection is acceptable and the rate adjustment based on the quantization control should be performed at the interval of 32 times as long as estimated RTT.