On the throughput analysis of rate-based and window-based congestion control schemes

The existing TCP protocols contribute to the stability of the Internet by deploying window-based additive-increase multiplicative-decrease (AIMD) congestion control. However, the window-based congestion control is not favorable in the existence of long propagation delay and for real-time multimedia traffic. Thus, the rate-based congestion control has become an attractive alternative for the links with high delay and for multimedia flows. In this paper, an analysis of the rate-based generic AIMD congestion control scheme is presented. The analytical model is validated via simulation experiments for a wide range of link conditions and the effects of rate-increase and decrease parameters on the performance are investigated. One important result of this analysis is that throughput performance of the rate-based schemes is inversely proportional to square-root of the propagation delay whereas that of the window-based schemes is known to be inversely proportional to the propagation delay itself. This result also justifies that the rate-based congestion control schemes have higher resilience to the high link delay than the window-based schemes. © 2003 Elsevier B.V. All rights reserved