Adaptive rate control in high-speed networks: performance issues

It is well established that increased network transmission speed reduces the effectiveness of feedback-based adaptive rate control mechanisms, due to the increased bandwidth propagation delay product. In this environment, differences in the propagation delays associated with the controlled sources become larger when measured in slots (transmission time of information unit), potentially inducing substantially diversified performance metrics. One of the objectives in this work is to quantify the potential unfairness as well as the reduced effectiveness of this rate control scheme in the presence of non-zero propagation delays. As the network speed increases, it is also expected that traffic sources will seem to be slower due to the relative increase of the information generation time and/or the decrease of the portion of the bandwidth required by a specific source. The other objective in this work is to investigate and quantify the expected increased effectiveness of this rate control scheme in the presence of non-zero propagation delays as the traffic sources become slower. The studies are carried out by formulating queuing models and evaluating the per-session cell loss probabilities and they are supported by numerical results. (C) 2001 Elsevier Science B.V. All rights reserved.