Throughput analysis of Scalable TCP congestion control

Scalable TCP (STCP) has been proposed a congestion control algorithm for high speed networks. We present a mathematical analysis of STCP's congestion window through the slow start and the congestion avoidance phases. We analyse the evolution of congestion windows for single and multiple flows and for Drop Tail queues with and without random loss. We derive throughput formulas for the different setups and reveal the inherent unfairness between different round trip times flows. Our mathematical analysis is compared to state-of-the-art network simulator (ns) results, which verifies our model's accuracy. With our analysis we want to adaptively control STCP's fixed parameters in order to overcome the fairness problems. These experiments are work in progress and will be presented in a sequel paper. © Periodica Polytechnica 2007.