Comparing Some High Speed TCP Versions under Bernoulli Losses

We compare the performance of Cubic, Compound TCP, HighSpeed TCP and Reno under a simple loss model, where each packet is dropped with probability p. Modeling the evolution of the congestion window with a Markov chain, we can use efficient numerical algorithms to compute the average window size (response function), the Coefficient of Variation (CoV) of the window and the average throughput. We find that, for smaller bandwidth delay products, Cubic can have a similar throughput to Reno while for larger values the throughput of all new versions is similar and larger than Reno. The CoV of Cubic has a peak but it is otherwise the smallest one. This peak corresponds with a sharp increase in the response function.