Decoupling congestion control and error control mechanisms in TCP and evaluating their performance over broadband satellite networks

In this paper, we propose a novel method to better evaluate the performance of TCP over broadband satellite networks. We decouple the most crucial parts of TCP that impact its performance in broadband satellite environments, namely congestion control and error control mechanisms. And then we re-design these two function blocks and make them become two individual arts. With these re-designed modules, we have investigated the interactions between various currently existing TCP congestion control and error control schemes, as well as their impact on TCP performance over a geostationary broadband satellite link with long propagation delay and high bit error rate. Simulation results have shown that some combinations of different congestion control and error control mechanisms can waste satellite link bandwidth with large numbers of retransmission packets and unnecessary retransmission packets. And the modified TCP NewReno implementation can avoid high amount of retransmissions and unnecessary retransmissions.