Dynamic congestion control to improve performance of TCP split-connections over satellite links

Satellites have played an important role in global telecommunications. However, transmission control protocol (TCP) suffers significant performance degradations over satellite links due to high bit error rate and long latency. Among methods proposed to alleviate the impact of satellite link characteristics on TCP performance, split TCP connections separated by performance enhancement proxies have been proven attractive because they can keep TCP configurations in the end systems unchanged. In this paper, we propose a new dynamic congestion control mechanism based on TCP selective acknowledgment (SACK), called dynamic SACK (DSACK), for the satellite segment in a split TCP connection. DSACK obtains immediate congestion feedback from the underlying layer, so as to efficiently prevent congestion and correctly differentiate between packet losses due to channel errors and congestion. Simulation results show that our novel mechanism improves TCP performance over satellite networks significantly, compared to standard TCP versions