Proxy-based connection-splitting architectures for improving TCP performance over satellite channels

Reliable transport protocols, such as TCP, have been designed and tuned for traditional wired networks, with little consideration given to wireless environments, such as satellite networks. TCP performs relatively well on such wired networks by adapting to end-to-end delay and to losses caused by congestion. However, in the case of satellite links, due to the special attributes of these links, such as high bit error rates and large propagation delays, TCP performance degrades significantly. The work described in this paper was motivated by the need for improving the performance of TCP over satellite channels. In this paper three connection-splitting architectures based on the use of transparent proxies were implemented and tested. Namely, this paper examines a single-TCP-interproxy-connection; a multiple-TCP-interproxy-connection and a UDP-based interproxy connection connection splitting architectures. The throughput increases obtained by the latter two architectures were very significant, with the UDP connection-splitting scheme even yielding a throughput improvement of an order of magnitude in some cases.