PEPsal: A Performance Enhancing Proxy for TCP Satellite Connections

Abstract

Internet communications with paths that include satellite link face some peculiar challenges, due to the presence of a long propagation wireless channel. Herein, we propose a Performance Enhancing Proxy (PEP) solution, called PEPsaI, which is, to the best of the authors' knowledge, the first open source Transmission Control Protocol (TCP) splitting solution for the GNU/Linux operating systems. PEPsaI improves the performance of a TCP connection over a satellite channel making use of the TCP Hybla, a TCP enhancement for satellite networks developed by the authors. The objective of the paper is to present and evaluate the PEPsal architecture by comparing it with end-to-end TCP variants (NewReno, SACK, Hybla), considering both performance and reliability issues. Performance is evaluated by making use of a testbed set up at the University of Bologna, to study advanced transport protocols and architectures for internet satellite communications. At present, PEPsaI is adopted, with success, by a satellite Internet provider.