An ENA algorithm to enhance the performance of TCP over satellite links

Abstract

Reliable Transport protocols, such as TCP, are tuned to perform well in terrestrial networks where most segment losses occur because of congestion. However, networks that involve satellite links also suffer from significant losses that are because of bit errors. TCP responds to all losses that are because of bit errors. TCP responds to all losses by invoking congestion control and avoidance algorithms, which result in degraded performance when using a satellite link. In this paper, we propose an Error Notification ACK (ENA) algorithm that distinguishes error segments from losses due to network congestion. We also propose a method for implementation of the algorithm and evaluate the performance of the Tahoe, Reno and SACK TCP algorithms with and without ENA. The results show the performance of the TCP algorithms with ENA to be superior to those without ENA. (C) 2002 Elsevier Science B.V. All rights reserved.