Robust Header Compression Over Long Delay Links

The enormous growth in the use of the IP-based multimedia and other applications has increased the need to use the available communication technologies including satellite and radio links efficiently. These wireless links generally induce high bit error rates and long delays. Moreover, the deployment of IP protocols over these links leads to significant header overhead. IP tunneling mechanisms, widely used in the network security, IPv4-to-IPv6 transition, and mobile networks also have long delay characteristics. This paper studies the behavior of one of the most commonly used Robust Header Compression (ROHC) mechanism over such long delay links and tunnels. We show the impact of long delay, high bit error rate, and packet reordering on ROHC performance. Some of the experiments have been conducted over L2TP tunnel between France and Korea. The results show that ROHC compression can be used over long delay links to reduce header overheads with certain limitations. The results presented in this paper will provide the basis for further designing header compression schemes specifically suited for links and tunnels with long delays.