TCP with end-to-end FEC

Abstract

In this paper we investigate the effects of combining end-to-end forward error correction (FEC) with TCP. FEC reduces the number of retransmissions and results in different congestion control behaviour, effectively running the network at a higher load. The interaction between TCP and FEC is discussed and the conclusion is that the FEC has to be adaptive to work efficiently. Unless the block length of the error correction is adapted to the window size of TCP, deadlocks can occur. A simple adaptation algorithm is proposed and the performance is evaluated by simulation. It is found that in certain scenarios the performance can be increased significantly, in particular for large delay and when losses are caused by noise.