TCP With Network Coding Enhanced in Bi-Directional Loss Tolerance

Transmission Control Protocol with Network Coding (TCP/NC) and its variants were developed to improve the goodput performance of TCP protocol in lossy networks. However, no TCP/NC enhancement work can get a high goodput performance in bi-directional packet loss environments, especially with a high degree and/or burst loss of ACK packets. Therefore, we propose a new scheme called TCP/NC with Bi-directional Loss Tolerance (TCP/NCwBLT) to maintain a goodput in a wide range of bi-directional loss environments by combining three techniques of “ACK accumulation”, “ACK retransmission”, and “Duplicate ACK generator” at the source and/or the sink sides. The simulation results on ns-3 show that TCP/NCwBLT always outperforms the various TCPs and a recent variant of TCP/NC when packet losses happen in both directions, and its advantage significantly increases at a high ACK loss rate.