Drop policy to enhance TCP performance in OBS networks

In optical burst-switched (OBS) networks, the loss of burst containing a number of IP packets occurs mostly due to contention rather than congestion so that a TO (Time Out) event will trigger unnecessary TCP congestion control resulting in significant throughput degradation (X. Yu, et al., 2004). Therefore, in this letter, we propose a drop policy (DP) with burst retransmission where a new concept of retransmission-count for bursts is introduced to mitigate unnecessary TCP congestion control. The analytical and simulation results show that the TCP throughput is improved by our proposed DP with burst retransmission.