Coordinated Multi-Layer Loss Recovery in TCP over Optical Burst-Switched (OBS) Networks

It is well-known that the bufferless nature of OBS networks causes random burst loss even at low traffic loads. When TCP is used over OBS, these random losses make the TCP sender decrease its congestion window even though the network may not be congested. This results in significant TCP throughput degradation. In this paper, we propose a coordinated multi-layer loss-recovery approach for TCP over OBS networks using Snoop and ARQ. We developed an analytical model for end-to-end TCP throughput using the hybrid approach over OBS and verified the results using simulations. We evaluate the performance of independent and coordinated Snoop and ARQ over an OBS network. Based on the numerical results, the proposed coordinated multi-layer Snoop and ARQ approach outperforms all other approaches at all traffic loads.