The Experimental Realization Of Burst Retransmission On OBS Network And The Evaluation Of Its TCP Performance

Optical Burst Switching (OBS) technology, which combines the flexible electronic processing technology and the high-speed optical transmission technology, is regarded as one of the promising solutions in the future IP over Dense Wavelength Division Multiplexing (DWDM) network and has attracted considerable research attention from both academic and industrial fields.Due to the bufferless nature of OBS core network and the one-way based signaling scheme, the OBS network suffers from random burst losses, even at low traffic loads, which leads to the performance degradation. The reduction of the random burst losses becomes a critical issue in OBS network. Fast recovery schemes which are employed to recover the lost burst in OBS layer are under consideration, such as burst retransmission and burst clone.In this dissertation, a burst retransmission scheme for reducing the burst losses in OBS network due to link fault is presented, which is also suitable for reducing the burst losses due to burst contention. The scheme is designed for reducing the Burst Loss Probability (BLP) by employing Link Fault Message (LFM), Automatic Retransmission Request (ARQ), Link Recovery Message (LRM) and temporarily stopping making channel reservation for the burst data. This dissertation includes the design of Field Programmable Gate Array (FPGA) of both of the edge nodes and core node, the first experimental realization of burst retransmission on OBS network and the evaluation of TCP performance over OBS network with burst retransmission. The experimental results show that the TCP throughput has a great improvement compared with that without burst retransmission and the improvement is influenced by several parameters such as TCP Retransmission Time Out (RTO), the burst length and the link fault time. For instance, when RTO equals to 200ms and the link fault time equals to 700ms, with burst lengths equal to 6.25Kbytes, 62.5Kbytes and 125Kbytes, the improvement with burst retransmission are 53Mbps, 33Mbps and 24Mbps, increased by 54.78%, 41.98% and 34.18%, respectively.