Certain investigations on burst contention in an OBS network employing combined buffering and retransmission

Abstract

The telecommunication networks are experiencing a continuous relentless increase in demand for more transmission capacity. This trend is strictly related with the exponential growth of the Internet and World Wide Web (WWW), both requiring high bandwidth. To support data traffic, three high capacity optical switching technologies are available. They are Optical Circuit Switching (OCS), Optical Packet Switching (OPS) and Optical Burst Switching (OBS). Out of these three, OBS has certain advantages over OCS and OPS. Burst contention is a major problem in OBS networks. Burst contention occurs when more than one burst try to reserve the same newlinewavelength (server) in the network. This work focuses on the impact of admission control, feedback, maintenance activity, impatient bursts (balking and reneging), negative bursts and server breakdown on the burst contention in an OBS network employing combined buffering and retransmission. Firstly, the effect of admission control, feedback and maintenance activity of the server is analysed against burst contention in an OBS network employing combined buffering with retransmission. The arriving burst is allowed to join the network with certain probability (admission control). Bursts are allowed to have maximum of two hops between the source and newlinedestination. If the server is free, one of the arriving burst reserves the server and others join the buffer for retransmission. The burst is first processed for transmission from source node to core node and then processed again for transmission from core node to destination node. If only one hop is enough to reach the destination, then the burst can be passed to the destination directly. Based on the feedback, the retransmission of bursts takes place. newline newline