On Controlling the Loss Rate in Optical Burst Switching Networks

Blocking is an extremely important performance issue in optical burst switching (OBS) networks because of the asynchronous nature of bufferless burst-mode switching. In this paper we revisit the timer-based burst assembly algorithm to generate Poisson-type burst traffic at source edge nodes. We then investigate the influences of burst characteristics on the loss rate of burst flows at the core nodes. Based on the analytical results, we make use of the burst assembly process to devise a feedback control scheme capable of achieving the required loss rate for a burst flow. Compared to other QoS control research on OBS networks, our work is more suitable for bufferless OBS networks because it 1) does not degrade the network throughput, 2) does not require any global network information to control the loss rate of a flow, 3) has a low time and computing complexity. We demonstrate the effectiveness of our method in the Just-In-Time (JIT) OBS network.