Ocs And Obs Performance Comparison Study

Optical networks have been promoted as potentially low cost solutions for transporting very high bandwidth traffic. Many candidate architectures have been proposed for future optical networks. However the final choice of architecture will be driven by considerations of performance and cost. At present, there is uncertainty as to which architecture will provide the best performance/cost trade-off. The Optical Circuit Switching (OCS) is one of the architectures considered for future optical networks. This network is a circuit-switched architecture with Optical Cross-Connects (OXCs) inter-connected with WDM links. Optical Burst Switching (OBS) is another possibility that has recently attracted consideration attention. An OBS network is an all-optical network, which switches variable-size data units, called bursts. One of the attractive features of OBS networks is that it provides routing without requiring OEO interfaces or optical buffering. However, OBS networks tend to have high blocking probability.In this paper, we establish a simulation model on which a fair performance comparison between OBS and OCS can be made. A flow-based traffic model is proposed for the fairness of the comparison. The performance of OBS and OCS paradigms is compared in terms of common performance metrics, packet loss rate and end-to-end delay. In the simulation, we used two traffic sources, which are Possion traffic and self-similar traffic, we changed the configuration of FDL (Fiber Delay Line) and TWC (Tunable Wavelength Converter), to compare these two paradigms more deeply. The simulation results show that it is difficult to say which one is better. Because in situation OBS performs better than OCS, but in other situation we got the opposite result. When in high flow intensity, the packet loss rate of OCS is even 10 times bigger than OBS. But in low flow intensity, there is no packet lose in OCS, but OBS has small packet loss rate because of the probability of burst contention. E2E delay of OCS doesn't change a lot while the flow intensity increases, but that of OBS increases while the flow intensity increases. In common situation, E2E delay of OBS is smaller than that of OCS. But use of FDL will cause the increase in E2E delay in OBS network, in some situation this metric of OBS is even higher than OCS.