Fibre Channel Arbitrated Loop Optimization And Simulation

Fibre channel is the newest technology of network and bus with low-delay, good-compatibility, highly-reliable, high-speed and long-distance. It supports multiple medias and devices and make it possible to support protocols of channel or net-work with the same interface.The Fibre channel arbitrated loop is the third and most recent addition to the The Fibre channel family of interconnection topologies. It is ideal for many small to mid-sized configurations where the cost of a sepatate fabric switch would be prohibitive. Arbitrated loop applications include storage subsystems, processor clustering, work group networking, and many other environments requiring modest connectivity combined with high transmission speeds.This thesis mainly proposes the configuration of Fiber channel, topologies and Principle of Fibre channel arbitrated loop. Aiming at the fairness Algorithm of arbitrated loop, I propose two modified schemes to improve the efficiency and latency.Sending time allocation of arbitrated loop of fibre channel is made to serve the purpose of real time transmission through the Internet. For real time communication and the application of arbitrated loop of fibre channel in the environment of real time communication, we have proposed sending time allocation scheme based on the periodical task model in real time system. The properties of scheme in real time communication have been analyzed. The proposed scheme has been proved to be capable of ensuring real time communication with a little sacrifice on sending time. After Seting up mathematical models I get the optimal values of sending time by the genetic algorithm toolbox based on Matlab 7.0.A improved programme was developed to improve the efficiency and latency assurance of fibre channel arbitrated loops. The node on the improved programme retrieves information from each arriving data frame and adds information to be sent to the frame. Simulations indicate that when all nodes on the relay loop need to send information, the efficiency reaches 100%.Since the communications do not need a wait period, the latency is assured so the system can be used in real time systems.Afterwards, the thesis implements the improved protocol based on NS-2 and designs simulation experiments. In this thesis, MATLAB program methods are used to accomplish statistical analysis of trace file data extraction and main attributes (latency) of network. The simulation results show that, in contrast with arbitrated loops, the improved arbitrated loops protocol improves average packet latency. It is especially applicable to the real time systems networks applications that require delay strictly.