Applied To The Mdf Multi-stage Clos Network To Optimize The Design And Routing Algorithm

The main distribution frame (MDF) is large switching system that is used to connect copper users of the telecommunications industry and infrastructure Room. The automatic MDF advanced by Simpler Networks Company has been widely concerned; its core is the space-space-space Clos switching network which is composed of a large number of micro-relay switching devices (MEMS). Clos is a scalable and multi-stage switching fabric. It serves as a channel linking role in MDF. However, as the explosive growth of networks users, the ports number of MDF is more and more. Excessive network switches of Clos are not suitable for the high costs. The blocking-Clos networks can effectively reduce network costs, without changing the scale of networks. But reducing costs will increase network congestion.In view of the above problems, the paper analyses the relationship between the performance and the structure of Clos in-depth. We finish the network designing and routing algorithm, which to reduce costs and the probability of blocking, and the simulation shows that the program is feasibleOn the one hand, the point is optimized design of Clos network which is to reduce congestion rate and the number of switches from the perspective of the network structure. First, the expansion of the network will bring more types of switching modules, the more types, the higher cost. Secondly, chip pin will restrict integration of the modules in the project. These problems must be taken into account in the design of this network. Chapter II analyses the traditional non-blocking and unconstrained network optimization design, on the basis of which we carry out a detailed analysis and theoretical analysis to the relationship of network size, series, switches number, switch module in the blocking-networks . we have integrated network optimization design and proved the accuracy of the theoretical analysis and the feasibility of network optimization design by simulation.On the other hand, routing algorithm improves the blocking performance of networks from perspective of the sessions routing. In Clos switching network, blocking occurs because of the randomly arrived traffics. Existing routing algorithms are mainly focused on finding a feasible path, but not an optimal one. Non-optimal path often means waste of resource and higher blocking rate. In this paper, we proposed a novel routing algorithm called Optimal Routing Algorithm Based on Probability (ORBP). In the algorithm, we first determine the possible sessions can be influenced by current path selection, and call them relative traffics; then we calculate the blocking rate of each path; at last, we choose the path with minimized blocking rate as the optimal path of current session.Finally, in order to certificate the rationality and feasibility of the network design with module bound and the blocking performance of the routing algorithm, we set up the network simulation model and on the basis of the model we realize the traditional algorithms and ORBP algorithm. We conducted a wide range of simulation and analysis of simulation results, promoting the next step in the direction of improving.