Study on the blocking rate of some special class three CLOS network
|School||University of Electronic Science and Technology|
|Course||Communication and Information System|
|Keywords||the three-stage CLOS network multi-ports scalability multicast blockingprobability|
The development of Internet technology and it’s wide applications let human society into a new times of information, the network business appears explosive growth by more and more communications and data services, with the application of optical fiber mature and the improving of the terminal processor performance, routing and switching network has become the bottleneck to restricting network development. While ensuring the basic functions and stability of the network, the design and research of current switching network has to consider the following aspects:large-capacity, multi-port, flexibility and scalability. The switching network must be able to adapt the changes of application environment, support more different rates and different ports business, besides, it must be able to dealing with the capacity expansion problem by rising network business.CLOS network with its many inherent merits has become one of the first choice to build the large capacity switching network architecture, among them, the most basic architecture is the three-stage CLOS network. The three-stage CLOS network has good reliability, high degree of flexibility and scalability, it can well satisfy the current network with huge changes and developments. The main research about CLOS network can be divided into two categories:certainty study and probability study. The certainty study mainly focus on designing routing algorithm and strategy for a given CLOS network making the network not happening block or reduced blocking probability. In the probability study, the research is focused on the blocking probability analysis of one kind of network model with the changes in the network structure, through this research we can effectively assess the feasibility of network design.In real application, with the influences by the changes of user guide’s demand, the expansion of the network capacity, the three-stage CLOS network can not realize the function of data switching well, thus forming some special structure of the three-stage CLOS network, such as multi-ports hybrid network, middle stage expand network and special multicast CLOS network, etc. There are few of researches on these special CLOS, based on these, the main jobs of this paper are the following three aspects: 1. Analyzes and sums up the characteristics of traditional symmetric three-stage CLOS network, give the conditions of parameters to meet the non-blocking network. Lists the main analysis models of three-stage CLOS network: Lee model, Jacobaeus model and Yang model.2. In practical applications, standard CLOS network structure is usually restricted by application environments. In order to improve performance of CLOS network, there are many special CLOS network structure. In this paper we introduce several kinds of typical scenes:multi-ports hybrid network, middle-stage extended network and special multicast CLOS network, and put forward the corresponding analysis model, besides, we theoretical analysis the similar blocking probability of these special CLOS networks.3. Through some numerical solution we analyzes the network blocking probability change trend and the reason, at the last, through the simulation we proved the change trend between the numerical results and the simulation results is consistent. The solving mathematical formulas and the analysis of network blocking probability in this paper can offer some references and basis for engineering application of network constructions.