Reliability Analysis And Design For Computer Network

With the rapid development of the computer network, provide satisfied services to user, we need to guarantee the quality of network service. As reliability is an important factor for the quality of service, network reliability related researches have received a lot of attentions from many researchers. Network reliability evaluation is the basis of the reliability related researches. The network reliability design, which can provide different options for network managers, is a hot topic in the field of network reliability related researches. As a network may contain faults, the fault tolerance is crucial because it can ensure the normal working of the network under the ill conditions. This paper mainly considers the computer network reliability analysis and design problems. The contents of this paper are as follows:1. A brief literature review on the background, development of network reliability and the re-lated work is provided.2. The reliability of the data transmitted through the shared link is investigated. By comparing the arriving time at the shared link of each data, we can determine whether there exists a prior conflict among the data or not. The influences of the time interval to generate the data and the amount of data on the reliability are also discussed.3. The optimal transmission line design based on the network reliability is studied. For the multi-state multi-source multi-sink computer network with fixed topology, we proposed a network transmission line assignment algorithm to maximize the network reliability under the cost constraints. First, for a certain transmission line configuration, we have proposed a reliability evaluation algorithm to calculate the reliability of each source node to each sink node under the cost constraints. Second, by combing the reliability evaluation algorithm and the non-dominated sorting genetic algorithm, we have proposed a reliability-based transmis-sion line optimization algorithm to find the optimal solutions of the problem. 4. The reliability-based backup path fault tolerance design with fixed working paths is consid-ered. This paper uses two link disjoint path as the working paths to transmit data simultane-ously, and uses another link disjoint path as the backup path. An algorithm to calculate the network reliability in the single working path failure case is proposed. Compared with the existing work which used two link disjoint paths as the working paths and used another two link disjoint paths as the backup paths, the proposed algorithm can greatly improve the net-work reliability in the single working path failure case. Also, the proposed algorithm needs few backup paths than the previous work.5. The reliability-based backup path fault tolerance design with non-fixed working paths is considered. This paper considered the optimal working and backup paths selection and the optimal bandwidth allocation problem. The aim is to minimize the network total construct-ing costs under the network reliability constraint in the multi-protocol label switching net-work. As the network total constructing costs and the network reliability possess a coupling relationship, we decoupled the original problem into two sub-problems equivalently:cost and reliability related sub-problems. The cost related sub-problem has been solved by other scholars. For reliability related sub-problem, we reduced the searching space for the solution through theoretical analysis. As the solutions to the two sub-problems are based on the same searching criteria, the optimal selection of the working and backup paths to original problem can be determined by combing the solutions to the two sub-problems. The original problem is an NP-hard problem, the proposed idea of this work has provided an alternative way to solve such NP-hard problems.The conclusions and future work are depicted at the end of the dissertation.