Modeling Analysis And Optimization Design Of Multipath Transfer

With the rapid development of network technology, the services become more diverse, which leads to the service requirements of network resources grow rapidly. It makes the current network being increasingly difficult to meet the rapidly growing demand for services. Therefore, the thought of multipath transfer gradually emerges, which is about using multiple paths instead of one path to provide transmission, so as to improve the service experience. The development of network technology also makes the access methods of terminals become more diverse, which makes multi-interface terminals be more common in the Internet. This trend makes the implementation of multipath transfer be possible.Based on the analysis of the existing multipath transfer technology, this dissertation conducts in-depth researches from four aspects:the performance and optimization of multipath transfer, the relationship between multipath transfer and network, the combination of multipath transfer and service, and multipath transfer in the Identifier Network. And the main work of this dissertation can be summarized as follows:(1) Firstly, this paper analyzes the performances of multipath transfer, and then designs an optimized implementation. A multipath transfer model is proposed to analyze throughput in the ideal state. It uses packet delay to calculate the release time of receive buffer, and get the relationship between receive buffer size and throughput. Then by comparing the throughput of single path transfer and multipath transfer, this paper gives the conclusion of critical receive buffer size which multipath transfer requests. After that, aiming at the data distribution problem of multipath transfer, this paper proposes a specifically optimized implementation of multipath transfer. Through the idea of autonomous learning, it is designed as a closed-loop learning system. While continuous testing different data distribution, the knowledge space could be constructed by the various distribution ratio and corresponding performances. Then the system could gradually optimize the parameters of multipath transfer based on the knowledge space, and gain the best transmission performance finally.(2) After analyzing multipath transfer in end-to-end situation, this paper aims at the situation of multipath transfer being used in the entire network scope. A network topology generation model and a services simulation model are proposed to analyze the relationship between multipath transfer and network. By setting the network topology parameters, the network topology generation model can construct network topology randomly for simulations. And by setting the services’ arrival rate and services’size, the services model can create random services stream, and simulate their transmission in the network. With these two models, this paper analyzes the performances of multipath transfer when it used in the entire network scope, and also the influences of different kinds of network topologies.(3) After analyzing the transmission problems of multipath transfer, this paper introduces the service requirements into multipath transfer, and realizes the optimizing decision for multipath transfer based on the specific service requirements. Firstly, transport geometry has been proposed. It can transform the transmission problems into geometric space. And based on the service experience equivalent line defined in the space, the optimization problem of multipath transfer can be solved in the geometric space. Secondly, an analytic hierarchy model is established between the application layer and the transport layer. In this model, the specific service requirements are seen as the goal hierarchy, the various kinds of path selection schemes for multipath transfer are seen as the alternative hierarchy, and the transmission performances are seen as the criterion hierarchy. With upper layer requirements and lower layer supports, this model could select an alternative multipath transfer method as a final judgment dynamically, based on the specific service and network environment.(4) At last, this paper designs the multipath transfer in the Identifier Network. A kind of mapping communication based on Connection Identifier (CID) is proposed. It uses the idea of CID in the Identifier Network to mark the process of obtaining a service, and send packets based on CID instead of IP address. This makes the connection became a logical concept, which can include multiple physical paths in one connection. Therefore, with the idea of CID, mapping communication can support multipath transfer well. Furthermore, the mapping between CID and network address in mapping communication will divide the communication process into three part, and make the access network and the core network be separated.