| The rapid growth of multimedia application and the increasing demand on building value-added service generate more requests on predicable service over Internet. This leads to great challenge to current network technology. For its outstanding ability on constraint-based routing and multi-protocol encapsulation,more and more ISPs accept MPLS as fundamental technology for future networks. The quality-of-service requirements for the timely delivery of multimedia information over MPLS networks raise new challenge to current technology. One of key issues is traffic engineering. The goal of traffic engineering is two folds:guaranteeing the end-to-end service quality over differentiated service network and achieving global efficiency in resource utilization.Many work have been published in this area. However,there still exist a lot of unsolved problems in this area. A few of examples are listed as follows:1) What's the most essential part of QoS provisioning in MPLS networks? 2) All existing routing algorithms try to adapt to network dynamics reactively,while built-in properties of internet traffic is overlooked;3) There has not been developed an effective routing mechanism for differentiated service networks,which has been found to face the problem of "Inter-class effect".We address the above problems,and goal of this dissertation is to give high performance,fair treating routing solutions for differentiated service network using MPLS. Based on theoretical analysis of switch routing network,we study the relationship between MPLS and end-to-end service quality. We propose routing algorithms based on traffic properties measured in time,spatial and service class. We evaluate these algorithms by theoretical analysis and simulation,discover their strength and weakness and compare them with existing algorithms. The major achievement of this dissertation is outlined in the following:1. Investigate the potential effect of switch routing on end-to-end service quality with both theoretical and experimental methods:it is found that service quality of LSP is better than that of IP routing if load on router is low or end-to-end bandwidth reservation is implemented,but LSP is more sensible to load on router. MPLS must be used in company with policy based routing and packet classification to provide end-to-end QoS service in Internet;2. A source routing framework is proposed to route traffic flows proactively over multiple paths,which tries to optimize routes for long-lived flows based on dispersity routing;based on mathematical analysis,our approach disperses incoming traffic flows onto multiple paths according to path qualities. Long-lived flows are detected and migrated to the shortest path if their QoS could be guaranteed there. Suggesting non-disjoint path set,four types of dispersion policies are analyzed,and flow classification policy which relates flow trigger with link state update period is investigated. Simulation experiments show that our approach outperforms traditional single path routing significantly.3. A differentiated routing algorithm is proposed to route network traffic based on RDM bandwidth allocation model. Advertising RDM model parameters and bandwidth utilization statics,different routing path is computed and established for different traffic class by using corresponding logical view of network. It is shown that DiffRoute can improve servicequality in differentiated network effectly while improving resource utilization.4. An architectural model of DiffServ/MPLS backbone is proposed to provide reliable,fair-treating QoS service in MPLS networks. Taking MPLS as fundamental packet forwarding mechanism,DiffServ as QoS provisioning model,our framework relizes high quality network service while balancing load across backbone. Defining relationship between InterServ service type,DiffServ service class and Exp field of MPLS label,the model could also provide efficient interconnecting service between different user networks. Simulation results show that DiffServ/MPLS backbone achives service...
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