Research On The Key Issues About Traffic Engineering In IP Networks

Traffic engineering (TE) with traditional routing protocols aims to determine andconfigure the best routing strategy by adapting link weights so that the overall networkperformance can be optimized. However, the network is moving toward the direction ofintellectualization, complexity, multi-service and multi-function. Under such situation,the existing traffic engineering solutions cannot fully solve some practical problems andmeet various application requirements such as load balancing for core-edge separationnetworks, flexible egress control, complex services deployment, fast failure recovery.This thesis adopted some new techiniques, i.e., EID-to-RLOC MappingAssignment(ERMA), Multi-topology Routing(MTR) and Loop Free Alternates(LFA),to solve these problems.This thesis investigated traffic engineering and its application in IP networks. Themain areas of research were focused on five aspects, Intradomain traffic engineering incore-edge separation networks, Interdomain traffic engineering in core-edge separationnetworks, hybrid Intradomain and Interdomain traffic engineering in current IPnetworks and traffic engineering approach for service composition and fast failurerecovery.1．Research on Intradomain traffic engineering in core-edge separation networksThis chapter proposed a new Intradomain traffic engineering framework calledERMAO in core-edge separation networks, where ERMA could be tuned to specify theingress points of inbound traffic. This framework incorporates two components, trafficdemand and routing protocol, to represent real networks. Accordingly, four ERMAoptimization schemes for different network scenarios are presented. Experimentalresults demonstrate that the maximum link utilization can be decreased by tuningERMA.2．Research on Interdomain traffic engineering in core-edge separation networksThis chapter also proposed Interdomain traffic engineering schemes in core-edgeseparation networks. Offline scheme involves the selection of edge routers. Optimizingthe selection of edge routers can balance the loads over Intradomain and Interdomain links. Besides this, an online optimization scheme based on ERMA is introduced toachieve better network performance, e.g., lower average packet delay.3．Research on hybrid Intradomain and Interdomain traffic engineering in currentIP networksDue to the interaction between Intradomain TE and Interdomain TE, this chapterpresented a flexible egress router selection scheme based upon Multi-topology routing.This scheme not only retains the hot-potato routing policy, but also achieves loadbalancing in the local domain.4．Research on service composition using traffic engineering approachThis chapter proposed a flexible framework to achieve service composition in IPnetworks. It involves placing programmable nodes, deploying services among thesenodes and directing traffic through them. With only one set of link weights, it isimpossible to represent all paths as shortest paths, i.e., partial traffic cannot be routedthrough required service nodes. In order to solve this problem, Multi-topology routing isintroduced to provide multiple optional paths over multiple set of link weights toguarantee service requirements. In this way, the complexity of service deployment isreduced, and the ability of the network to provide complex services is also enhanced.5．Research on full protection against single link or node failure using trafficengineering approachThis chapter presented some protection schemes against single link or node failure.These schemes are based on the Loop free alternates standard. On one hand,Multi-topology routing technique is incorporated to construct backup topologies for thenetworks with given link weight. On the other hand, link-weight tuning and edge addingare combined to design full protection schemes for the networks with adjustable linkweights. All the above schemes involve traffic engineering approach, i.e., link weightssetting, and improve the quality of Loop free alternates protection drastically.