MPLS Traffic Engineering Load Balance Algorithm Using Deviation Path

With the development of Internet, the number of Internet users is becoming bigger andbigger, along with the explosive growth of the network scale and the emergence of a lot of newservices, the speed of information expansion is pretty high. However, the network bandwidthexpansion and upgrading is relatively slow, in addition, the Shortest Path First algorithms likeOSPF and IS-IS are very likely to cause network congestion. As a result, the Internet isoverwhelmed and the network congestion problem is more and more serious. More over,congestion is one of the main reasons that cause bad network service and bad user perception. Soit is petty fatal for the Internet development that we must reduce congestion、 guarantee the QoSand improve the performance of the network. In order to solve the problems that caused by thedevelopment of network size, Traffic Engineering is proposed as a network optimization controltechnology. By using TE, we can balance the network and make full use of the network resource,as well as guarantee the QoS.With explicit routing technology, MPLS is pretty good at network traffic management andcontrol. Thus MPLS is perfect to support the implement of TE, and become the best solution ofTE. By using ER-LSP, MPLS can choose a path that steer clear of the hotspots for the traffic andas a result congestion is reduced、 the network is balanced and the performance of network isimproved.In order to choose a path that can achieve TE goals, MPLS-TE uses constraint-basedrouting technology to solve the path selection problem. This thesis analyzes some typical TEconstraint-based algorithms at first, and proposes a new MPLS TE load balance algorithm calledLBDP (Load Balance Algorithm Using Deviation Path). The basic idea of LBDP is as follows:We regard a link as congested when its bandwidth utilization reaches the specified threshold weset. After congestion is detected, we reroute a flow that travel through the congested link toanother idle path that calculated by deviation path method. After all, we use NS2(NetworkSimulator) to simulate and evaluate LBDP. The result of the simulation shows that LBDP caneffectively reduce the network congestion、balance the workload between different links andcan improve the network performances with lower delay, smaller packet loss and higherthroughput.