The Research And Development Of Resilient Routing And Traffic Engineering Technology In Space Network

In the research field of network technology,routing and traffic engineering are separated areas.In some papers,mechanisms are designed to guarantee QoS(quality of service)in FRR(fast reroute).However,without considering the global influence,these mechanisms only work for the traffic affected by a single point failure.And relevant research in the area of space network is still blank.In fact,link failure and congestion are always closely related.In fact,traffic distribution entirely depends on the network topology and routing structure.So link and node failures not only reduce the overall bandwidth resources,but also changes the traffic distribution.As congestion will also lead to the decline of the quality of service,it is not a correct way to discuss route reconstruction without considering traffic load balance.In this thesis,a hybrid solution to solve the problems of route reconstruction and traffic balance is proposed.Firstly,when there is no failure a pair of primary and alternative routing tables are built based on SDN mode,between which there is no overlap paths.In the context of occasional failure scenarios,path switching on the node near the failure would ensure reliable communication,furthermore,LF_DRA routing protocol will be used to search an available path when the two paths are both invalid.As for the problem of traffic engineering,all business traffic are labeled as latency-sensitive or bandwidth-sensitive,two different routing structures are built for them to avoid resource competition.When failure occurs,the latency-sensitive traffic is given higher priority to use the shortest path,and the bandwidth-sensitive traffic is switched to detour path.When the traffic is excessively concentrated and the congestion cannot be solved by switching routing tables,LF_DRA protocol or the MEO layer will be used.In order to verify the proposed protocol.Simulation models were developed in NS2 and all verification experiments were base on real traffic matrix.