Research On The Technology Of Segment Routing Based SDN Traffic Engineering

In recent years,with the rapid expansion of the number of Internet users and network business scale,the traffic running on the network has an explosive growth.While the network operators constantly extend the link bandwidth and improve the router port at a rate,due to the lack of effective traffic management mechanism,the network resource utilization rate is still very low.Therefore,the research of using traffic engineering technology to optimize the network resource allocation has significant meanings on improving network resource utilization rate and reducing the network cost.This paper is based on the national 973 project "Research on the Architecture of the Reconfigurable Fundamental Information Communication Network",and concentrates on the traffic engineering technology in Software-Defined Network.Based on the customized service path oriented segment routing technology,this paper especially studies the point of traffic scheduling and traffic protection in traffic engineering,and then designs a software defined network segment routing system.In summary,the paper's main research results are the following:1.To solve the problem of poor load balancing performance and difficult path deployment in traditional network,a multi-path flow mechanism based on network utilization maximization is designed.Firstly,the multi-path flow optimization model is set up to achieve the co-optimal scheduling of the data stream.Secondly,the multi-path flow scheduling problem is transformed into the simplest segment sequence selection problem with segmented routing algorithm and the simplest segment sequence generation algorithm.Finally,the traffic flow scheduling algorithm is proposed.In the end,experimental results show that,under the same network traffic model,compared with the typical multi-path streaming mechanism,our mechanism effectively improves the bisection bandwidth of networks,reduces the transmission delay of short stream,and also have a lower flow table storage overhead.2.Considering the multiple link or node fault problem in traffic scheduling,a network topology embedding based multi-fault recovery mechanism is proposed.Firstly,in order to achieve fast recovery of failures,a linkage-loop backup system aiming at fast recovery for multi-fault problem is proposed with SR technology in dataplane.Secondly,to avoid second failure caused by breakdown in some links due to the overload problem in failure recovery,an optimal traffic smoothing algorithm is proposed to balance the traffic among links where the traffic goes beyond the threshold.Finally,experiments result show that the proposed scheme could not only raise the success rate of failure recovery,but also deal with the overload problem in failure recovery,which protects the network in failure avoidance scope.3.In view of the validation requirements of the SR based traffic scheduling and traffic protection mechanism mentioned above,this paper based on the development of programmable routing platform ONOS designs an SDN based SR traffic transfer system and implements its prototype system.The prototype system integrates the above two models of traffic scheduling and traffic protection.Compared with current routing system,this system not only supports the function of service QoS assurance,but also has an advantage in traffic protection and resource cost.