Research On Traffic Scheduling Technology Based On SDN

With the continuous development of network scale,the problem of low utilization of network bandwidth is becoming more and more serious.The reason is that the traditional traffic scheduling technologies use their own network nodes as the center to calculate the path to reach the destination node,and they do not have the global network view.Therefore,it is difficult to carry out the optimal traffic scheduling.Meanwhile,the requirements of current business applications to QoS are becoming higher and higher,and the network using traditional traffic scheduling technology has not been able to meet the requirements of current business applications to QoS.Software defined network(SDN)is a new network architecture,which decouples the control layer of the network device from the forwarding layer and integrates the control layer into an independent controller.Through this controller,a global network view can be obtained.Therefore,to solve the problems of traditional network traffic scheduling technology,the research of SDN based traffic scheduling technology has become a hot topic.The main work of this thesis is the research of SDN-based traffic scheduling technology.Based on the study of traditional traffic scheduling and SDN key technologies,this paper participates in the actual project of SDN based traffic scheduling.The requirement analysis of the project is carried out,and the traffic scheduling algorithm module in the SDN based traffic scheduling system is implemented,and further research is carried out for the constrained routing algorithm module.First,in order to achieve the function of the constrained routing algorithm module,this thesis designs an improved CSPF algorithm based on SDN.The algorithm is composed of multi-objective routing algorithm under multiple constraints and sub-optimal path algorithm.Using the global network view provided by SDN and the user defined application constraints,Multi-objective routing algorithm under multiple constraints can achieve the multi-constraint and multi-objective routing,improve the network bandwidth utilization,and meet the QoS requirements of business applications.The sub-optimal path algorithm is a supplement of multi-objective routing algorithm under multiple constraints.The algorithm relaxes the constraints to calculate the path and guarantees the service transmission reachability when the multi-constraint and multi-objective routing algorithm does not find the path.Then,the improved CSPF algorithm,Dijkstra algorithm,Widest-Shortest Path algorithm and Least Delay Path algorithm are simulated and compared under different network topologies.The applicability and superior performance of the improved CSPF algorithm based on SDN are verified.At the same time,the sub-optimal path function of the algorithm is simulated to verify the algorithm's guarantee for the reachability of service transmission.Finally,the actual SDN environment is built,and the improved CSPF algorithm based on SDN is tested under this environment.The results verify the effectiveness of the algorithm in the SDN environment and meet the requirements of QoS in business applications.