Research On SDN Routing And Flow Table Updating Strategy Based On Improved Ant Colony Algorithm

Software Defined Networking(SDN)aims to solve the increasingly prominent problems of traditional networks,such as the inability to flexibly schedule network resources and low management efficiency.The main feature of SDN is to decouple the control plane from the data plane.The scheduling of data flow in SDN requires the routing algorithm of the SDN controller to select the optimal path to transmit the data flow.The update of the route by the SDN controller needs to be implemented by sending the flow table to the switch through the southbound interface.How to optimize the routing algorithm into an algorithm that selects the optimal path based on the real-time link status,and how to ensure the consistency of the flow table update and reduce the load during the flow table distribution process are the main research directions of load balancing.This article focuses on the routing algorithm and the flow table update strategy.The main work is as follows:(1)Aiming at the difficulty of SDN routing strategy to adapt to real-time link status,Propose SDN routing strategy based on ant colony optimization algorithm.On the basis of the application of the ant colony algorithm,its shortcomings are improved,the pheromone update volatilization mechanism is redesigned,the importance of the pheromone parameter in the algorithm is adjusted,and the update of the pheromone in the algorithm and its importance are changed according to the phased needs to ensure the algorithm The search capability in the early stage and the convergence speed in the later stage,combined with the characteristics of SDN centralized control,calculate the optimal path of the transmission data stream based on the link status of the entire network.(2)Aiming at the consistency of the flow table update strategy in SDN.Propose an update strategy of SDN flow table based on time sequence and collection.First,divide the new and old paths into different sets according to the application of the relevant SDN switch,analyze the load of the data flow on the controller and the switch when the new and old paths are converted,and use the characteristics of data flow transmission to update the relevant switches in a certain order to the different sets of switches.While ensuring the consistency of the flow table update,it reduces the load of the controller and the space load of the switch flow table.(3)Perform simulation experiments on the proposed SDN routing strategy based on the ant colony optimization algorithm and the SDN flow table update strategy based on time sequence and aggregation.The experimental results prove that compared with the traditional routing algorithm,it reduces the delay of the data stream in the network during the transmission process and increases the throughput;The flow table update strategy based on time sequence and set ensures the consistency of the flow table update,and reduces the control load and the load of the switch flow table space.