Optimization Of SDN Routing Control Strategy Oriented Fault Analysis

Software Defined Network(SDN)is a new type of network architecture whose design concept is to separate the control plane of the network from the data forwarding plane,thus achieving programmable control of the underlying hardware through the centralized software controller and flexible network resources on-demand scheduling.As one of the mainstream research directions of the future network,SDN has been researched and applied more and more in its control-data separation and the centralized control of logic.The centralized control feature of SDN brings controllability,security and rationality,which at the same time produced reliability issues.Fault recovery technology is one of the important ways to improve the reliability of SDN system,based on the analysis of SDN network structure and OpenFlow v1.3 protocol,this thesis summarized the faulty recovery mode of SDN,and studies the key technologies of fault recovery mode and data plane virtual network mapping.For the different fault recovery modes,this thesis firstly analyzes and simulates the problems of the switch nodes or links in the SDN network and its topology.Secondly,based on the failure problem of the non-service quality guarantee flow and the fault problem based on the quality of service guarantee flow,the concept of NodeRank and OP-MaxMatch(Oriented Platform-MaxMatch)algorithm and OP-BFS(Oriented Platform-Breadth First Search)algorithm are proposed considering different node attributes and link attributes.The OP-MaxMatch algorithm updates the shortest path value and the selection node for the passive recovery mode,considering the neighbor set of nodes,the union of the neighbor nodes of the nodes in the identified set,and the difference set between the union and the identified set;For proposed recovery mode,OP-BFS algorithm limits the number of hops to reduce the complexity of the search space and physical network bandwidth resources waste.Finally,this thesis made simulations on OP-MaxMatch algorithm and OP-BFS algorithm.The experimental results show that the two fault recovery algorithms can find the best path between the specified virtual nodes in a short time and realize the network fault recovery.Compared with other existing algorithms,they have higher virtual network request reception rate and long-term average revenue.At the same time,experiments show OP-MaxMatch algorithm is more efficient than the OP-BFS algorithm.