Research On SDN Network Path Optimization Mechanism Based On INT Model

SDN enables network researchers to centrally control network behavior through programming,providing new solutions for solving problems in traditional networks.However,the current SDN network programming is limited to the control level,and the data level still depends on the hardware switch.The development cycle that enables hardware to support new protocols is long,and it takes four years to enable fixed-functional chips to support new protocols,which is not conducive to the verification of new ideas by network researchers and hinders the development of the network.End-to-end path optimization is a key technology that guarantees the quality of service.In the SDN network,logically centralized control makes it possible to perform path planning from the global perspective of the network.The separation of the control layer and the data layer causes the control layer to focus on the logical control,and the data layer only needs to pay attention to the forwarding of the packet,which provides the possibility for the realization of the complex control logic.P4 has the features of protocol independence,target independence,and field reconfigurable.P4 allows researchers to control switches "top-down" by first specifying how a switch processes packets.This frees researchers from the constraints of data layer.The research in this paper is based on SDN network.Firstly,the data plane programming language P4 is introduced,and an accurate end-to-end one-way delay information collection mechanism is designed based on the INT model.Then introduce the research status of path optimization mechanism in the current SDN network,and design a multi-constraint multi-path optimization mechanism based on Dijkstra's algorithm.A SDN network path optimization system that can perform network monitoring,path optimization,and path switching is designed and implemented.At the end of this paper,the Mininet network simulation environment is used to test the function of the system,and the correctness and effectiveness of the end to end path optimization control mechanism proposed in this paper is verified.The end-to-end path optimization control mechanism designed in this paper mainly includes the following content:(1)Using P4 to customize the data layer switch,and use P4 Runtime to collect network state information,monitor the user-requested service,and provide the decision-making basis for the end to end path optimization system.(2)Taking full advantage of the characteristics of SDN network centralized control,amulti-constrained multi-path optimization algorithm based on Dijkstra algorithm is designed and implemented.Based on the algorithm,a feasible result set is quickly found,and when the path is switched,the feasible solution is directly extracted from the current result set and verified,thereby improving the link convergence.(3)Based on the P4 Runtime API,a path switching algorithm and a solution to deal with the flow entry of old path is designed.