Research On Semi-centralized SDN Routing Technology For Data Center Network

In the Software Defined Networking(SDN)architecture,the network control function is separated from network devices(switches/routers)and integrated to the central node controller,while switches are used to implement functions on the data plane(data forwarding based on the flow table).On large-scale data center networks,calculation and distribution of the routing/flow table are completely processed by the central controller,and the controller has become the bottleneck and vulnerability for network performance.To solve these problems,this essay proposes a semi-centralized SDN routing technology based on the data center network.Its main idea is that each SDN switch node constructs a basic flow table for itself without involving the controller so that the SDN switch can implement basic data forwarding based on the flow table.Meanwhile,the controller is responsible for routing(troubleshooting,security and QoS)of a higher level,thus greatly reducing controller's loads.In addition,immediate network failure detection and recovery is an important indicator for evaluating actual values of a network.On a data center network,short-time link failures may bring great economic losses.Therefore,it is necessary to make researches on the failure detection and recovery technology on the SDN network.This essay makes studies on the troubleshooting mechanism on advanced routing on the SDN controller,and designs a partial roundabout troubleshooting mechanism based on the basic flow table through compared and analysis the shortcomings of the existing fault handling mechanism.In this way,the controller can detect network failures in a timely manner and can recover the failures in short time to implement troubleshooting in advanced routing on controllers.Finally,a performance test is performed on the semi-centralized SDN routing technology based on the Ryu controller and mininet simulation platform from the perspectives for controller loads and link failure recovery time.The test results indicate that the technology can effectively reduce loads on the controller and the partial roundabout troubleshooting mechanism can be used for immediate and effective failure recovery.