Research On NDN Routing Strategy Based On SDN Centralized Topology Update

Named Data Networking(NDN)meets the needs of future networks for mass content transmission,but lacks mature routing strategies.Software Defined Network(SDN)can provide great help for the improvement and implementation of NDN routing strategy by virtue of its separation of control plane and data plane,global vision and network programmability.The existing SDN-based NDN routing strategy concentrates the routing topology updating function and routing calculation function in the SDN controller,which results in high delay of the first packet of the content request and high load of the SDN controller.In addition,these strategies do not give full play to SDN's global vision and network programmability.The NDN routing strategy based on SDN centralized topology update solves the above problems.Firstly,it separates the two key functions of routing.Topology update function is centralized in SDN controller,while routing calculation function is distributed in NDN content node,which can reduce the delay of the first packet and the load of the SDN controller.Secondly,it takes advantage of global view and network programmability to obtain network topology information and link information.Then load weighted optimization is carried out to generate the optimized topology map,which is then sent to the NDN content node.After receiving new content requests,each NDN content node can directly carry out routing calculation locally,and adopt a more appropriate routing algorithm based on the optimized topology graph.The s:imulation results show that in the NDN routing strategy based on SDN centralized topology update,the delay of the first packet of the content request data stream is reduced by an average of 90%,the load of the SDN controller is reduced by an average of 10%to 30%,and the entire network realizes an effective load balancing.