A framework of using OpenFlow to handle transient link failure

Due to the default settings of the OSPF, the network takes several tens of seconds to recover from a failure. During the convergence, the network service will be disrupted. This paper proposed a framework of using OpenFlow to handle the transient link failure. OpenFlow separate the data and control plane by shifting the management to a remote centralized controller and the forwarders just forward packets based on flow table. We exploit OpenFlow technology into the existing routers. The routing information database (RIB) and the flow table construct a two-layer forwarding structure. When link failure happens, the controller computed the backup paths for the destinations that affected by the failure link and sent the related flow table to the OpenFlow forwarders. All the packets received by the forwarders will be compared against flow table entries first. If the packets matched with the flow table, the corresponding actions of the flow entries will be taken. Otherwise, the packets will be processed by the RIB. After the network recovering from the failure, the controller will remove the temporary flow table used to bypass the failed link in the forwarders and the RIB will take over the packets forwarding. Experiments results demonstrate that the proposed framework have a low packet loss to the link failure.