Openflow Path Fast Failover Fast Convergence Mechanism

Whenever there is a link failure in the network, OpenFlow controller can react by computing a new backup path and provide the information to the affected node or the node can switch to backup path locally using the predefined backup path table provided by the OpenFlow controller. Setting predefined backup paths, results in a faster network rerouting time compared to backup path that establish on demand. However, it may lead to the use of sub-optimal backup path. In this paper, we present a fast and efficient failover mechanism for redirecting traffic flows to more optimal backup path when there is a link failure or congestion problem. We introduce a switch flow entry expiry mechanism to immediately reroute traffic to backup path to reduce the network restoration time. To update the switch with more optimal path information, the controller require a round trip to the network and this can introduce to slow network convergence. We proposed a local pre-calculated path dataset mechanism in Openflow controller to allow fast network convergence.