Fast failover mechanism for software defined networking-openflow based

Path protection and restoration mechanism must be implemented to provide a reliable network. 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 switching time compared to backup path that establish on demand. However, it may lead to the use of non-optimal backup path. In this paper, we present a fast and efficient failover mechanism for redirecting traffic flows to optimal path when there is a link failure or congestion problem. Our method uses the switch flow entry expiry feature to reroute traffic to backup path and additional help of buffer in OpenFlow switches to reduce switching delay and packet loss.