Routing algorithm optimization for software defined network WAN

Software Defined Network (SDN) provides a new fine-grained interface enables the routing algorithm to have an a global view of the network throughputs, connectivity and flows at the data-path. This paper aims to provide a novel approach for dynamic routing algorithm for Software Defined Network in Wide Area Network (SDN-WAN); based on using a modified shortest-widest path algorithm with a fine-grained statistical method from the OpenFlow interface, called Shortest-Feasible OpenFlow Path (SFOP). This algorithm is designed to identify the optimal route from source to destination, providing efficient utilization of the SDN-WAN resources. It achieves this aim by considering both the flow requirements and the current state of the network. SFOP computes the optimal path which provides the feasible bandwidth with the lowest hop count (delay). That will present better stability in SDN communication, QoS, and usage of available resources. Moreover, this algorithm will be the base for an SDN controller because it extracts the widest available bandwidth from source to destination for a single path. It enables the controller to decide whether it is enough to use this simple algorithm only, or if a more complicated algorithm that provides larger bandwidth such as multiple-path algorithms is needed. Finally, a testbed has been implemented using MATLAB Simulator, Pox controller, and Mininet emulator will be discussed. The latency comparison of SFOP algorithm with three other algorithm's latencies shows that this algorithm finds better latency for an optimal path. Evidence will be shown that demonstrates that SFOP has good stability in dynamic changes of SDN-WAN.