A cost-effective and load-balanced controller placement method in software-defined networks

A network incorporates nodes, and each node can communicate with each other through some links. An efficient way to maintain the communication between nodes is to divide a network into several subnetworks, called clusters. We have developed a new clustering algorithm and applied our method for the controller placement in software-defined networks (SDNs). Placing a controller in its appropriate location by balancing the loads and optimizing the latency even in case of a failure scenario becomes a challenging task. Thus, we have proposed a multi-controller placement algorithm that can minimize the average (Sw-Co) latency in such a way that the network switches are fairly distributed over clusters. This distribution helps to balance loads of switches among controllers even in the case of a controller failure scenario. We have also simulated three other existing algorithms for comparison. Experiment results show that our algorithm is a cost-effective solution as compared with other existing algorithms. We have also shown that our proposed method balanced loads of switches between controllers in a SDN network and generates lower average (Sw-Co) latency with and without a controller failure.