Sequential game theory based multi criterion network partitioning for controller placement in software defined wide area networks

The task of determining the number and location of controllers to be deployed in software defined network (SDN) affects various network performance metrics. Large-scale networks are typically divided into multiple domains of smaller size and then deploy one or more controller(s) in each domain. In this paper, we propose a sequential game theory based multi-criteria partitioning scheme for controller placement in large-scale SDN. The proposed scheme automatically identifies the optimal number of domains to be created in the network while considering multiple conflicting objectives. The proposed strategy comprises of three stages. The first stage generates the initial composition of domains. The second stage identifies the actual number of domains to be created in the network and the temporary composition of these domains by formulating several finite multi action two player sequential games. The third stage generates homogeneous domains by formulating several single action two player sequential games. The second and third stages are repeated until there is no improvement in the system objectives. We utilized a game tree for representing the finite sequential game. We also presented a backward induction algorithm for computing the player’s best response strategies, also known as Nash equilibrium. The proposed strategy is evaluated on medium and large-scale networks from Internet Topology Zoo. Further, the performance of the proposed approach was compared with three existing approaches from the literature. Although the complexity of the proposed SGTCP approach is asymptotically higher than existing approaches, the proposed approach converges rapidly in practice and the actual time it takes is quite low. The proposed approach outperforms existing state-of-the-art network partitioning approaches for controller placement in SDN.