Optimal controller placement in Software Defined Networks (SDN) using a non-zero-sum game

In this paper, we discuss optimal controller placement for Software Defined Networks (SDN) and propose a non-zero-sum game based distributed technique. Our proposed technique is a simple and low-complexity solution which runs in real-time. This can be implemented as an optimization engine at each SDN controller. The optimization engine at each controller computes a payoff function and compares its own payoff value with that of neighbors and takes appropriate decisions such that either new controllers should be added, or existing controllers should be deleted or offloading should be performed between controllers dynamically. We have conducted extensive simulations and verified the usability of the proposed scheme. We also propose a deployment framework which can be implemented using OpenFlow enabled platforms. Use of this technique not only can improve Quality of Services (QoS - minimum packet drops and delay) but also can save cost of deployment and operation.