Optimal placement of controllers in a resilient SDN architecture

The SDN (Software Defined Networking) paradigm brings flexibility to the network management and is an enabler to reduce the energy consumption of the networks. However deploying a set of SDN controllers to manage a Wide Area Network is still a challenge as it implies to determine the right number of controllers to install and their locations within the network. In this paper, we give the key performance criteria that should be taken into account to provide a “good” placement in terms of Quality of Service and we propose an integer linear programming formulation of the resilient controller placement problem. This formulation provides the optimal number of controllers and their location while embedding QoS and load balancing constraints for several level of backup controllers.