Minimizing Multi-Controller Deployment Cost in Software-Defined Networking

Aiming at various issues, such as performance, load-balance and robustness, of Software-Defined Networking (SDN) controller cluster, several deployment strategies have been proposed. As a supplement, our work delivers a cost-effective multicontroller deployment strategy in terms of economic benefits. In this paper, we formalize a Cost-optimized Multi-Controller Deployment (CO-MCD) problem by concerning the controller's deployment cost and the network service's delay cost. Meanwhile, we characterize the communication between the controller and the switch using a queuing system, and design an algorithm to determine the optimal deployment in the specified environment. Simulation results validate that the proposed algorithm can always obtain a deployment solution which minimizes the economic cost of the entire SDN network. This work aims at being a useful primer to provide insights regarding the economic impact of multiple controllers in the realistic SDN deployment, so that network owners plan their investments more rationally.