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A reliable controller deployment strategy based on network condition evaluation in SDN

As a new network paradigm, Software Defined Networking (SDN) decouples control plane from data plane and has the programmability. With the network size increases, the control plane usually deploys multiple controllers to solve the scalability of SDN. However, it also introduces a new issue that is how to place controller reliably in the network. Meanwhile, the unreliable multi-controller deployment will bring about low network stability and high packet loss rate. In order to address this problem, we propose a Reliable Controller Deployment (RCD) strategy based on network condition evaluation. Firstly, we build a multi-controller network model and define the evaluation parameters for network condition, which include the node reliability and path quality. Then, through considering the weighted node reliability and path quality simultaneously, RCD assesses the controller nodes and selects the optimal locations for controller deployment. Moreover, we design the corresponding algorithm with the help of simulated annealing to implement this strategy. Finally, the simulation results show that RCD has the better performance in controller reliability and network stability.