Abstract:

oftware defined networking (SDN) expands the flexibility and programmability of networks by decoupling control logic from data forwarding, and becomes a hot topic in the area of future networks. SDN can face the challenge of controller performance bottleneck in its practical deployments, so it is necessary to understand the performance characteristics of SDN controllers. For this end, we first analyze the arrival process and the processing time of PacketIn messages in SDN controllers.Then, we propose a capacitylimited performance evaluation model of SDN controllers M/M/1/m based on the queuing theory. As a further step, we derive its performance parameters, including the average waiting queue length, the average queue time, the average queue length and the average sojourn time. Finally, the proposed performance model is evaluated via experiments by using the controller performance measurement tool Cbench. Experimental results indicate that the estimated delays of our model are closer to the measured delays than those of other existing models, thus providing a more accurate description of SDN controller performance.

Key words: software defined networking (SDN), controller performance evaluation, queuing model, average sojourn time