Hybrid SDN: Evaluation of the impact of an unreliable control channel

Software defined networking (SDN) setups in general assume a perfect control channel between network devices and the centralized controller. Whilst this may be the case in certain controlled contexts such as data centers, when moving to wide area networks, this assumption does not necessarily hold true anymore. Therefore, there is the need to evaluate the impact of unreliable control plane behavior in SDN scenarios. This paper evaluates the impact of a lossy control channel on data plane throughput and latency. Additionally, it presents a hybrid SDN approach that dynamically switches between centralized and distributed operation at nodes, depending on the control channel packet loss ratio. Results show that throughput and latency at data plane can be maintained at acceptable level even in the presence of substantial control channel losses.