Enduring Node Failures through Resilient Controller Placement for Software Defined Networks

Software Defined Networking (SDN) is an emerging paradigm for network design and management. By providing network programmability and separation of control and data planes, SDN offers salient features such as simplified and centralized management and control, reduced complexity and accelerated innovation. However, SDN introduces new challenges that should be addressed properly in order to benefit from its unprecedented capabilities. Due to the (logically) centralized control in SDN, the resilience of the control plane has a great impact on the functioning of the whole system. In this case, resilient controller placement problem (how many controllers are needed and where to place them to provide higher reliability) is a hot research topic that affects the reliability and performance of SDN in Wide Area Networks (WANs). Thus, we define a resilient controller placement problem, which satisfies a set of constraints, some of which are missing in the existing solutions. The acquired results on real tier-1 US service provider network topologies demonstrate the effectiveness of the approach. This can give helpful insights to the network operators for designing or modifying their network topologies to enhance the resilience of the control plane in SDN.