Improving Resiliency in SDN using Routing Tree Algorithms

The ability to recover the control logic after a failure is detected in specific time window is called resiliency. The Software Defined Network (SDN) is an emerged and powerful architecture which allow to separate the control plane from forwarding. This decoupling architecture brings new difficulties to the network resiliency because link failure between switch and controller could defunct the forwarding plane. It has been identified that the resiliency of the network can be improved by choosing the correct place for the controller and by choosing proper routing tree once the controller location is known. In this work, we have analysed the performance of various Routing Tree algorithms on different network topology generated by Bernoulli Random Graph model and found that Greedy Routing Tree (GRT) provides the maximum resiliency. The Closeness Centrality Theorem has proposed to find the best controller position and later analysed the performance of various single controller placement algorithms on GRT for finding the overall improvement of the resiliency of the network.