A multi-fault recovery oriented deployment strategy of backup controllers in SDN

In Software Defined Network (SDN), the control network is a logically mapped network that is like the brain and control center of the entire network. The reliability of the control network is the ability to survive failures of switching nodes on a large scale. However, there are few studies that consider the control network of SDN as a whole. In this work, we took the SDN control network as a standalone network that is separate from the underlying switching network. We developed a model to evaluate the average reliability of the control network in the presence of multiple failures of the underlying switching networks based on its topology characteristics. Then we searched for the optimal solutions of the model through an opposite learning revised sparrow search algorithm, based on which we proposed a multiple fault recovery oriented deployment strategy of backup controllers in SDN. The simulated experiment shows that the revision of the algorithm is effective and our proposed strategy could help us increase the reliability of the control network to a significant extent.