On Resilience of Split-Architecture Networks

The split architecture network assumes a logically centralized controller, which is physically separated from a large set of data plane forwarding switches. When the control plane becomes decoupled from the data plane, the requirement to the failure resilience and recovery mechanisms changes. In this work we investigate one of the most important practical issues in split architecture deployment, the placement of controllers in a given network. We first demonstrate that the location of controllers have high impact on the network resilience using a real network topology. Motivated by such observation, we propose a min-cut based controller placement algorithm and compare it with greedy based approach. Our simulation results show significant reliability improvements with an intelligent placement strategy. Our work is the first attempt on the resilience properties of a split architecture network.