A Distributed Controller Approach Using P2P Protocol for Software Defined Networks

The main advantage of software defined network (SDN) is a separation of data and control planes to facilitate network management functions. This separation nevertheless poses a scalability and availability problem for controllers in the control plane. Controllers become a single point of failure in SDN. This paper presents an approach of a hybrid controller network for improving scalability and availability in both local and global domains. This approach extends controller architecture to providing direct communication among controllers in the global domain. It applies a peer-to-peer (P2P) protocol for controllers to facilitate group formation and data synchronization. We have extended the prototyping implementation of the Gnutella protocol to evaluate the performance of the hybrid controller network and to simulate controller failure and switch migration. The experimental results show that controllers perform large data update efficiently with low extra workload as number of controllers increase significantly.