Creating Scalable Distributed Control Plane in SDN to Rule Out the Single Point of Failure

In Software Defined Network (SDN) distributing the control plane brings tremendous benefits and reinforce the performance, scalability, and security. In SDN, a single controller provides a global view of the network status. Therefore, the controller is responsible for configuring the data plane devices. Because all control plan responsibilities are managed by a single controller, these benefits come at a high cost due to the threat of a single point of failure in the SDN network. The contribution of this work is a method to alleviate the mentioned threat. A fault-tolerant solution, which makes possible to deliver high availability and scalable new services for distribution of controllers, is proposed. The solution is based on the applications Zookeeper, Redis. The Ryu controller and Mininet are used to emulate the Software Defined Network. The prototype implementation enables multiple Ryu controllers to execute their own functions in fault-tolerant manner employing a centralized service for preserving configuration information named Redis. The functional validation of the proposed solution is presented in the paper.