Paper Title
Various Role of the Multiple Controllers in SDN Environment

The Software Defined Networking (SDN) is one of the most promising technology in networking, which decouples the control plane from the data plane. Therefore, all the control logic is transfer to the SDN controller, which provides a centralized logical view of an entire network. But it also increases the chance of a failure in the network due to a single controller. To eliminate the single point of failure (SPOF) in the network by using the multiple controllers in SDN. This paper main focuses on how to increases the scalability, reliability, and high availability of services in the network.For this purpose, the various roles of multiple controllers (Equal, Master, and Slave) are used in the Software Defined Networks. In the simulation, the Ryu SDN controller and Mininet tools are utilized. During the simulation to analyse, what is happen when a SPOF occurs in the network and how to use the different roles of the multiple controllers which help to reduces the threat of a single point of failure in the SDN network. When a SPOF occurs in SDN then the value of the packet loss parameter is increasing gradually till the single controller becomes again in working condition. Thus, to resolve this problem by using multiple controllers in the networks and also evaluate their performance in the multi deployment of the controller on SDN. Keywords - SDN, SPOF, Multiple Controllers, Equal, Master-Slave