Control plane of software defined networks: A survey

Software Defined Networking (SDN) has been proposed to solve ossifications of Internet. The main motivation of SDN is to separate the control plane and data plane, enabling a centralized control. In this way, the network infrastructure becomes an open and standardized resource. Hence, it can be managed and utilized in a more efficient way. The controller is the key infrastructure in the SDN and provides programming interfaces to the entire network. Then, various applications can be written to perform management tasks and offer new functionalities on the controller. In this survey, we present many essential research issues about the controller, and especially focus on the control architecture, performance, scalability, placement, interface and security. The aim of this paper is to provide an up-to-date view to the SDN controller.