An implementation of multi-domain Software Defined Networking

Software Defined Network (SDN) is an emerging architecture which can simplify network management and enable innovation through network programmability by decoupling the control plan and the data plan of the network. However, traditional SDN architecture is not suitable for all cases; a single controller may become a performance bottleneck in a wide area network. While current multiple controller solutions always make the network more complex and harder to be managed than traditional SDN network. In this paper, we proposed a new architecture for multi-domain software defined networks, which divided the control platform into two layers vertically. The bottom layer consists of local controllers, which only has the knowledge of the local domain it controls. And the top layer is coordinating controller controlling all local controllers. The communications between local controllers and coordinating controller use a standard NBI as communication protocol which is also the protocol used when controllers (both local controllers and coordinate controllers) communicate with applications. We implemented the architecture and our evaluations show the feasibility of it.