Research On Software-Defined Networking Architecture In Large Scale Networks

Software Defined Networking(SDN), which decouples the control plane from the data plane and assembles the control ability of switches to a centralized controller, has improved the flexibility and independency and shown a lot of merits.In this paper, we propose a controller configuration algorithm in multi-domain network, called Greedy Sub-Graph Cover Problem algorithm(GSGCP), which figures out the least number of controllers to cover the whole network, where we assume none of the controllers is able to monitor the complex networks alone due to capacity constraints. The algorithm addresses this NP-hard problem effectively, and shows its advantage compared to Random Algorithm. The GSGCP algorithm also provides the configuration table, mapping the controllers and the domains coveredMoreover, on the basis of vertical structure of control layer, this paper proposes the simple communication protocol between root controller and local controllers. And further elaborate procedure about switching and load balancing. Simulation results verify the correctness of the protocol.In the end, the dissertation summarizes our research ideas and methods of this topic, and points out the potential research about large-scale SDN network.