Controller-proxy: Scaling network management for large-scale SDN networks

Software defined networking (SDN) decouples the control and data plane of a network, which then drastically increases its flexibility and programmability. In large-scale networks such as data center networks, the scalability of a network is often limited by the SDN control plane because of a high flow arrival rate and uneven hotspot distribution. The objective of this paper is to design new mechanisms that utilize the computing resources in switches to scale up the SDN control plane without sacrificing the advantages of SDN. For this purpose, we propose the controller-proxy method, in which the SDN control plane can dynamically delegate a part of the event-processing logic to switches and utilize the computing resources in switches instead of handling OpenFlow events in the controllers. Experimental results show that controller-proxy method can reduce the workload of the control plane and improve the scalability of SDN networks by relieving the control path bottleneck.