WiPCon: A Proxied Control Plane for Wireless Access Points in Software Defined Networks

摘要

Software-Defined Networking (SDN) supports programmability by refactoring the network control plane. An SDN logically centralizes the control plane of network entities at the controller level. To achieve scalability, reliability, and availability, it is inevitable for the control plane to be configured as physically distributed. However, current deployments adopt a single SDN controller mainly due to problems of management complexity and costly maintenance. In this paper, we present a novel SDN architecture called a Wireless Proxy Controller (WiPCon) in order to increase the control plane efficiency of wireless networks. WiPCon involves a proxied control plane for wireless access points (APs) supporting SDN. It has a hybrid architecture in that the proxy SDN controller within the AP performs some of the main SDN controller roles, such as responding to specific network events, collecting wireless information, and local cooperation, although the control plane of the APs moves to the main SDN controller. Even though a single main SDN controller is used, WiPCon has robustness when it comes to network partitions or control bottlenecks, and flexibly copes with scalability issues that originate from dense deployment of APs. We analyzed various network factors through a preliminary implementation of WiPCon. Consequently, we verified that the proposed architecture efficiently supports control scalability and considerably reduces control overhead of the main SDN controller.