Adaptive flow monitoring in SDN architecture

The SDN controllers maintain the flow tables to manage all the data flows passing through the SDN switches. In some cases, monitoring activities are required for the specific flows to detect the special events. Current de facto standard of SDN architecture enforces SDN switch to stay awake all the time from the time it receives the event monitoring request from SDN controller to catch the target event on the corresponding flow. This mechanism might disturb the fundamental SDN philosophy, which recommends the SDN switch to focus on the data forwarding, resulting in the degrading the performance of the whole SDN network. In order to tackle this problem in the real world domain, this paper focuses on the flow monitoring procedure described in OpenFlow specification version 1.4[1]. Starting from pointing out the problem of the current procedure in OpenFlow specification 1.4, we propose the detailed brand-new procedure, improved message format, and the system configuration to resolve the corresponding problem. The proposed idea can help the network service provider to build and operate their networks more efficiently and effectively.