Graph Modeling for OpenFlow Switch Monitoring

Network monitoring allows network administrators to facilitate network activities and to resolve issues in a timely fashion. Monitoring techniques in software-defined networks are either (i) active, where probing packets are sent periodically, or (ii) passive, where traffic statistics are collected from the network forwarding elements. The centralized nature of software-defined networking implies the implementation of monitoring techniques imposes additional overhead on the network controller. We propose Graph Modeling for OpenFlow Switch Monitoring (GMSM), which is a lightweight monitoring technique. GMSM constructs a flow-graph overview using two types of asynchronous OpenFlow messages: packet-in and flow-removed, which improve monitoring and decision making. It classifies new flows based on the class of service. Experimental findings suggest that using GMSM leads to a decrease in network overhead resulting from the communication between the controller and the switches, with a reduction of 5.7% and 6.7% compared to state-of-the-art approaches. GMSM reduces the controller's CPU utilization by more than 2% compared to other monitoring methods. Overhead reduction comes with a slight reduction of approximately 0.17 units in the estimation accuracy of links utilization because GMSM allows the user to monitor the network subject to a selected class of service, as opposed to having an exact view of the network utilization.