Collaborative Route Management to Mitigate Congestion in Multi-Domain Networks Using SDN

In software-defined networking (SDN), a controller monitors switches and directs them to process packets, thereby making network management easier. In this paper, we consider an SDN-based network with multiple connected domains, where each domain contains a set of switches supervised by a controller. Moreover, flows can have different priorities. Then, we propose a multi-domain collaborative route management (MCRM) scheme to schedule routing paths of flows to improve network performance. Each controller adaptively adjusts the paths of some flows in the domain based on their priorities to avoid congestion. However, when congestion occurs, but no paths can be adjusted, the controller borrows links from another domain. To build such cross-domain paths, two controllers exchange information through the XPub/XSub framework. This link borrowing mechanism results in heterogeneous flows, where a link carries the interior flows in its domain and the link-borrowing flows from exterior domains. Then, MCRM handles heterogeneous flows on the congested links by adopting OpenFlow meter and group tables. Simulation results show that MCRM can efficiently increase network throughput and decrease packet loss.