A centralized hybrid routing model for multicontroller SD-WANs

The increasing complexity of contemporary mobile and application-centric networks is pushing traditional WAN architectures to its limit. Due to the rise of Cloud-based services and edge-computing, the intersite data transfer volume in enterprise networks is rising rapidly. Moreover, enterprises are tending to integrate several communication technologies such as broadband, LTE, MPLS, and so forth for a high-available dynamic WAN connectivity, which a traditional WAN does not support natively. Additionally, its distributed computing model results in the control-plane traffic to consume a significant amount of backhaul bandwidth. Software-defined WAN (SD-WAN) is a generation shift that adapts the centralized model of SDN to WAN that fills the bottlenecks of its predecessor. It provides over twice the bandwidth having the same backhaul with more manageability, autonomy, and security of the network. In this article, we propose a hybrid routing model for multicontroller SD-WANs that computes all-possible routes proactively and serve them on-demand. The proposed model results in a rapid convergence across the edge devices. The article further discusses the synchronization mechanism among several controllers and a test-bed implementation to conduct the experiments.