A Centralised Hybrid Routing Model for Multi-Controller 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 Cloudbased services and Edge-computing, the inter-site data transfer volume in enterprise networks is rising rapidly. Moreover, enterprises are tending to integrate several communication technologies such as Broadband, LTE, MPLS, etc. for a high-available dynamic WAN connectivity, which a traditional WAN doesn’t support natively. Additionally, its distributed computing model results in the Control-plane traffic to consume a significant amount of backhaul bandwidth. Software-Defined WAN (SDWAN) 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 1 with more managibility, autonomy, and security of the network. In this article, we propose a hybrid routing model for multi-controller SD-WANs that computes all-possible routes proactively and serve them on-demand. It results in a rapid convergence across the edge devices. The article further discusses the synchronization mechanism among several controllers and a testbed implementation to conduct the experiments.