Informed Network Routing for SD-WAN enabled SaaS Optimization: An M365 Proof of Concept

The majority of applications nowadays reside in the cloud, allowing users to utilize remote resources and services providing flexibility and low cost access to a large range of applications. An inherent part of cloud operations is monitoring, which allows to survey the performance of the consumed applications and take corrective actions whenever a performance drift is noticed. Nonetheless, cloud telemetry tools are only concentrating in monitoring the data center infrastructure that hosts the cloud native applications, failing to assure the performance in a user to cloud continuum fashion. Hence, in this paper, we propose a two-way monitoring approach, leveraging Software Defined Wide Area Network (SD-WAN) capabilities. Specifically, by installing monitoring probes in both the WAN and cloud infrastructures, cloud vendors can monitor user traffic and provide application performance view on network links, in order to take Informed Network Routing (INR) decisions. Our results, using Microsoft 365 (M365) as a proof of concept, clearly show the benefit of the two-way monitoring approach in various traffic congestion scenarios. Additionally, since this is a first-of-its-kind solution, we also propose the foundations of a new communication protocol that can leverage the proposed two-way monitoring approach in larger scale and multi-vendor Software as a Service (SaaS) environments.