This thesis deals with Software-Defined Wide Area Networks (SD-WAN). It defines the term, presents its different variations available on the market and contrasts it to a typical MPLS network, based on criteria such as quality of service, link aggregation capabilities and price.Laboratory tests are conducted to compare the performances of one traditional and two SD-WAN connections to the cloud over redundant links, in terms of resilience to added latency, packet loss, bandwidth aggregation and failover capacities. An example company with a typical network is presented to study whether the current solution is satisfactory and how it could be improved. This thesis finds that the performance of network is no longer satisfactory due to the compa...