SD-WAN is an acronym for software-defined networking in a wide area network (WAN). SD-WAN simplifies the management and operation of a WAN by decoupling the networking hardware from its control mechanism. By enhancing or even replacing traditional branch routers with virtualization appliances that can control application-level policies and offer a network overlay, less expensive consumer-grade Internet links can act more like a dedicated circuit. Research firm Gartner has defined an SD-WAN as having four required characteristics:

• The ability to support multiple connection types, such as MPLS, Last Mile Fiber Optic Network or through high speed cellular networks e.g. 4G LTE and 5G wireless technologies

• The ability to do dynamic path selection, for load sharing and resiliency purposes

• A simple interface that is easy to configure and manage

• The ability to support VPNs, and third party services such as WAN optimization controllers, firewalls and web gateways