WAN providers in the 43512 code have significantly less expensive service thanks to Software-defined Wide Area Networks (SD-WAN) which replace costly WAN routers with software/hardware combinations in the parts of the network that do not require the full capablities of the router. SD-WAN can be software only, or a combination of hardware and software. Versitility is found in SD-WAN's ability to give it's customers exactly what they require and no more. As the customer's needs change at any site in the network, SD-WAN is an adaptive technology.