A certified WAN professional is an expert who deals with wide area networking technology for the business. They supervise the installation, maintenance, and of a wide area network and associated computer hardware and software.Wide area network (WAN) is a data network, typically used for linking computers, that spans a wide topographical area. WANs can be used to connect cities, states, or even international boundaries. WANs are often utilized by bigger corporations or organizations to facilitate the interchange of data, and in a wide range of corporations with facilities at multiple locations have embraced WANs. how to become a field engineer