Crux LX is a plug-and-play device as it comes pre-configured for most common needs. It just needs to be powered on, and like any other Access Point (AP) or router, its wireless radio or SSID (as described on the box) is available for devices to connect. For it to connect to internet it needs a wired ethernet (RJ45) connector coming from your cable or fiber modem, as you would with any other AP or router. For voice communication, Crux LX acts like a SIP server. To start making calls, you could download any of the SIP client application or softphone application that accepts three inputs: Extension number, Password and IP Address of Crux LX. These three credentials allow a SIP client to register with Crux LX and you are ready to call one another!