The 3CX Phone System consists of the server software (the “IP PBX server”), one or more SIP soft or hardware phones, and optionally includes a VOIP Gateway to allow for calls to be made via regular PSTN lines. The system can use the existing computer wiring (and share the network point with the computer) and can be installed on an existing, non dedicated server. Scale to more extensions simply by adding more SIP phones. Say goodbye to expensive, proprietary, phone system expansion modules!