X16 Plus VoIP Expansion Capacities: When installed in the system server, the VoIP expansion card enables addition of up to (16) IP phones. IP phones supported include XBLUE IP8g and IP9g IP phones, and IP based cordless phones sold by XBLUE. The IP phones may be set up as Remote Extensions for use at home offices and branch offices. Up to (8) XBLUE VoIP telephone lines may also be connected to the system. When the VoIP card is installed the number of analog phone company lines is reduced to a maximum of (4) per system. Alternatively, with the VoIP Expansion card and the (2) port line expansion card installed in the server you may use up to (6) analog phone company lines and (6) XBLUE VoIP telephone lines. Only (1) VoIP card may be added to each X16 Plus system server.