SIP IP PABX Phone system with 4 to 96 FXS/FXO ports SIP trunks for least cost calls 120 IP users Billing, MOH ... group, Auto-Attendant, 3-way-conference; Embedded SoHo IP PBX phone system with 4,8 or 16 FXO analog ports, and ... or VPN, it allow extensions to be boundled with cell phone, and it also directly integrates with VoIP service provider networks ...