SIP IP PABX Phone system with 4 to 96 FXS/FXO ports SIP trunks for least cost calls 120 IP users Billing, MOH, IVR, Recording ... for SOHO useressupport 4 to 96 analog ports (extensions and pstn trunks)up to 120 IP users, can be working under NAT ... SoHo IP PBX phone system with 4,8 or 16 FXO analog ports, and 8,16,24 FXS local extensions; and 60 IP users in local ...