SIP IP PABX Phone system with 4 to 96 FXS/FXO ports SIP trunks for least ... Billing, MOH, IVR, Recording All-in-One SIP IP PABX for SOHO useressupport 4 to 96 analog ports (extensions and ... , 3-way-conference; Embedded SoHo IP PBX phone system with 4,8 or 16 FXO analog ports, and 8,16 ... , 60 remote extensions, and 8 to 16 analog trunks. With its flash memory capacity, RT20 also supports built-in IVR ...