... 120 IP users Billing, MOH, IVR, Recording All-in-One SIP IP PABX for SOHO useressupport 4 to ... 16,24 FXS local extensions; and 60 IP users in local or remote, support SIP and DDNS, Can ... , GUI for management; The RT20 is an All-in-One converged communication system for small and mid-size ... trunks. With its flash memory capacity, RT20 also supports built-in IVR, calls records, and downloads for color ring ...