• SIP version 2 • Dual-tone multifrequency (DTMF) tone detection and generation • Voice Activity Detection (VAD) • Comfort Noise Generation (CNG) compatible • Silence suppression • Call waiting, call waiting caller ID (FXS ports only) • Caller ID with name/ number • Caller ID blocking • Call forwarding: no answer, busy, all • Do not disturb • Call transfer, call return, call back on busy • Fax: G.711 pass-through or real-time fax over IP via T.38 fax relay (T.38 support is dependent on fax machine and network/transport resilience) • Supports multiple voice codecs: G.711a, G.711u, G.726,G.729A, G.723.1 • SIP over TLS • Three-way conference calling with local mixing • Per-call authentication and associated routing • Call blocking with toll restriction • Delayed disconnect • Distinctive ringing: calling and called number • Off-hook warning tone • Selective/anonymous call rejection • VoIP to PSTN (USA) service call origination and termination • PSTN (USA) to VoIP service call origination and termination • Forward calls to VoIP service: selective, authenticated, all • Forward calls to PSTN service: selective, authenticated, all • Automatic PSTN fallback (loss of power or IP service to unit, with quiescence to normal operations): fixed fallback pairing of FXS ports to FXO ports • Advanced inbound and outbound call routing • Independent configurable dial plans (1 per port) • Force PSTN disconnection |