VoIP: Support SIP protocol for intergration with VoIP systimes, intergrated with SIP/PBX. Support ONVIF protocol for interaction with security systems, integrated with ONVIF VMS/NVR. Support SIP features: secondary/backend SIP server, IPv4 (IPv6 futhur). Support codecs: OPUS, G711U, G711A, GSM, MP3, WAV.