Telephone

Telephony functions allow users to make VoIP phone calls using soft phones or IP desk phones. VoIP calls may also be made to and from the Public Switched Telephone Network (PSTN) using standard 3rd party VoIP gateway hardware. Phone calls are initiated and controlled in call control signaling data packages. Actual voice stream is transmitted separately in RTP data packages. Signaling and stream data packages travel in different physical IP network connections and also often in different physical modules within the system.