I am new to asterisk and have a confusion about the role of a pbx in a voip setup. What I understand is
A traditional PBX (PSTN) performs call routing and is itself involved in the call. i.e the pbx remains in the ‘circuit’ for entire call duration.
An IP pbx also routes the calls but isinvolved only in call setup. Once the call is established, the RTP/voice packets bypass the pbx and the two users communicate directly.
Is my notion true?
If this is the case, then asterisk pbx should have nothing to do with the real time protocol (RTP). But the asterisk source code contains the file ‘rtp.c’ which ‘supports RTP and RCTP’. What is its purpose ?
Can anyone clarify this?