In message <tdjesr$h4nf$1...@dont-email.me
I do. I'm not trying to trip anyone up. It's a very long time since I
wrote a SIP UA, so I've forgotten a lot of stuff. But I am aware that
moves were being made to control recording of RTP in air traffic control
applications by means of RTSP; the sessions were to be set up by SIP,
but, rather than set up a new session for every radio transmission, the
session would remain open and the recordings demarcated by using RTSP,
thus avoiding the delay of setting up a new session and therefore missing
crucial fragments of audio. Hence it seemed possible that RTSP had got
into wider use with SIP.
RTSP is a misnomer as it's a control protocol, not a streaming protocol.
I just checked with Wikipedia to refresh my memory. But I guess they
couldn't call it RTCP because that name is already taken by the RTCP
part of RTP.