Comment 4 for bug 1182580

> Maybe VOIP-clients should have a slightly different protocol (similar
> to MRPIS2) that is tailored for all communication software. For
> example
> VOIP-clients do not generate "track changed" or "pause" events.
> VOIP-clients generate start/stop and call-title messages.

There are some statuses in SIP sessions like:
Call Paused (by peer)
Pause/Resume Call (paused by user)
Conference (connected to more than one peer) - "track changed"
Mute Call

I write it after observing Linphone.

Overhaul, I agree, VOIP-clients should indeed have a different protocol.