Hi Magnus,
The section 7.7, "RTSP URI extension" in this draft looks like saying an extension of RTSP request URI, while I understand that 5.3.3.1 of 3GPP TS26.234 just defines a special format of SDP a=control URI for 3GPP service.
Therefore, the possible revise would be:
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7.7. SDP a=control URI format
In 3GPP RTSP streaming session, a=control URI must have a track ID information. The value of a=control URI, stream identifiers must be expressed using the following syntax:
streamIdentifier = <stream-id-token>"="<stream-id>
stream-id-token = 1*alpha
stream-id = 1*digit
This stream-id must be equal to the value of track-ID field in the track header (tkhd) box associated with the media track of "3GP" file format [PSS-3GP].
When hinted track is used, embedded SDP must also follow this rule.
In 3GPP, streaming-server profile of 3GP format defines hinted track.
(See 5.3.3.1 of [PSS-234]).
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In generic RTSP streaming, we could use a free format, e.g. a=control:audio or a=control:video. But in 3GPP, a=control must contain trackID or streamID with '='. We understand this is the main point of this clause.