Subject: [siprec] Learning SessionIDs when a participant in a conference is acting as SRC

From: "Ram Mohan R (rmohanr)" <[email-masked]>
Date: Tue, 12 Jul 2016 17:19:25 +0000

Hi all,

Recently found the following gap in the SIPREC standards in the case of
Conference recording.

As mentioned in  Section 3.1.5 of [RFC7245], in case of conference it is
possible that Focus or a participant can be acting as SRC. Lets consider
the scenario where one of the participant in the conference is acting as
SRC and forking media to a SRS. As mentioned in the same section the
participant[SRC] may, for example, use the conference event package as
described in [RFC4575] to obtain information about other participants that
it provides to the SRS within the recording metadata.

Now SIPREC metadata (RFC7865) has SipSessionID as one of the parameters
that can be conveyed in the Metadata from SRC to SRS. In a conference
depending on the type/way by which the conference is setup the SessionIDs
can be different between each participant and Focus. Look at section 10.4
and 10.5 in 
https://datatracker.ietf.org/doc/draft-ietf-insipid-session-id/?include_tex
t=1.

Since the current Conference event package [RFC4575] has no way to convey
the list of sessionId tuples of a conference, the metadata carried from
SRC (participant in conference) to SRS does not contain these details.
This would cause problems w.r.t co-relation as the SRS would not have all
the IDs.

I would like to hear if any one has implemented conference recording and
have faced similar issue and if they have a way to fix this.

I do see it would be useful to carry SipSessionID in conference event
package so that the SRC which subscribes to the package can receive that
information and send in metadata. Does any one else thing there is a value
in having this ?

Regards,
Ram