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Re: [rtcweb] Proposal for dealing with CNAMEs and MSIDs for synchronization

"Charles Eckel (eckelcu)" <eckelcu@cisco.com> Thu, 07 February 2013 20:08 UTC

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From: "Charles Eckel (eckelcu)" <eckelcu@cisco.com>
To: Eric Rescorla <ekr@rtfm.com>, Stefan Hakansson LK <stefan.lk.hakansson@ericsson.com>
Thread-Topic: [rtcweb] Proposal for dealing with CNAMEs and MSIDs for synchronization
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Date: Thu, 07 Feb 2013 20:08:49 +0000
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Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] Proposal for dealing with CNAMEs and MSIDs for synchronization
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> -----Original Message-----
> From: rtcweb-bounces@ietf.org [mailto:rtcweb-bounces@ietf.org] On
> Behalf Of Eric Rescorla
> Sent: Thursday, February 07, 2013 3:03 PM
> To: Stefan Hakansson LK
> Cc: rtcweb@ietf.org
> Subject: Re: [rtcweb] Proposal for dealing with CNAMEs and MSIDs for
> synchronization
> 
> 
> 
> On Thu, Feb 7, 2013 at 11:59 AM, Stefan Hakansson LK
> <stefan.lk.hakansson@ericsson.com> wrote:
> 
> 
> 	On 02/07/2013 08:43 PM, Eric Rescorla wrote:
> 
> 
> 
> 
> 
> 
> 		    My question is basically: what if the sender creates two
> 		    MediaStreams for which all tracks have local sources
> (cam's,
> 		    mike's), sends them to a peer, will the RTP streams for
> both
> 		    MediaStreams have the same or different CNAME?
> 
> 		    I argued for that they should have the same.
> 
> 
> 		Yes, I think this is a separate (and fraught) question. :)
> 
> 
> 
> 	Separate question, but I think the answer should be documented
> (regardless on if it is "same", "different" or "implementers choice").
> 
> 
> 
> Agreed.

I think SHOULD is the correct thing to document. I can imagine there will be cases in which the sender will be a somewhat distributed app that does not really know that the media source should be synchronized, so it will assign a different CNAME.
The rest of the proposal sounded good as well.

Cheers,
Charles
 
> -Ekr
> 
> 
> 
> 		-Ekr
> 
> 
> 		        4. There are two ways for MSID and CNAME to be
> inconsistent.
> 		        - If MSID indicates synchronization but different CNAMEs
> are
> 		        provided,
> 		            synchronization is not attempted.
> 		        - If MSID indicates no synchronization but the same
> CNAME is used,
> 		            then the tracks shall be synchronized, even though
> they
> 		        appear in
> 		            different MediaStreams.
> 
> 		        -Ekr
> 
> 
> 
> 
> 		        _________________________________________________
> 		        rtcweb mailing list
> 		        rtcweb@ietf.org <mailto:rtcweb@ietf.org>
> 		        https://www.ietf.org/mailman/__listinfo/rtcweb
> <https://www.ietf.org/mailman/__listinfo/rtcweb>
> 		        <https://www.ietf.org/mailman/listinfo/rtcweb
> <https://www.ietf.org/mailman/listinfo/rtcweb> >
> 
> 
> 		    _________________________________________________
> 		    rtcweb mailing list
> 		    rtcweb@ietf.org <mailto:rtcweb@ietf.org>
> 		    https://www.ietf.org/mailman/__listinfo/rtcweb
> <https://www.ietf.org/mailman/__listinfo/rtcweb>
> 		    <https://www.ietf.org/mailman/listinfo/rtcweb
> <https://www.ietf.org/mailman/listinfo/rtcweb> >
> 
> 
> 
> 
>

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