Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcweb-signaling - seq/sessionId vs sess-version/sess-id (Section 5.2.1 and 5.2.2)

Christer Holmberg <christer.holmberg@ericsson.com> Wed, 19 October 2011 12:49 UTC

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From: Christer Holmberg <christer.holmberg@ericsson.com>
To: Cullen Jennings <fluffy@cisco.com>, "rtcweb@ietf.org" <rtcweb@ietf.org>, "public-webrtc@w3.org" <public-webrtc@w3.org>
Date: Wed, 19 Oct 2011 14:49:44 +0200
Thread-Topic: [rtcweb] SDP Offer/Answer draft-jennings-rtcweb-signaling - seq/sessionId vs sess-version/sess-id (Section 5.2.1 and 5.2.2)
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Cc: Jonathan Rosenberg <jonathan.rosenberg@skype.net>
Subject: Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcweb-signaling - seq/sessionId vs sess-version/sess-id (Section 5.2.1 and 5.2.2)
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Hi,

What is the relation between the seq/sessionId values and the SDP sess-version/sess-id values (part of the SDP o= line), and why do we need seq/sessionId in the first place?

AFAIK, the only reason for having the seq/sessionId values is when sending an OK message, since there will be no SDP (and therefor no SDP sess-version/sessionId). Or, are there any other reasons?

I think the draft should say something about the correlation.

And, IF we need seq/sessionId, should we say that the SDP sess-version/sess-id values must be identical - or, at least saying that they must be set and incremented according to the SDP rules? I think that would help in SIP/SDP interworking cases. Otherwise the interworking gateway will have to check, keep track of, and possibly modify, the sess-version/sess-id values.

Regards,

Christer






> -----Original Message-----
> From: rtcweb-bounces@ietf.org 
> [mailto:rtcweb-bounces@ietf.org] On Behalf Of Cullen Jennings
> Sent: 15. lokakuuta 2011 6:09
> To: rtcweb@ietf.org; public-webrtc@w3.org
> Cc: Jonathan Rosenberg
> Subject: [rtcweb] SDP Offer/Answer draft-jennings-rtcweb-signaling
> 
> 
> Jonathan and I submitted a new draft on setting up media 
> based on the SDP Offer/Answer model. The ASCII flows are a 
> bit hard to read so until I update them, I recommend reading 
> the PDF version at 
> 
> http://tools.ietf.org/pdf/draft-jennings-rtcweb-signaling-00.pdf
> 
> Clearly the draft is an early stage but we plan to revise it 
> before the deadline for the IETF 82. Love to get input - 
> particularly on if this looks like generally the right 
> direction to go. 
> 
> 
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