Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcweb-signaling - More-coming and final answer (Section 5.2.3)

Cullen Jennings <fluffy@cisco.com> Thu, 20 October 2011 00:41 UTC

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From: Cullen Jennings <fluffy@cisco.com>
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Date: Wed, 19 Oct 2011 18:41:30 -0600
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To: Christer Holmberg <christer.holmberg@ericsson.com>
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Cc: Jonathan Rosenberg <jonathan.rosenberg@skype.net>, "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcweb-signaling - More-coming and final answer (Section 5.2.3)
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all good questions and I should clarify in the draft … inline

On Oct 19, 2011, at 7:06 , Christer Holmberg wrote:

> 
> Hi,
> 
> A couple of questions regarding the usage of the more-coming flag:
> 
> Q1. If one sends an ANSWER with the more-coming flag set to 'true', is it allowed to later send *additional* ANSWER(s) with the flag set to 'true' (before sending the final ANSWER)?

Yes 
> 
> Q2. Are there restrictions when it comes to changing information in a non-final answer and a final answer? Or, can the final answer be completely different from previously sent non-final ANSWERS? In "legacy" O/A there are restrictions.

Any answer has to be a valid answer for the offer but other than that, no restrictions, so the final answer can change everything from an earlier one. 

> 
> Q3. Must the answerer wait for OK for a non-final ANSWER before sending a new ANSWER (non-final or final)?

hmm - not sure :-)  I think the answer to needs to be yes but we should think about this and work through the design choices. 

> 
> Q4. If the answer to Q3 is "no", how does the answerer know to which ANSWER an OK message applies? AFAIK, the seq/sessionId values are identical for all ANSWERs associated with a specific OFFER.
> 
> Q5. The text says, that while the OFFER is "open", ie a final ANSWER has not been sent, the answerer is not allowed to send an OFFER. I assume that also applies to the offerer, ie it is not allowed to send a new OFFER until it has received a final ANSWER - even if it has received one or more non-final ANSWERs. Maybe it's obvious, but I think it would be good to explictily add some text about that (if my assumption is correct, that is :).

yes - agree. 
 
> 
> 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. 
>> 
>> 
>> _______________________________________________
>> rtcweb mailing list
>> rtcweb@ietf.org
>> https://www.ietf.org/mailman/listinfo/rtcweb