Re: [rtcweb] No Plan - but what's the proposal

Emil Ivov <> Wed, 05 June 2013 15:21 UTC

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Date: Wed, 05 Jun 2013 17:21:40 +0200
From: Emil Ivov <>
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To: Cullen Jennings <>
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Subject: Re: [rtcweb] No Plan - but what's the proposal
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On 05.06.13, 02:40, Cullen Jennings wrote:
> On Jun 4, 2013, at 4:07 AM, Iñaki Baz Castillo <>
> wrote:
>> 2013/6/3 Emil Ivov <>rg>:
>>>>> We create an offer that would describe the media types and
>>>>> the bundle. We use that offer to also describe capabilities
>>>>> in terms of maximum resolutions, supported header extensions,
>>>>> potentially max-ssrc-s, etc.
>>>>> It is up to the application how to handle the rest. If it
>>>>> needs to transmit additional signalling: let it. If it wants
>>>>> to encode that in SDP, great. If it wants to attach it in
>>>>> JSON next to the browser generated SDP, that also works.
>>>> Great - I have super news for you. The WG agree to do that a
>>>> year or more ago.
>>> So I've heard indeed.
>>> Unfortunately however, it seems that we might have forgotten this
>>> decision. We are now trying hard to come up with a signalling
>>> mechanism that will do everything with Offer/Answer.
>> I think there is a misunderstanding here. I understand from Emil's
>> mail that media re-negotation or streams addition after the first
>> SDP O/A is not carried as a new full SDP O/A. Am I right?
> I'm just trying to understand what the "No Plan" proposal is. I have
> not even started to think about what parts of if I like. So far, the
> more we talk about this, the more confused I get. I think some simple
> examples that showed what O/A got passed across the API from the JS
> into the browser for applications with multiple video steams would
> really help.

Then, in case you've missed any of these:

You asked how Plan A endpoints would work with No Plan browsers here:

The reply, with sample SDP went here:

You then moved the thread to MMUSIC and asked to see the answer here:

In the above you also asked how the answerer could refuse one video 
stream. I replied with the SDP answer and additional sample signalling here:

I don't think I've seen any additional questions from you since then.You 
are now saying that the situation is still unclear, so please let me 
know if I can help in any way. Otherwise we could also switch to 
whatever problems you have with the approach itself.

In the mean time, again on MMUSIC, Eric has asked for more detailed 
examples including sample JS code here:

Enrico has put up a very helpful and very complete example to this here:

I added a nit here: