Re: [MMUSIC] MMUSIC WG June 17th virtual interim agenda

Flemming Andreasen <> Fri, 14 June 2013 21:16 UTC

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Date: Fri, 14 Jun 2013 17:15:55 -0400
From: Flemming Andreasen <>
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Cc: Ari Keränen <>, mmusic <>
Subject: Re: [MMUSIC] MMUSIC WG June 17th virtual interim agenda
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On 6/14/13 4:53 PM, Emil Ivov wrote:
> Hey Flemming,
> On 14.06.13, 22:00, Flemming Andreasen wrote:
>> Hi Emil
>> Per some of the previous discussion threads (see e.g.
>> there is clearly some ambiguity around exactly what an m-line conveys,
>> both with and without bundle. This lack of clarity potentially affects
>> all of the different plan proposals as well as as 4566bis,  and as such
>> is an entirely reasonable discussion to have in MMUSIC.
> OK, so doesn't this mean all plans should be given equal time to 
> discuss their take on this issue?
I don't believe it is or should be a plan-specific discussion, so no.

>> To the extent
>> that resolution of this impacts progress on the Plan A versus Plan B
>> discussion, it is also an appropropriate discussion to have next week.
> Sorry, I am confused again. No Plan, Plan A and Plan B demonstrate 
> versions of SDP that can be used in multi-stream scenarios. Yet, for 
> some reason we will only be discussing the validity of Plan A and Plan 
> B's approaches.
> Could you please explain why that is?
Because "no plan" doesn't seem to be asking MMUSIC to do anything and 
when we clarified with the RTCWeb chairs whether "no plan" should be in 
scope for the MMUSIC interim meeting discussion the answer was no; that 
part of the discussion belongs in RTCWeb. If you want to argue against 
that, you need to do so on the RTCWeb list with the RTCWeb chairs.

> The only explanation I could find was that No Plan's SDP usage was too 
> obvious and valid and there wasn't anything to discuss about it.
> Just to be clear: we have been using a No Plan-like approach for Jitsi 
> video conferencing for quite a long time now. I believe other popular 
> vendors of conferencing solutions have been doing the same.

Ok. This is all part of an entirely reasonable discussion to have, but 
currently, it should be taking place on the RTCWeb mailing list. As 
noted previously (by Ted I believe) it may also be helpful to split the 
"no plan" draft in two; an MMUSIC specific portion with 
asks/clarifications for MMUSIC and an RTCWeb specific part.


-- Flemming

> Cheers,
> Emil
>> What is not appropriate at this time however is to turn that into a
>> discussion of choosing "no plan" for RTCWeb since MMUSIC cannot (and
>> should not) make that decision (as clarified by the RTCWeb chairs as 
>> well).
>> Thanks
>> -- Flemming
>> On 6/14/13 3:33 PM, Emil Ivov wrote:
>>> On 14.06.13, 21:10, Ari Keränen wrote:
>>>> On 6/14/13 10:02 PM, Emil Ivov wrote:
>>>>> On 14.06.13, 20:20, Ari Keränen wrote:
>>>>>> Hi all,
>>>>>> Given the guidance from the RTCWEB WG chairs that the "no-plan"
>>>>>> discussion should essentially happen at the RTCWEB WG, the MMUSIC
>>>>>> interim meeting on June 17th will be focused on Plan A and Plan B.
>>>>> I assume this implies that MMUSIC considers it entirely 
>>>>> appropriate to
>>>>> use SDP for signalling multiple streams the way No Plan suggests 
>>>>> (i.e.
>>>>> one m= line can carry as many RTP flows as it likes). So much so, 
>>>>> that
>>>>> no further discussion is necessary on the subject.
>>>>> Could you please confirm that I am reading this properly?
>>>> This means that the interim time should be used mainly to discuss 
>>>> plan A
>>>> vs plan B merits, not whether RTCWEB should use A/B, or no-plan.
>>> Sure. I get this and I find it very reasonable.
>>> However, just as Plans A and B, No Plan says: here's an SDP that you
>>> can use when doing multiple streams.
>>> So, I just want to confirm that we will not be discussing the SDP
>>> sides of the proposal in No Plan because they make perfect sense from
>>> an MMUSIC point of view and no discussion is really necessary. It'll
>>> be up to other working groups to decide whether they'd like to use
>>> that particular (and valid) approach.
>>> Emil