Re: [rtcweb] JSEP-04: Nits and niggles

Justin Uberti <juberti@google.com> Fri, 27 September 2013 17:34 UTC

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From: Justin Uberti <juberti@google.com>
Date: Fri, 27 Sep 2013 10:34:05 -0700
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To: Harald Alvestrand <harald@alvestrand.no>
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Subject: Re: [rtcweb] JSEP-04: Nits and niggles
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Thanks for these comments. Agree with your suggestions, will fix in the
next version.


On Thu, Sep 19, 2013 at 3:19 PM, Harald Alvestrand <harald@alvestrand.no>wrote:

>  On 09/19/2013 10:55 PM, Suhas Nandakumar wrote:
>
>  Regarding a=ssrc comment above,
> The text from RFC5576 says this
>
>  Each "ssrc" media attribute specifies a single source-level attribute
>    for the given <ssrc-id>.  For each source mentioned in SDP, the
>    source-level attribute "cname", defined in Section 6.1 <http://tools.ietf.org/html/rfc5576#section-6.1>, MUST be
>    provided.  Any number of other source-level attributes for the source
>    MAY also be provided.
>
>  given the above, would it be cname attribute for a given ssrc that should be mandated at the minimum ?
>
>
> Thanks, that makes sense to me. Updating JSEP to say "add a line with
> a=ssrc cname=<cname>" sounds like something that does what we want and is
> consistent with 5576.
>
>
>  Cheers
>
> Suhas
>
>
>
> On Thu, Sep 19, 2013 at 5:54 AM, Harald Alvestrand <harald@alvestrand.no>wrote:
>
>> I'm sure we'll have lots of things to discuss about JSEP. I just thought
>> I'd get these out of the way.
>>
>> - Usage of MSID. In addition to the a=msid: lines, the session-level
>> generation procedure needs to say that a line "a=msid-semantic:WMS <id>" is
>> added to the session-level description, containing the IDs of the
>> MediaStreams that are signalled.
>>
>> - a=ssrc lines. The spec (5.2.1 second list last bullet) simply says "an
>> a=ssrc line". But RFC 5576 specifies that all ssrc lines contain an
>> attribute. Suggestion: define one that does no harm (role=primary?)
>>
>> - recycling of m= lines. The section in 5.2.2 (subsequent offers) that
>> talks about this doesn't mention that the media in the m-line has to match,
>> although section 5.3.1 (initial answer) actually talks about it. I'm
>> assuming that's an oversight.
>>
>> I'd suggest pulling the language about "selecting an appropriate m-line
>> for a track" out in a separate subsection, so that we have one place to
>> point to for this.
>>
>> Out of time, let's get these ones out of the way for -05....
>>
>>
>>
>> _______________________________________________
>> rtcweb mailing list
>> rtcweb@ietf.org
>> https://www.ietf.org/mailman/listinfo/rtcweb
>>
>
>
>
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