Re: [MMUSIC] Mirja Kühlewind's Discuss on draft-ietf-mmusic-sctp-sdp-23: (with DISCUSS)

Christer Holmberg <> Thu, 02 March 2017 10:28 UTC

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From: Christer Holmberg <>
To: Roman Shpount <>, Ben Campbell <>
Thread-Topic: =?windows-1254?Q?Mirja_K=FChlewind's_Discuss_on_draft-ietf-mmusic-sctp-sd?= =?windows-1254?Q?p-23:_(with_DISCUSS)?=
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Subject: Re: [MMUSIC] =?cp1254?q?Mirja_K=FChlewind=27s_Discuss_on_draft-ietf-m?= =?cp1254?q?music-sctp-sdp-23=3A_=28with_DISCUSS=29?=
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There may be some minor editorial nits, but in general I am ok with the pull request.



From: Roman Shpount <<>>
Date: Thursday 2 March 2017 at 07:25
To: Ben Campbell <<>>
Cc: Christer Holmberg <<>>, Mirja Kuehlewind <<>>, "<>" <<>>, Eric Rescorla <<>>, "<>" <<>>, Flemming Andreasen <<>>, "<>" <<>>, "<>" <<>>
Subject: Re: Mirja Kühlewind's Discuss on draft-ietf-mmusic-sctp-sdp-23: (with DISCUSS)


I have submitted the pull request to address these comments:

I hope that after Christer reviews and merges the pull request, we should have the latest set of comments addressed.

If we need more information about framing, I believe it should go into TCP/DTLS related draft, since all that draft-sctp-sdp is doing is reusing the same framing for exactly the same reasons.


Roman Shpount

On Wed, Mar 1, 2017 at 9:57 PM, Ben Campbell <<>> wrote:
Hi all,

It seems like this conversation has not completed. What do we need to get to closure?

A few thoughts of my own:

- I'm not adverse to making non-ICE implementors look at the ICE specs for framing information, as long as the citations are precise enough that they don't need to read the entirety of ICE. (And the information is really there.)

- I am adverse to repeating normative text. I'm okay with adding informational text about non-ICE usage, as long as it is general enough to avoid confusion about where the authoritative text resides.

- If people think that ICE is not sufficiently specified, we can work on that. But I don't think the burden of doing that belongs to this draft.

- The draft is in fact IESG approved in its current state. Material changes should be kept to the minimum.

On 27 Feb 2017, at 7:06, Christer Holmberg wrote:



Also I¹m not sure if the ICE part is fully specified. In your previously
mail you wrote

"As far as TCP/DTLS/SCTP transport tag is concerned, please note that ICE
end points are supposed to send a re-INVITE after nomination process is
completed with the selected candidate address in the m= line. So, if tcp
candidate is selected, re-INVITE must be sent with TCP/DTLS/SCTP
transport tag in the m= line. Also, any offers/answers after the ICE
nomination is complete, are supposed to send the currently selected
candidate in the m= line, which will also be TCP/DTLS/SCTP in case tcp
candidate is selected.³

>From what I understood from ekr, you might not in any case send an
re-invite; but maybe I understood this wrongly. I guess that could also
be further explained in the draft.

Ekr was talking about the specific re-INVITE that is sent directly after
ICE nomination. *Other* re-INVITEs can always be sent during the session.
But, that is not specific to this draft.