Subject: [MMUSIC] Is ice-mismatch media or session level?

From: Roman Shpount <[email-masked]>
Date: Fri, 26 Apr 2019 16:48:59 -0400

Hi All,

This is another change related to
https://github.com/suhasHere/ice-sip-sdp/pull/1

RFC 5245 defined ice-mismatch as session level attribute. Draft ice-sip-sdp
changed it to media-level and rewrote some of the text that ICE mismatch
will occur per m= line. Considering that this is not a backwards compatible
change I have reverted this and changed ice-mismatch to session level.

Please let me know what you think.
_____________
Roman Shpount

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From: Christer Holmberg <[email-masked]>
Date: Sat, 27 Apr 2019 17:48:48 +0000

Hi,

Before we just change something back we need to think what the reason for the change to media-level was. Could it be related to RTCWEB?

Regards,

Christer

________________________________
From: mmusic <[email-masked]> on behalf of Roman Shpount <[email-masked]>
Sent: Friday, April 26, 2019 11:48 PM
To: mmusic WG
Subject: [MMUSIC] Is ice-mismatch media or session level?

Hi All,

This is another change related to  https://github.com/suhasHere/ice-sip-sdp/pull/1<https://protect2.fireeye.com/url?k=44a258ae-18287a47-44a21835-0cc47ad93e2e-9956334850115e5f&u=https://github.com/suhasHere/ice-sip-sdp/pull/1>

RFC 5245 defined ice-mismatch as session level attribute. Draft ice-sip-sdp changed it to media-level and rewrote some of the text that ICE mismatch will occur per m= line. Considering that this is not a backwards compatible change I have reverted this and changed ice-mismatch to session level.

---

From: Roman Shpount <[email-masked]>
Date: Mon, 29 Apr 2019 16:44:43 -0400

Hi Christer,

Thank you for reviewing and responding.

On Sat, Apr 27, 2019 at 1:48 PM Christer Holmberg <
[email-masked]> wrote:

> Before we just change something back we need to think what the reason for
> the change to media-level was. Could it be related to RTCWEB?
>
>
This is definitely not RTCWEB related, since RTCWEB should never generate
ice-mismatch or use it for any reason.

The ice-mismatch attribute was session only according to RFC 5245 Section
21.1.4 (https://tools.ietf.org/html/rfc5245#section-21.1.4). At the same
time, according to RFC 5245 Section 15.3 (
https://tools.ietf.org/html/rfc5245#section-15.3), ice-mismatch is media
level attribute only. This being said, according to RFC 5245 Section 6.1 (
https://tools.ietf.org/html/rfc5245#section-6.1), ice-mismatch applies to
the whole session, but it is specified per m= line. According to errata
3149 (https://www.rfc-editor.org/errata/eid3149), ice-mismatch should be
media level. So, it is a bit of a mess.

I can change ice-mismatch back to media level, but what we need to clarify
then is the following: If ice-mismatch is present in the m= line, does it
stop ICE processing for the whole session or for this m= line only?

If it stops ICE processing for the whole session then it makes little or no
sense being specified per m= line. If it only stops processing for specific
m= line, then ice-mismatch probably also makes sense at the session level
to stop ICE processing for the whole session.

I am definitely open to input here.
_____________
Roman Shpount