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Re: [rtcweb] Replacing a=extmap mapping in re-offer, is it legal?

Iñaki Baz Castillo <ibc@aliax.net> Mon, 07 August 2017 14:18 UTC

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From: Iñaki Baz Castillo <ibc@aliax.net>
Date: Mon, 07 Aug 2017 16:18:16 +0200
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To: Christer Holmberg <christer.holmberg@ericsson.com>
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Subject: Re: [rtcweb] Replacing a=extmap mapping in re-offer, is it legal?
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On Mon, Aug 7, 2017 at 4:10 PM, Christer Holmberg
<christer.holmberg@ericsson.com> wrote:
> My assumption is that it by default is always allowed to re-negotiate SDP attribute values. And, if it's not, it should be explicitly indicated.

SDP O/A is really error prune. This must end. It cannot happen that,
for every renegotiation (which may be it just wants to add/remove a
track) everything regarding ICE, DTLS, codecs. extmap, etc etc must be
re-inspected.


> You said that Chrome keeps the previously negotiated value. Does Chrome still accept the new offer?

AFAIR it does not complain, but it's hard to know whether Chrome keeps
the previously negotiated ext mapping or respects the new one, since
another "SDP O/A related bug" happens:

https://bugzilla.mozilla.org/show_bug.cgi?id=1247725


This is really crazy. I hope we can drop SDP from WebRTC soon. This is not sane.

-- 
Iñaki Baz Castillo
<ibc@aliax.net>

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