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Re: [MMUSIC] Faster ICE by role reversal?

Martin Thomson <martin.thomson@gmail.com> Wed, 30 July 2014 23:00 UTC

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Date: Wed, 30 Jul 2014 16:00:09 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Jonathan Lennox <jonathan@vidyo.com>
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Cc: mmusic <mmusic@ietf.org>
Subject: Re: [MMUSIC] Faster ICE by role reversal?
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On 30 July 2014 15:56, Jonathan Lennox <jonathan@vidyo.com> wrote:
> The offerer can’t send its own connectivity checks until it receives an answer, because it needs the remote ufrag and password.  Without this, it doesn’t have any valid pairs, and so can’t send any media.

Of course.  But you could do all the computation necessary for
generating the ServerHello and accompanying messages (which in TLS 1.3
is quite a bit).

> This suggestion might still save half an RTT, though? I’d need to work through a full ladder diagram to figure it out.

That's the idea.  I haven't plotted it all out either, but I think
that this is the fastest possible start assuming that you don't send
any DTLS messages prior to getting a successful connectivity check
response.

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