[rtcweb] Question about ICE-Lite server

Iñaki Baz Castillo <ibc@aliax.net> Fri, 04 July 2014 13:15 UTC

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From: =?UTF-8?Q?I=C3=B1aki_Baz_Castillo?= <ibc@aliax.net>
Date: Fri, 4 Jul 2014 15:15:11 +0200
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To: "rtcweb@ietf.org" <rtcweb@ietf.org>
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Subject: [rtcweb] Question about ICE-Lite server
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Hi,

In case of aggressive ICE the controlling agent (let's say: the
client), and assuming the client has IPv4 and IPv6 and the ICE-Lite
server as well, the server will receive multiple STUN Requests with
USE-CANDIDATE and will decide which one to select based on computed
candidate-pair priorities (so both the client and server select the
same as they follow the same algorithm).

Now my question is: let's assume that the server is just provided with
local ICE username and password, but knows nothing about the fields in
ICE candidates (let's assume that the SDP is negotiated by other
entity which does not notify the media server about ICE candidate
parameters others than local username and password).

So the media server just knows its local ICE username and password,
but it receives a ICE Request with USE-CANDIDATE on the IPv4 interface
and another on the IPv6 interface.

Can the ICE server determine which pair to select (the IPv4 or the
IPv6) by just inspecting the PRIORITY attribute in both STUN Requests
and select the one with highest value?

Or does the server need to assign priority, component and all the ICE
stuff to its interfaces and also be provided with the client's and its
own ICE candidates?

Thanks a lot.

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