[rtcweb] Question about ICE-Lite server

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

Return-Path: <ibc@aliax.net>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 049AA1B28F8 for <rtcweb@ietfa.amsl.com>; Fri, 4 Jul 2014 06:15:34 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.678
X-Spam-Level:
X-Spam-Status: No, score=-1.678 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FM_FORGED_GMAIL=0.622, MIME_8BIT_HEADER=0.3, RCVD_IN_DNSWL_LOW=-0.7] autolearn=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id o9HagPLXARnX for <rtcweb@ietfa.amsl.com>; Fri, 4 Jul 2014 06:15:33 -0700 (PDT)
Received: from mail-qc0-f170.google.com (mail-qc0-f170.google.com [209.85.216.170]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id DE5621B2875 for <rtcweb@ietf.org>; Fri, 4 Jul 2014 06:15:32 -0700 (PDT)
Received: by mail-qc0-f170.google.com with SMTP id l6so1500049qcy.15 for <rtcweb@ietf.org>; Fri, 04 Jul 2014 06:15:32 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:from:date:message-id:subject:to :content-type:content-transfer-encoding; bh=5W4kVFJgnUEPcHB98mloMnAKoZUpFrdS0pzXM8+C7dg=; b=hdcMZoe4UYm9UVGO+jZI7MOIx5KSJuNyngSNpP/1X4o/hePcBdD3CzaSO5NoDXz2aw AtLrydrrYhpGikPPJVNtJkd5MLsC8Oi08Pvbs51YdI6YCf6DTgTziz8Wbx5b2USd0Fk7 ohlJBWKuoC6TdDV0r5jW8BQ0fwcT8Vm2zk6X8N7b473F6XdWKB6Vjss5f+jXtTicI6Wz kd2PHEq+bN6TJzVGujwmCqp0ZkJonHrsahZkuoBer+zYzDVMPslT1X/GuWBmhk0CgtwP ZOq7XyPr362hGjW1E5ypIsq9oVo2eVo1wbSQlxw0Su4pwHQQ8j29OUb6Bu09zV9grdq6 vrrw==
X-Gm-Message-State: ALoCoQkjFqZCty+7jRF1NrZCZnbStPITAB5U7mHjQa6AGmhcNfoT+wwAhWHO5RfeGsc8NxQeWcgP
X-Received: by 10.140.34.55 with SMTP id k52mr17346587qgk.13.1404479731577; Fri, 04 Jul 2014 06:15:31 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.96.234.131 with HTTP; Fri, 4 Jul 2014 06:15:11 -0700 (PDT)
From: Iñaki Baz Castillo <ibc@aliax.net>
Date: Fri, 04 Jul 2014 15:15:11 +0200
Message-ID: <CALiegf=kLtiUKoue=ahXP4fUhLJNNd8vCaQTECQxjK5R7cjLTQ@mail.gmail.com>
To: "rtcweb@ietf.org" <rtcweb@ietf.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: http://mailarchive.ietf.org/arch/msg/rtcweb/qP4aOHj5zSm34N94omWtUD5CJII
Subject: [rtcweb] Question about ICE-Lite server
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb/>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 04 Jul 2014 13:15:34 -0000

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>