Re: [MMUSIC] New Version Notification for draft-wing-mmusic-ice-mobility-01.txt

Emil Ivov <emcho@jitsi.org> Mon, 17 September 2012 17:09 UTC

Return-Path: <emil@sip-communicator.org>
X-Original-To: mmusic@ietfa.amsl.com
Delivered-To: mmusic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A2EC621F8723 for <mmusic@ietfa.amsl.com>; Mon, 17 Sep 2012 10:09:07 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.249
X-Spam-Level:
X-Spam-Status: No, score=-3.249 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, HELO_EQ_FR=0.35, RCVD_IN_DNSWL_LOW=-1]
Received: from mail.ietf.org ([64.170.98.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id p5-8eRYaP+K4 for <mmusic@ietfa.amsl.com>; Mon, 17 Sep 2012 10:09:06 -0700 (PDT)
Received: from mail-wi0-f172.google.com (mail-wi0-f172.google.com [209.85.212.172]) by ietfa.amsl.com (Postfix) with ESMTP id 417F521F86E4 for <mmusic@ietf.org>; Mon, 17 Sep 2012 10:09:06 -0700 (PDT)
Received: by wibhi8 with SMTP id hi8so2246163wib.13 for <mmusic@ietf.org>; Mon, 17 Sep 2012 10:09:05 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=message-id:date:from:organization:user-agent:mime-version:to:cc :subject:references:in-reply-to:content-type :content-transfer-encoding:x-gm-message-state; bh=g/UuI5fKcRr8k5bH79DKjf6gb/Idn9JeLZoURlxIwH4=; b=eTSflDoqRBCjpnMsONtK9GLiJvmRL593la1dyvtYE6dTDogmbH90zzXm+QFIZkX0To bbMKfVElpsYnHcqboPKR4wzzSmXquQKVRYFm2NqoLyX27z0FlirY8CStP6cVmnsvTmyK j8auqT7bTnx72SVrf+fVR7izOrahNYRbJZhicb5IweQbk7+vUjthMPzD/YsDMAdsRvTK Hv29fX9TkiSyvocj6QDjYnAchyPEmee5aVgWnGx7qIxc5Kc520CBOWZVB9prx5XTYQzg DKwjgFmwNjhY7/K3PjXpLYOAZT5H+w+n20M3uZv+4gfQIbEbaKDiEvbuIgTFf3FfDYiK BQsg==
Received: by 10.216.136.227 with SMTP id w77mr5921703wei.111.1347901745207; Mon, 17 Sep 2012 10:09:05 -0700 (PDT)
Received: from pastropnet.u-strasbg.fr (pastropnet.u-strasbg.fr. [130.79.90.87]) by mx.google.com with ESMTPS id do5sm27086621wib.10.2012.09.17.10.09.01 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 17 Sep 2012 10:09:03 -0700 (PDT)
Message-ID: <5057592B.9070904@jitsi.org>
Date: Mon, 17 Sep 2012 19:08:59 +0200
From: Emil Ivov <emcho@jitsi.org>
Organization: Jitsi
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:14.0) Gecko/20120713 Thunderbird/14.0
MIME-Version: 1.0
To: "Tirumaleswar Reddy (tireddy)" <tireddy@cisco.com>
References: <913383AAA69FF945B8F946018B75898A052D666F@xmb-rcd-x10.cisco.com> <5051A76A.7090606@jitsi.org> <913383AAA69FF945B8F946018B75898A147AA88C@xmb-rcd-x10.cisco.com>
In-Reply-To: <913383AAA69FF945B8F946018B75898A147AA88C@xmb-rcd-x10.cisco.com>
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7bit
X-Gm-Message-State: ALoCoQmD/LCROStzHYt1OMHVncsVpZIBQrz08ShLg2IqY8emqqXT7biBIP7Bp6mWRwPm0tnnqcgJ
Cc: "Prashanth Patil (praspati)" <praspati@cisco.com>, "mmusic@ietf.org" <mmusic@ietf.org>, "Dan Wing (dwing)" <dwing@cisco.com>
Subject: Re: [MMUSIC] New Version Notification for draft-wing-mmusic-ice-mobility-01.txt
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Multiparty Multimedia Session Control Working Group <mmusic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mmusic>, <mailto:mmusic-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/mmusic>
List-Post: <mailto:mmusic@ietf.org>
List-Help: <mailto:mmusic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mmusic>, <mailto:mmusic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 17 Sep 2012 17:09:07 -0000

Hey Tiru,

On 17.09.12, 18:47, Tirumaleswar Reddy (tireddy) wrote:
> Hi Emil -
>  
> Thanks for the comments. we are in the process of updating the draft -
>  
> We are planning to add the high-lighted sentence in Introduction, please
> let us know if you have any further comments.
>  
> Although ICE does allow an "ICE restart", this is done by sending a
> re-INVITE which goes over the SIP signaling path. The SIP signaling path
> is often slower than the media path (which needs to be recovered as
> quickly as possible), consumes an extra half round trip, and incurs an
> additional delay if the mobility event forces the endpoint to re-connect
> with its SIP proxy. *When a device changes its IP address, it is
> necessary for it to re-establish connectivity with its SIP proxy, which
> can be performed in parallel with the steps described in this document.*
> This document describes how mobility is performed entirely in the media
> path, without the additional delay of re-establishing SIP connectivity,
> issuing a new offer/answer, or the complications of multiple SIP offers.
> This document considers re-establishing bi-directional media the most
> critical aspect of a successful mobility event, and its efforts are
> towards meeting that goal.
>  
> We will also added the following text at the end of section 3.1
>  
> *The Mobile device would also in parallel re-establish connection with
> the SIP proxy and if the ICE connectivity checks in the previous steps
> are not successful then issues new offer/answer and restarts ICE.*

The above statement implies that the mobile node would need to first
declare failure of ICE mobility and only then would it try an ICE
restart. Yet, declaring failure would take many seconds with the default
STUN timers so as a result handover latency is probably going to worsen
more often than not.

Besides, even in cases where ICE mobility succeeds, an ICE restart could
still allow the use of higher priority candidates.

Wouldn't it make more sense to always perform an ICE restart in parallel
and basically consider ICE mobility a best effort attempt to shorten
handover latency?

Emil
--
https://jitsi.org
>  
> --Tiru.
>  
>> -----Original Message-----
>> From: Emil Ivov [mailto:emcho@jitsi.org]
>> Sent: Thursday, September 13, 2012 2:59 PM
>> To: Tirumaleswar Reddy (tireddy)
>> Cc: mmusic@ietf.org
>> Subject: Re: [MMUSIC] New Version Notification for draft-wing-mmusic-ice-
>> mobility-01.txt
>> 
>> Hey Tiru,
>> 
>> One thing that I think this document is not very clear about is its
>> relationship to standard mobility handling (i.e. through ICE restart).
>> 
>> As far as I can see, ICE restart is only mentioned when describing its
>> inefficiency.
>> 
>> You did confirm in Vancouver that ICE Mobility is only meant as an
>> optimisation that would only take place until the ICE restart completes
>> but I don't see it anywhere in the text. Or am I missing something?
>> 
>> Cheers,
>> Emil
>> 
>> On 20.07.12, 13:36, Tirumaleswar Reddy (tireddy) wrote:
>> > Hi all,
>> >
>> > Dan, Prashanth and I have submitted a draft that explains how
>> > endpoint mobility can be achieved using ICE.  Two mechanisms are
>> > shown, one where both endpoints support ICE and another where only
>> > one endpoint supports ICE. When only one endpoint supports ICE, a
>> > TURN server provides mobility.
>> >
>> > _http://www.ietf.org/internet-drafts/draft-wing-mmusic-ice-mobility-01.txt_
>> >
>> >  Please let know your comments. If time permits we'd present the
>> > draft in Vancouver.
>> >
>> > Regards, Tiru.
>> >
>> >> -----Original Message----- From: Tirumaleswar Reddy (tireddy) Sent:
>> >> Friday, July 20, 2012 3:18 PM To: _mmusic@ietf.org_ <mailto:mmusic@ietf.org> Subject: FW: New
>> >> Version Notification for draft-wing-mmusic-ice- mobility-01.txt
>> >>
>> >> -----Original Message----- From: _internet-drafts@ietf.org_ <mailto:internet-drafts@ietf.org>
>> >> _[mailto:internet-drafts@ietf.org]_
> <mailto:[mailto:internet-drafts@ietf.org]> Sent: Tuesday, July 17, 2012 3:52
>> >> AM To: Dan Wing (dwing) Cc: Prashanth Patil (praspati);
>> >> Tirumaleswar Reddy (tireddy) Subject: New Version Notification for
>> >> draft-wing-mmusic-ice-mobility- 01.txt
>> >>
>> >>
>> >> A new version of I-D, draft-wing-mmusic-ice-mobility-01.txt has
>> >> been successfully submitted by Dan Wing and posted to the IETF
>> >> repository.
>> >>
>> >> Filename:   draft-wing-mmusic-ice-mobility Revision:         01 Title:
>> >> Mobility with ICE (MICE) Creation date:     2012-07-16 WG ID:
>> >> Individual Submission Number of pages: 12 URL:
>> >> _http://www.ietf.org/internet-drafts/draft-wing-mmusic-_
>> >> ice-mobility-01.txt Status:
>> >> _http://datatracker.ietf.org/doc/draft-wing-mmusic-ice-_ mobility
>> >> Htmlized:        _http://tools.ietf.org/html/draft-wing-mmusic-ice-_
>> >> mobility-01 Diff:
>> >> _http://tools.ietf.org/rfcdiff?url2=draft-wing-mmusic-_
>> >> ice-mobility-01
>> >>
>> >> Abstract: This specification describes how endpoint mobility can be
>> >> achieved using ICE.  Two mechanisms are shown, one where both
>> >> endpoints support ICE and another where only one endpoint supports
>> >> ICE.
>> >>
>> >>
>> >>
>> >>
>> >> The IETF Secretariat
>> > _______________________________________________ mmusic mailing list
>> > _mmusic@ietf.org_ <mailto:mmusic@ietf.org>
> _https://www.ietf.org/mailman/listinfo/mmusic_
>> >