Re: [rtcweb] draft-ietf-rtcweb-use-cases-and-requirements-05 addition around IPv6 only and dualstack

Harald Alvestrand <harald@alvestrand.no> Mon, 26 September 2011 09:55 UTC

Return-Path: <harald@alvestrand.no>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E649221F8B57 for <rtcweb@ietfa.amsl.com>; Mon, 26 Sep 2011 02:55:02 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -108.915
X-Spam-Level:
X-Spam-Status: No, score=-108.915 tagged_above=-999 required=5 tests=[AWL=1.684, BAYES_00=-2.599, RCVD_IN_DNSWL_HI=-8, USER_IN_WHITELIST=-100]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id QCPo5WAGHNX4 for <rtcweb@ietfa.amsl.com>; Mon, 26 Sep 2011 02:55:02 -0700 (PDT)
Received: from eikenes.alvestrand.no (eikenes.alvestrand.no [158.38.152.233]) by ietfa.amsl.com (Postfix) with ESMTP id F165921F8B40 for <rtcweb@ietf.org>; Mon, 26 Sep 2011 02:55:01 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1]) by eikenes.alvestrand.no (Postfix) with ESMTP id DD5C839E112; Mon, 26 Sep 2011 11:57:43 +0200 (CEST)
X-Virus-Scanned: Debian amavisd-new at eikenes.alvestrand.no
Received: from eikenes.alvestrand.no ([127.0.0.1]) by localhost (eikenes.alvestrand.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qOgTFURTE3+F; Mon, 26 Sep 2011 11:57:43 +0200 (CEST)
Received: from hta-dell.lul.corp.google.com (62-20-124-50.customer.telia.com [62.20.124.50]) by eikenes.alvestrand.no (Postfix) with ESMTPS id 2CFB939E048; Mon, 26 Sep 2011 11:57:43 +0200 (CEST)
Message-ID: <4E804C96.1090701@alvestrand.no>
Date: Mon, 26 Sep 2011 11:57:42 +0200
From: Harald Alvestrand <harald@alvestrand.no>
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.21) Gecko/20110831 Thunderbird/3.1.13
MIME-Version: 1.0
To: Magnus Westerlund <magnus.westerlund@ericsson.com>
References: <4E801CFE.4030504@ericsson.com>
In-Reply-To: <4E801CFE.4030504@ericsson.com>
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 8bit
Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] draft-ietf-rtcweb-use-cases-and-requirements-05 addition around IPv6 only and dualstack
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.12
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: Mon, 26 Sep 2011 09:55:03 -0000

On 09/26/11 08:34, Magnus Westerlund wrote:
> Hi,
>
> (as individual)
>
> I would suggest that some section for general requirements that aren't
> use case specific is created and at least one such requirement is added.
>
> The requirement is the need to support IPv4 only, IPv6 only and
> dual-stack deployments as required by our charter. I think this should
> be added into the use-case and requirement document for two reasons.
> First, that is located next to the other requirements, secondly because
> W3C has decided to use our document also, I think it is important that
> such a general requirement both on protocols and any address field in
> the API handling both address families are covered.
I support adding those requirements.

I think that it can also be instantiated within the specific use cases, 
such as:
- Point to point call: One endpoint on IPv4, the other endpoint on IPv6
- Multipoint call (with and without central server): One user on IPv4, 
one user on IPv6

This is a limitation of the use-case-based model; it gets messy to 
shoehorn all the "permutations" of situations into a single set of use 
cases, without the list of use cases growing impossibly long or the use 
cases' description expanding into incomprehensibility.

On balance, I think having a "considerations applicable to all 
scenarios" section saying:

- Clients can be on IPv4-only
- Clients can be on IPv6-only
- Clients can be on dual-stack
- Clients can be on wideband (10s of Mbits/sec)
- Clients can be on narrowband (10s to 100s of Kbits/sec)
- Clients can be on variable-media-quality networks (wireless)
- Clients can be on congested networks
- Clients can be on firewalled networks with no UDP allowed
- Clients can be on networks with cone NAT
- Clients can be on networks with symmetric NAT

might be a good way to go forward.

A particular query on v4/v6 interoperation: Should we make it a 
requirement that dual-stack to IPv4 always use the IPv4 native path 
rather than a gateway functionality (and the converse for IPv6), or 
should we just be silent about it?
I think it may affect some tuning of the ICE address selection 
algorithm, in particular if we encounter 6to4 addresses. There might be 
RFCs we can cite already.


> Cheers
>
> Magnus Westerlund
>
> ----------------------------------------------------------------------
> Multimedia Technologies, Ericsson Research EAB/TVM
> ----------------------------------------------------------------------
> Ericsson AB                | Phone  +46 10 7148287
> Färögatan 6                | Mobile +46 73 0949079
> SE-164 80 Stockholm, Sweden| mailto: magnus.westerlund@ericsson.com
> ----------------------------------------------------------------------
>
> _______________________________________________
> rtcweb mailing list
> rtcweb@ietf.org
> https://www.ietf.org/mailman/listinfo/rtcweb
>