[Softwires] New version of 4rd-U - with plain Encapsulation as a variant

Rémi Després <despres.remi@laposte.net> Sat, 28 January 2012 17:59 UTC

Return-Path: <despres.remi@laposte.net>
X-Original-To: softwires@ietfa.amsl.com
Delivered-To: softwires@ietfa.amsl.com
Received: from localhost (localhost []) by ietfa.amsl.com (Postfix) with ESMTP id A7AC021F84EA for <softwires@ietfa.amsl.com>; Sat, 28 Jan 2012 09:59:46 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.3
X-Spam-Status: No, score=-2.3 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, MIME_8BIT_HEADER=0.3, NO_RELAYS=-0.001]
Received: from mail.ietf.org ([]) by localhost (ietfa.amsl.com []) (amavisd-new, port 10024) with ESMTP id 5GzoQA1YkmRi for <softwires@ietfa.amsl.com>; Sat, 28 Jan 2012 09:59:46 -0800 (PST)
Received: from smtp1-g21.free.fr (smtp1-g21.free.fr [IPv6:2a01:e0c:1:1599::10]) by ietfa.amsl.com (Postfix) with ESMTP id 7E91121F84E6 for <softwires@ietf.org>; Sat, 28 Jan 2012 09:59:42 -0800 (PST)
Received: from [IPv6:2a01:e35:8a6d:d900:129a:ddff:fe6b:c6fb] (unknown [IPv6:2a01:e35:8a6d:d900:129a:ddff:fe6b:c6fb]) by smtp1-g21.free.fr (Postfix) with ESMTP id 1DFAB94004B for <softwires@ietf.org>; Sat, 28 Jan 2012 18:59:36 +0100 (CET)
From: Rémi Després <despres.remi@laposte.net>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Date: Sat, 28 Jan 2012 18:59:35 +0100
Message-Id: <C992D2F8-5E8C-4601-B07D-37AB2B7E72D3@laposte.net>
To: Softwires WG <softwires@ietf.org>
Mime-Version: 1.0 (Apple Message framework v1084)
X-Mailer: Apple Mail (2.1084)
Subject: [Softwires] New version of 4rd-U - with plain Encapsulation as a variant
X-BeenThere: softwires@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: softwires wg discussion list <softwires.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/softwires>, <mailto:softwires-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/softwires>
List-Post: <mailto:softwires@ietf.org>
List-Help: <mailto:softwires-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/softwires>, <mailto:softwires-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 28 Jan 2012 17:59:46 -0000

Hello all,

The new version of the proposed unified 4rd has just ben posted.
It is available at:

A major evolution since the previous version has been to have in it two variants.
- The Header-mapping variant is as in the previous version
- The Encapsulation variant is added after comments received, and accepted, that some use cases cannot be satisfied if the Header-mapping variant is the only one. 

Compared to the alternative approach of several MAP documents, the single-document approach is expected to avoid duplicate specifications, and to facilitate consistency checks of the design.
- Header-mapping provides more complete transparency to IPv4 packets than solutions using twice the IPv6/IPv4 translation of RFC6145.
- It has also the advantage of a simpler and self-sufficient specification.
- The algorithm which permits BRs to forward datagram fragments without datagram reassembly is included.
- The problem of fragmented datagrams from shared address CEs that must have different Identification if they go to common destinations is covered.
- The design re-introduces the Domain IPv6 suffix which in some earlier 4rd designs, and somehow has been lost. 
- The port-set algorithm is without parameter.

All questions and comments will be most welcome.