Re: [Softwires] Draft 4rd-u-05 is available

Behcet Sarikaya <> Mon, 12 March 2012 22:09 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 6C77F21E811B for <>; Mon, 12 Mar 2012 15:09:08 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -3.413
X-Spam-Status: No, score=-3.413 tagged_above=-999 required=5 tests=[AWL=-0.114, BAYES_00=-2.599, MIME_8BIT_HEADER=0.3, RCVD_IN_DNSWL_LOW=-1]
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id DI6JoY3DhCPP for <>; Mon, 12 Mar 2012 15:09:07 -0700 (PDT)
Received: from ( []) by (Postfix) with ESMTP id 3824921F8A8D for <>; Mon, 12 Mar 2012 15:09:06 -0700 (PDT)
Received: by iazz13 with SMTP id z13so8235162iaz.31 for <>; Mon, 12 Mar 2012 15:09:05 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113; h=mime-version:reply-to:in-reply-to:references:date:message-id :subject:from:to:cc:content-type:content-transfer-encoding; bh=79bjUDXhGyiHWC50YbPokbucODNyia7nCiMkiAK5A48=; b=p6ur/1bcHL4q/5gB6+hS91AsvP2+EV1s7+8Zciac1yqbj6WJ2/qFuARVIDZS94zKNe yfN00HnZsnIl4r4VKxOCLcGBDUsCh1kLuyb5VQsI/DhEni1LyxcT7fIsCwwYEZvSnqVY 25/bK6osdPS5bRfvCdSYJxkxT92bnYLLAUG2W2yfTJN+EG7qaoHS2aNrTWGPFyNnXOXG QA9cPGHmNhvHvhDpcGmCVFS7AH8PYskKnk54PyMDPg9N+M+OsSrnpT2LVYjrNnU0ihVz IZ9tIajcLj1DiwVlL78qA2Z6Ig8EjXjWW3RmnseQWqFwUjwK8cUroWiCGAAE6ZBMCz2l Jsvg==
MIME-Version: 1.0
Received: by with SMTP id vl10mr17440145icb.55.1331590145764; Mon, 12 Mar 2012 15:09:05 -0700 (PDT)
Received: by with HTTP; Mon, 12 Mar 2012 15:09:05 -0700 (PDT)
In-Reply-To: <>
References: <>
Date: Mon, 12 Mar 2012 17:09:05 -0500
Message-ID: <>
From: Behcet Sarikaya <>
To: Rémi Després <>
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: quoted-printable
Cc: Softwires WG <>
Subject: Re: [Softwires] Draft 4rd-u-05 is available
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: softwires wg discussion list <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Mon, 12 Mar 2012 22:09:08 -0000

Hi Remi,

My quick comments:
editorial on abstract:
- The 4rd automatic tunneling mechanism makes IPv4 Residual Deployment
   possible via IPv6 networks without maintaining for this per-customer
   states in 4rd-capable nodes (reverse of the IPv6 Rapid Deployment of
remove: for this.
Better still have a sentence like:
 4rd specifies a protocol mechanism to support Pv4  via a
   service provider's (SP's) IPv6 network without maintaining per-customer
   states in 4rd-capable nodes (reverse of the IPv6 Rapid Deployment of
- To cope with the IPv4 address shortage, customers can be
   assigned IPv4 addresses with restricted port sets.

It is not customers but it is CPE or CEs, right?

- 4rd-capable customer nodes can exchange packets of their
   IPv4-only applications via stateful NAT64s that are upgraded to
   support 4rd tunnels (in addition to their IP/ICMP translation of
replace "of" with "with"


I don't understand NAT64+ discussion in this draft (it has been added
in -04). Why do you need it?
In NAT64, IPv6 packet is not created by CE but by the host with the
help of DNS64.Where is DNS64 in your draft, except for a reference to
RFC 6147 which is a bogus reference.
NAT64 helps IPv6 only hosts to communicate with IPv4 only servers over
an IPv6 network. So it has almost nothing to do with 4rd.

One thing you can do is to say that NAT64 could be colocated with 4rd
BR if Pref64 of NAT is chosen to match 4rd prefix. In that case you
need to add support for RFC6145 stateful packet translation as well as
the NAT state in 4rd BRs. Is this what you would like to do?

Maybe I missed something.



On Mon, Mar 12, 2012 at 9:56 AM, Rémi Després <> wrote:
> Hello, all,
> An updated version of draft-despres-softwire-4rd-u is now available at
> Differences with -04 include:
> - DHCPv6 options are now specified
> - various errors and typos are corrected
> - some clarifications are added, following received questions and comments
> - the CE-behind-CPE use case has been revised (mix of CEs behind CPEs and within CPEs)
> - An editor's note has been added, following a WG-ML discussion, about an additional Mapping-rule parameter that might be needed to assign privileged ports to to some shared-address CEs.
> - Document layout has been adjusted as a result of other modifications.
> - the authors list has been completed.
> Questions and comments are most welcome.
> Regards,
> RD
> _______________________________________________
> Softwires mailing list