Re: [Softwires] I-D Action: draft-ietf-softwire-lw4over6-06.txt

[Ole Troan <[e-mail]>]

a few initial comments:

s/connectivity services/connectivity/
s/OPTION_SW46_LW/OPTION_S46_CONT_LW/

section 5.1
   An IPv6 address from an assigned prefix is also required for the lwB4
   to use as the encapsulation source address for the softwire.  In
   order to enable end-to-end provisioning, the IPv6 address is
   constructed by taking a /64 prefix assigned to the WAN interface and
   suffixing 64-bits for the interface identifier.  As there may be
   multiple WAN prefixes, of which only one can be used for lw4o6, the
   CPE is provisioned with the logic to select the correct one.  The /
   128 prefix is then constructed as follows:

that seems awfully hand-wavy?
how is the CPE supposed to pick which prefix to use? does it have to be from the WAN interface?
could it be from the PD block as well?

reference MAP for the interface-id? (or perhaps just state that it is the same)
define PSID somewhere? (reference MAP document)?

why SHOULD the a-bits be 0? isn't that an operational choice?

I really don't think overriding the ICMP type 1 code 5 is appropriate to signal "no binding".
do you think the BR reachability check from RFC5969 could be adopted instead?

should you say something about using anycast addresses for the AFTR?

a general comment. we're going to have quite a bit of redundant text between the MAP documents and the LW46 document, e.g. ICMP handling, fragmentation. I don't have a big problem with that as such, but should ensure that the text isn't conflicting at least.

cheers,
Ole

On 11 Feb 2014, at 8:54 , [e-mail] wrote:

> 
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the Softwires Working Group of the IETF.
> 
>        Title           : Lightweight 4over6: An Extension to the DS-Lite Architecture
>        Authors         : Yong Cui
>                          Qiong Sun
>                          Mohamed Boucadair
>                          Tina Tsou
>                          Yiu L. Lee
>                          Ian Farrer
> 	Filename        : draft-ietf-softwire-lw4over6-06.txt
> 	Pages           : 22
> 	Date            : 2014-02-10
> 
> Abstract:
>   Dual-Stack Lite (RFC 6333) describes an architecture for transporting
>   IPv4 packets over an IPv6 network.  This document specifies an
>   extension to DS-Lite called Lightweight 4over6 which moves the
>   Network Address and Port Translation (NAPT) function from the
>   centralized DS-Lite tunnel concentrator to the tunnel client located
>   in the Customer Premises Equipment (CPE).  This removes the
>   requirement for a Carrier Grade NAT function in the tunnel
>   concentrator and reduces the amount of centralized state that must be
>   held to a per-subscriber level.  In order to delegate the NAPT
>   function and make IPv4 Address sharing possible, port-restricted IPv4
>   addresses are allocated to the CPEs.
> 
> 
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-ietf-softwire-lw4over6/
> 
> There's also a htmlized version available at:
> http://tools.ietf.org/html/draft-ietf-softwire-lw4over6-06
> 
> A diff from the previous version is available at:
> http://www.ietf.org/rfcdiff?url2=draft-ietf-softwire-lw4over6-06
> 
> 
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
> 
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
> 
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