Re: [v6ops] A way forward for 464XLAT

[Rémi Després <[e-mail]>]

Hi, Cameron,

Sorry for the late answer (was on second priority for a few days).

Le 2012-03-27 à 12:38, Cameron Byrne a écrit :

> hi,
> 
> On Tue, Mar 27, 2012 at 1:17 AM, Rémi Després <[e-mail]> wrote:
>> 
>> Le 2012-03-27 à 04:34, Fred Baker a écrit :
...
>>> 
>>> The objections raised in the working group come down to:
>>>   - the authors of said other documents would like to have a conversation with the 464XLAT folks
>>>   - What's this about a prefix::/96?
>>>   - What's this about a proxy service?
>> 
>> There was also a point about NAT44 in CLAT nodes or not (point discussed on the ML)
>> 
> 
> The NAT44 text on the CLAT has been integrated here:
> 
> http://tools.ietf.org/html/draft-ietf-v6ops-464xlat-01#section-6.5
> 
> "Alternatively, the CLAT may do NAT44
>   such that all private IPv4 sourced LAN packets appears from one
>   private IPv4 address which is statelessly translated to one IPv6
>   address that the CLAT will own as a host IPv6 address from an IPv6
>   /64 interface."

Thanks, good enough for me.

>> May I add that the relationship between 464XLAT and BIH (RFC6535) would also be worth clarifying. (I see high similarity: v4 only applications communicating in IPv6).
>> 
> 
> BIH explicitly does not allow double translation, it's scope is
> explicitly limited to the case of using IPv4 applications to IPv6-only
> servers.  I objected to this limitation in BEHAVE.  But, it is what it
> is.

BIH "recommends" to avoid double translation.
This AFAIK permits it if good reasons are found.

> That said, 464XLAT authors have found rfc6145 to be the best fit for
> IPv4->IPv6 translation, including support for the function in a more
> generic node such as a router (home gateway CPE, mobile phone as a
> host, mobile phone as a wifi router, ...)

BIH does include RFC6145 translation.

> where BIH is constrained to
> a host only style implementation that relies on host level API
> modification and interaction

A host can also be also a router, in particular if it includes a NAT44.
I see nothing that prevents using it in this case.

>>>   - What's this about normative language?
>> 
>>>   - How does it fit the the mdt-softwire-map specifications, which
>>>     appear to have a growing consensus behind them in softwire?
>> 
>> The point made during the meeting was about the work in Softwire in general. replacing this point by a reference to the mdt draft is a biased interpretation.
>> In Softwire, a choice between MAP and Unified is scheduled for Friday morning. As chair of v6ops, it would be better to avoid making a Softwire choice before the scheduled debate has taken place (IMHO).
>> Thanks.
>> 
> 
> I hope my previous emails have made the case for a stateful solution
> clear and useful

I thought we had both understood that there are needs for stateful AND ALSO for stateless, in particular where mesh topologies are desirable. This depends on provider cases.
End of this issue for me.  

> As it stands, there is no workable stateful (more IPv4 address
> efficient / intensive) IETF method of operating in an IPv6-only access
> network.  

> NAT64/DNS64 is not workable, since 15% of applications on
> mobile (something similar for desktop) fail to work without some way
> to deal with IPv4 specific sockets and IPv4 literals.

Can we agree to only say that NAT64/DNS64 is NOT SUFFICIENT? (Without saying that it doesn't do work for what it has been designed for). 

Regards,
RD

> 
> CB
>> regards,
>> RD
>> 
>> 
>>> 
>>> Before you continue reading this note, please stop and read these two sections:
>>>   http://tools.ietf.org/html/rfc2026#section-4.2.2
>>>   http://tools.ietf.org/html/rfc2026#section-5
>>> 
>>> From my perspective, and from reading those definitions, an Informational Document is a white paper, while a BCP is something that a significant and relevant part of the Internet COmmunity agrees to, and
>>> 
>>> ...since the Internet itself is composed of networks operated by a great
>>>  variety of organizations, with diverse goals and rules, good user
>>>  service requires that the operators and administrators of the
>>>  Internet follow some common guidelines for policies and operations.
>>> 
>>> In other words, operational service models, while not strictly speaking "protocols", can be described in a BCP *standard* as "how to implement a certain service". This is in no sense "the best" or "only way to deploy RFCs 6145/6146", but it might be "the best way to deploy the CLAT service". v6ops is authorized, by charter, to write informational and BCP documents.
>>> 
>>> And since a BCP describes the set of things that one MUST or SHOULD do in deploying such a service, RFC 2119 language regarding that specific service may be acceptable in a BCP describing that service.
>>> 
>>> 
>>> With that preparatory reasoning, it seems to me that we need to separate the contentious parts of the specification so that uncontentious parts can go forward, and other parts can be discussed - whether in this working group or another one.
>>> 
>>> 
>>> Given the points of contention, it seems that the separation needs to be among three documents.
>>> 
>>> The first is a specification - a BCP - for the CLAT service. It refers to RFCs 6052/6144/6145/6146/6147, and describes how translation is used in this context using normative language. It does not refer to a prefix::/96; it refers to RFC 6052. My understanding is that several people have said that this specification is interesting and useful.
>>> 
>>> The second is a separate specification for the proxy service, which is contentious. Being separated, it can be discussed and beaten to death as needed. The first specification says that the CLAT service MAY implement this proxy service. I'm not sure whether that is BCP or Informational; we can discuss that in the context of the rest of the discussion of the proxy service.
>>> 
>>> The third is a report on the trial deployment of the CLAT service by the various companies in question. This is an informational document.
>>> 
>>> Am I making sense? Would this be an acceptable way forward?
>> 
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