Re: [Softwires] Unified proposal for stateless IPv4 Residual Deployments (4rd-U) - Contributors?

Mark Townsley <> Tue, 29 November 2011 17:44 UTC

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From: Mark Townsley <>
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Date: Tue, 29 Nov 2011 18:44:25 +0100
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To: Alain Durand <>
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Subject: Re: [Softwires] Unified proposal for stateless IPv4 Residual Deployments (4rd-U) - Contributors?
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On Nov 29, 2011, at 6:33 PM, Alain Durand wrote:

> Remi,
> Thank you for starting this discussion on the mailing list.
> Let me clarify my chair perspective on 4rd-u
> You brought this to the Taipei meeting as an attempt to 'unify' encapsulation and translation.
> I have always been of the opinion that fewer options are better, so I support attempts at converging the solution space.
> The caveat is, if the proponents of the other solutions are not inclined to adopt the new 'unified' scheme,
> we end up with just one more incompatible solution.
> Now, I have observed during the Taipei meeting a certain level of interest to understand better the 4rd-u proposal,
> as some of technical characteristics were not clear to the majority of the working group.
> WIth that and the previous point in mind, I'd like to encourage you to keep working on 4rd-u and come back next meeting
> in Paris. I hope by them those technical characteristics will be clearly understood by the working group and we could
> form a wg consensus  as to whether this work is useful or distracting.

I don't think we need 4 months to make this decision. Further, it seems very inconsistent to call an Interim meeting on this general solution space in order to speed convergence, and then turn around and give a very long meeting cycle as a deadline for what amounts to a relatively small piece of the overall solution space. 

- Mark

> Alain.
> On Nov 29, 2011, at 10:31 AM, Rémi Després wrote:
>> Hi all,
>> Some IETF-82 participants have expressed wishes to pursue the work on 4rd-U. Alain mentioned to me he would be interested, as Softwire chair, he would be interested in having at IETF 83 not only the MAP proposal (with its Encapsulation and Translation variants), but also a 4rd-U proposal. He also said I would be welcome to lead the effort. 
>> To start the work, I therefore plan to edit in December a new version of the 4rd-U draft. It will be in particular updated  to delete the Max-PSID/Max-EA-bits mechanism.
>> For the discussion starting from it, the plan is to have a 4rd-U mailing list on the IETF site.
>> On this list, all those wishing to contribute to the 4rd-U proposal will be invited to participate (including, of course, those who are already interested in MAP, both approaches remaining open at this stage).
>> Please le me know if you plan to contribute.
>> For those who attended the Softwire session in Taipei, please note that the serious objection against 4rd-U expressed by several participants during the meeting has been, soon after, acknowledged to be invalid (
>> Also, other (less important) objections have been answered in, without reaction so far. 
>> Best regards,
>> RD
>> _______________________________________________
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