Le 2012-04-10 à 11:21, Wojciech Dec a écrit :

> 
> 
> On 10 April 2012 10:23, Rémi Després <[email protected]> wrote:
> 
> Le 2012-04-10 à 09:59, Wojciech Dec a écrit :
> 
>> 
>> 
>> On 10 April 2012 09:31, Rémi Després <[email protected]> wrote:
>> Le 2012-04-10 à 07:35, GangChen a écrit :
>> 
>> > Hello all,
>> >
>> > I have tried to work hard and technically contribute to all documents:
>> > MAP-algorithm, MAP-T, MAP-E, MAP-Deployment, 4rd-U, and also cosigned
>> > with all of them. Please allow me to share some points here.
>> >
>> > Basic idea of MAP algorithm were originally built on 4rd and DIVI
>> > (draft-despres-softwire-4rd,draft-murakami-softwire-4rd,
>> > draft-xli-behave-divi, ..). It was improved by design team members and
>> > evolved into "polarized solutions"(as Jan mentioned), i.e. MAP-T and
>> > MAP-E. Identical address format is used for -T and -E. Backing to the
>> > earlier version of MAP document, it included all features (e.g.
>> > Checksum-neutrality, Vbit etc.). Some people were in favor of it; some
>> > thought it not key points. For example, CNP is desirable for
>> > translation solution. But it's in some extent against current tunnel
>> > implementation, because encapsulation requires fixed IPv6 address
>> > representing an endpoint depending on tunnel code today. People have
>> > to sacrifice this feature in order to keep the benefits of unified
>> > address format. However, that obviously is of value to transparency.
>> > (PS: CNP is also a feature in RFC6296, stateless IPv6-to-IPv6 Network
>> > Prefix Translation).
>> >
>> > 4rd-U was trying to keep all merits together considering trade-off
>> > points. It was targeted to be reversible process and full transparency
>> > which I guess is important for a stateless design. Meanwhile, some
>> > additional extensions have to be considered. It's maybe a point to
>> > bring up "endless discussion" on the list.
>> >
>> > I agree with what Yiu said it's hard to simply answer YES or NO at
>> > this time. Both solutions deserve spending more time, because these
>> > solutions were born only for half a year.
>> 
>> +1
>> 
>> > Implementation may need more
>> > time and operation normally will also need to wait.
>> >
>> > OTOH, I'm still not fully convinced MAP-E and -T should be treated as
>> > one solution.
>> 
>> +1
>> (They were previously considered to be two distinct candidates for standard 
>> track.)
>> 
>> > I like MAP-E or -T to be deployed as a separate
>> > solution. However, coexistence means operators should have double
>> > packages inspection toolkits, double operational rules delivery and
>> > double provisioning costs. In some cases, translation solution is
>> > exclusive to encapsulation (Please see more in
>> > draft-dec-stateless-4v6).
>> > Even you can implement in the same box,
>> > that's very inconvenient for operation and subscriber.
>> 
>> +1
>> With MAP-T+E, subscribers wouldn't have the same service depending on which 
>> specification their local operator has chosen, with subtle differences they 
>> shouldn't be concerned with.
>> 
>> The service would be the same. Note: NAT64 based services are a reality 
>> today, and although you may think differently, no operator calls "checksum 
>> neutrality" a service (with this apparently being the main feature of 
>> 4rd-u). 
> 
> Please avoid inventing my thoughts to then criticize them.
> The key service offered by 4rd-U is complete IPv4 transparency (a MAP-E 
> property) combined with compatibility with IPv6-only O&M-tools (a MAP-T 
> property). Checksum neutrality is just a tool.
> 
> That is not a service as an operator would typically see it. In any case, 
> there is nothing preventing MAP from supporting the purported IPv4 
> transparency, but so far there has been no consensus that this is actually 
> desirable, or worthwhile.
>  
> 
>> What more, given that 4rd-U needs to be combined with BIH, the claim of it 
>> offering some "unified" solution, different operationally from MAP is bogus. 
>> If anything this combination and the fact that there is a IPv6.1 being 
>> created actually makes 4rd-u operations a major challenge in comparison to 
>> what we know of as IPinIP tunnelling or NAT64 with MAP.
> 
> The need for an IPv6 6.1 is AFAIK an invention of yours, not something needed 
> by 4rd-U.
> 
>  4rd-u does change the basic semantics of fields in IPv6,

???
(If you would have evidence that everything isn't backward compatible, please 
share this information.)

> and that is not my invention.
> 
> 
>> Remi, at one point you stated publicly that you would withdraw 4rd-u should 
>> it not gain WG consensus.
> 
> (*) I said, and confirm, that my personal work is to achieve a single 
> standard, not to have 3.  
> My appreciation is that 4rd-U is more than ever the best candidate for this 
> since the idea of having only MAP-T OR MAP-E on standard track has ben 
> abandoned. 
> 
> 4rd-u requires coupling with BIH, so it's not a single standard by any means 
> (not to mention the changes to IPv6).

4rd-U is is a Softwire solution (IPv4 via IPv6).
IPv4-only to IPv6-only communication is a different subject, already covered by 
a standard-track RFC.
If there are criticisms of this existing RFC, they belong to a different forum.

RD



>> You also chose to quit the MAP design team, where your proposals failed to 
>> get consensus.
> 
> Conditions in which the 4rd-U approach has been rejected, in an improvised 
> meeting in Taipei, has already been commented.
> 
> The design team worked on the principles of common consensus and seeking 
> compromise in an effort to create a solution that addressed the core problems 
> and the agreement of the Beijing meeting in a timely manner. Concepts that 
> are apparently foreign to those who choose first to work on the design team 
> and then abandoned the team to seek the personal advancement of their own 
> solution.
> As mentioned, forming a new WG for 4rd-X, if not actually an RD WG, is a 
> worthy idea that should be considered, allowing the rest of the world to 
> proceed with getting things done.
> 
> -Woj.
>  
> 
> There has been after that no alternative to a separate work, approved by the 
> chair. 
> result is the self contained and complete 4rd-U specification, which, despite 
> aggressive comments made on the list and in meetings, has already arisen 
> substantial interest in the WG.
>  
>  
>> At this stage it appears that not only you are not intending to honour you 
>> public statement,
> 
> See (*) above.
> 
>> but also in general disputing the process of establishing consensus in the 
>> WG. One is tempted to see it that no consensus other than "consensus on your 
>> terms" is what you really want, and those terms change with each new draft 
>> revision.
> 
> ???
> 
>> Perhaps its time for draft 4rd-X in a new WG...
> 
> ???
> 
> RD
> 
> 
>> 
>> -Woj.
>>  
>> 
>> RD
>> 
>> 
>> 
>> > According
>> > RFC6180, it is fundamental two different solution.
>> >
>> > BRs
>> >
>> > Gang
>> > _______________________________________________
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>> > [email protected]
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>> 
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> 
> 

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