Le 2012-03-15 à 10:02, Maoke a écrit :

> 
> 
> 2012/3/15 Rémi Després <[email protected]>
> Maoke,
> 
> Let's try, once more, to understand each other.
> 
> If we assume that MAP-T CEs (and BRs) now MUST translate DCCP (which is 
> AFAIAC a positive result of our discussion):
> a) Such a CE can communicate with an IPv6-only host including in DCCP.
> b) The same would apply to UDP lite if MAP-T would also require UDP-lite 
> translation.
> c) If a MAP-T CE communicates via a NAT64 (which is based on RFC6145, i.e. 
> with DCCP optional), DCCP is broken if the NAT64 doesn't translate DCCP (as 
> permitted by RFC6145).
> d) If RFC6146 (NAT64) and/or RFC6145 would be modified to also impose DCCP 
> translation, nodes complying with modified versions and those complying with 
> previous versions wouldn't be guaranteed to interwork for DCCP.
> 
> If we don't agree on this, there is still something to be clarified between 
> us.
> 
> surely do not. RFC6146 clearly states:
>    The current specification only defines how stateful NAT64 translates
>    unicast packets carrying TCP, UDP, and ICMP traffic. Multicast
>    packets and other protocols, including the Stream Control
>    Transmission Protocol (SCTP), the Datagram Congestion Control
>    Protocol (DCCP), and IPsec, are out of the scope of this
>    specification.

I said "If RFC614... would be modified to also impose DCCP translation" => I 
take the point that you are not interested in that, but I don't think there was 
a contradiction.
OK?

RD


> 
> - maoke
>  
> If we agree, I have nothing else on this point.
> 
> Regards,
> RD
> 
> 
> 
> If, as you suggest, 
> 2012-03-15 02:04, Maoke:
> 
>> 2012/3/14 Rémi Després <[email protected]>
>> 
>> Le 2012-03-14 à 10:46, Maoke a écrit :
>>> 
>>> 2012/3/14 Rémi Després <[email protected]>
> ...
>>>   
>>> Changing DCCP support from optional to mandatory in RFC6145 isn't backward 
>>> compatible (an upgraded node isn't guaranteed to interwork with a non 
>>> upgraded node).
>>> 
>>> the CE/BR specified RFC6145-compliant might be a problem but MAP-T is still 
>>> in development. if we state to enforce DCCP mandatorily rather than 
>>> optional in MAP-T, a MAP-T-compliant CE/BR won't has the backward 
>>> compatible problem. to this extend, MAP-T is at the same kick-off line of 
>>> the 4rd-U. 
>> 
>> 1. I agree that, between CEs and BRs, there can be no problem for DCCP 
>> (provided the draft is completed to this effect). The comparison table was 
>> explicitly made with existing drafts, and intended to be updatable. 
>> 
>> 2. The MAP-T draft is also claimed to allow "communication between 
>> IPv4-only, as well as any IPv6 enabled end hosts, to native IPv6-only 
>> servers in the domain that are using IPv4-mapped IPv6 address". In this 
>> case, AFAIK, the backward compatibility problem exists  
>> Thought? 
>> 
>> surely it does not exist. that statement applies to the MAP-T-compliant 
>> equipments, when it is used as a IPv4-to-IPv6 single translator or as an 
>> native IPv6 router. same deployment of equipments should support 
>> double-translation, single-translation, and native IPv6 accesses 
>> simultanenously. that's one of the points of the MAP-T. 
>> 
>> - maoke
>>  
>> 
>> 
>>> To be even more precise, H6 of the comparison table can be:
>>> "For ISPs that don't provide all CE nodes, and for shared IPv4 addresses, 
>>> DCCP and UDP-Lite are supported, as well as future protocols using the TCP 
>>> checksum algorithm and ports at the same place"
>>> 
>>> i actually think the original text is fine. "For .... shared IPv4 
>>> addresses" is not needed for 4rd-U, to my understanding, nor needed to 
>>> MAP-T.
>> 
>> Will see what to do, then, when changes to the MAP-T draft concerning DCCP 
>> are known. 
>> 
>> RD
>> 
>> 
>>>  
>>> 
>>> maoke 
>>>  
>>> 
>>> Does this cover the point?
>>> 
>>> RD
>>> 
>>> 
>>> 
>>> 
>>>> 
>>>> ;-)
>>>> maoke 
>>>>  
>>>> 
>>>>> but this is not my point. my point is: there must be something we don't 
>>>>> know ("non omnia possumus omnes"). even we have gone through the RFCs, 
>>>>> there might be some other proprietary L4 protocols, or experimental 
>>>>> protocols. even they are minority, i don't think ignoring their existance 
>>>>> in our solution fits the spirit of the Internet. it might be argued that 
>>>>> NAT44 doesn't support such L4 protocols now, but an L4 protocol owner may 
>>>>> makes his own NAT44, either attached to the CE or separated. if 4rd-U 
>>>>> respects such an effort, it should state "currently blahblabla L4 
>>>>> protocols are supported". the similar statement applies to the RFC6145 or 
>>>>> MAP as well.
>>>> 
>>>>> i somehow am hard to accept words like "far fetched theoretical problem". 
>>>> 
>>>> If I had thought it might be so, I would have avoided the word.
>>>> 
>>>> 
>>>>> the L4-recalculate is a generic, architectural solution, surely needing 
>>>>> codes for every L4 protocol. but this generality in architecture makes 
>>>>> RFC6145 or MAP-T equipment be easily enhanced to support anything new 
>>>>> with the same logic. but for the 4rd-U BR, it looks to me we cannot have 
>>>>> the unified logic for all (even limited to existing and well-known) L4 
>>>>> protocols. 
>>>>> 
>>>>> only my 2 cents. 
>>>> 
>>>> With amendments above, the point is AFAIK completely covered: everything 
>>>> is rigorously true, and worth noting.
>>>> Thanks for the useful reference to the RDP of RFC1151.
>>>> 
>>>> RD 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>> 
>>> 
>> 
>> 
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> 
> 

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