Re: [IPFIX] Fwd: Last Call: <draft-ietf-ipfix-text-adt-07.txt> (Textual Representation of IPFIX Abstract Data Types) to Proposed Standard

[Paul Aitken <[e-mail]>]

Brian, please see inline.


On 17/07/2014 15:40, Brian Trammell wrote:
> hi Paul,
>
> thanks for the comments/review. Commentcomments inline:
>
> On 17 Jul 2014, at 16:05, Paul Aitken <[e-mail]> wrote:
>
>> Benoit, Brian, All,
>>
>> 4.  Data Type Encodings
>>
>>
>>     Each subsection of this section defines a textual encoding for the
>>     abstract data types defined in [RFC7012].
>>
>>
>> Is 7012 the correct reference? Isn't IANA's IPFIX registry now understood to be the master reference?
>> (ie, http://www.iana.org/assignments/ipfix/ipfix.xhtml#ipfix-information-element-data-types)
> For IEs, yes. This is a reference to the abstract data types defined in section 3.1 of RFC 7012, not the Information Element definitions.

Sure, the definitions are irrelevant here. Notice that I linked the IE 
*data types* registry.


>> With a view to extensibility, this document doesn't say what to do if/when new data types are added to IANA (eg, see ietf-ipfix-mib-variable-export).
>> eg even one line to say that they can be represented in a default or limited way, or that they cannot be represented at all -  in which case, how should the representation be extended in future, if needs be?
> I presume that this would have to be done by a future draft that updates this RFC, referencing a draft that updates Section 3.1 of RFC 7012, but we can say so explicitly.
>
> Note that every ADT that's been added or considered since RFC 5102 has been more or less a hack that only makes sense within the binary encoding, and as such doesn't need a text representation. The RFC 6313 ADTs are only interesting in the context of the RFC 7101 encoding of the ADTs, and are explicitly noted as such in section 4.11.
>
> mib-variable-export is a more interesting case, but I don't think it really applies here. The point of this work is to allow interoperability for textual representations of values for Information Elements taken from the IPFIX Information Element registry. The point of mib-variable-export is to allow IPFIX (or rather, the binary encoding of records defined in RFC 7011, to which the representation is quite tightly bound) to export Information Elements in a _different_ type space. And most probably, the right way to do that would be to directly define textual representations for MIB data directly (which I presume already exist; I'm not by any stretch of the imagination an SNMP geek.)

My point wasn't about MIBs per se; rather, about adding new data types. 
But brain-fart, the mib-export draft adds new semantics (not types) - so 
it's not a super example. However the point stands: mention 
extensibility at least briefly.

Thanks,
P.


>> Appendix A / Figure 1:
>>
>> While Figure 1 in this draft initially seems identical to Figure 1 in section10.2 of 7013, there are some important differences between them:
>>
>> 7013:
>> 	 sourceIPv4Address(8)<ipv4Address>[4]{key}
>> 	 destinationIPv4Address(12)<ipv4Address>[4]{key}
>>
>> Figure 1:
>>           sourceIPv6Address(27)<ipv4Address>[4]{key}
>>           destinationIPv6Address(28)<ipv4Address>[4]{key}
>> 	 ...
>>           tcpControlBits(6)<unsigned8>[1]
>>           flowEndReason(136)<unsigned8>[1]
>>
>>
>>
>>
>> This has been wrong since -00 :
>>
>>           sourceIPv6Address(27)<ipv4Address>[4]{key}
>>           destinationIPv6Address(28)<ipv4Address>[4]{key}
>>
>> (Figure 2 shows a length of 16 for these, so presumably s/v4/v6/ and s/[4]/[16]/ in the above definitions.)
> Yep, thanks for the catch.
>
>> And tcpControlBits:
>>
>>           tcpControlBits(6)<unsigned8>[1]
>>
>> - has been revised to unsigned16 [RFC7125]. Changing this would also make Figure 2 align more neatly.
> It'll probably still be exported as 1 byte everywhere, but the type is indeed unsigned16
>
>> Figure 3: it's not clear how the strings for the timestamp, IPv6 address, and protocol identifier fields get mapped to the corresponding dateTimeMilliseconds, ipv6address, and unsigned8 types shown in Figures 1 and 2. eg, conversion is required between "tcp" and 6, so the draft should mention that.
> It does:  section 4.2, paragraph 2:
>
>     In the special case that the unsigned Information Element has
>     identifier semantics, and refers to a set of codepoints, either in an
>     external registry, a sub-registry, or directly in the description of
>     the Information Element, then the name or short description for that
>     codepoint as a string MAY be used to improve readability.
>
> Thanks, cheers,
>
> Brian
>
>> On 16/07/2014 23:33, Benoit Claise wrote:
>>> Dear IPFIX WG,
>>>
>>> In the text below, I explain the reason behind the second IETF LC:
>>> During the IESG telechat, the IESG concluded that this document should be
>>> Proposed Standard, and not Informational as initially proposed in v6.
>>> This IETF LC should focus on the Proposed Standard changes in the
>>> latest version.
>>>
>>>
>>> Regards, Benoit
>>>
>>> -------- Original Message --------
>>> Subject:	[IPFIX] Last Call: <draft-ietf-ipfix-text-adt-07.txt> (Textual Representation of IPFIX Abstract Data Types) to Proposed Standard
>>> Date:	Wed, 16 Jul 2014 15:24:27 -0700
>>> From:	The IESG <[e-mail]>
>>> Reply-To:	<[e-mail]>
>>> To:	IETF-Announce <[e-mail]>
>>> CC:	<[e-mail]>
>>>
>>> The IESG has received a request from the IP Flow Information Export WG
>>> (ipfix) to consider the following document:
>>> - 'Textual Representation of IPFIX Abstract Data Types'
>>>    <draft-ietf-ipfix-text-adt-07.txt>
>>>
>>> During the IESG telechat, the IESG concluded that this document should be
>>> Proposed Standard, and not Informational as initially proposed in v6.
>>> This IETF LC should focus on the Proposed Standard changes in the
>>> latest version.
>>>
>>> The IESG plans to make a decision in the next few weeks, and solicits
>>> final comments on this action. Please send substantive comments to the
>>>
>>> [e-mail]
>>>   mailing lists by 2014-07-30. Exceptionally, comments may be
>>> sent to
>>> [e-mail]
>>>   instead. In either case, please retain the
>>> beginning of the Subject line to allow automated sorting.
>>>
>>> Abstract
>>>
>>>
>>>     This document defines UTF-8 representations for IPFIX abstract data
>>>     types, to support interoperable usage of the IPFIX Information
>>>     Elements with protocols based on textual encodings.
>>>
>>>
>>>
>>>
>>> The file can be obtained via
>>>
>>> http://datatracker.ietf.org/doc/draft-ietf-ipfix-text-adt/
>>>
>>>
>>> IESG discussion can be tracked via
>>>
>>> http://datatracker.ietf.org/doc/draft-ietf-ipfix-text-adt/ballot/
>>>
>>>
>>>
>>> No IPR declarations have been submitted directly on this I-D.
>>>
>>>
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