RE: Alvaro Retana's No Objection on draft-ietf-6man-ipv6-alt-mark-08: (with COMMENT)

[Giuseppe Fioccola <[e-mail]>]

Dear Alvaro,
Thank you for your review. 
Please find my answers inline tagged as [GF].

Regards,

Giuseppe

-----Original Message-----
From: Alvaro Retana via Datatracker <[e-mail]> 
Sent: Tuesday, August 10, 2021 6:12 PM
To: The IESG <[e-mail]>
Cc: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]
Subject: Alvaro Retana's No Objection on draft-ietf-6man-ipv6-alt-mark-08: (with COMMENT)

Alvaro Retana has entered the following ballot position for
draft-ietf-6man-ipv6-alt-mark-08: No Objection

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The document, along with other ballot positions, can be found here:
https://datatracker.ietf.org/doc/draft-ietf-6man-ipv6-alt-mark/



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COMMENT:
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(1) I support the DISCUSS positions from Lars, Roman, and Martin.

(1a) Of special concern to me is Martin's point about the relationship between this document and rfc8321/8889, and the potential ability to reference this work without proper review by the ippm WG.  Note that neither RFC is explicit about the criteria to complete the respective experiments; the Shepherd writeup for rfc8321 [a] states that "the measurement utility of this extension still is to be demonstrated at a variety of scales in a plurality of network conditions." Furthermore, I am not aware of discussions about the maturity of
rfc8321 in the ippm WG.

[GF]: We already had an offline discussion last year with 6MAN chairs, IPPM chairs and ADs (in particular with Magnus Westerlund). RFC 8321 was originally labeled as Experimental because it came from an experimental deployment. Indeed the initial application of the method was done by using marking fields that are not intended for performance measurements (in case of IPv4, we used two bits from the DSCP fields or the unused bit of the IPv4 header). For this reason, we could not follow the Standards Track in IPPM and the document was considered Experimental, even if the description of the methodology is protocol agnostic and can be applicable to different protocols. Regarding the maturity, I think the experiment, started in 2010, is done (https://datatracker.ietf.org/doc/html/rfc8321#section-5.1) and now the methodology is mature to make it applicable and standard for IPv6. We discussed last year the relationship between this document and RFC 8321 / RFC 8889 with the IPPM chairs (Tommy Pauly and Ian Swett), and they suggested to have RFC 8321 as informative reference. We also asked Mirja Kühlewind, that did the AD review for RFC 8889, and she gave a similar advice. It was also highlighted that, in the case of RFC 8321, Experimental and Informational can be considered at the same maturity level. For this reason, the detailed description of the methodology in RFC8321 has been included in this document to enable the informative reference.

[a] https://datatracker.ietf.org/doc/draft-ietf-ippm-alt-mark/shepherdwriteup/

(2) There are several references to I-D.fioccola-v6ops-ipv6-alt-mark, which was replaced by draft-fz-6man-ipv6-alt-mark and ultimately by this document.  IOW, it looks like this document refers to an old version of itself.  Since the references are mostly about analysis made in the early drafts, it may be better to include some of that in an appendix instead.

[GF]: I see. I can remove this reference and report the relevant considerations in the document.