Subject: Re: [tsvwg] Genart telechat review of draft-ietf-tsvwg-ecn-experimentation-05

From: "Black, David" <[email-masked]>
Date: Fri, 1 Sep 2017 21:45:44 +0000

Brian,

Thanks for the prompt review.

> Comment: Very clear from the technical standpoint. 

Thank you!

> I understand the desire for brevity, but this bothers me a bit. What is
> the reader to make of RFC3168 Section 20.2, for example? My feeling is
> that a short Appendix outlining the specific updates would be useful.
> There's already too much spaghetti to untangle.

RFC 3168 Section 20.2 is the rationale for the ECN Nonce and hence would be
deleted. Request noted, I'll consult with the draft shepherd and responsible
AD to figure out whether to do this.

> I see no reason why RFC3540 and RFC5622 need to be normative references
> (and therefore downrefs). They aren't required reading in order to
> understand this draft.

OTOH, both are affected by this draft:

In reverse order, this draft updates RFC 5622 - that seems to merit a
normative reference.    This draft also provides the rationale for the
status change of RFC 3540 to Historic, which also seems to merit a
normative reference.

Thanks, --David

> -----Original Message-----
> From: Brian Carpenter [mailto:[email-masked]]
> Sent: Thursday, August 31, 2017 10:02 PM
> To: [email-masked]
> Cc: [email-masked]; [email-masked]
> Subject: Genart telechat review of draft-ietf-tsvwg-ecn-experimentation-05
> 
> Reviewer: Brian Carpenter
> Review result: Ready with Issues
> 
> Gen-ART Last Call review of draft-ietf-tsvwg-ecn-experimentation-05
> 
> I am the assigned Gen-ART reviewer for this draft. The General Area
> Review Team (Gen-ART) reviews all IETF documents being processed
> by the IESG for the IETF Chair.  Please treat these comments just
> like any other last call comments.
> 
> For more information, please see the FAQ at
> <http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
> 
> Document: draft-ietf-tsvwg-ecn-experimentation-05.txt
> Reviewer: Brian Carpenter
> Review Date: 2017-09-01
> IETF LC End Date: 2017-09-14
> IESG Telechat date: 2017-09-14
> 
> Summary: Ready with (minor) issues
> --------
> 
> Comment: Very clear from the technical standpoint.
> --------
> 
> Minor Issues:
> -------------
> 
> > 3.  ECN Nonce and RFC 3540
> ...
> > o  Updates RFC 3168 [RFC3168] to remove discussion of the ECN Nonce
> >    and use of ECT(1) for that Nonce.  The specific text updates are
> >    omitted for brevity.
> 
> I understand the desire for brevity, but this bothers me a bit. What is
> the reader to make of RFC3168 Section 20.2, for example? My feeling is
> that a short Appendix outlining the specific updates would be useful.
> There's already too much spaghetti to untangle.
> 
> I see no reason why RFC3540 and RFC5622 need to be normative references
> (and therefore downrefs). They aren't required reading in order to
> understand this draft.
> 
> --

---

From: Brian E Carpenter <[email-masked]>
Date: Sat, 2 Sep 2017 11:41:23 +1200

> AD to figure out whether to do this.

Thanks. It's not intended as a blocking issue.

> status change of RFC 3540 to Historic, which also seems to merit a

Well, my understanding is that a normative reference is needed only
when the citing document cannot be understood and implemented
without reading the cited document.

Again it's not a blocking comment - although there is a technical error
in the Last Call message: it flags the downref to 5622, but not that to 3540.
I don't know if that's a tool error or an AD error ;-).

    Brian

---

From: Spencer Dawkins at IETF <[email-masked]>
Date: Sat, 2 Sep 2017 13:37:50 -0500

Hi, Brian,

> I don't know if that's a tool error or an AD error ;-).

As Bran is too polite to say, the AD sees the generated Last Call
announcement before it's sent.

I just regenerated the Last Call announcement, and it's still only naming
one draft as a normative downref. But the AD didn't notice that, so blaming
the tools was the wrong answer :-)

It's a 3-day weekend in the US, so any updated Last Call announcement won't
go out until Tuesday, anyway.

So, let's talk about that.

I just re-read the draft, focusing on the places where it refers to RFC
3540.

This draft explains the ECN Nonce experiment inline, although it cites 3540
as its reference, and explains that the experiment required ECT(0) and
ECT(1), but the experiment is over, and hasn't been deployed on the
Internet in any significant way, so we want ECT(1) back, for other
experiments.

It also refers to 3540 when it changes a registration in the Transmission
Control Protocol (TCP) Header Flags registry, but I believe this draft
explains the IANA actions requested well enough that IANA wouldn't need to
read 3540 to carry out the requested action.

I could be convinced that this draft explains why we want ECT(1) back well
enough that it's not necessary to actually read 3540, and since we're
declaring 3540 Historic, we actually kinda hope no one reads it in the
future except archaeologists in cyberspace.

But unless that reference really is informational, it remains a normative
downref that was omitted from the Last Call announcement.

David, I don't mind re-issuing the Last Call announcement if you think
still think the reference is normative, but you might want to take a look
at the text in the draft, and see how badly it needs to be normative,
before letting me know.

Spencer

---

From: Spencer Dawkins at IETF <[email-masked]>
Date: Mon, 4 Sep 2017 21:09:08 -0500

Just to end the suspense,

On Sep 2, 2017 13:37, "Spencer Dawkins at IETF" <
[email-masked]> wrote:

Hi, Brian,

Spencer

Mirja and I talked this morning, and the score is

It's normative:2
It's informative:2

between me, Brian, David, and Mirja, so I took that as a sign that moving
that reference to Informative References isn't obviously ok.

I edited the Last Call text and re-issued the Last Call requests for both
the draft and the status change document, so they stay in sync.

The Secretariat was likely off today (US Labor Day), so it might take a day
for the Last Calls to pop out.

Thanks to everyone for your help.

Spencer

---

From: "Black, David" <[email-masked]>
Date: Wed, 20 Sep 2017 22:45:13 +0000

Brian,

I'm about to post the -06 version of this draft.   The concern on RFC 3168 impact of the ECN nonce removal was resolved by listing the four major changes (and you were correct that the change to Section 20.2 is subtle - I got it wrong on my first attempt in responding to your email).  Here's the specific text that I've added to Section 3 of the draft:

   The four primary updates to RFC 3168 that remove discussion of the
   ECN nonce and use of ECT(1) for that nonce are:

   1.  Remove the paragraph in Section 5 that immediately follows
       Figure 1; this paragraph discusses the ECN nonce as the
       motivation for two ECT codepoints.

   2.  Remove Section 11.2 "A Discussion of the ECN nonce." in its
       entirety.

   3.  Remove the last paragraph of Section 12, which states that ECT(1)
       may be used as part of the implementation of the ECN nonce.

   4.  Remove the first two paragraphs of Section 20.2, which discuss
       the ECN nonce and alternatives.  No changes are made to the rest
       of Section 20.2, which discusses alternate uses for the fourth
       ECN codepoint.

   Additional minor changes remove other mentions of the ECN nonce and
   implications that ECT(1) is intended for use by the ECN nonce; the
   specific text updates are omitted for brevity.

The proverbial "rest of the story" is that an RFC 3168bis effort appears to be a good idea, e.g., as RFC 6040 has already made some visible changes. The preferred 3168bis timing appears to be after we understand the outcomes of the current proposed of experiments, as they're likely to result in another round of changes to RFC 3168.

Many thanks, and chalk this up as one more instance where a GenART review has visibly improved the quality of a draft,  --David

> From: Brian E Carpenter [mailto:[email-masked]]
> Sent: Friday, September 1, 2017 7:41 PM
> To: Black, David <[email-masked]>; [email-masked]
> Subject: Re: Genart telechat review of draft-ietf-tsvwg-ecn-
> experimentation-05
>

---

From: Brian E Carpenter <[email-masked]>
Date: Thu, 21 Sep 2017 14:03:27 +1200

Thanks David. That completely responds to my comments.

Regards
   Brian