Re: [apps-discuss] Apps Dir review for: draft-kucherawy-dkim-atps-11

"Murray S. Kucherawy" <msk@cloudmark.com> Fri, 09 December 2011 18:41 UTC

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From: "Murray S. Kucherawy" <msk@cloudmark.com>
To: Claudio Allocchio <Claudio.Allocchio@garr.it>, "apps-discuss@ietf.org" <apps-discuss@ietf.org>, "draft-kucherawy-dkim-atps.all@tools.ietf.org" <draft-kucherawy-dkim-atps.all@tools.ietf.org>
Date: Fri, 9 Dec 2011 10:41:57 -0800
Thread-Topic: [apps-discuss] Apps Dir review for: draft-kucherawy-dkim-atps-11
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Subject: Re: [apps-discuss] Apps Dir review for: draft-kucherawy-dkim-atps-11
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> -----Original Message-----
> From: apps-discuss-bounces@ietf.org [mailto:apps-discuss-bounces@ietf.org] On Behalf Of Claudio Allocchio
> Sent: Friday, December 09, 2011 8:29 AM
> To: apps-discuss@ietf.org; draft-kucherawy-dkim-atps.all@tools.ietf.org
> Cc: iesg@ietf.org
> Subject: [apps-discuss] Apps Dir review for: draft-kucherawy-dkim-atps-11

Hi Claudio, thanks for your review.

> Major Issues:
> 
> The only major issue which I really see in the specification is the
> impact not only on DNS because of the increased number of queries, but
> on the efficiency of the e-mail glogal system in general.
> 
> It is true that in 9.3 this topic is correctly described, and a
> possible alternate query mechanism depicted. However the real issue
> which I see is not a load on DNS, but a greatly increased "timout risk"
> on MTAs. One of the "experiment" scope should also be to verify the
> impact that adding this new feature has on the whole messaging system
> in terms of MTAs efficiency and effects of timeouts. We already know
> well that, one of the first very evident effects which happens when DNS
> "is slow" is a serious disruption on MTAs performances. Even if DNS is
> performing correctly, adding more queries might trigger more easily
> these performance disruptions in MTAs.
> 
> I this suggest an explicit "guidance" on how to handle the experiment,
> and monitor also this issue, and evaluate its impact. Probably section
> 9.3 and the introduction are the appropriate spots to do this.
> 
> This is even more important if the adoption of this specification grows
> significantly because it proves useful.

Thanks for that suggestion.  Since as you say Section 9.3 already gives this a reasonable treatment, I've instead extended Section 7 to draw specific attention to what 9.3 says, and asked that participants in the experiment pay close attention to how the added DNS work might cause MTA latency.  Is that sufficient?

>   Minor Issues:
> 
> Section 3. Discussion
> 
> The title of the paragraph seems not so clear for the reader. It could
> be better to name it either "Scope of this specification" or "Roles and
> Scope of this specification".

I've changed it to simply "Roles and Scope".

> Also some sentences probably need a better phrasing:
> 
> "Participation in this protocol is divided into three parties:"
> 
> I would suggest:
> 
> "The actors involved into the implementation of this (experimental)
> protocol are:"

Someone else already suggested changing it to "The context of this protocol involves the following roles", so I'll just leave that as-is.

> and below
> 
> "An Author participates in this protocol if it..." -->
>    "An Author implements this protocol if it..."
> 
> "A Verifier participates in this protocol if..." -->
>    "A Verifier implements this protocol if it..."

Done and done.

> -------
> 
> Section 4.1 Extension to DKIM
> 
> the sentence:
> 
>     "domain-name" and "key-h-tag-alg" are imported from [DKIM].
> 
> I guess it means:
> 
>     for the definition of "domain-name" and "key-h-tag-alg" see [DKIM]
>     (section x.y).
> 
> There was long discussion on other WGs about correct handling of ABNF
> cross refereces between RFCs, thus the above change is more clear and
> conformant to that discussion, too.

I've used the "are imported from" numerous times before without any resistance or concern.  But anyway, I've changed it to "are defined in".

> Section 5. Interpretation
> 
> I would add an explicit sentence stating what to do in case the
> Verifier fails in the verification. Just a reference to DKIM procedure
> for this cases, in order not invent further potentially different
> actions.

I've changed the first sentence so that it starts with: "For each DKIM signature that verifies, ..."  Is that sufficient?

> -------
> 
> Section 9.1 and Section 4.2
> 
> I suggest to add explicitly the explanation from section 9.1:
> 
> "the hash and encode steps are done merely to convert any third-party
> domain name to a fixed width in the construction of the DNS query."
> 
> also to section 4.2, bullet point 5, where the convertion of the domain
> name is specified.

I'd prefer to add a forward reference from 4.2 to 9.1 rather than copying text.  That's done now in the working copy.

Thanks again,
-MSK