Subject: Genart last call review of draft-kucherawy-dispatch-zstd-01

From: Vijay Gurbani <[email-masked]>
Date: Thu, 19 Apr 2018 07:54:35 -0700

Reviewer: Vijay Gurbani
Review result: Ready with Nits

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

<https://trac.ietf.org/trac/gen/wiki/GenArtfaq>.

Document: draft-kucherawy-dispatch-zstd-01
Reviewer: Vijay K. Gurbani
Review Date: 2018-04-19
IETF LC End Date: 2018-04-23
IESG Telechat date: Not scheduled for a telechat

Summary: Ready with 1 minor issue and some nits.

Major issues: 0

Minor issues: 2
 
Nits/editorial comments:  3

Minor:
- S4: "... and the usual precautions apply."  Here, what are the "usual
 precautions"?  Are they the ones enumerated below?  If so, then
 perhaps restate as "... and the usual precautions apply, as enumerated
 below.".

 If the usual precautions are not enumerated below, then a reference should
 be provided to a resource(s) that enumerates such precautions.

- S5: I am curious, why should we remove this section prior to publication?
 It contains pointers to code that is invaluable to implementors.  At the
 most, I would advise excising company name (Facebook) from the section,
 but I would advocate strongly to retain this section as the draft becomes
 a RFC.

Nits/Typos:
- S2.1.1: The value of the magic number: 0xFD2FB528 --- is there any
 significance to it?  Any insight on how you arrived at this will be
 interesting.  (I am relating this magic number to the SIP magic cookie
 "z9hG4bK" which was chosen so that the probability was very small of
 older implementations to randomly pick a branch ID that started with
 these characters.)

- S2.1.1: s/the origina/the original/

- S2.1.1.3.1.1: "Value ?0" --> should it be "Value 00"?

---

From: Yann Collet <[email-masked]>
Date: Fri, 20 Apr 2018 23:22:08 +0000

Hi

I can answer the following 2 minor points: 

`?0` means it can be either `10` or `00`.
Aka, only the last bit `0` matters.

    - S2.1.1: The value of the magic number: 0xFD2FB528 --- is there any significance to it?  

This value was selected to be less probable to find at the beginning of some random file.
It avoids trivial patterns (0x00, 0xFF, repeated bytes, increasing bytes, etc.),
contains byte values outside of ASCII range,
and doesn't map into UTF8 space.
It reduces chances that a text file be able to represent this value by accident.

For all other points, I have no comment, and agree with reviewer.

Rgds

Yann Collet
Facebook

On 4/19/18, 07:55, "Vijay Gurbani" <[email-masked]> wrote:

    Reviewer: Vijay Gurbani

    
    <https://urldefense.proofpoint.com/v2/url?u=https-3A__trac.ietf.org_trac_gen_wiki_GenArtfaq&d=DwICaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=_EwH5jTAHV32G13ENXwVrw&m=aMabi5qTp6wXqc6KXVjyGEgbdV5SaoN7tcHeDarFUI8&s=G_jKtEolxxcUUP2uN78WXkDdXi9KsGgZPh0RD34zvIw&e=>.

    
    Major issues: 0
    
    Minor issues: 2

    Minor:

    
    Nits/Typos:

---

From: Vijay Gurbani <[email-masked]>
Date: Sat, 21 Apr 2018 19:56:09 -0500

Yann: Thank you for your response.

Please see inline.

> Aka, only the last bit `0` matters.

When I read that section, it did not strike me that you were using regular
expressions (as far as I can remember, there was no use of regexps in the
section, but I don't have the draft open in front of me).  Thus, it looked
like a typo to me.  My advice, especially if there is no general use of
regular expressions in the draft, would be to spell it out by saying "00 or
01".  But the end decision is up to you, of course.

> significance to it?

OK; that's what I thought.  Up to you if you want to add an explanatory
sentence.  Won't hurt.

That's all.  Thanks!

>     <https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__trac.ietf.org_trac_gen_wiki_GenArtfaq&d=DwICaQ&c=
> 5VD0RTtNlTh3ycd41b3MUw&r=_EwH5jTAHV32G13ENXwVrw&m=
> aMabi5qTp6wXqc6KXVjyGEgbdV5SaoN7tcHeDarFUI8&s=G_
> jKtEolxxcUUP2uN78WXkDdXi9KsGgZPh0RD34zvIw&e=>.
>

---

From: Yann Collet <[email-masked]>
Date: Wed, 25 Apr 2018 17:44:09 +0000

Thanks Vijay

These are good suggestions.
I’ll use them to improve the spec.

Regards,

Yann

From: Vijay Gurbani <[email-masked]>
Date: Saturday, April 21, 2018 at 17:56
To: Yann Collet <[email-masked]>
Cc: "[email-masked]" <[email-masked]>, "[email-masked]" <[email-masked]>, "[email-masked]" <[email-masked]>, "[email-masked]" <[email-masked]>
Subject: Re: Genart last call review of draft-kucherawy-dispatch-zstd-01

On Fri, Apr 20, 2018 at 6:22 PM, Yann Collet <[email-masked]<mailto:[email-masked]>> wrote:
Hi

When I read that section, it did not strike me that you were using regular expressions (as far as I can remember, there was no use of regexps in the section, but I don't have the draft open in front of me).  Thus, it looked like a typo to me.  My advice, especially if there is no general use of regular expressions in the draft, would be to spell it out by saying "00 or 01".  But the end decision is up to you, of course.

OK; that's what I thought.  Up to you if you want to add an explanatory sentence.  Won't hurt.
That's all.  Thanks!

Rgds

Yann Collet
Facebook

On 4/19/18, 07:55, "Vijay Gurbani" <[email-masked]<mailto:[email-masked]>> wrote:

    Reviewer: Vijay Gurbani

    Major issues: 0

    Minor issues: 2

    Minor:

    Nits/Typos: