Subject: [Ntp] draft-schiff-ntp-chronos-03

From: Erik Kline <[email-masked]>
Date: Wed, 20 Nov 2019 19:28:53 +0800

Just a note to say that, FWIW, I have read draft -03.  I found it
relatively straightforward and comprehensible.

For me, the link to the paper didn't work, though that might have been an
artifact of the IETF network at the time I was trying.  Nevertheless, I was
able to find the paper with some light searching, though I haven't had the
chance to read it.

If the paper provides, or the authors know of, any operational guidance on
a value for w in "common practice", that might be useful to include
somewhere in the document (apologies if I've missed it).

-ek

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From: Neta R S <[email-masked]>
Date: Thu, 21 Nov 2019 11:30:34 +0200

Hi,

I am not sure why the link to the paper doesn't work, I'll fix it in the
next draft.
However, the proper link is:
https://www.ndss-symposium.org/wp-content/uploads/2018/02/ndss2018_02A-2_Deutsch_paper.pdf

Regarding the "w" parameter:
- It denotes an upper bound on the distance from the UTC of the local time
at any NTP server with an accurate clock (“truechimer”).
- We analyzed "w" value empirically in section 5.B, and set it to 25 ms,
such that over 83% of the servers (on average) are considered honest
servers.
- This value also used for the security analysis in section 4.B.

Best,
Neta

On Wed, Nov 20, 2019 at 1:29 PM Erik Kline <[email-masked]> wrote:

> _______________________________________________
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From: Erik Kline <[email-masked]>
Date: Thu, 21 Nov 2019 17:45:59 +0800

Neta,

Thanks for the corrected link.

I see that the value of w you reference is in the paper; I think it might
be of some benefit if it were also mentioned in the draft (or in an
appendix section in the draft).  Perhaps others feel differently.

Thanks again,
-ek

On Thu, Nov 21, 2019 at 5:30 PM Neta R S <[email-masked]> wrote:

>> If the paper provides, or the authors know of, any operational guidance
>> on a value for w in "common practice", that might be useful to include

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From: Neta R S <[email-masked]>
Date: Thu, 21 Nov 2019 11:48:10 +0200

Sure, I'll add its value on the next draft.

Thanks,
Neta

On Thu, Nov 21, 2019 at 11:46 AM Erik Kline <[email-masked]> wrote:

>> - It denotes an upper bound on the distance from the UTC of the local
>> time at any NTP server with an accurate clock (“truechimer”).
>>> For me, the link to the paper didn't work, though that might have been
>>> an artifact of the IETF network at the time I was trying.  Nevertheless, I
>>> was able to find the paper with some light searching, though I haven't had
>>> the chance to read it.
>>>