Re: [Ntp] Antw: [EXT] [Errata Verified] RFC5905 (5020)

Thank you, Sandy!

I'll file a feature request for a new erratum state: "AD is clearly
confused"  =)

On Thu, Jul 28, 2022 at 10:51 AM Sandy Ginoza <sginoza@amsl.com> wrote:

> Hi Erik,
>
> The errata has been set to Reported, so you should be able to access to it
> again.  Let me know if you run into any issues.
>
> Thanks,
> Sandy
>
>
> > On Jul 28, 2022, at 10:35 AM, Erik Kline <ek.ietf@gmail.com> wrote:
> >
> > Ah, yes, I think was not paying sufficient attention to the sign of
> various expressions.
> >
> > I can ask for the erratum to be reopened so that I can revise that.  May
> I copy from your explanation here to prepare the rejection explanation?
> >
> > On Thu, Jul 28, 2022 at 10:19 AM Steven Sommars <
> stevesommarsntp@gmail.com> wrote:
> > I don't get it.
> >
> > Theta is "the offset of B relative to A".   The proposed revision is
> >    1/2 * [(T2-T1) + (T4-T3)]
> > Example: Let's assume that B and A are exactly synced to UTC and that
> the network delay is 50msec in each direction.
> >     T2-T1 is the NTP mode 3 request delay (including network delay).
> This gives 50 msec
> >     T4-T3 is the NTP mode 4 response delay (including network delay).
>  This gives 50 msec.
> > The proposed revision gives 100msec/2 = RTT/2, not the expected offset
> of zero.
> >
> > The RFC5905 formula seems correct.
> >     theta = T(B) - T(A) = 1/2 * [(T2-T1) + (T3-T4)]
> > but might have been clearer had it been written:
> >     theta = T(B) - T(A) = 1/2 * [(T2-T1) - (T4-T3)]
> >
> >
> > On Thu, Jul 28, 2022 at 4:54 AM Ulrich Windl <
> Ulrich.Windl@rz.uni-regensburg.de> wrote:
> > >>> RFC Errata System <rfc-editor@rfc-editor.org> schrieb am 27.07.2022
> um
> > 17:06 in
> > Nachricht <20220727150611.170A66AB09@rfcpa.amsl.com>:
> > > The following errata report has been verified for RFC5905,
> > > "Network Time Protocol Version 4: Protocol and Algorithms
> Specification".
> > >
> > > --------------------------------------
> > > You may review the report below and at:
> > > https://www.rfc-editor.org/errata/eid5020
> > >
> > > --------------------------------------
> > > Status: Verified
> > > Type: Technical
> > >
> > > Reported by: Ferenc Wágner <wferi@niif.hu>
> > > Date Reported: 2017-05-15
> > > Verified by: Erik Kline (IESG)
> > >
> > > Section: 8
> > >
> > > Original Text
> > > -------------
> > > theta = T(B) - T(A) = 1/2 * [(T2-T1) + (T3-T4)]
> > >
> > > Corrected Text
> > > --------------
> > > theta = T(B) - T(A) = 1/2 * [(T2-T1) + (T4-T3)]
> >
> > If that's wrong, RFC 1305 would be just as wrong, because it says (page
> 25 in
> > PDF):
> > ((Ti−2 − Ti−3) + (Ti−1 − Ti)) / 2
> > ,
> >
> > >
> > > Notes
> > > -----
> > > The corresponding code line in A.5.1.1. agrees with this correction:
> > >
> > > offset = (LFP2D(r->rec - r->org) + LFP2D(r->dst - r->xmt)) / 2;
> > >
> > > taking Figure 7 into account:
> > >
> > > | org       | T1         | origin timestamp      |
> > > | rec       | T2         | receive timestamp     |
> > > | xmt       | T3         | transmit timestamp    |
> > > | dst       | T4         | destination timestamp |
> > >
> > > --------------------------------------
> > > RFC5905 (draft-ietf-ntp-ntpv4-proto-13)
> > > --------------------------------------
> > > Title               : Network Time Protocol Version 4: Protocol and
> > > Algorithms Specification
> > > Publication Date    : June 2010
> > > Author(s)           : D. Mills, J. Martin, Ed., J. Burbank, W. Kasch
> > > Category            : PROPOSED STANDARD
> > > Source              : Network Time Protocols
> > > Area                : Internet
> > > Stream              : IETF
> > > Verifying Party     : IESG
> > >
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> >
> >
> >
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>