Re: [Rpm] actively measuring owd successfully using icmp

[Matt Mathis <mattmathis@google.com>]

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icmp_timestamp has not been removed, and in Linux it is still present in
the shared icmp code used by both IPv4 and IPv6.

More likely a bug that has never been noticed, because nobody bothered to
test it.  I note that most icmp documentation doesn't even mention it's
existence.

If a kernel bug, most likely a corrupted checksum.  But my bet would be
code outright missing from the library.

Good luck!

Thanks,
--MM--
The best way to predict the future is to create it.  - Alan Kay

We must not tolerate intolerance;
       however our response must be carefully measured:
            too strong would be hypocritical and risks spiraling out of
control;
            too weak risks being mistaken for tacit approval.


On Sat, Dec 11, 2021 at 5:20 AM Sebastian Moeller via Rpm <
rpm@lists.bufferbloat.net> wrote:

> Two notes.
> 1) Technically it is not OWD that is measured, but "OWD + unknown_offset",
> but since the goal is to evaluate the delta between the current delay and a
> history delay aggregate, the unknown offset does not matter too much, and
> as it turns out quite a lot of the tested reflectors are reasonably well
> synchronized already (to my utter, utter surprise).
> 2) It appears that ICMPv6 removed the timestamp option, does anybody here
> have a link to the discussions that lead to this somewhat unfortunate
> decision?
>
> Best Regards
>         Sebastian
>
>
> > On Dec 11, 2021, at 13:59, Dave Taht via Rpm <rpm@lists.bufferbloat.net>
> wrote:
> >
> > Somewhere in this thread the actual working method is buried, but:
> >
> > https://forum.openwrt.org/t/cake-w-adaptive-bandwidth/108848/944
> >
> > --
> > I tried to build a better future, a few times:
> > https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
> >
> > Dave Täht CEO, TekLibre, LLC
> > _______________________________________________
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> > https://lists.bufferbloat.net/listinfo/rpm
>
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