On Mon, Sep 04, 2023 at 10:29:28AM +0200, Miroslav Lichvar wrote:
> On Mon, Sep 04, 2023 at 01:34:48PM +0700, James Clark wrote:
> > The IES3110-8TF-R web UI has some configuration options that suggest it
> > supports unicast.
Ok, I got the switch and I can confirm it modifies the correction
field in NTP-over-PTP messages as a one-step transparent clock.
I did a quick test with two I210 NICs in a single machine connected to
the switch. I tried few different pairs of ports. With the worst one
and unmodified chronyd I see an asymmetry of about 25 ns and jitter of
about 140 ns. When I apply the PTP correction the asymmetry disappears
and jitter drops to 10 ns.
Here is a plot of the raw offset from the measurements log:
https://i.imgur.com/S6iywgH.png
I am happy to hear this works. That's an impressive graph.
I'm attaching the patch if you want to test it.
Thanks!
I'm curious about how well this works when there are multiple switches between server/client. I've got two slightly different variants of this switch, so I could potentially test this.
James