John Ackermann N8UR wrote:
Geoff Powell said the following on 04/23/2006 05:42 PM:
Is PPS kernel discipline compiled into the default FreeBSD kernel?
No, but it's a pretty easy thing to turn on -- you add a line to the
config file and tell it to go. Pretty straightforward, *once* you
In message [EMAIL PROTECTED], Geoff Powell writes:
Meanwhile, FreeBSD with your patches on a NET4501 will give units of
microseconds?
It's all in stock FreeBSD, no patches needed.
The major problem you will have is that NTPD isn't very good once
you get down into microseconds.
Yes, I am aware
In article [EMAIL PROTECTED], Poul-Henning Kamp
[EMAIL PROTECTED] writes
In message [EMAIL PROTECTED], Geoff Powell writes:
So you'd recommend a 4501, with FreeBSD in Compact Flash? I wanted to
use CF anyway, since a box running 24/7 is not the best environment in
which to have moving parts. The
I've just started getting interested in precision timekeeping - if you
can call an offset from UTC that is measured in units of milliseconds
precision.
My current timeserver is a Buffalo Linkstation, patched to run Debian
Stable, and slaved via 2MBit ADSL to my ISPs Stratum 2 timeserver, using
You'll get more than you expect -- the offset you're observing on
ADSL is very likely wrong, because the delays your packets experience
on adsl aren't symmetric. NTP assumes symmetry. So I wouldn't
actually believe that a 1ms offset is really 1ms off, depending on
the RTT to your ISP.
David Andersen wrote:
You'll get more than you expect -- the offset you're observing on ADSL
is very likely wrong, because the delays your packets experience on
adsl aren't symmetric. NTP assumes symmetry. So I wouldn't actually
believe that a 1ms offset is really 1ms off, depending on the
In article [EMAIL PROTECTED], John Ackermann N8UR
[EMAIL PROTECTED] writes
FreeBSD is definitely the best tuned OS for NTP timekeeping, but Linux
can do OK. The biggest problem is that there's no kernel support for
PPS signals in the 2.6 series of kernels. There is a patch available
for a few
In article [EMAIL PROTECTED], David
Andersen [EMAIL PROTECTED] writes
You'll get more than you expect -- the offset you're observing on
ADSL is very likely wrong, because the delays your packets experience
on adsl aren't symmetric. NTP assumes symmetry. So I wouldn't
actually believe that
Geoff Powell wrote:
And - most OSes should do the trick. FreeBSD has a really nice
precision timekeeping interface, though -- and it makes a marvelously
solid time server. I'm running it on a few Net4801s and recommend
it. You can very easily build an image for it using another
In article [EMAIL PROTECTED], John Pettitt
[EMAIL PROTECTED] writes
I'll second the soekris box - my box time.no-such-agency.net is a 4801
running FreeBSD with a GPS18LVC.You can expect offsets in the +/-
5us range except when the box is stressed - the standard xtal in the box
is not
Geoff Powell said the following on 04/23/2006 05:42 PM:
Is PPS kernel discipline compiled into the default FreeBSD kernel?
No, but it's a pretty easy thing to turn on -- you add a line to the
config file and tell it to go. Pretty straightforward, *once* you find
the instructions.
I am not
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