[questions] Re: NTP community feels broken
On Friday, June 17, 2022 at 2:24:05 PM UTC-4, chris wrote: > That's correct, but the various issues with the system have been > discussed for years, yet nothing ever gets done about it. That's the > point that Philip above was making... Of course working with Harlan is difficult. Coming here to advise us of that won't result in any changes. Fortunately there are alternatives so there's no need to fret about the "reference" implementation. The issue with your posts is that they were confusing. Or wrong. -- This is questions@lists.ntp.org Subscribe: questions+subscr...@lists.ntp.org Unsubscribe: questions+unsubscr...@lists.ntp.org
[questions] Re: NTP community feels broken
On Friday, June 17, 2022 at 2:33:35 PM UTC-4, David Woolley wrote: > On 17/06/2022 19:14, Paul G wrote: > > Where is it in this > > tarball:http://www.eecis.udel.edu/~ntp/ntp_spool/ntp4/ntp-4.2/ntp-4.2.8p15.tar.gz > > > > > > If it's not there then you're probably in the wrong list/group. > This group is about the NTP protocol I said probably because other major projects have (or should have) their own discussion channels. -- This is questions@lists.ntp.org Subscribe: questions+subscr...@lists.ntp.org Unsubscribe: questions+unsubscr...@lists.ntp.org
[questions] Re: NTP community feels broken
On Friday, June 17, 2022 at 2:12:52 PM UTC-4, chris wrote: > Nothing to do with products. ntp.org has a monitoring system that polls > every server in its database to verify that it's reachable. Perhaps you mean pool.ntp.org. It's in the ntp.org namespace but it's a separate project run by Ask Bjørn Hansen. -- This is questions@lists.ntp.org Subscribe: questions+subscr...@lists.ntp.org Unsubscribe: questions+unsubscr...@lists.ntp.org
[questions] Re: NTP community feels broken
On Friday, June 17, 2022 at 11:24:31 AM UTC-4, chris wrote: > It's the code that polls ntp servers to verify that they are up. Where is it in this tarball: http://www.eecis.udel.edu/~ntp/ntp_spool/ntp4/ntp-4.2/ntp-4.2.8p15.tar.gz If it's not there then you're probably in the wrong list/group. -- This is questions@lists.ntp.org Subscribe: questions+subscr...@lists.ntp.org Unsubscribe: questions+unsubscr...@lists.ntp.org
[questions] Re: NTP community feels broken
On Friday, June 17, 2022 at 9:37:15 AM UTC-4, chris wrote: > The problem is the monitoring software What software product/program do you mean? -- This is questions@lists.ntp.org Subscribe: questions+subscr...@lists.ntp.org Unsubscribe: questions+unsubscr...@lists.ntp.org
Re: [ntp:questions] Quality vs. Quantity
(I inadvertently sent this only to Terje Mathisen) On Sun, Mar 23, 2014 at 12:07 AM, Danny Mayer wrote: What do you mean by load-balancing? NTP cannot be load-balanced. Of course it can (at some cost). On Sun, Mar 23, 2014 at 3:43 AM, Terje Mathisen wrote: You really do NOT want load-balancing of ntp servers!!! Ideally the server would manage this but address based load balancing (presumably as practiced by USNO) solves some problems. DNS balancing (viz. time.nist.gov or pool.ntp.org) is pretty weak but some of that can be mitigated in the server. Still I'd rather have three IP addresses fronting 300 servers than three IP addresses fronting three servers assuming the goal is resilient remote service. But I might still question the assumptions of the OP (the question is unclear) since I expect the number of queries to central public infrastructure to decline over time as the number of clients decrease. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Roof antenna, which one, would you bother?
On Friday, January 3, 2014 5:54:45 AM UTC-5, Ralph Aichinger wrote: Or would you not bother at all, and just put some puck into the window (which probably works too)? I'd put a timing antenna in the attic (used Symmetricom 58532A/VIC100s, which I have, are cheap). I have one near the ceiling on the upper floor and it's fine for a modern (SMT) GPS but only acceptable for older (T-bolt) units. I also have mag puck in south facing window. The 58532A is much better. Finish up with a GPS with some internal visibility (e.g. SMT), a Symmetricom/Agilent/HP splitter and Bob's your uncle. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How to determin hardware latency for PPS offset given simple tools.
On Thursday, June 20, 2013 5:51:50 PM UTC-4, E-Mail Sent to this address will
be added to the BlackLists wrote:
enable stats [etc. etc.]
As noted earlier I've done that or it's not applicable. E.g. I only use the
PPS driver and my seconds are numbered by an appliance that doesn't run ntpd.
On one system at a time, ...
have several other NTP servers configured {I usually shoot for 6 to 10}
I don't have six to ten stratum one servers (but maybe I should) and it doesn't
seem useful to compare my 500 microsecond offsets to non-local clocks.
with all involved systems continuously running for more than one day;
take an average ...
In another thread (and some here) I explain how I've done that and I don't
really like the e.g. 124 microsecond time1 I derived. However it does result
in O(1) microsec. offsets between some of my clocks.
perhaps the PPS signal is inverted?
It's not.
It seemed like David Taylor covered that on may 25th.
Yes. While I appreciate the suggestions and the good will behind them they
don't seem informed by my question/problem description.
My key point is that ntpq appears to be telling me odd things. E.g. my network
is low latency, symmetric and consistent but some of my offsets are one or two
orders of magnitude beyond other offsets.
So my question is how to find what I hope is hardware latency using the tools
at hand or the coverse given multiple S1 clocks with O(10) microsecond offsets
which one is right.
I expect I will move a set of them to a 10/100 switch and see if that makes a
difference.
Ideally all my clocks pairs would look like this (both have time1 0):
localhost oPPS(0) .PPS. ... 3770.0000.001 0.001
black +aster .PPS. ... 3770.065 -0.003 0.004
localhost oPPS(0) .PPS. ... 3770.0000.000 0.004
aster +black .PPS. ... 3770.0660.007 0.010
But maybe some of them are just not up to the task:
aster *ntp1 .PPS. ... 3770.5260.129 0.166
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Re: [ntp:questions] How to determine hardware latency for PPS offset given simple tools.
On Friday, June 21, 2013 9:16:28 PM UTC-4, Charles Elliott wrote: You may be making a mistake using stratum 1 servers All the S1 servers are on my local network. I (temporarily) have six. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How to determin hardware latency for PPS offset given simple tools.
On Sunday, May 26, 2013 5:25:28 PM UTC-4, unruh wrote: Lan will have delays of the order of .15ms (worse for gigabit) This not the delay reported by ntpq. Is it wrong or are you talking about another measurement? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How to determin hardware latency for PPS offset given simple tools.
On Saturday, May 25, 2013 1:06:48 AM UTC-4, unruh wrote: GPS receivers are not particularly good time sources UNLESS you use PPS. All of my clocks use PPS and in fact none of them use GPS to number the seconds except the one that uses refid GPS. That clock is a purpose built NTP-equivalent server called a Laureline which uses PPS and numbers seconds via serial input. Per the refclock document the PPS/NMEA (20/22) drivers use time1 to correct for PPS offset while 22 uses time2 to correct for serial latency. Since the clocks differ by O(100 microsec) without time1 correction I assumed that was internal rather than network latency. If you use PPS they should all agree to the 1micro second level. They do per ntpq given resp. 124, 151 and 85 microsecond time1. grabbing times via the net from the those computers will be dominated by network issues. I've been assuming that since I get fairly consistent offsets (fudged or not) and jitter that network latency is not the culprit. But I'm clearly confused about something. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How to determin hardware latency for PPS offset given simple tools.
On Saturday, May 25, 2013 3:05:13 AM UTC-4, David Taylor wrote: What happens with the fudge set to zero? Please show the table for each machine. Showing 192.168.0.2 and .244 with time1 = 0 as compared to the first post where time1 was ~100 microsec. These two have gigabit interfaces. 0.2 is driven by a Garmin 18x and 0.244 is driven by a Firefly (I). 0.2 remote refid st t when poll reach delay offset jitter == o127.127.22.0.PPS.0 l18 3770.000 -0.001 0.002 +192.168.0.244 .PPS.1 u-8 3770.075 -0.128 0.001 *192.168.0.210 .GPS.1 u78 3770.5190.117 0.098 0.244 remote refid st t when poll reach delay offset jitter == o127.127.22.0.PPS.0 l58 3770.0000.000 0.002 +192.168.0.2 .PPS.1 u48 3770.0790.132 0.003 +192.168.0.210 .GPS.1 u48 3770.5470.253 0.135 *192.168.0.192 .PPS.1 u38 3770.4750.262 0.036 ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] How to determin hardware latency for PPS offset given simple tools.
I have four GPS receivers into four different computers. I've assumed that I should be able to get small offsets between them but to do so I need to set time1. If that's the correct approach how do I pick the right system to be the benchmark. So far I've just been assuming that the purpose built M. Tharp server should have the lowest latency but I'm not sure -- in any case, at present, I can't adjust it. Each machine in the truncated table below (except 210) has a time1 value derived in an ad hoc fashion. l rrefid st delay offset jitter == 1 o22.0 .PPS.0 0.000 -0.001 0.001 2 +244 .PPS.1 0.0680.000 0.006 2 *210 .GPS.1 0.514 -0.008 0.136 2 +192 .PPS.1 0.4550.008 0.032 I feel as if this topic should be clearly explained somewhere but I've been unable to find it. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] PPS woes
I split the gps+pps (20) into gps and pps (20 22) and that solved the problem. I do wish I knew what happened. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
