[ntp:questions] Re: NTP Stats within norm?

Scott L. Glidden scottg at industrial-logic.com
Tue May 30 13:15:58 UTC 2006


> Err. . . .  What sort of a "fudge factor" are you talking about?

To offset the delay from using Bluetooth vs. RS232

>
> If you have a GPS receiver, you will probably get better time from it than 
> you can get over the internet.   If you have a receiver designed for 
> timing service, there should be no question about it.  But even a receiver 
> designed for navigation might still deliver better time than the internet.

I will post my current stats at the bottom of this page..

> Your GPS receiver will make your server Stratum 1.  Other stratum 1 
> servers may wish to peer with you; this is something you should discuss 
> with the owners thereof.  Your chances of finding someone to peer with are 
> better if: you have a reliable environment; e.g. you don't reboot 
> randomly, you don't succumb to power failures unless they are of extended 
> duration, your network connection is 24x7 and maybe you have redundant 
> network connections.  A static IP address is pretty much a requirement. 
> I'd say that a GPS receiver designed for timing service is probably also a 
> requirement.

The whole server farm is on a APC Smart UPS 2200 va and 1400 va (Server 
2003, Solaris 10, FreeBSD, Linux 2.6) Static IP

>
> People who operate stratum 1 servers may be hobbyists such as I, but it's 
> more likely that they have compelling business requirements for accurate 
> and reliable time.

Yes, to keep my server logs sane. To help tie events together to determine 
cause/effect, etc...

Here is a screen cap of my current stats. NTPD has not settled as I just did 
a restart to tweak my fudge factor, so I imagine jitter should improve over 
time..

[root at ns2 scripts]# ./ntpstat
     remote           refid      st t when poll reach   delay   offset 
jitter
==============================================================================
*GPS_NMEA(0)     .GPS.            0 l   35   64  377    0.000    3.501 
2.729
+time-a.nist.gov .ACTS.           1 u  225  256  377   48.358    0.560 
7.257
+time-b.nist.gov .ACTS.           1 u  221  256  377   50.417   -0.309 
7.289
+ntp1.twc.weathe .CDMA.           1 u  222  256  377   33.810    2.548 
1.752
+ntp2.twc.weathe .CDMA.           1 u  227  256  377   34.419    4.382 
3.312
+ns1.usg.edu     130.207.244.240  2 u  220  256  377   25.399    1.904 
3.178
+ns2.usg.edu     .GPS.            1 u  220  256  377   31.233    1.589 
2.328
+ns3.usg.edu     65.212.71.102    2 u  226  256  377   26.641    1.430 
3.278
-ns4.usg.edu     130.207.244.240  2 u  222  256  377   32.992    3.330 
3.656
-caesar.cs.wisc. 129.7.1.66       2 u  223  256  377   47.108   -3.876 
2.212
+ntp2.usno.navy. .USNO.           1 u  219  256  377   55.524    1.911 
3.212
+ntp1.usno.navy. .USNO.           1 u  227  256  377   55.743    1.295 
2.919
assID=0 status=0474 leap_none, sync_uhf_clock, 7 events, 
event_peer/strat_chg,
version="ntpd 4.2.1p252-RC at 1.1514 Tue May 16 11:30:27 UTC 2006 (1)",
processor="i686", system="Linux/2.6.11-6mdksmp", leap=00, stratum=1,
precision=-19, rootdelay=0.000, rootdispersion=9.081, peer=3640,
refid=GPS, reftime=c826c3aa.fe11bedb  Tue, May 30 2006  9:14:18.992,
poll=9, clock=c826c3ce.07aca035  Tue, May 30 2006  9:14:54.029, state=4,
offset=2.441, frequency=-39.483, jitter=3.202, noise=2.517,
stability=0.436






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