Leap second tonight

Tero Toikkanen Tero.Toikkanen at nebula.fi
Wed Mar 18 03:11:22 CDT 2009


> Not being a time geek, since Cisco's were called out for being wild
> jitter-mongers... how much jitter are we talking about?
> 
> Clock is synchronized, stratum 2, xxxxxxxxxxxxxxxxxxxxxxxx
> nominal freq is 250.0000 Hz, actual freq is 249.9989 Hz, precision is 2**18
> reference time is CD6A7CD4.45A9BB00 (19:47:32.272 UTC Tue Mar 17 2009)
> clock offset is 2.0581 msec, root delay is 29.62 msec
> root dispersion is 6.81 msec, peer dispersion is 3.30 msec
> 
> Are we talking about +/- 30 seconds, or a problem bounded by +/- 30 msec?

I've actually been gathering some statistics on this using Munin (http://munin.projects.linpro.no/) on my linux server. There's currently 10 ntp servers being monitored and one of them is a 7600-series Cisco, which is handling quite a bit of traffic (CPU load around 20%). Here are the Munin graphs for it http://dx.fi/alt/ntp/7600.png (times in Finnish time, UTC+2).

In comparison, here are the same graphs for time1.mikes.fi (a stratum-2 clock provided by the Finnish Centre for metrology and accreditation) http://dx.fi/alt/ntp/time1.mikes.fi.png and for Netnods stratum-1 clock in Stockholm http://dx.fi/alt/ntp/ntp1.sth.netnod.se.png

Best regards,
--
Tero Toikkanen
Nebula Oy




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