nanog mailing list archives

Re: NIST NTP servers


From: Eygene Ryabinkin <rea+nanog () grid kiae ru>
Date: Thu, 12 May 2016 05:23:55 +0300

Wed, May 11, 2016 at 05:20:28PM -0700, Scott Weeks wrote:
--- mel () beckman org wrote:
From: Mel Beckman <mel () beckman org>

Accurate time to the millisecond is pretty much 
essential for any network troubleshooting. Say 
you want to diagnose a SIP problem. You collect 
transaction logs from both phones, the VoIP 
gateway, and the PBX. Now you try to merge them 
to derive the sequence of events. You NEED 
millisecond accuracy.
----------------------------------------

If all logs are sent to a unix server that does 
syslogd the log entries would go into the file
in order no matter what timestamp is on them.

Modulo latencies and jitter from different machines to the log server.
Millisecond precision can be harmed by this, easily.  Especially by
jitter and order of millisecond here isn't something non-existent
in a long-distant networks.
-- 
Eygene Ryabinkin, National Research Centre "Kurchatov Institute"

Always code as if the guy who ends up maintaining your code will be
a violent psychopath who knows where you live.


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