[Lowfer] NTP software

[kg5nm at comcast.net]

NTP is not built into any Windows operating system.  Microsoft chose SNTP which is a very different solution to the operating system time problem.

SNTP uses a jam-sync approach whereby every "x" seconds it force-corrects the system time regardless of it's error.  This creates a saw-tooth drift shape determined by the local clock drift rate and the update interval.

NTP uses a complex algorithm to continuously update the system clock.  The instantaneous time error of an NTP corrected operating system will always be dramatically lower unless you manage to check the SNTP corrected system immediately following an update.

There is a version of NTP available to the time savvy Windows user:  http://www.meinberg.de/english/sw/ntp.htm

Anyone using Dimension 4, AboutTime or any other SNTP-based solution should at LEAST understand what they are really doing to their system clock.  David Taylor's NTPmonitor (http://www.david-taylor.myby.co.uk/software/net.htm) will intuitively show you what is really going on with SNTP.

Whether SNTP is the right solution for you is between you and the problem you are solving but once you study this for about 5 minutes you will realize that you can do dramatically better for very little effort.

73's de kg5nm


----- Original Message -----
From: "Stewart Bryant" <stewart at g3ysx.org.uk>
To: "Discussion of the Lowfer (US, European, &amp; UK) and MedFer bands" <lowfer at mailman.qth.net>
Sent: Wednesday, December 31, 2008 3:27:03 AM GMT -07:00 US/Canada Mountain
Subject: Re: [Lowfer] NTP software

jrusgrove at comcast.net wrote:
> I use D4time on both 98 and XP.
> 
> http://www.thinkman.com/dimension4/
> 
> Jay
> 

For windows XP or Vista, or most other O/S,
NTP is built into the O/S. You should tweek the
update parameter to update the O/S clock more
frequently as it is set very high (weekly) by
default in M$, and you need it to be shorter.

When picking a server, the goal is not to
find the best quality server per se, but to
find the one that gives the best time delivered
to you. So a higher stratum time server within
your own ISP may well be better than a low
stratum further away.

NTP works best when it is left to run rather than
being turned on/off as it needs to train the
path and the oscillator.

Stewart/G3YSX




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