Is there lag in a time sync?
 

Kia Ora
When I sync my PC by accessing a time source eg US Naval Observatory, is there
a detectable lag when my PC automatically updates.
I am in New Zealand, half way round the world on wireless access to my ISP.
Thanks
Mac

Re: Is there lag in a time sync?
 

On Fri, 7 May 2004 19:06:36 +0000 (UTC), Mac Lynch wrote:

>Kia Ora
>When I sync my PC by accessing a time source eg US Naval Observatory, is there

No source closer to your location? Answer lots..... see link below.

>a detectable lag when my PC automatically updates.

Shouldn't be. For Unices/Windows systems the NTP software should have an
option to log corrections. Otherwise if you set your clock to the wrong
date/time. Wait for the update (log file/event log) to arrive and check
if there is a delay.

You didn't mention anything about OS , if the time is actually correct
or it's wrong each time you start your PC, what client you may be using.

You have to be careful not to always use distant sources / stratum 1
some sources will block these requests. There is a polite way to do
things with NTP requests. Basically email the sysadmin for access if
required, use local sources, try and observe the service areas listed as
per examples,

http://www.eecis.udel.edu/~mills/ntp/clock1a.html

Basically it's Stratum 1/2 - ISP/Governent Lab/Other - You.

If you want to compare your PC time with other local / remote sources
try something like

http://www.satsignal.net/
top right - Net Tools / NTP Monitor

Again the polite way to use this is to maybe run it for only a few
minutes, if you are connecting to Stratum 1 / 2 servers.

If you have your own LAN, for Windows PCs user Tardis
http://www.kaska.demon.co.uk/ (as a server) to time sync from an
external source and re-broadcast to Win/Linux clients on your LAN. This
is the preferred route rather than you making multiple outgoing
requests.

For more info, (lots more) and technical try the newsgroup
comp.protocols.time.ntp
or same group
http://groups.google.com/groups?grou...ocols.time.ntp


>I am in New Zealand, half way round the world on wireless access to my ISP.

Doesn't matter, for you :-) that's the right side, half way round from
here.

http://www.ntp.org/
See 'Time Servers' list on the right hand side.


http://www.google.com/search?q=new+zealand+ntp+source
See the guide on the 1st link from that search.


Me

Re: Is there lag in a time sync?
 

Mac Lynch wrote:

> Kia Ora
> When I sync my PC by accessing a time source eg US Naval Observatory, is
> there a detectable lag when my PC automatically updates.
> I am in New Zealand, half way round the world on wireless access to my
> ISP. Thanks
> Mac
>
Time sync software detects any delay and adjusts for it. However, on the
Internet, "halfway around the world" is virtually the same as next door:
signals travel at the speed of light. There may be some delay in checking a
remote server because the signal must pass through more routers, but as I
said that's taken into account. You didn't specify which software you are
using to update your clock so I can't help you beyond that. You might check
the manual for your software and see if you can tell it to use a server
that is closer to you. google will help you find one. They all use the same
protocol so you don't have to worry about incompatibilities with your
software. If you are /that/ concerned with your clock being spot on, there
are some applications which will consult several servers and average
between them; some of these will even adjust your system's clock to
compensate for the drift. --Oh wait, that's Linux ntpd; never mind.

--
Gary G. Taylor * Rialto, CA
gary at donavan dot org / http:// geetee dot donavan dot org
"The two most abundant things in the universe
are hydrogen and stupidity." --Harlan Ellison