[time-nuts] OT: NTP server questions

[Chris Albertson]

On Tue, Nov 30, 2010 at 6:46 AM, Robert Darlington
<rdarlington at gmail.com> wrote:
> Basically I need something to provide time within one second.  I can't roll
> my own in this case.

I assume you don't have internet access.  If you had access only a few
times per day you can get better than 1 second using remote servers.

It's not the cost but the fact that you will have one more computer to
haul around
and you add another single point failure to the system.
For 1 second accuracy you could simply run NPT servers on one or more
of the othercomputers.   Run an NTP server process on each of the
other servers and
plug in a standard USB GPS unit.  If you are driving around likely you even
have a GPS unit already.  Yes it needs to operate in that environment
but what can be more robust than zero additional hardware?

If the requirement is for no beter than 100 ms there is no need for a dedicated
server hardware for NTP.  In fact you should run an NTP server process
on all your server computers so as not to have a single point of
failure.    Also
you be surprised how well a group of NTP peers maintain time even when
cut off from a tier one server.  The clients can figure out which of several
servers have the best clocks and can do about 1 second per day even with
no GPS link

So in this case I'd suggest not buying a dedicated NTP server at all.  Then
yopu have near cost, zero space, zero power and zero chance of failure.

-- 
=====
Chris Albertson
Redondo Beach, California