[ntp:questions] ntp server specs

Chris Albertson albertson.chris at gmail.com
Mon Jun 13 06:08:54 UTC 2011

On Sun, Jun 12, 2011 at 3:55 PM, chipper <black at intre.nt> wrote:
> If I wanted to feed a group of linux machine from a common PPS source, what
> hardware and which Linux would I need?

So now you are saying yu are NOT gong to use NET over Ethernet but
send a PPS to each computer.
That can work but yu will need to build a PPS distribution network.
The first quuestion Ihave is what is the distance.  Are al the
computers in one room, in the same rack? or is this a large campus and
some are 1,000 feet away.   It can be done.   You can use cat-5 wire
for a PPS and it will go abut as far as Ethernet but of course hubs
and switches will not work.

ANy recent Linux kernel will work.  It needs to have PPS built-in.

A reasonable design would be to have NTP serve the time to the
computers using some pool servers as a reference and then also
distribute PPS

At home I push PPS throough cat-5 wire for abut 80 feet and I use an
RS-232 driver chip and send the signal over cat-5 at rs232 voltage
levels.   I would not try to send TTL level that far.  For very long
runs use RS442.  442 is good or for at least 1,000 feet.
Chris Albertson
Redondo Beach, California

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