[ntp:questions] Time server question

Chris xxx.syseng.yyy at gfsys.co.uk
Tue Jun 25 16:04:02 UTC 2019

On 06/25/19 10:52, David Taylor wrote:
> On 25/06/2019 01:33, Chris wrote:
> []
>> Thanks for all the replies. I guess the next thing to do is to build
>> a working system, then evaluate to see how it can be improved. All
>> the kit is in the same rack and with dedicated hardware interfaces,
>> network latency shouldn't be a problem. This is effectively a real
>> time requirement, so any code running needs to be consistent in terms
>> of  response time to minimise jitter on the timing. Need to get
>> a feel for acceptable delay and response times, so will look to see
>> what others have done in the past.
>> I like the idea of using a 1 pps signal from the gps for fine tuning.
>> Rough time and date via the network ntp and the 1pps to fine tune it.
>> That could maintain the stratum 1 timing quality, as the 1pps is
>> generally within 10's of nS of UTC, but need to look into how ntpd
>> would handle that and also how to introduce that into the system.
>> Already use an ex telco gps for a lab frequency standard, but of
>> course, frequency != time of day. A dedicated embedded solution might
>> be the best bet, but other options might include a cheap netgear
>> router to provide the isolation, as it would only be handling ntp
>> packets at low and consistent system and network load.
>> Nothing is ever as easy as it seems, as usual...
>> Chris
> Chris, would one or more of these help?
> http://www.leobodnar.com/shop/index.php?main_page=product_info&products_id=272
> No OS to get in the way.

Thanks, neat looking box, but already have the gps ntp servers. The
question was how to maintain the stratum one accuracy while
going through a firewall device to the net. looks like all the
hard work has been done though. Open source comes to the rescue
yet again...


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