[ntp:questions] Which ntp driver?
GDowd at symmetricom.com
Fri Mar 31 23:04:24 UTC 2006
Dare I admit that I haven't climbed the Wiki mountain yet? It seems to
be a contentious issue. Having said that, I'm all for notes on
application and suitability of the refclock drivers as well as common
usage. It would be nice after the release comes out to review, or
debate, the future of refclock drivers and their format. Dave's How to
build a refclock driver has been around for quite a while and is not
quite accurate anymore. Moreso if the configuration structure changes.
Of course, no one wants to change the existing stuff and possibly break
a legacy application but maybe we could deprecate some of the drivers.
Things I have thought about (in no particular order):
Do they all have to work forever?
Could we get burst/iburst to apply -or- Is there any reason to cap
minpoll. on a refclock (w/in reason)
Are we stuck in pll mode with high update rates. Can I use a different
filter on a refclock?
Is there a limitation on the number of useful samples I can capture per
poll (e.g. acts)
Does the prefer keyword work properly for refclocks? (to prevent
Can we please stop getting year from the host processor (when year is
available in driver) [make -g work for refclock]
Clarify the required data in refclock driver (and what is
dynamic/static) [e.g. I change refid on fly]
Add a private memory pointer to refclock structure to hold my data.
gdowd at symmetricom dot com (antispam format)
Technologist, TT&M Div.
"The current implementation is non-obvious and may need to be improved."
From: Danny Mayer [mailto:mayer at ntp.isc.org]
Sent: Friday, March 31, 2006 2:21 PM
To: Greg Dowd
Cc: questions at lists.ntp.isc.org
Subject: Re: [ntp:questions] Which ntp driver?
It would probably be useful to set up a table in the Twiki to show what
refclock drivers to use with which hardware along with the parameters
that should be set for each configuration. Otherwise it seems like a
Greg Dowd wrote:
> I haven't used these myself but our tech support guys say the output
> is likely the same on all of them. If no one chimes in, I'd suggest
> trying the GPS one, 15.
> Message: 10
> Date: 28 Mar 2006 12:33:33 -0800
> From: "vwvr6vw" <brian.l.hostetler at lmco.com>
> Subject: [ntp:questions] Which ntp driver?
> To: questions at lists.ntp.isc.org
> Message-ID: <1143578013.289572.36030 at z34g2000cwc.googlegroups.com>
> Content-Type: text/plain; charset="iso-8859-1"
> I am planning on hooking up a TrueTime XL-DC GPS receiver to an IBM
> processor running AIX 4.3. I'm new to ntp and I would like to know
> which ntp driver should be used for connecting to this receiver? The
> options I see are as follows:
> 5 - GOES TRUETIME
> 11 - OMEGA_TRUETIME
> 15 - GPSTM_TRUTIME
> 25 - TRUETIME
> Others seem to be using option 5. Is there any documentation around
> that shows which driver should be used?
> Greg Dowd
> gdowd at symmetricom dot com (antispam format) Technologist, TT&M Div.
> Symmetricom, Inc.
> "The current implementation is non-obvious and may need to be
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