[aklug] Re: ntp and freebsd?

On Sat, Mar 24, 2012 at 1:51 PM, Christopher Brown <cbrown@woods.net> wrote=
:
> On 3/16/12 4:47 PM, Shane Spencer wrote:
>> On Fri, Mar 16, 2012 at 3:45 PM, Leif Sawyer <lsawyer@gci.com> wrote:
>>> GCI has stratum one time here in Anchorage and down in Seattle.
>>>
>>> ntp.gci.net =3DA0slaves off of it, so it's stratum-2 =3DA0 which is fin=
e
>>> for nearly everybuggy.
>>>
>>
>> Sweet.. what makes up the Stratum 1 devices?
>
>
> The most common source for a Stratum 1 NTP system is GPS.
>
>
> At the base level, it could be a high end consumer type GPS units with
> timing outputs (has a X PPS (pulse per second), usually 1PPS) to provide
> interval, and serial output of time that can be identified accurately
> against the pulse it applies to (there are a number of low end units
> with 1PPS out but faulty Q/C in the design phase. =A0They output the data=
,
> but you cannot accurately match serial fed time data with which pulse it
> applied to). =A0Generally needs a good fixed external antenna with a clea=
r
> view to work well.
>
>

Indeed. I wasn't sure if GPS was considered Stratum 1. I had to use
USB GPS devices when working on machines that didn't have RTCs. I'd
get the initial time sync then let NTP start up and start tuning
during boot up.
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Received on Sat Mar 24 21:02:37 2012