Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread William Unruh 
On 2017-02-02, sean  wrote:
> On 2017-02-01, David Taylor  wrote:
>>
>> Sean,
>>
>> Thanks for your comments - much of the Web site is comprised of my own 
>> notes to remind me what to do next time!  Still waiting for one minor 
>> operation, and then to see if (or should it be when?) the Crohn's returns.
>>
>
> Well your self made notes for yourself have proven to have a rich amount
> of helpful information. :) Keep the faith with your healing.
>
>> Unfortunately I can't be part of the pool as my ISP doesn't offer static 
>> addresses.
>>
>
> I posted a followup whether a hostname could be used in lieu leui of an
> IP address. I understand it can't change every few hours/days. Does your
> changed that frequently?
>
>> I don't know whether FreeBSD is better than Linux any more, others will 
>> need to answer that.  My FreeBSD box refused to update from FreeBSD 7 to 
>> FreeBSD 8, so I stuck Linux on it in desperation!
>
> Wow, those versions are well before my time with FreeBSD. I'm not sure
> if I'll be that concerned about the OS, and rather focus on the GPS
> equipment you linked to below.
>
>>
>> Another low-cost device is the Sure evaluation board:
>>
>>http://www.satsignal.eu/ntp/Sure-GPS.htm
>>
>>  
>> http://www.ebay.com/itm/SKG16A-Bluetooth-RS232-USB-UART-GPS-Module-Demo-Board-/230844194302
>>
>
> Thanks for the link! That's about half the price of the garmin and would
> likely get me better precision than just syncing to the NTP pool.

Yes.
>
>> Windows uses NTP but not with the reference implementation, so of 
>> unknown quality, and not manageable in the same way.  It used to be 
>> lousy, and I've not tested since then.
>>
>
> I think I'll install the ntp client on my windows machine and see what
> kind of time I can get.

You would probably be better off syncing a linux machine to the gps
board and then syncing the windows machine to that over the local Lan.


>
>> What will be good enough depends on your needs.  The lowest cost might 
>> be the Sure board attached to an existing FreeBSD box, running 24 x 7 
>> and in as stable a thermal environment as necessary.  Both the Raspberry 
>> Pi and BeagleBone Black are low-power devices and therefore low-cost to 
>> run 24 x 7, with the BBB having a slightly better Ethernet 
>> implementation if you need to get down to the tens of microseconds 
>> level, but with the Raspberry Pi have a much wider support even though 
>> it might offer (approx) fifties of microseconds.  Judge for yourself here:
>>
>>http://www.satsignal.eu/ntp/BBB-vs-RPi.html
>>
>> If you already have an RPi doing something, adding a NTP server to its 
>> tasks will make little extra load for an environment with a thousand or 
>> more clients
>>
>
> Incidentally I do have a BBB and a few raspberry pis. The BBB goes back
> and forth to/from work so I won't be able to use that as the NTP host.
>
> As an aside, have you done anything with SDR? You may be interested in
> this:
> https://github.com/flightaware/piaware
>

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Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread sean 
On 2017-02-01, David Taylor  wrote:
>
> Sean,
>
> Thanks for your comments - much of the Web site is comprised of my own 
> notes to remind me what to do next time!  Still waiting for one minor 
> operation, and then to see if (or should it be when?) the Crohn's returns.
>

Well your self made notes for yourself have proven to have a rich amount
of helpful information. :) Keep the faith with your healing.

> Unfortunately I can't be part of the pool as my ISP doesn't offer static 
> addresses.
>

I posted a followup whether a hostname could be used in lieu leui of an
IP address. I understand it can't change every few hours/days. Does your
changed that frequently?

> I don't know whether FreeBSD is better than Linux any more, others will 
> need to answer that.  My FreeBSD box refused to update from FreeBSD 7 to 
> FreeBSD 8, so I stuck Linux on it in desperation!

Wow, those versions are well before my time with FreeBSD. I'm not sure
if I'll be that concerned about the OS, and rather focus on the GPS
equipment you linked to below.

>
> Another low-cost device is the Sure evaluation board:
>
>http://www.satsignal.eu/ntp/Sure-GPS.htm
>
>  
> http://www.ebay.com/itm/SKG16A-Bluetooth-RS232-USB-UART-GPS-Module-Demo-Board-/230844194302
>

Thanks for the link! That's about half the price of the garmin and would
likely get me better precision than just syncing to the NTP pool.

> Windows uses NTP but not with the reference implementation, so of 
> unknown quality, and not manageable in the same way.  It used to be 
> lousy, and I've not tested since then.
>

I think I'll install the ntp client on my windows machine and see what
kind of time I can get.

> What will be good enough depends on your needs.  The lowest cost might 
> be the Sure board attached to an existing FreeBSD box, running 24 x 7 
> and in as stable a thermal environment as necessary.  Both the Raspberry 
> Pi and BeagleBone Black are low-power devices and therefore low-cost to 
> run 24 x 7, with the BBB having a slightly better Ethernet 
> implementation if you need to get down to the tens of microseconds 
> level, but with the Raspberry Pi have a much wider support even though 
> it might offer (approx) fifties of microseconds.  Judge for yourself here:
>
>http://www.satsignal.eu/ntp/BBB-vs-RPi.html
>
> If you already have an RPi doing something, adding a NTP server to its 
> tasks will make little extra load for an environment with a thousand or 
> more clients
>

Incidentally I do have a BBB and a few raspberry pis. The BBB goes back
and forth to/from work so I won't be able to use that as the NTP host.

As an aside, have you done anything with SDR? You may be interested in
this:
https://github.com/flightaware/piaware

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Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread sean 
On 2017-02-01, Miroslav Lichvar  wrote:
> On 2017-02-01, sean  wrote:
>> On 2017-01-30, William Unruh  wrote:
>>> You do not say which OS you use. Windows (which version?), Mac, linux,
>>> BSD?
>>
>> Primarily FreeBSD and OpenBSD, but also Linux. Knowning that, what's
>> that mean in terms of a ntp client?
>
> IIRC openntpd runs on all these systems, but reference clocks are
> supported only on OpenBSD. chrony supports FreeBSD and Linux (both with
> refclocks), but not OpenBSD. ntpd supports everything.
>

Cool. I'll probably install ntpd on my one windows laptop system to get
more accurate time to the NTP pool.

>>> chrony does not work on windows. ntpd is what what tends to ship with
>>> linux distros. chrony gives better time discipline but has a smaller
>>> user group. 
>>
>> Well if I use Chrony with a GPS unit on something like a raspberry pi,
>> would I be able to be apart of the NTP pool or is it limited to NTPD
>> users only?
>
> Yes, you can do that. The pool project page recommends ntpd, but it's
> not a requirement. There are quite a few openntpd and chrony servers in
> the pool, including a couple of my own.
>

ah, cool. I didn't know I could see the ntp source. I'll have to check
that out. I don't know if I'll be able to join the pool because I don't
have a static IP. Although, if I register with a DNS name, couldn't I
just update the A record if/when it changes?
something like time.example.com.

Thanks!

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Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread Dan Drown 

Quoting Jakob Bohm :

1. Do you know if anyone has tried using the real-time coprocessors on
  the BBB to more accurately track the PPS signal?


I have a driver for the BBB's input capture timer hardware here:  
https://github.com/ddrown/pps-gmtimer


There's a bug in the recent BBB kernels (4.4.17-ti) that I haven't  
been able to track down.  When you enable timer2, the ethernet  
hardware loses link.  So this driver only works on the older  
3.8.x-bone kernels.


The results were 30%-50% better offsets with pps-gmtimer vs pps-gpio.   
Both numbers are dwarfed by the network interface jitter for NTP  
clients (which is in the 15us-20us range for my environment).


There's some more info here (including a histogram comparing pps-gpio  
vs pps-gmtimer):  
https://blog.dan.drown.org/beaglebone-black-timer-capture-driver/



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Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread Brian Inglis 
On 2017-01-31 22:55, sean wrote:
> On 2017-01-30, David Taylor  wrote:
>> On 30/01/2017 04:13, sean wrote:
>>> I'm real interested in NTP and accurate time, hence why I'm on this
>>> newsgroup. I would like to look into getting a time sensor and I hear
>>> the Garmin GPS 18X is what some folks run unless they need much more
>>> precision. Is this still a pretty well regarding GPS unit for pretty
>>> accurate (I know that's highly subjective) time keeping? This would be
>>> a hobbyist thing and I'm not running an important business, if you were
>>> going to ask.
>>> Next question...Do most folks here use the NTPD client, or it is a
>>> mixture of Chrony and openNTPD? Maybe some folks just go with what ships
>>> with their OS?
>>> The comparison chart is pretty nice and lays each option out nicely:
>>> https://chrony.tuxfamily.org/comparison.html
>>> I think that's all for now. Feel free to provide any URLs to any
>>> resources I should check out about time sycing, NTP, etc.
>> I have been running NTP on multiple systems since 2002, including Linux 
>> and Windows (2000 and later), both with hardware sync (GPS18, GPS18x and 
>> multiple GPS devices for the Raspberry Pi), and with LAN and Wi-Fi 
>> network sources.  I find NTP easy to manage and monitor over multiple 
>> systems, and the fact that it runs on Windows, and can accept GPS 
>> devices on Windows very valuable.  You can easily get within 10 
>> microseconds in Linux (but be careful of the temperature and GPS antenna 
>> location), and within 200 microseconds on Windows when using an attached 
>> GPS/PPS device.
> Thank you for the reply. I found your website about 3 weeks ago and got
> the urge to checkout GPS devices, like the GPS18, Raspberry pi options,
> etc. Thank you for it and all of the graphs. You certainly have many Pis
> keep track of the time! I don't recall, are you apart of the NTP Pool?
> I found your website to have a wealth of great information that's quite
> well compiled and thoughout. I hope your health is much better this
> year and that you're on the road to recovery.
> Primarily I run FreeBSD and was surprised to learn that it can have
> better precision than Linux, although the articles I read were FreeBSD
> 8.0 era. Do you find FreeBSD generic kernel comparable with Linux? From
> what it sounds like, a Raspberry Pi with the device below will give me
> "pretty accurate" (my words) time, which I can use to sync my devices in
> my home.
>>http://www.satsignal.eu/mrtg/performance_ntp.php
>> For the Raspberry Pi:
>> https://store.uputronics.com/index.php?route=product/product_id=81
> That's pretty well priced, cheaper than the Garmin

For that and the below you also need power supply, antenna, and interface.

http://www.ebay.com/itm/Trimble-Resolution-T-Timing-GPS-module-12ns-1pps/252474351979

http://www.ebay.com/itm/UBLOX-LEA-5T-high-precision-timing-GPS-module-dev-board-1PPS-USB-RS232-ntp-ser/251785217093

For easy as Pi there's the GPS HAT:

https://www.adafruit.com/product/2324

which works fine on the Pi3 if you disable BT or switch BT to 
the mini-uart with a DT overlay despite AdaFruit statement 
(do web search for Adafruit Ultimate GPS HAT Pi3 NTP).

Cheapest Garmin 18x LVC I have found anywhere is US$60 (shipping 
extra) from my local dealer who also ships world wide from LV, NV:

http://www.gpscity.com/garmin-gps-18x-high-sensitivity-lvc.html
http://www.gpscity.ca/garmin-gps-18x-high-sensitivity-lvc.html

I run both of the above and average offset is low us with offset 
spiking up to about +/-50us, probably temperature swings. 

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread David Taylor 

On 01/02/2017 10:59, Jakob Bohm wrote:
[]

As I am looking at the BBB myself, here are some extra questions:

1. Do you know if anyone has tried using the real-time coprocessors on
  the BBB to more accurately track the PPS signal?

2. I presume the BBB could be put in a shielded case (I see some
  offered online).  Any experience with that?

Enjoy
Jakob


Jakob,

(1) No.  Do you mean using the counters to record the timing of the PPS 
more precisely?


(2) No, but without the BBB radiates more interference than the RPi.

--
Cheers,
David
Web: http://www.satsignal.eu

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Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread David Taylor 

On 01/02/2017 05:55, sean wrote:
[]

Hi Dave,

Thank you for the reply. I found your website about 3 weeks ago and got
the urge to checkout GPS devices, like the GPS18, Raspberry pi options,
etc. Thank you for it and all of the graphs. You certainly have many Pis
keep track of the time! I don't recall, are you apart of the NTP Pool?

I found your website to have a wealth of great information that's quite
well compiled and thoughout. I hope your health is much better this
year and that you're on the road to recovery.

Primarily I run FreeBSD and was surprised to learn that it can have
better precision than Linux, although the articles I read were FreeBSD
8.0 era. Do you find FreeBSD generic kernel comparable with Linux? From
what it sounds like, a Raspberry Pi with the device below will give me
"pretty accurate" (my words) time, which I can use to sync my devices in
my home.



   http://www.satsignal.eu/mrtg/performance_ntp.php

For the Raspberry Pi:


https://store.uputronics.com/index.php?route=product/product_id=81



That's pretty well priced, cheaper than the Garmin


In terms of installations, I think that NTP will have by far the
greatest number, and of the three you listed, only NTP runs on Windows.


Well I don't really have any Windows installations, but I will keep NTP
in mind when I want to run time syncing on Windows. As an aside, what
does Windows natively use to keep time and sync?

Thanks,
Sean


Sean,

Thanks for your comments - much of the Web site is comprised of my own 
notes to remind me what to do next time!  Still waiting for one minor 
operation, and then to see if (or should it be when?) the Crohn's returns.


Unfortunately I can't be part of the pool as my ISP doesn't offer static 
addresses.


I don't know whether FreeBSD is better than Linux any more, others will 
need to answer that.  My FreeBSD box refused to update from FreeBSD 7 to 
FreeBSD 8, so I stuck Linux on it in desperation!


Another low-cost device is the Sure evaluation board:

  http://www.satsignal.eu/ntp/Sure-GPS.htm


http://www.ebay.com/itm/SKG16A-Bluetooth-RS232-USB-UART-GPS-Module-Demo-Board-/230844194302

Windows uses NTP but not with the reference implementation, so of 
unknown quality, and not manageable in the same way.  It used to be 
lousy, and I've not tested since then.


What will be good enough depends on your needs.  The lowest cost might 
be the Sure board attached to an existing FreeBSD box, running 24 x 7 
and in as stable a thermal environment as necessary.  Both the Raspberry 
Pi and BeagleBone Black are low-power devices and therefore low-cost to 
run 24 x 7, with the BBB having a slightly better Ethernet 
implementation if you need to get down to the tens of microseconds 
level, but with the Raspberry Pi have a much wider support even though 
it might offer (approx) fifties of microseconds.  Judge for yourself here:


  http://www.satsignal.eu/ntp/BBB-vs-RPi.html

If you already have an RPi doing something, adding a NTP server to its 
tasks will make little extra load for an environment with a thousand or 
more clients


--
Cheers,
David
Web: http://www.satsignal.eu

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Re: [ntp:questions] Help with RESTRICT

2017-02-01 Thread David Taylor 

On 31/01/2017 23:35, Phil Lee wrote:
[]

That would be correct IF your LAN is on 192.168.0.n
The zero should be replaced with whichever of the /24 subnets under
192.168 is relevant for the actual LAN address scheme.  Some DHCP
servers on routers default to 192.168.1.n, for example.

[]

Well, of course!  I only showed that as a working example.  I hope the 
address specification issues of the OP can be resolved.


--
Cheers,
David
Web: http://www.satsignal.eu

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Re: [ntp:questions] Time syncing with something other than ntpd

2017-02-01 Thread Jakob Bohm 

On 01/02/2017 06:55, sean wrote:

On 2017-01-30, David Taylor  wrote:

On 30/01/2017 04:13, sean wrote:

Hi All,

I'm real interested in NTP and accurate time, hence why I'm on this
newsgroup. I would like to look into getting a time sensor and I hear
the Garmin GPS 18X is what some folks run unless they need much more
precision. Is this still a pretty well regarding GPS unit for pretty
accurate (I know that's highly subjective) time keeping? This would be
a hobbyist thing and I'm not running an important business, if you were
going to ask.

Next question...Do most folks here use the NTPD client, or it is a
mixture of Chrony and openNTPD? Maybe some folks just go with what ships
with their OS?
The comparison chart is pretty nice and lays each option out nicely:
https://chrony.tuxfamily.org/comparison.html

I think that's all for now. Feel free to provide any URLs to any
resources I should check out about time sycing, NTP, etc.


Sean,

I have been running NTP on multiple systems since 2002, including Linux
and Windows (2000 and later), both with hardware sync (GPS18, GPS18x and
multiple GPS devices for the Raspberry Pi), and with LAN and Wi-Fi
network sources.  I find NTP easy to manage and monitor over multiple
systems, and the fact that it runs on Windows, and can accept GPS
devices on Windows very valuable.  You can easily get within 10
microseconds in Linux (but be careful of the temperature and GPS antenna
location), and within 200 microseconds on Windows when using an attached
GPS/PPS device.



Hi Dave,

Thank you for the reply. I found your website about 3 weeks ago and got
the urge to checkout GPS devices, like the GPS18, Raspberry pi options,
etc. Thank you for it and all of the graphs. You certainly have many Pis
keep track of the time! I don't recall, are you apart of the NTP Pool?

I found your website to have a wealth of great information that's quite
well compiled and thoughout. I hope your health is much better this
year and that you're on the road to recovery.

Primarily I run FreeBSD and was surprised to learn that it can have
better precision than Linux, although the articles I read were FreeBSD
8.0 era. Do you find FreeBSD generic kernel comparable with Linux? From
what it sounds like, a Raspberry Pi with the device below will give me
"pretty accurate" (my words) time, which I can use to sync my devices in
my home.



   http://www.satsignal.eu/mrtg/performance_ntp.php

For the Raspberry Pi:


https://store.uputronics.com/index.php?route=product/product_id=81



That's pretty well priced, cheaper than the Garmin


In terms of installations, I think that NTP will have by far the
greatest number, and of the three you listed, only NTP runs on Windows.


Well I don't really have any Windows installations, but I will keep NTP
in mind when I want to run time syncing on Windows. As an aside, what
does Windows natively use to keep time and sync?



Microsoft's own NTP/SNTP client, known as W32Time.  It has 3 major
operational modes:

- Triggered SNTP mode, where it is launched (briefly) from a weekly
 "cron" job, this is the default for machines not in a domain (because
 such machines also default to hitting the same overloaded public
 server, but the two settings are not tied directly).

- A regular NTP/SNTP mode with registry/command line options to set NTP
 modes etc., this is the default for machines in a domain (because such
 machines also default to using the W32Time on the nearest domain
 controller as its time source).  Instructions for switching to this
 mode are somewhat hard to find, to reduce the risk of dumb users
 enabling this mode while still using one of the overloaded public
 servers.

- A broken SNTP mode where various protocol details are wrong, this was
 a property of old versions of W32Time but is still mentioned in
 various NTPD related documents.


Enjoy

Jakob
--
Jakob Bohm, CIO, Partner, WiseMo A/S.  https://www.wisemo.com
Transformervej 29, 2860 Søborg, Denmark.  Direct +45 31 13 16 10
This public discussion message is non-binding and may contain errors.
WiseMo - Remote Service Management for PCs, Phones and Embedded

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