Mischanko, Edward T wrote:
> My understanding is that IP addresses in the
> 192.168.xxx.xxx range are not routable?
RFC1918 Private Networks: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
Those IPv4 reserved addresses may not be internet routable,
however they are internal enterprise intranet routab
mischanko=arcelormittal@lists.ntp.org
> [mailto:questions-
> bounces+edward.mischanko=arcelormittal@lists.ntp.org] On
> Behalf Of A C
> Sent: Tuesday, August 30, 2011 3:25 PM
> To: questions@lists.ntp.org
> Subject: Re: [ntp:questions] Questions about joining
> pool.ntp.org
>
On 2011-08-31, Chris Albertson wrote:
> positional accuracy is
>
> On Wed, Aug 31, 2011 at 9:08 AM, unruh wrote:
>
>> On 2011-08-31, Uwe Klein wrote:
>> > David J Taylor wrote:
>> >> How does this square with those who claim 4ns from their GPS devices?
>> >
>> > Pfft.
>> >
>> > The defining docum
positional accuracy is
On Wed, Aug 31, 2011 at 9:08 AM, unruh wrote:
> On 2011-08-31, Uwe Klein wrote:
> > David J Taylor wrote:
> >> How does this square with those who claim 4ns from their GPS devices?
> >
> > Pfft.
> >
> > The defining document is rather old I guess. A lot happened in between
unruh wrote:
On 2011-08-31, Uwe Klein wrote:
David J Taylor wrote:
How does this square with those who claim 4ns from their GPS devices?
Pfft.
The defining document is rather old I guess. A lot happened in between.
( I looked into GPS in my diploma thesis ~1987 and not much after that )
T
unruh wrote:
> On 2011-08-31, Uwe Klein wrote:
>> David J Taylor wrote:
>>> How does this square with those who claim 4ns from their GPS devices?
>>
>> Pfft.
>>
>> The defining document is rather old I guess. A lot happened in between.
>> ( I looked into GPS in my diploma thesis ~1987 and not muc
On 2011-08-31, Uwe Klein wrote:
> David J Taylor wrote:
>> How does this square with those who claim 4ns from their GPS devices?
>
> Pfft.
>
> The defining document is rather old I guess. A lot happened in between.
> ( I looked into GPS in my diploma thesis ~1987 and not much after that )
The GPS
David J Taylor wrote:
How does this square with those who claim 4ns from their GPS devices?
Pfft.
The defining document is rather old I guess. A lot happened in between.
( I looked into GPS in my diploma thesis ~1987 and not much after that )
GPS over time is not a static thing. Space and Gro
It is well below 0dB.
ahh, here:
http://www.northwoodlabs.com/AN101.pdf
around -22dB
you get a "win" by correlation with the CA PR pattern (~1000 bits).
( you need better than +6dB S/N afair)
uwe
Thanks for that pointer, Uwe. That -22dB is for a perfect receiver, as
well. The document lea
Greg Hennessy wrote:
On 2011-08-28, David J Taylor wrote:
Don't forget the sideband
energy from these digital transmissions, and the below zero
signal-to-noise ratio of GPS.
I really doubt the signal to noise ratio of GPS is below zero.
Below unity I would believe.
It is well below 0dB.
"Greg Hennessy" wrote in message
news:j3jrme$u87$1...@dont-email.me...
On 2011-08-28, David J Taylor
wrote:
Don't forget the sideband
energy from these digital transmissions, and the below zero
signal-to-noise ratio of GPS.
I really doubt the signal to noise ratio of GPS is below zero.
Belo
On 8/30/2011 2:22 PM, Rob wrote:
>
> Also make sure that you have no NAT or connection-tracking firewall
> between your server and the internet.
>
> (NAT would actually be acceptable when it is a statically configured
> one-to-one address translation, not one that ends up building a session
> tab
On 2011-08-30, Chris Albertson wrote:
>> If you care about microseconds or nanoseconds, shortwave radio is a poor
>> choice. The length of the radio propagation path changes constantly! Not by
>> much but if you care about the nanoseconds. . . .
>>
>> If you REALLY NEED the nanoseconds, buy an at
On 2011-08-28, David J Taylor wrote:
> Don't forget the sideband
> energy from these digital transmissions, and the below zero
> signal-to-noise ratio of GPS.
I really doubt the signal to noise ratio of GPS is below zero.
Below unity I would believe.
__
> If you care about microseconds or nanoseconds, shortwave radio is a poor
> choice. The length of the radio propagation path changes constantly! Not by
> much but if you care about the nanoseconds. . . .
>
> If you REALLY NEED the nanoseconds, buy an atomic clock and have it
> calibrated by your
Richard B. Gilbert wrote:
The speed of light and/or electrical signals, radio waves, etc. are
*approximately* the same! The speed of an electrical signal in copper
wire is slightly less than the speed of light in vacuum! It will be
different again if the wires are aluminum rather than copp
On 8/30/2011 12:05 AM, NPG wrote:
On 8/29/2011 9:59 PM, Chris Albertson wrote:
The other source of time is CDMA. This is a signal sent from cell towers.
This can be better then WWV/WWVB. There are many CDMA based NTP
servers. Some pool servrs are CDMA but I bet you will not find any WW
On 8/29/2011 11:57 PM, NPG wrote:
On 8/29/2011 9:47 PM, unruh wrote:
On 2011-08-29, NPG wrote:
On 8/29/2011 5:03 PM, Chris Albertson wrote:
On Mon, Aug 29, 2011 at 12:43 PM, NPG wrote:
Stupid noob question alert.
Does GPS provide better accuracy?
Depending on which GPS receiver, GPS can
On Tue, Aug 30, 2011 at 8:22 AM, unruh wrote:
> On 2011-08-30, Chris Albertson wrote:
> >> The time stuff I understand, even the radio wave propogation stuff,
> >> though obviously not as well as others here.
> >> I'm not sure what "cable length", "speed of light delay", or "velocity
> >> factor"
On 8/30/2011 11:22, Rob wrote:
Also make sure that you have no NAT or connection-tracking firewall
between your server and the internet.
(NAT would actually be acceptable when it is a statically configured
one-to-one address translation, not one that ends up building a session
table like a con
On 2011-08-30, NPG wrote:
> On 8/30/2011 2:28 AM, David Lord wrote:
>>
>> GPS or other radio time sources are not an essential requirement
>> for pool membership.
>
> Correct.
Agreed. However, gps are cheap, and give great time for you to deliver.
You do need to have somewhere to put the anten
NPG wrote:
> On 8/30/2011 2:28 AM, David Lord wrote:
>>
>> GPS or other radio time sources are not an essential requirement
>> for pool membership.
>
> Correct.
>
>> What is essential is a static ip address,
>> reliable 24/7 internet connection and good choice or internet
>> ntp servers.
>
> Th
On 8/30/2011 2:28 AM, David Lord wrote:
>
> GPS or other radio time sources are not an essential requirement
> for pool membership.
Correct.
> What is essential is a static ip address,
> reliable 24/7 internet connection and good choice or internet
> ntp servers.
That we have.
:-)
I've implem
Rob wrote:
> unruh wrote:
>> And we keep hearing about the UK jamming GPS for hours at a time in
>> regions of the UK.
>
> Yes, we keep hearing about that from the UK.
> But what about other countries, probably they do the same thing but
> we don't hear about it because there are no nice bullet
On 2011-08-30, Chris Albertson wrote:
>> The time stuff I understand, even the radio wave propogation stuff,
>> though obviously not as well as others here.
>> I'm not sure what "cable length", "speed of light delay", or "velocity
>> factor" is all about.
>>
>
> What I was getting at was that that
unruh wrote:
> And we keep hearing about the UK jamming GPS for hours at a time in
> regions of the UK.
Yes, we keep hearing about that from the UK.
But what about other countries, probably they do the same thing but
we don't hear about it because there are no nice bulletins posted to
usenet abo
Chris Albertson wrote:
I'm (very slowly) working on a project at home to compare WWV and GPS. The
purpose is to measure the ionosphere. "Lag" in the WWV signal can tell you
about radio propagation.
Same for the DCF77 timesource in Europe.
OT: recently read an article about using GPS receive
> The time stuff I understand, even the radio wave propogation stuff,
> though obviously not as well as others here.
> I'm not sure what "cable length", "speed of light delay", or "velocity
> factor" is all about.
>
What I was getting at was that that better GPS receivers are so accurate
with thei
"unruh" wrote in message
news:slrnj5ogfa.m9l.un...@wormhole.physics.ubc.ca...
[]
And we keep hearing about the UK jamming GPS for hours at a time in
regions of the UK.
.. in military area, military tests just like any nation will carry out.
Likely /your/ nation included!
I have yet to see
NPG wrote:
On 8/29/2011 9:59 PM, Chris Albertson wrote:
The other source of time is CDMA. This is a signal sent from cell towers.
This can be better then WWV/WWVB. There are many CDMA based NTP
servers. Some pool servrs are CDMA but I bet you will not find any WWV
based servers
OK, I'm
NPG wrote:
I'm not sure what "cable length", "speed of light delay", or "velocity
factor" is all about.
It's a basic tenet of modern physics that information cannot travel
faster than the speed of light. That applies not just in free space,
like radio waves, but also in cables. In practice
On 8/29/2011 9:47 PM, unruh wrote:
> On 2011-08-29, NPG wrote:
>> On 8/29/2011 5:03 PM, Chris Albertson wrote:
>>> On Mon, Aug 29, 2011 at 12:43 PM, NPG wrote:
Stupid noob question alert.
Does GPS provide better accuracy?
>>> Depending on which GPS receiver, GPS can be MANY or
On 8/29/2011 9:59 PM, Chris Albertson wrote:
>
> The other source of time is CDMA. This is a signal sent from cell towers.
> This can be better then WWV/WWVB. There are many CDMA based NTP
> servers. Some pool servrs are CDMA but I bet you will not find any WWV
> based servers
OK, I'm lea
On 2011-08-30, j...@specsol.spam.sux.com wrote:
> Chris Albertson wrote:
>> On Mon, Aug 29, 2011 at 1:46 PM, wrote:
>>
>>> Harlan Stenn wrote:
>>> > GPS can be done very affordably and can offer great time. There are
>>> > several *potential* pitfalls:
>>> >
>>> > - It is *possible* for the U
On 2011-08-29, NPG wrote:
> On 8/29/2011 5:03 PM, Chris Albertson wrote:
>> On Mon, Aug 29, 2011 at 12:43 PM, NPG wrote:
>>> Stupid noob question alert.
>>> Does GPS provide better accuracy?
>>>
>>>
>> Depending on which GPS receiver, GPS can be MANY orders of magnitude better.
>> The best GPSe
On Mon, Aug 29, 2011 at 4:10 PM, John Hasler wrote:
> NPG writes:
> > A Meinberg with GPS & WVV would be cool.
>
> WWVB would give you substantially better accuracy than WWV (though not
> nearly as good as GPS).
One big problem with WWVB is that you can't receive it most of the day.
Much easie
On 8/29/2011 7:10 PM, John Hasler wrote:
> NPG writes:
>> A Meinberg with GPS & WVV would be cool.
>
> WWVB would give you substantially better accuracy than WWV (though not
> nearly as good as GPS).
Typo, I meant WWVB.
:-)
--
Sincerely,
Nathan Gibbs
Systems Administrator
Christ Media
http:/
Chris Albertson wrote:
> On Mon, Aug 29, 2011 at 1:46 PM, wrote:
>
>> Harlan Stenn wrote:
>> > GPS can be done very affordably and can offer great time. There are
>> > several *potential* pitfalls:
>> >
>> > - It is *possible* for the US Gov't to detune the GPS system (locally or
>> > in-gene
On 8/29/2011 2:38 PM, unruh wrote:
> Meinberg also makes GPS receivers which are probably very
> reliable and robost-- probably more so than the Sure device.
> On the other hand you can buy something like 20 or more Sure
> units for one Meinberg.
Then, there is the commercial packaging issue,
NPG writes:
> A Meinberg with GPS & WVV would be cool.
WWVB would give you substantially better accuracy than WWV (though not
nearly as good as GPS).
--
John Hasler
jhas...@newsguy.com
Dancing Horse Hill
Elmwood, WI USA
___
questions mailing list
quest
On Mon, Aug 29, 2011 at 1:46 PM, wrote:
> Harlan Stenn wrote:
> > GPS can be done very affordably and can offer great time. There are
> > several *potential* pitfalls:
> >
> > - It is *possible* for the US Gov't to detune the GPS system (locally or
> > in-general). Since GPS is now increasing
On 8/29/2011 5:38 PM, unruh wrote:
> On 2011-08-29, NPG wrote:
>> On 8/27/2011 1:16 PM, unruh wrote:
>>> On 2011-08-27, NPG wrote:
>
> First ask what your requirements are and then you can buy the equipment
> to meet those. You do not want to find yourself in the position of the
> car buyer who
On 8/29/2011 5:03 PM, Chris Albertson wrote:
> On Mon, Aug 29, 2011 at 12:43 PM, NPG wrote:
>> Stupid noob question alert.
>> Does GPS provide better accuracy?
>>
>>
> Depending on which GPS receiver, GPS can be MANY orders of magnitude better.
> The best GPSes have a one sigma error on the puls
On 2011-08-29, Harlan Stenn wrote:
> GPS can be done very affordably and can offer great time. There are
> several *potential* pitfalls:
>
> - It is *possible* for the US Gov't to detune the GPS system (locally or
> in-general). Since GPS is now increasingly used for "human safety"
> things,
On 2011-08-29, NPG wrote:
> On 8/27/2011 1:16 PM, unruh wrote:
>> On 2011-08-27, NPG wrote:
>>> Long range plans.
>>> Does anyone know the current price of a meinberg M300 with WWVB receiver.
>>> I've asked them for a quote, but haven't heard back yet.
>>> My guess ~ $1,000 - $2,000.
>>
>> Why w
Harlan Stenn wrote:
> GPS can be done very affordably and can offer great time. There are
> several *potential* pitfalls:
>
> - It is *possible* for the US Gov't to detune the GPS system (locally or
> in-general). Since GPS is now increasingly used for "human safety"
> things, the costs/risks
On Mon, Aug 29, 2011 at 12:43 PM, NPG wrote:
>
> > Get a Sure gps receiver for $50 do a bit
> > of wiring, and get far greater accuracy than from WWV
>
> Stupid noob question alert.
> Does GPS provide better accuracy?
>
>
Depending on which GPS receiver, GPS can be MANY orders of magnitude better
GPS can be done very affordably and can offer great time. There are
several *potential* pitfalls:
- It is *possible* for the US Gov't to detune the GPS system (locally or
in-general). Since GPS is now increasingly used for "human safety"
things, the costs/risks for doing this have gone up si
On 8/27/2011 1:16 PM, unruh wrote:
> On 2011-08-27, NPG wrote:
>> Long range plans.
>> Does anyone know the current price of a meinberg M300 with WWVB receiver.
>> I've asked them for a quote, but haven't heard back yet.
>> My guess ~ $1,000 - $2,000.
>
> Why would you want to do that?
Why not?
On 8/27/2011 2:27 AM, Chuck Swiger wrote:
> Hi--
>
> On Aug 26, 2011, at 8:34 PM, NPG wrote:
>> What we plan to do.
>> Add 1 more stratum 2 server and 2 stratum 1 servers to the internal
>> server's sync list.
>> When we are sure that things are working right, make our internal NTP
>> server acces
David Woolley wrote:
John Hasler wrote:
Shipping products lacking adequate filtering for adjacent band
interference just because those bands are not presently in use is just
plain bad engineering.
The new adjacent channel signal could be arbitrarily strong. You have to
make some assumptions,
"John Hasler" wrote in message
news:87pqjpzei4@thumper.dhh.gt.org...
David writes:
Putting anything powerful and widespread next to a weak-signal
satellite band in use by consumer appliances is just plain crazy
planning, in fact it's a complete lack of planning!
Shipping products lacking
"Brian Utterback" wrote in message
news:4e5aa449.3090...@oracle.com...
[]
There are two sides with different figures. The GPS industry says that
500,000,000 units would be affected. The company LightSquared says it is
really 200,000. The DOD standards for GPS receivers issued in 2008 says
that
I wrote:
> Shipping products lacking adequate filtering for adjacent band
> interference just because those bands are not presently in use is just
> plain bad engineering.
David writes:
> The new adjacent channel signal could be arbitrarily strong. You have
> to make some assumptions,
The consum
On 2011-08-28, John Hasler wrote:
> David writes:
>> Putting anything powerful and widespread next to a weak-signal
>> satellite band in use by consumer appliances is just plain crazy
>> planning, in fact it's a complete lack of planning!
>
> Shipping products lacking adequate filtering for adjace
On 08/28/11 11:23, David J Taylor wrote:
> "Brian Utterback" wrote in message
> news:4e5a2a83.6030...@oracle.com...
> []
>> According to the FCC info, the problem is due to old GPS units not
>> sufficiently filtering out the adjacent bands that were previously
>> empty. Since the bands are current
John Hasler wrote:
Shipping products lacking adequate filtering for adjacent band
interference just because those bands are not presently in use is just
plain bad engineering.
The new adjacent channel signal could be arbitrarily strong. You have
to make some assumptions,
__
David writes:
> Putting anything powerful and widespread next to a weak-signal
> satellite band in use by consumer appliances is just plain crazy
> planning, in fact it's a complete lack of planning!
Shipping products lacking adequate filtering for adjacent band
interference just because those ban
"Brian Utterback" wrote in message
news:4e5a2a83.6030...@oracle.com...
[]
According to the FCC info, the problem is due to old GPS units not
sufficiently filtering out the adjacent bands that were previously
empty. Since the bands are currently empty, I am not so sure that it is
only older unit
On 08/28/11 01:47, David J Taylor wrote:
> That's the FCC in the US, Bill, not the UK. Allowing a high-power
> signal on an adjacent frequency to GPS may well block GPS if it is
> allowed to go ahead. The UK GPS events are one-off military tests, like
> every country likely carries out.
>
> An e
"unruh" wrote in message
news:slrnj5i9jn.uul.un...@wormhole.physics.ubc.ca...
[]
Why would you want to do that? Get a Sure gps receiver for $50 do a bit
of wiring, and get far greater accuracy than from WWV (assuming that the
UK does not proceed with its apparent plans to permanantly block GPS.
On 2011-08-27, NPG wrote:
> In the near future, we plan to put a public ntp server online and join
> pool.ntp.org.
>
> I think I understand all that needs to be done, but want to bounce it
> off some people who know what they are doing, before this project gets
> underway.
>
> What we have.
> An i
Hi--
On Aug 26, 2011, at 8:34 PM, NPG wrote:
> What we have.
> An internal host running NTPd and syncing with 2 stratum 2 servers on
> the internet. All internal hosts syncing with the internal NTP server.
>
> What we plan to do.
> Add 1 more stratum 2 server and 2 stratum 1 servers to the inter
In the near future, we plan to put a public ntp server online and join
pool.ntp.org.
I think I understand all that needs to be done, but want to bounce it
off some people who know what they are doing, before this project gets
underway.
What we have.
An internal host running NTPd and syncing with
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