"David Woolley" wrote in message
news:hve58p$8l...@news.eternal-september.org...
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Windows tends to use a broken SNTP. Recent versions can be configured
to act as (almost?) compliant NTP clients and servers.
[]
.. but thanks to the great work of Dave Hart, Meinberg, and others
recently Win
"Richard B. Gilbert" wrote in message
news:fcgdnxzbxfvy7ifrnz2dnuvz_sadn...@giganews.com...
[]
If you have a GPS timing receiver (different from navigation receiver),
with a PPS output, one edge of that pulse should be accurate to within
50 nanoseconds. A serial output will tell you which sec
"Marcelo Pimenta" wrote in message
news:aanlktilffevh94cief43-ewqbc2dtqev4dbbpfs1d...@mail.gmail.com...
[]
Yes, I agree. But we were talking about NTP using Ethernet, so... that's
impossible
Even with Ethernet, temperature variations at the client will have a
noticeable effect (at least they
Marcelo Pimenta wrote:
2010/6/17 Richard B. Gilbert
Marcelo Pimenta wrote:
Yes!! My question is about ms(MILIsecond) a collegue of this forum said
that
NTP give nsec accurancy... Is impossible to have usec imagine nsec!
Thanks
If you have a GPS timing receiver (different from navigation
Steve Kostecke wrote:
On 2010-06-17, Marcelo Pimenta wrote:
Here's a snapshot of my "main" system showing an offset of 340us
(0.340ms) from it's sys_peer over a switched GigE LAN ...
Which doesn't mean the error is .34 ms; it is quite likely less than
.1ms, assuming no systematic componen
David Woolley wrote:
> SNTP as used on Windows to access the Microsoft timeserver certainly
> can't. Anything that runs on Windows that sets the clock on ever
> poll almost certainly can't for any reasonable application load. On
> Linux you have to beware of interrupt latency, NIC interrupt
> ag
On 2010-06-17, Marcelo Pimenta wrote:
> Yes, I agree. But we were talking about NTP using Ethernet, so... that's
> impossible
Here's a snapshot of my "main" system showing an offset of 340us
(0.340ms) from it's sys_peer over a switched GigE LAN ...
remote refid st t when poll reach
Marcelo Pimenta wrote:
I thought that SNTP was used in a kind of "Intranet" with no routers and no
internet, so the low latency there is no need of so much calculations to
adjust the clock.
As W32Time is not fully NTP compliant, out of the box, it is probably
currently true that most SNTP us
Rob wrote:
With NTP a single query does not affect the time so much, because
successive queries are fed through a filter to find the average, and
the time is not stepped but slowly changed to the new value. So when
there is an occasional delay in your network it will not affect the
time accura
2010/6/17 Richard B. Gilbert
> Marcelo Pimenta wrote:
>
>> Yes!! My question is about ms(MILIsecond) a collegue of this forum said
>> that
>> NTP give nsec accurancy... Is impossible to have usec imagine nsec!
>>
>> Thanks
>>
>>
> If you have a GPS timing receiver (different from navigation recei
In article ,
Marcelo Pimenta writes:
>I thought that SNTP was used in a kind of "Intranet" with no routers and no
>internet, so the low latency there is no need of so much calculations to
>adjust the clock.
I haven't been able to figure out what you are really trying to ask.
The packets on the
Marcelo Pimenta wrote:
Yes!! My question is about ms(MILIsecond) a collegue of this forum said that
NTP give nsec accurancy... Is impossible to have usec imagine nsec!
Thanks
If you have a GPS timing receiver (different from navigation receiver),
with a PPS output, one edge of that pulse sho
Yes!! My question is about ms(MILIsecond) a collegue of this forum said that
NTP give nsec accurancy... Is impossible to have usec imagine nsec!
Thanks
2010/6/17 David J Taylor
> David,
>>
>> CONGRATULATIONS!!! Very good tests and presentations!! Very very good!!!
>> You
>> gave me real result
David,
CONGRATULATIONS!!! Very good tests and presentations!! Very very good!!!
You
gave me real results and all your reports are consistent and show that
it's
impossible to have usec and nsec precision using NTP though Ethernet.
You
have SO stack latency and it's a Layer 7 protocol!!!
One m
2010/6/17 David J Taylor
> NTP can deliver a time accuracy of 1nsec?? I my point of view, NTP
>> includes
>> methods to estimate the round-trip path delay between the server and
>> client
>> but the performance is limited by SO stack latency, it is an Application
>> Layer protocol.
>>
>
> Marcel
On 6/17/2010 7:54 AM, Kiss Gabor wrote:
> Is there any way to configure which IPv6 address is used as
> source address when ntpd sends a query to a lower stratum NTP server?
>
> Gabor
>
Not yet. That's the query-on functionality that I have been
implementing. I've just been swamped with other is
2010/6/17 Rob
> Marcelo Pimenta wrote:
> >> > In my case, I have* only one* network. My Time Server is not a
> machine,
> >> is a
> >> > meinberg GPS. In my point of view, if my source time were machines,
> maybe
> >> A Meingerg GPS IS a machine.
> >>
> >
> > I agree, I said machines equipment l
Marcelo Pimenta wrote:
>> > In my case, I have* only one* network. My Time Server is not a machine,
>> is a
>> > meinberg GPS. In my point of view, if my source time were machines, maybe
>> A Meingerg GPS IS a machine.
>>
>
> I agree, I said machines equipment like PC computers with Windows or Lin
On Jun 13, 12:21 am, Rob Neal wrote:
> On Fri, Jun 11, 2010 at 02:26:13PM -0700, apobrien wrote:
> > Hello list,
>
> > I have a set of proprietary hardware timing cards (Symmetricom
> > bc635PCIe) which synchronize their clocks using a dedicated
> > interconnect. As you might imagine the timing c
NTP can deliver a time accuracy of 1nsec?? I my point of view, NTP
includes
methods to estimate the round-trip path delay between the server and
client
but the performance is limited by SO stack latency, it is an Application
Layer protocol.
Marcelo, here's what /my/ NTP achieves:
http://www.
Marcelo Pimenta wrote:
> Yep but I have an equipment for specific use with RFC2030 implemented
> because of a standard that I have follow that say it is mandatory SNTP -
> RFC2030. My equipment ask for time every minute and frequence tolerance of
> the crystal is less then 1ms/min. They are in a i
Marcelo Pimenta wrote:
> I thought that SNTP was used in a kind of "Intranet" with no routers and no
> internet, so the low latency there is no need of so much calculations to
> adjust the clock.
No, SNTP is used by software manufacturers who are too lazy to implement
full NTP.
_
2010/6/17 unruh
> On 2010-06-16, Marcelo Pimenta wrote:
> > 2010/6/16 Rob
> >
> (...)
>
> > In my case, I have* only one* network. My Time Server is not a machine,
> is a
> > meinberg GPS. In my point of view, if my source time were machines, maybe
> A Meingerg GPS IS a machine.
>
I agree, I
2010/6/17 unruh
> On 2010-06-16, Marcelo Pimenta wrote:
> > 2010/6/15 unruh
> >
> >> On 2010-06-14, Marcelo Pimenta wrote:
> >> > Hi everybody!!
> >> >
> >> > My question is about Time Accuracy of NTP/SNTP protocol. I want to
> know
> >> if
> >> > is possible to have precision of 1ms(could be
2010/6/16 Maarten Wiltink
> "Marcelo Pimenta" wrote in message
> news:aanlktilaoduniqjgpigohpzvjcv_zmsw_tr7naj6b...@mail.gmail.com...
>
> > [...] accuracy of 1ms. On a local network 100usec?? Even if we use
> > only switches(no routers), how is that possible if I have 4 types of
> > Latency incr
2010/6/16 David Woolley
> Marcelo Pimenta wrote:
>
>
>> Rob, my understading about the use of SNTP and NTP is: while SNTP provides
>> time synchronization within *one *network, NTP allows a global time
>>
>
> You are confusing it with timed. SNTP also expects to use global time, and
> NTP can be
Is there any way to configure which IPv6 address is used as
source address when ntpd sends a query to a lower stratum NTP server?
Gabor
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unruh wrote:
> OK, if that is the way your virtual system works, (Ie it delivers the
> system time via /dev/rtc) then so be it. I would say it is terrible,
> since it uses a predefined item ( rtc) to deliver something totally
> different ( the system time of the underlying host)
That is the main
On 2010-06-16, Marcelo Pimenta wrote:
> 2010/6/16 Rob
>
>> Marcelo Pimenta wrote:
>> > The idea to have this is not overload the network asking time every
>> second
>> > to keep my accurancy in 1ms in 100% of time. And the second reason is
>> about
>> > how many ms your clock will be wrong in 59
On 2010-06-16, Marcelo Pimenta wrote:
> 2010/6/15 unruh
>
>> On 2010-06-14, Marcelo Pimenta wrote:
>> > Hi everybody!!
>> >
>> > My question is about Time Accuracy of NTP/SNTP protocol. I want to know
>> if
>> > is possible to have precision of 1ms(could be < 1 ms?) using SNTP in a
>> > network
On 2010-06-16, Jacobs, Kevin J. wrote:
> I had an interesting experience with a Cisco router as "ntp master 9" using
> itself as an NTP source and it's neighboring switch as the only other NTP
> source.
> The switch had the exact same configuration right back at the router!. So
> what happens
On 2010-06-16, Krejci, Pavel wrote:
> Hi,
>
>> -Original Message-
>> From: unruh [mailto:un...@wormhole.physics.ubc.ca]
>> Sent: Tuesday, June 15, 2010 7:15 PM
>> To: questions@lists.ntp.org
>> Subject: Re: [ntp:questions] Reference clock driver for /dev/rtc
>>
>> On 2010-06-15, Krejci, Pa
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