Re: [ntp:questions] Two servers, one client : one problem
On 5/3/2011 12:58 PM, Yann I. wrote: Hi ! I have some problems about the configuration of ntp servers and client. You'll find the configurations used for the test and some outputs (of "ntpq -p" for example). First of all, the both servers are standalone and are not synchronized with an external ntp server. Later, they'll be connected to external ntp server. Later... The servers and client don't use iptable. NTP is hierarchical! It expects to get time from an external source such as NTP servers on the internet. The hierarchy starts with an "atomic clock" such as those operated by NIST or equivalent. These are referred to as "Stratum 1". Servers that get time from a stratum 1 server are referred to as "Stratum 2". Servers that get time from a stratum 2 server are referred to as "Stratum 3". It looks as if you have created, or attempted to create a "circle jerk". Another problem is that you have only two servers configured. If they disagree, which one will you believe? Four servers are required for the minimum "robust" configuration. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Two servers, one client : one problem
On 2011-05-04, Richard B. Gilbert wrote: > On 5/3/2011 12:58 PM, Yann I. wrote: >> Hi ! >> >> I have some problems about the configuration of ntp servers and client. >> You'll find the configurations used for the test and some outputs (of "ntpq >> -p" for example). >> First of all, the both servers are standalone and are not synchronized with >> an external ntp server. Later, they'll be connected to external ntp server. >> Later... >> The servers and client don't use iptable. >> > > > NTP is hierarchical! It expects to get time from an external source > such as NTP servers on the internet. The hierarchy starts with an > "atomic clock" such as those operated by NIST or equivalent. These are > referred to as "Stratum 1". Servers that get time from a stratum 1 > server are referred to as "Stratum 2". Servers that get time from a > stratum 2 server are referred to as "Stratum 3". > > It looks as if you have created, or attempted to create a "circle jerk". > > Another problem is that you have only two servers configured. If they > disagree, which one will you believe? Four servers are required for the > minimum "robust" configuration. Three are required. Four is an additional "belts and braces". Three allow two to outvote one rogue clock. Four allow you to outvote two disparate rogue clocks but fail on two rogue clocks which agree with each other. Ie, a minimum is three. > ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Windows time question.
"unruh" wrote in message news:slrnis0nra.4on.un...@wormhole.physics.ubc.ca... [...] > Unfortunately , AFAIK, usb is terrible for delivering a PPS-- ie no > interrupt lines-- IIRC, USB is polled at 1000 Hz. That means that, if done well, it should be able to gather PPS with an error of 0.5 ms at most. Probably still a sight better than NTP over WAN. I understand that the PPS from GPS units tends to come from a well- chosen flank on a 10 MHz signal. Quite a difference in degree admittedly (4 zeroes!), but not in kind. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Two servers, one client : one problem
On 2011-05-03, BlackLists wrote: > They are syncing just fine with their own Local clock? [snip] > The PCs are syncing to themselves, and drifting away >in whatever direction their oscillators, power management, > virtual host time sharing & thermal variances take them. The Undisciplined Local Clock driver merely allows ntpd to claim to be synced to a time source. ntpd adjusts the kernel (i.e. "local") clock; it _never_ actually syncs to it. > Then again, what do I know, I'm no expert. The solution is to configure all of the systems to poll a common reference source. -- Steve Kostecke NTP Public Services Project - http://support.ntp.org/ ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Windows time question.
On 2011-05-03, David J Taylor wrote: >> As the OP who started this (long and sometimes ammusing) thread... >> >> I do carry a GPS receiver with me, but sadly not PPS capable, I use it >> for location determination/tracking/navigating etc. Maybe I should >> include a GPS18 or 16 in the already bulging Laptop bag I lug arround. > > Even better if there were on on a USB stick, and you had a handy USB > extension lead! Unfortunately , AFAIK, usb is terrible for delivering a PPS-- ie no interrupt lines-- the problem with having only two data lines (one beign signal ground) . > > How critical is your time need? If it's within minutes, then the PC's > clock is likely good enough. If it's in the UK or Europe, I would be > surprised if pool servers did not get you well within the second - perhaps > within 100msec - particularly if you set the servers based on the country > you're in. I suspect that if you need closer than tens of milliseconds, > carrying round a GPS 18x LVC (which I jokingly suggested) may actually be > necessary. NTP was designed when connections were nothing like as good as > they are now, and is supposedly robust in those circumstances. It is > designed for 24-hours operation, though. > > 73, > David > ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Two servers, one client : one problem
Yann I. wrote: > I have some problems about the configuration of ntp > servers and client. > You'll find the configurations used for the test and some > outputs (of "ntpq -p" for example). > First of all, the both servers are standalone and are not > synchronized with an external ntp server. Later, they'll > be connected to external ntp server. > Later... > The servers and client don't use iptable. > > My problem is the following : > I don't understand why the client can't be synchronized > with one of the servers. The servers are seen as a > "falsetickers"... The "ntpq associations" shows me a > "reject" but I don't understand the reason... They are syncing just fine with their own Local clock? They seem to indicate the reason they won't sync with the other server: flash=800 peer_loop You might try ntpd -g on the servers and client, and _maybe_ they will all start & stay close enough together. However I think your plan is designed to fail. The PCs are syncing to themselves, and drifting away in whatever direction their oscillators, power management, virtual host time sharing & thermal variances take them. If you want them to sync to each other (instead of themselves), perhaps try removing the local clock driver in the ntp's .conf? Otherwise you likely need a more stable time base than the typical PC oscillator. Replace their oscillators with a Temperature Compensated Oscillator, Oven Controlled Oscillator, or Rubidium based Oscillator? Discipline their local clocks from an external source (e.g. PPS)> Turn off spread spectrum clocking in the BIOS? Turn off CPU core power management? Turn off OS power management? Don't run NTP in virtual hosts? Then again, what do I know, I'm no expert. -- E-Mail Sent to this address will be added to the BlackLists. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Windows time question.
unruh wrote: interrupt lines-- the problem with having only two data lines (one beign signal ground) Are you sure. I would expect them to be a balanced pair. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Windows time question.
As the OP who started this (long and sometimes ammusing) thread... I do carry a GPS receiver with me, but sadly not PPS capable, I use it for location determination/tracking/navigating etc. Maybe I should include a GPS18 or 16 in the already bulging Laptop bag I lug arround. Even better if there were on on a USB stick, and you had a handy USB extension lead! In any case, with most hotel's now, you can't open the windows (the ones in the outside wall of the room, not the OS!) enough, to get anything sensible outside to get a decent view of the sky. Many do not open at all, many are also now using "K Glass" that has a coating on it for thermal reasons, that appears to seriously attenuate GPS signals. Yes, sometimes you're unlucky, but other times my GPS 60CSx does get a lock. I have also encountered problems many times with GPS RX's used for "normal satnav" purposes in the vicinity of some hotels, due I suspect to the *Huge* ammount of EM crap that seems to radiate from such establishments these days, in many, you cant even listen to FM radio in your room, let alone AM (or Shortwave for WWV etc!) So much for EMC regs eh? Not to mention power-line data transmission Even mobile phone signals are heavily attenuated (or spoiled?) "in room", leaving only the expensive hotel wifi network (if it's working) as a comm's route out... Not that mobile internet is any good for timekeeping! I think from the latencies I sometime see, they use moonbounce to get back to base Free Wi-Fi is certainly one of my considerations now when choosing a hotel, and I've usually found that NTP works well enough over that. I have in one instance, had to use one of the "long range" BlueTooth adapters, to bt to a phone in the car, from a room (that luckily) overlooked the car park, to get any 'net conectivity. Naff latency, but I got my work done! I've also done the same trick, hoisting the phone some 50' up a mast in a plastic bag on a halyard (it was raining!) to get a signal on a remote customer site with no landline, then bt in remote sim mode to use the phone from the car! And that was just for a voice call! Never been that desperate! As earlier, the problem was a clash of interests between XP's own W32Time, and the National Instruments time discoverer/server, foisted on me by an update to other software (from our principle) that blindly and stupidly updates ALL of the NI installed tools and utilities, causing other problems too, not just the lockups. Most tiresome. Now I've id'd the problem, I can work arround it. But as earlier, the info about the pool servers and (perhaps) not needing the location tags was good to know, though from what else I read, it's debatable if it will work reliably and predicably in practice for a traveling laptop. Thanks for the info and insight peeps. Regards. DaveB How critical is your time need? If it's within minutes, then the PC's clock is likely good enough. If it's in the UK or Europe, I would be surprised if pool servers did not get you well within the second - perhaps within 100msec - particularly if you set the servers based on the country you're in. I suspect that if you need closer than tens of milliseconds, carrying round a GPS 18x LVC (which I jokingly suggested) may actually be necessary. NTP was designed when connections were nothing like as good as they are now, and is supposedly robust in those circumstances. It is designed for 24-hours operation, though. 73, David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Two servers, one client : one problem
On 2011-05-03, Yann I. wrote: > I have some problems about the configuration of ntp servers and > client. You'll find the configurations used for the test and some > outputs (of "ntpq -p" for example). First of all, the both servers > are standalone and are not synchronized with an external ntp server. They need a common time reference. Or one needs to follow the other. > Later, they'll be connected to external ntp server. Later... Then you need to configure one to poll the other. > The servers and client don't use iptable. The ntpq peer billbords you've posted show that the ntpds are able to poll each other (note the non-zero values in the reach, delay, and offset columns). > My problem is the following : I don't understand why the client can't > be synchronized with one of the servers. The servers are seen as a > "falsetickers"... The "ntpq associations" shows me a "reject" but I > don't understand the reason... [snip] > remote refid st t when poll reach delay offset jitter > >== > xsrv01-cba LOCAL(0) 5 u 10 64 377 0.135 267.274 4.308 > xsrv02-yil LOCAL(0) 5 u 59 64 377 0.127 -56.638 0.427 The problem is that xsrv01 and xsrv02 are 323.885 milliseconds apart. If you were using NTP as it was designed (i.e. with a common time reference) this would not be an issue. -- Steve Kostecke NTP Public Services Project - http://support.ntp.org/ ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Two servers, one client : one problem
On Tue, May 3, 2011 at 9:58 AM, Yann I. wrote: > My problem is the following : > I don't understand why the client can't be synchronized with one of the > servers. The servers are seen as a "falsetickers"... > The "ntpq associations" shows me a "reject" but I don't understand the > reason... The short answer is that your two server's time is far enough apart that ntpd decides "something is not right" Longer answer: see www.eecis.udel.edu/~mills/ntp/html/select.html This explains the clock selection algorithm in some detail. The fix is easy. Add some pool servers the the conf files of your two local servers. Or if more accuracy is required add some pool servers and a GPS timing receiver (with PPS) to your two local servers. -- = Chris Albertson Redondo Beach, California ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] Two servers, one client : one problem
Hi ! I have some problems about the configuration of ntp servers and client. You'll find the configurations used for the test and some outputs (of "ntpq -p" for example). First of all, the both servers are standalone and are not synchronized with an external ntp server. Later, they'll be connected to external ntp server. Later... The servers and client don't use iptable. My problem is the following : I don't understand why the client can't be synchronized with one of the servers. The servers are seen as a "falsetickers"... The "ntpq associations" shows me a "reject" but I don't understand the reason... Thank you for your help. Regards, Yann I. Here are the configuration files and some outputs for the servers and the client (which are on the same LAN without iptables) : = Server 01 (srv01-cba) = Configuration file : -- server 127.127.1.0 fudge 127.127.1.0 stratum 4 driftfile /var/lib/ntp/drift peer srv02-yil Output of "ntpq -p" : --- remote refid st t when poll reach delay offset jitter == *LOCAL(0).LOCL. 4 l 27 64 3770.0000.000 0.001 srv02-yil LOCAL(0) 5 u 917 1024 376 15.406 -263.19 20.361 Several outputs : --- # ntpq -p associations Temporary failure in name resolution [root@localhost etc]# ntpq ntpq> associations ind assID status conf reach auth condition last_event cnt === 1 18629 9614 yes yes none sys.peer reachable 1 2 18630 9014 yes yes nonereject reachable 1 ntpq> ntpq> rv 18629 assID=18629 status=9614 reach, conf, sel_sys.peer, 1 event, event_reach, srcadr=LOCAL(0), srcport=123, dstadr=127.0.0.1, dstport=123, leap=00, stratum=4, precision=-20, rootdelay=0.000, rootdispersion=10.000, refid=LOCL, reach=377, unreach=0, hmode=3, pmode=4, hpoll=6, ppoll=10, flash=00 ok, keyid=0, ttl=0, offset=0.000, delay=0.000, dispersion=0.924, jitter=0.001, reftime=d16aac9e.b6dea2a2 Tue, May 3 2011 16:32:30.714, org=d16aac9e.b6dea2a2 Tue, May 3 2011 16:32:30.714, rec=d16aac9e.b6deb68c Tue, May 3 2011 16:32:30.714, xmt=d16aac9e.b6de9123 Tue, May 3 2011 16:32:30.714, filtdelay= 0.000.000.000.000.000.000.000.00, filtoffset=0.000.000.000.000.000.000.000.00, filtdisp= 0.000.961.922.873.814.765.726.66 ntpq> ntpq> rv 18630 assID=18630 status=9014 reach, conf, 1 event, event_reach, srcadr=srv02-yil, srcport=123, dstadr=10.0.0.226, dstport=123, leap=00, stratum=5, precision=-20, rootdelay=0.000, rootdispersion=11.307, refid=LOCAL(0), reach=376, unreach=0, hmode=1, pmode=1, hpoll=10, ppoll=10, flash=800 peer_loop, keyid=0, ttl=0, offset=-303.907, delay=15.333, dispersion=26.270, jitter=20.352, reftime=d16aaad0.4019aeab Tue, May 3 2011 16:24:48.250, org=d16aaae8.401958ba Tue, May 3 2011 16:25:12.250, rec=d16aaae8.8fdc99be Tue, May 3 2011 16:25:12.561, xmt=d16aabeb.b6b664e1 Tue, May 3 2011 16:29:31.713, filtdelay=15.33 15.44 15.41 15.34 15.31 15.23 15.25 15.22, filtoffset= -303.91 -283.55 -263.19 -242.87 -222.58 -202.30 -182.10 -161.92, filtdisp= 11.47 26.86 42.24 57.61 72.96 88.33 103.72 119.10 = Server 02 (srv02-yil) = Configuration file : -- server 127.127.1.0 fudge 127.127.1.0 stratum 4 driftfile /var/lib/ntp/drift peer srv01-cba Output of "ntpq -p" : --- remote refid st t when poll reach delay offset jitter == *LOCAL(0).LOCL. 4 l 31 64 3770.0000.000 0.001 srv01-cba LOCAL(0) 5 u 136 1024 3770.001 314.047 20.291 Several outputs : --- # ntpq ntpq> associations ind assID status conf reach auth condition last_event cnt === 1 24386 9614 yes yes none sys.peer reachable 1 2 24387 9014 yes yes nonereject reachable 1 ntpq> ntpq> ntpq> rv 24386 assID=24386 status=9614 reach, conf, sel_sys.peer, 1 event, event_reach, srcadr=LOCAL(0), srcport=123, dstadr=127.0.0.1, dstport=123, leap=00, stratum=4, precision=-20, rootdelay=0.000, rootdispersion=10.000, refid=LOCL, reach=377, unreach=0, hmode=3, pmode=4, hpoll=6, ppoll=10, flash=00 ok, keyid=0, ttl=0, offset=0.000, delay=0.000, dispersion=0.931, jitter=0.001, reftime=d16aad97.4018f4c0 Tue, May 3 2011 16:36:39.250, org=d16aad97.4018f4c0 Tue, May 3 2011 16:36:39.250, rec=d16aad97.4019042a Tue, May 3 2011 16:36:39.250, xmt=d16aad97.4018d1f3 Tue, May 3 2011 16:36:39.250, filtdelay= 0.000.000.000.0
Re: [ntp:questions] Windows time question.
DaveB wrote: In article , david- tay...@blueyonder.co.uk.invalid says... "Rob" wrote in message news:slrnir54hp.hnj.nom...@xs8.xs4all.nl... [] The initial question: | Due to my wandering use of a laptop for, "work" (cough!) Often away | from the office, and our server, but with local internet access (Hotel | WiFi etc). | | What UK based "RELIABLE" (cant emphasize that enough) UK time server(s) | would the group recomend I point Windows time sync' to? and the subsequent discussion about the NTP pool and its reliability, and how many servers from the pool one would resonably use to get good results without overloading a voluntarily provided service, is a good and valid discussion on its own. There is no need to pollute that discussion by talking about GPS receivers yet again. It is not a solution for the original poster, and it does not contribute to the discussion about either of the topics brought up. You may be exited about your new GPS receiver toy, but there is no need to recommend that hammer as the only tool one will ever need. It isn't. .. and why shouldn't someone consider taking a GPS 18x LVC as a portable time reference? As the OP who started this (long and sometimes ammusing) thread... I do carry a GPS receiver with me, but sadly not PPS capable, I use it for location determination/tracking/navigating etc. Maybe I should include a GPS18 or 16 in the already bulging Laptop bag I lug arround. In any case, with most hotel's now, you can't open the windows (the ones in the outside wall of the room, not the OS!) enough, to get anything sensible outside to get a decent view of the sky. Many do not open at all, many are also now using "K Glass" that has a coating on it for thermal reasons, that appears to seriously attenuate GPS signals. I have also encountered problems many times with GPS RX's used for "normal satnav" purposes in the vicinity of some hotels, due I suspect to the *Huge* ammount of EM crap that seems to radiate from such establishments these days, in many, you cant even listen to FM radio in your room, let alone AM (or Shortwave for WWV etc!) So much for EMC regs eh? Even mobile phone signals are heavily attenuated (or spoiled?) "in room", leaving only the expensive hotel wifi network (if it's working) as a comm's route out... Not that mobile internet is any good for timekeeping! I think from the latencies I sometime see, they use moonbounce to get back to base I have in one instance, had to use one of the "long range" BlueTooth adapters, to bt to a phone in the car, from a room (that luckily) overlooked the car park, to get any 'net conectivity. Naff latency, but I got my work done! I've also done the same trick, hoisting the phone some 50' up a mast in a plastic bag on a halyard (it was raining!) to get a signal on a remote customer site with no landline, then bt in remote sim mode to use the phone from the car! And that was just for a voice call! As earlier, the problem was a clash of interests between XP's own W32Time, and the National Instruments time discoverer/server, foisted on me by an update to other software (from our principle) that blindly and stupidly updates ALL of the NI installed tools and utilities, causing other problems too, not just the lockups. Now I've id'd the problem, I can work arround it. But as earlier, the info about the pool servers and (perhaps) not needing the location tags was good to know, though from what else I read, it's debatable if it will work reliably and predicably in practice for a traveling laptop. Sometimes I use a notebook from a pub and am limited to using mobile broadband dongle via usb port. Latency can be as high as 10 seconds if ntp is used normally so I use 'burst' with a couple of server lines in my ntp.conf which gets me within a few milliseconds. The particular servers I abuse are my own. I also have a GPS 18x-LVC but would have to use a serial2usb adaptor which doesn't give me the few microsecond offset vs PPS via real serial or parallel port and also it's difficult to find a location that has good GPS reception so I don't carry it with me. My larger notebooks have both serial and parallel ports and are within a few microseconds when GPS is usable. David Thanks for the info and insight peeps. Regards. DaveB ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP server with no network, no GPS signal
In article , albertson.ch...@gmail.com says... > > On Fri, Apr 29, 2011 at 4:10 AM, Cristian Seres > wrote: > > Hi! > > > > I am looking for a solution to install an NTP server in a very restricted > > network which can not be connected to other networks even through a firewall > > because of strict security policy. RS232 and usb are ok. Using GPS or DCF77 > > reference clocks would require a long antenna wire to get signal. Installing > > the antenna cable would be expensive, but there is good LAN cabling between > > a space with good GPS signal and the room with high security. > > This is easy. Install the GPS but use a very short antenna cable. > Then the output of a GPS is in two parts (1) A serial data stream and > (2) a pulse per second. Both of these can go over the LAN cable. > > You never want a long antenna cable because of the losses in a long > run. It is best to keep that cable short and send the data from the > PS back over a digital cable Using some RS232<>RS422/485 converters, then you can use as long as needed (within reason) UTP cable. (Especially for the PPS signal.) Ready made converter assemblies are available, as are the chips to make your own. The extra delay is minimal, and will be stable in any case, as such converters are more or less analogue devices internally. Use either PoE or local power for the GPS device itself (and serial adapters.) Do not rely on feeding plain 12/5 or 3V DC up a "spare pair" in the UTP cable, the resistive losses can make that problematical. PoE handles it much better if a local (to the GPS) power source can't be provided. At the "secure" end, you will need more serial converters to get back to RS232, (& PoE injector if used) and run the NTP daemon on the secure PC, or use a separate timekeeping PC, on the "secure" LAN. Depending on your detailed security needs. Just my take on it, but I know nothing, even having done just this in the past for my own needs, so don't believe anything I say... I built my serial adapters from parts I had, and found suitable PoE kit on a well known web based auction site. 12V in 12V out (with up to 0.7A available at the remote end, more than enough!) good regulation, with 48V on the wire. Lynksys kit I think it was. Remember though, that anything like this in a commercial environment, could violate any local electrical safety rules, as it is not galvanicaly isolated, unlike normal LAN cable endpoints. Plus, even if it was, a lightning hit sort of negates any of that... Regards. DaveB. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Windows time question.
In article , david- tay...@blueyonder.co.uk.invalid says... > > "Rob" wrote in message > news:slrnir54hp.hnj.nom...@xs8.xs4all.nl... > [] > > The initial question: > > | Due to my wandering use of a laptop for, "work" (cough!) Often away > > | from the office, and our server, but with local internet access (Hotel > > | WiFi etc). > > | > > | What UK based "RELIABLE" (cant emphasize that enough) UK time > > server(s) > > | would the group recomend I point Windows time sync' to? > > > > and the subsequent discussion about the NTP pool and its reliability, > > and how many servers from the pool one would resonably use to get good > > results without overloading a voluntarily provided service, is a good > > and valid discussion on its own. > > > > There is no need to pollute that discussion by talking about GPS > > receivers > > yet again. It is not a solution for the original poster, and it does > > not contribute to the discussion about either of the topics brought up. > > > > You may be exited about your new GPS receiver toy, but there is no need > > to recommend that hammer as the only tool one will ever need. It isn't. > > .. and why shouldn't someone consider taking a GPS 18x LVC as a portable > time reference? > As the OP who started this (long and sometimes ammusing) thread... I do carry a GPS receiver with me, but sadly not PPS capable, I use it for location determination/tracking/navigating etc. Maybe I should include a GPS18 or 16 in the already bulging Laptop bag I lug arround. In any case, with most hotel's now, you can't open the windows (the ones in the outside wall of the room, not the OS!) enough, to get anything sensible outside to get a decent view of the sky. Many do not open at all, many are also now using "K Glass" that has a coating on it for thermal reasons, that appears to seriously attenuate GPS signals. I have also encountered problems many times with GPS RX's used for "normal satnav" purposes in the vicinity of some hotels, due I suspect to the *Huge* ammount of EM crap that seems to radiate from such establishments these days, in many, you cant even listen to FM radio in your room, let alone AM (or Shortwave for WWV etc!) So much for EMC regs eh? Even mobile phone signals are heavily attenuated (or spoiled?) "in room", leaving only the expensive hotel wifi network (if it's working) as a comm's route out... Not that mobile internet is any good for timekeeping! I think from the latencies I sometime see, they use moonbounce to get back to base I have in one instance, had to use one of the "long range" BlueTooth adapters, to bt to a phone in the car, from a room (that luckily) overlooked the car park, to get any 'net conectivity. Naff latency, but I got my work done! I've also done the same trick, hoisting the phone some 50' up a mast in a plastic bag on a halyard (it was raining!) to get a signal on a remote customer site with no landline, then bt in remote sim mode to use the phone from the car! And that was just for a voice call! As earlier, the problem was a clash of interests between XP's own W32Time, and the National Instruments time discoverer/server, foisted on me by an update to other software (from our principle) that blindly and stupidly updates ALL of the NI installed tools and utilities, causing other problems too, not just the lockups. Now I've id'd the problem, I can work arround it. But as earlier, the info about the pool servers and (perhaps) not needing the location tags was good to know, though from what else I read, it's debatable if it will work reliably and predicably in practice for a traveling laptop. Thanks for the info and insight peeps. Regards. DaveB ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
