Re: [ntp:questions] New NTP server to add in the pool
Elia S. ad...@nospamspadhausen.com wrote: Hello the server is added in the website of the pool. http://www.pool.ntp.org/scores/109.168.118.249 But why on this page http://support.ntp.org/bin/view/Servers/SubmittingYourListEntriesViaEmail It tells to send the entries via email??? I have sent mails there with no answer, and I am not on list. You are confused between two different lists of NTP servers. When you want to enter the ntp server pool you must use the website www.pool.ntp.org not support.ntp.org. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] New NTP server to add in the pool
Elia S. ad...@nospamspadhausen.com wrote: Hello I have already registered in the list and my server is graphed and activated. I would like to enter in the browsable list of NTP server of IT, where I think that the email is needed to be sent. Then be patient. It clearly says there may be a delay in processing. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] New NTP server to add in the pool
Hello I have already registered in the list and my server is graphed and activated. I would like to enter in the browsable list of NTP server of IT, where I think that the email is needed to be sent. Rob ha scritto nel messaggio news:slrnjg82nu.ofi.nom...@xs8.xs4all.nl... Elia S. ad...@nospamspadhausen.com wrote: Hello the server is added in the website of the pool. http://www.pool.ntp.org/scores/109.168.118.249 But why on this page http://support.ntp.org/bin/view/Servers/SubmittingYourListEntriesViaEmail It tells to send the entries via email??? I have sent mails there with no answer, and I am not on list. You are confused between two different lists of NTP servers. When you want to enter the ntp server pool you must use the website www.pool.ntp.org not support.ntp.org. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] New NTP server to add in the pool
Ok !!! :) ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] Visualization of clock control
Hi, I wrote a tool to visualize the data generated by the clknetsim simulator and I thought some of you might find it interesting. The goal was to show how a clock is controlled by NTP client and at the same time see its offset from true time and the NTP measurements (the actual offset and delay seen by the client). Here are some example runs of the tool captured to animated gifs: http://mlichvar.fedorapeople.org/clknetsim/chrony_ntp/vis/visclocks_10us.gif http://mlichvar.fedorapeople.org/clknetsim/chrony_ntp/vis/visclocks_100us.gif http://mlichvar.fedorapeople.org/clknetsim/chrony_ntp/vis/visclocks_1000us.gif The simulations were done with a clock wandering at 1 ppb/s, 10/100/1000us network jitter with exponential distribution and the NTP clients were configured to use 64s polling interval. The white line is the reference clock. The red line is the clock controlled by ntp and green is chrony. The blue lines are the NTP measurements made by chrony. Both clients were getting the same data, but the polling intervals were not exactly the same so the frequency changes in the red line don't match exactly with the blue lines. The tool is included in the clknetsim git as visclocks.py. It also has a game mode, where you control the frequency and phase of the clock by mouse and you can try to beat the other clients. :) -- Miroslav Lichvar ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] New NTP server to add in the pool
On 2012-01-04, Rob nom...@example.com wrote: You are confused between two different lists of NTP servers. When you want to enter the ntp server pool you must use the website www.pool.ntp.org not support.ntp.org. That is not true. The Pool has code to retrieve the PoolMembers from http://support.ntp.org/s1 and http://support.ntp.org/s2 -- Steve Kostecke koste...@ntp.org NTP Public Services Project - http://support.ntp.org/ ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] New NTP server to add in the pool
On 2012-01-04, Elia S. ad...@nospamspadhausen.com wrote: I have already registered in the list and my server is graphed and activated. I would like to enter in the browsable list of NTP server of IT, where I think that the email is needed to be sent. Please follow the instructions at http://support.ntp.org/Servers/ManagingYourListEntries#Creating_a_new_List_entry -- Steve Kostecke koste...@ntp.org 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 and Wi-Fi - starts well, frequency steps?
In article LWIMq.52547$ee3.24...@newsfe04.iad, unruh un...@invalid.ca wrote: On 2012-01-03, Rod Dorman r...@panix.com wrote: In article jdqcs5$ppn$1...@dont-email.me, David Woolley david@ex.djwhome.demon.invalid wrote: Rod Dorman wrote: But thats my point, it says nothing about transport layer protocols. I'm just trying to understand Dave Hart's statement As it says nothing about them, it means that all transport protocols get the same resilience, other things being equal (UDP opens the possibility of multicast). which appears to claim the UDP over WiFi is guaranteed which I've never seen stated before. In a network with a WiFi element, the WiFi element is the most likely one to lose packets and force retransmissions, and therefore cause NTP packets to arrive with large delays. To a large extent it does guarantee delivery compared with what would happen if it didn't retransmit. I take guaranteed delivery when mentioning a transport protocol to mean end-to-end, not just that one hop of it will retransmit. The network IS hop to hop. Only if the WAP is the NTP server. If its some other host in your LAN or if its out in the WAN then theres going to be more that one hop and any router along the route could decide to drop the UDP packet. And we are getting really far away from the original question. The answer seems to be that wireless can typically have large, assymetric delays, which plays havoc with ntp. Esp if some link which typically has a delay, suddenly has a shorter delay (due to typical retransmission, and suddenly none on some packet). (the ntp filter algorithm tends to throw away packets with longer delays, but grabs and uses packets with shorter delays. Thus if there is an occasional longer delay, that does not matter, but if there is only an occasional shorter asymmetric delay, ntp will use that.) I've got no issues with that, my only objection was the implied claim that if WiFi was involved the UDP transport protocol was suddenly redefined to be guaranteed. -- -- Rod -- rodd(at)polylogics(dot)com ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Visualization of clock control
On 4 Jan, 2012, at 22:54 , Miroslav Lichvar wrote: Here are some example runs of the tool captured to animated gifs: http://mlichvar.fedorapeople.org/clknetsim/chrony_ntp/vis/visclocks_10us.gif http://mlichvar.fedorapeople.org/clknetsim/chrony_ntp/vis/visclocks_100us.gif http://mlichvar.fedorapeople.org/clknetsim/chrony_ntp/vis/visclocks_1000us.gif The simulations were done with a clock wandering at 1 ppb/s, 10/100/1000us network jitter with exponential distribution and the NTP clients were configured to use 64s polling interval. That's pretty neat. I think, however, that the clock wander of 1 ppb/s is about an order of magnitude too large for real life, at least for machines kept in an air conditioned room (and the behavior of clocks in machines subject to environmental variations probably can't be modeled by wander at all). My measurements against precise hardware tended towards a value of 1ppb/10s, which is also consistent with the 10^-8/1000s which sometimes shows up on Allan variance plots (I think there's a square root relationship in there if the wander is a truly random walk). The other difficulty with respect to real life may be modeling network jitter as exponential, since I believe the probability distribution for network delays is heavy-tailed (i.e. with extreme values way over-represented; this is a problem when using statistics which assume the underlying error distribution is gaussian). I don't know how to fix that, though. Dennis Ferguson ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
