NTPsec

ntp03.maillink.ch

Report generated: Tue Apr 1 22:45:04 2025 UTC
Start Time: Tue Mar 25 22:45:01 2025 UTC
End Time: Tue Apr 1 22:45:01 2025 UTC
Report Period: 7.0 days

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Local Clock Time/Frequency Offsets

local offset plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Time Offset -66.988 -40.168 -21.883 0.024 22.174 35.838 56.093 44.057 76.006 13.512 0.046 µs -4.2 12.7
Local Clock Frequency Offset -3.016 -2.959 -2.865 -2.779 -2.704 -2.692 -2.684 0.161 0.267 0.054 -2.781 ppm -1.423e+05 7.433e+06

The time and frequency offsets between the ntpd calculated time and the local system clock. Showing frequency offset (red, in parts per million, scale on right) and the time offset (blue, in μs, scale on left). Quick changes in time offset will lead to larger frequency offsets.

These are fields 3 (time) and 4 (frequency) from the loopstats log file.



Local RMS Time Jitter

local jitter plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Time Jitter 1.452 2.494 3.260 7.080 14.546 17.998 23.374 11.286 15.504 3.541 7.761 µs 6.159 18.4

The RMS Jitter of the local clock offset. In other words, how fast the local clock offset is changing.

Lower is better. An ideal system would be a horizontal line at 0μs.

RMS jitter is field 5 in the loopstats log file.



Local RMS Frequency Jitter

local stability plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Frequency Jitter 0.027 0.206 0.298 0.641 1.434 2.255 3.350 1.136 2.049 0.393 0.726 ppb 5.249 22.08

The RMS Frequency Jitter (aka wander) of the local clock's frequency. In other words, how fast the local clock changes frequency.

Lower is better. An ideal clock would be a horizontal line at 0ppm.

RMS Frequency Jitter is field 6 in the loopstats log file.



Local Clock Time Offset Histogram

local offset histogram plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Offset -66.988 -40.168 -21.883 0.024 22.174 35.838 56.093 44.057 76.006 13.512 0.046 µs -4.2 12.7

The clock offsets of the local clock as a histogram.

The Local Clock Offset is field 3 from the loopstats log file.



Local Temperatures

local temps plot

Local temperatures. These will be site-specific depending upon what temperature sensors you collect data from. Temperature changes affect the local clock crystal frequency and stability. The math of how temperature changes frequency is complex, and also depends on crystal aging. So there is no easy way to correct for it in software. This is the single most important component of frequency drift.

The Local Temperatures are from field 3 from the tempstats log file.



Local Frequency/Temp

local freq temps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -3.016 -2.959 -2.865 -2.779 -2.704 -2.692 -2.684 0.161 0.267 0.054 -2.781 ppm -1.423e+05 7.433e+06
Temp ZONE0 48.500 50.700 51.800 54.000 55.100 56.200 57.300 3.300 5.500 1.126 53.689 °C

The frequency offsets and temperatures. Showing frequency offset (red, in parts per million, scale on right) and the temperatures.

These are field 4 (frequency) from the loopstats log file, and field 3 from the tempstats log file.



Local GPS

local gps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
nSats 4.000 7.000 8.000 9.000 11.000 12.000 12.000 3.000 5.000 1.030 9.263 nSat 533.5 4451
TDOP 0.520 0.540 0.600 0.870 1.200 1.430 2.100 0.600 0.890 0.202 0.882 48.96 213.2

Local GPS. The Time Dilution of Precision (TDOP) is plotted in blue. The number of visible satellites (nSat) is plotted in red.

TDOP is field 3, and nSats is field 4, from the gpsd log file. The gpsd log file is created by the ntploggps program.

TDOP is a dimensionless error factor. Smaller numbers are better. TDOP ranges from 1 (ideal), 2 to 5 (good), to greater than 20 (poor). Some GNSS receivers report TDOP less than one which is theoretically impossible.



Server Offsets

peer offsets plot

The offset of all refclocks and servers. This can be useful to see if offset changes are happening in a single clock or all clocks together.

Clock Offset is field 5 in the peerstats log file.



Server Offset 195.176.26.206

peer offset 195.176.26.206 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 195.176.26.206 -132.425 -104.320 -81.219 -41.779 -5.265 19.434 47.435 75.954 123.754 23.279 -42.067 µs -30.64 114.4

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2001:638:610:be01::103 (ptbtime3.ptb.de)

peer offset 2001:638:610:be01::103 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:638:610:be01::103 (ptbtime3.ptb.de) -4.016 -2.792 -2.761 -2.709 -2.657 -2.634 -2.609 0.104 0.157 0.051 -2.711 ms -1.554e+05 8.366e+06

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2606:4700:f1::1 (time.cloudflare.com)

peer offset 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.251 0.514 0.602 0.733 0.928 1.072 1.136 0.326 0.558 0.104 0.746 ms 252.8 1687

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2606:4700:f1::123 (time.cloudflare.com)

peer offset 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 0.353 0.520 0.600 0.834 1.063 1.095 1.175 0.463 0.575 0.146 0.841 ms 122.9 655.4

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2a00:d78:0:712:94:198:159:11 (nts1.time.nl)

peer offset 2a00:d78:0:712:94:198:159:11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) -465.223 -0.442 -0.357 -0.163 0.593 0.983 16.995 0.949 1.425 21.182 -1.283 ms -22.86 444.4

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se)

peer offset 2a01:3f7:2:44::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 3.944 4.301 4.319 4.367 4.414 4.444 7.742 0.094 0.143 0.080 4.368 ms 1.528e+05 8.183e+06

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2a02:168:420b:4::7b:12 (ntp02.maillink.ch)

peer offset 2a02:168:420b:4::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) -63.702 -48.166 -34.477 0.496 41.322 54.546 74.468 75.799 102.712 22.946 2.219 µs -3.309 7.8

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 2a02:168:420b:d::7b:12 (ntp01.maillink.ch)

peer offset 2a02:168:420b:d::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) -83.346 -38.986 -23.235 10.788 52.660 73.716 109.968 75.895 112.702 23.016 11.990 µs -1.2 4.503

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 85.195.224.28

peer offset 85.195.224.28 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 85.195.224.28 -565.655 -263.249 -173.267 56.328 153.960 206.897 332.702 327.227 470.146 95.479 36.714 µs -3.466 11.88

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset PPS(0)

peer offset PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset PPS(0) -74.393 -45.718 -24.874 2.678 20.749 32.077 58.157 45.623 77.795 14.372 0.957 µs -4.383 13.81

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset SHM(0)

peer offset SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(0) -735.066 -587.329 -498.502 -377.297 -327.958 -302.030 -3.278 170.543 285.299 55.718 -389.908 ms -536.5 4513

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset SHM(2)

peer offset SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(2) -906.234 -0.046 -0.026 0.002 0.020 0.031 0.054 0.045 0.077 9.346 -0.103 ms -100.5 9745

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Jitters

peer jitters plot

The RMS Jitter of all refclocks and servers. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 195.176.26.206

peer jitter 195.176.26.206 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 195.176.26.206 0.000 0.014 0.020 0.059 0.408 1.120 4.459 0.388 1.106 0.286 0.129 ms 8.945 130.1

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:638:610:be01::103 (ptbtime3.ptb.de)

peer jitter 2001:638:610:be01::103 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:638:610:be01::103 (ptbtime3.ptb.de) 0.000 19.497 27.080 63.032 263.837 484.488 1,292.374 236.757 464.991 100.266 95.708 µs 4.294 34.37

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2606:4700:f1::1 (time.cloudflare.com)

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 13.485 21.308 29.562 71.436 296.664 537.300 1,008.541 267.102 515.992 104.519 108.742 µs 3.362 19.91

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2606:4700:f1::123 (time.cloudflare.com)

peer jitter 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.000 18.295 27.576 63.619 329.588 506.919 852.927 302.012 488.624 108.397 105.435 µs 2.61 12.08

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2a00:d78:0:712:94:198:159:11 (nts1.time.nl)

peer jitter 2a00:d78:0:712:94:198:159:11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) 0.000 0.047 0.076 1.235 5.924 22.652 465.271 5.848 22.605 26.227 4.116 ms 9.364 133.3

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se)

peer jitter 2a01:3f7:2:44::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 0.000 0.021 0.028 0.071 0.304 0.909 43.254 0.276 0.888 1.355 0.167 ms 27.48 874.1

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch)

peer jitter 2a02:168:420b:4::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) 0.000 3.763 5.549 17.363 42.449 52.712 86.289 36.900 48.949 11.513 19.806 µs 3.561 10.59

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2a02:168:420b:d::7b:12 (ntp01.maillink.ch)

peer jitter 2a02:168:420b:d::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) 0.000 13.172 17.918 48.587 388.178 987.742 2,029.785 370.260 974.570 164.624 105.615 µs 3.401 25.11

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 85.195.224.28

peer jitter 85.195.224.28 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 85.195.224.28 0.000 13.198 21.618 78.539 289.318 572.526 1,158.899 267.700 559.328 107.103 112.204 µs 3.154 19.75

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter PPS(0)

peer jitter PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter PPS(0) 0.000 0.342 0.813 1.812 3.173 4.720 25.918 2.360 4.378 0.809 1.884 µs 8.122 45.22

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter SHM(0)

peer jitter SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(0) 0.000 4.925 8.023 29.322 103.114 163.829 503.009 95.091 158.904 36.094 39.284 ms 4.033 32.81

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter SHM(2)

peer jitter SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(2) 0.000 0.001 0.001 0.005 0.017 0.024 906.242 0.016 0.023 13.213 0.382 ms 43.14 2494

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -3.016 -2.959 -2.865 -2.779 -2.704 -2.692 -2.684 0.161 0.267 0.054 -2.781 ppm -1.423e+05 7.433e+06
Local Clock Time Offset -66.988 -40.168 -21.883 0.024 22.174 35.838 56.093 44.057 76.006 13.512 0.046 µs -4.2 12.7
Local RMS Frequency Jitter 0.027 0.206 0.298 0.641 1.434 2.255 3.350 1.136 2.049 0.393 0.726 ppb 5.249 22.08
Local RMS Time Jitter 1.452 2.494 3.260 7.080 14.546 17.998 23.374 11.286 15.504 3.541 7.761 µs 6.159 18.4
Server Jitter 195.176.26.206 0.000 0.014 0.020 0.059 0.408 1.120 4.459 0.388 1.106 0.286 0.129 ms 8.945 130.1
Server Jitter 2001:638:610:be01::103 (ptbtime3.ptb.de) 0.000 19.497 27.080 63.032 263.837 484.488 1,292.374 236.757 464.991 100.266 95.708 µs 4.294 34.37
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 13.485 21.308 29.562 71.436 296.664 537.300 1,008.541 267.102 515.992 104.519 108.742 µs 3.362 19.91
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.000 18.295 27.576 63.619 329.588 506.919 852.927 302.012 488.624 108.397 105.435 µs 2.61 12.08
Server Jitter 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) 0.000 0.047 0.076 1.235 5.924 22.652 465.271 5.848 22.605 26.227 4.116 ms 9.364 133.3
Server Jitter 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 0.000 0.021 0.028 0.071 0.304 0.909 43.254 0.276 0.888 1.355 0.167 ms 27.48 874.1
Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) 0.000 3.763 5.549 17.363 42.449 52.712 86.289 36.900 48.949 11.513 19.806 µs 3.561 10.59
Server Jitter 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) 0.000 13.172 17.918 48.587 388.178 987.742 2,029.785 370.260 974.570 164.624 105.615 µs 3.401 25.11
Server Jitter 85.195.224.28 0.000 13.198 21.618 78.539 289.318 572.526 1,158.899 267.700 559.328 107.103 112.204 µs 3.154 19.75
Server Jitter PPS(0) 0.000 0.342 0.813 1.812 3.173 4.720 25.918 2.360 4.378 0.809 1.884 µs 8.122 45.22
Server Jitter SHM(0) 0.000 4.925 8.023 29.322 103.114 163.829 503.009 95.091 158.904 36.094 39.284 ms 4.033 32.81
Server Jitter SHM(2) 0.000 0.001 0.001 0.005 0.017 0.024 906.242 0.016 0.023 13.213 0.382 ms 43.14 2494
Server Offset 195.176.26.206 -132.425 -104.320 -81.219 -41.779 -5.265 19.434 47.435 75.954 123.754 23.279 -42.067 µs -30.64 114.4
Server Offset 2001:638:610:be01::103 (ptbtime3.ptb.de) -4.016 -2.792 -2.761 -2.709 -2.657 -2.634 -2.609 0.104 0.157 0.051 -2.711 ms -1.554e+05 8.366e+06
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.251 0.514 0.602 0.733 0.928 1.072 1.136 0.326 0.558 0.104 0.746 ms 252.8 1687
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 0.353 0.520 0.600 0.834 1.063 1.095 1.175 0.463 0.575 0.146 0.841 ms 122.9 655.4
Server Offset 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) -465.223 -0.442 -0.357 -0.163 0.593 0.983 16.995 0.949 1.425 21.182 -1.283 ms -22.86 444.4
Server Offset 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 3.944 4.301 4.319 4.367 4.414 4.444 7.742 0.094 0.143 0.080 4.368 ms 1.528e+05 8.183e+06
Server Offset 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) -63.702 -48.166 -34.477 0.496 41.322 54.546 74.468 75.799 102.712 22.946 2.219 µs -3.309 7.8
Server Offset 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) -83.346 -38.986 -23.235 10.788 52.660 73.716 109.968 75.895 112.702 23.016 11.990 µs -1.2 4.503
Server Offset 85.195.224.28 -565.655 -263.249 -173.267 56.328 153.960 206.897 332.702 327.227 470.146 95.479 36.714 µs -3.466 11.88
Server Offset PPS(0) -74.393 -45.718 -24.874 2.678 20.749 32.077 58.157 45.623 77.795 14.372 0.957 µs -4.383 13.81
Server Offset SHM(0) -735.066 -587.329 -498.502 -377.297 -327.958 -302.030 -3.278 170.543 285.299 55.718 -389.908 ms -536.5 4513
Server Offset SHM(2) -906.234 -0.046 -0.026 0.002 0.020 0.031 0.054 0.045 0.077 9.346 -0.103 ms -100.5 9745
TDOP 0.520 0.540 0.600 0.870 1.200 1.430 2.100 0.600 0.890 0.202 0.882 48.96 213.2
Temp ZONE0 48.500 50.700 51.800 54.000 55.100 56.200 57.300 3.300 5.500 1.126 53.689 °C
nSats 4.000 7.000 8.000 9.000 11.000 12.000 12.000 3.000 5.000 1.030 9.263 nSat 533.5 4451
Summary as CSV file


Glossary:

frequency offset:
The difference between the ntpd calculated frequency and the local system clock frequency (usually in parts per million, ppm)
jitter, dispersion:
The short term change in a value. NTP measures Local Time Jitter, Refclock Jitter, and Server Jitter in seconds. Local Frequency Jitter is in ppm or ppb.
kurtosis, Kurt:
The kurtosis of a random variable X is the fourth standardized moment and is a dimension-less ratio. ntpviz uses the Pearson's moment coefficient of kurtosis. A normal distribution has a kurtosis of three. NIST describes a kurtosis over three as "heavy tailed" and one under three as "light tailed".
ms, millisecond:
One thousandth of a second = 0.001 seconds, 1e-3 seconds
mu, mean:
The arithmetic mean: the sum of all the values divided by the number of values. The formula for mu is: "mu = (∑xi) / N". Where xi denotes the data points and N is the number of data points.
ns, nanosecond:
One billionth of a second, also one thousandth of a microsecond, 0.000000001 seconds and 1e-9 seconds.
percentile:
The value below which a given percentage of values fall.
ppb, parts per billion:
Ratio between two values. These following are all the same: 1 ppb, one in one billion, 1/1,000,000,000, 0.000,000,001, 1e-9 and 0.000,000,1%
ppm, parts per million:
Ratio between two values. These following are all the same: 1 ppm, one in one million, 1/1,000,000, 0.000,001, and 0.000,1%
‰, parts per thousand:
Ratio between two values. These following are all the same: 1 ‰. one in one thousand, 1/1,000, 0.001, and 0.1%
refclock:
Reference clock, a local GPS module or other local source of time.
remote clock:
Any clock reached over the network, LAN or WAN. Also called a peer or server.
time offset:
The difference between the ntpd calculated time and the local system clock's time. Also called phase offset.
σ, sigma:
Sigma denotes the standard deviation (SD) and is centered on the arithmetic mean of the data set. The SD is simply the square root of the variance of the data set. Two sigma is simply twice the standard deviation. Three sigma is three times sigma. Smaller is better.
The formula for sigma is: "σ = √[ ∑(xi-mu)^2 / N ]". Where xi denotes the data points and N is the number of data points.
skewness, Skew:
The skewness of a random variable X is the third standardized moment and is a dimension-less ratio. ntpviz uses the Pearson's moment coefficient of skewness. Wikipedia describes it best: "The qualitative interpretation of the skew is complicated and unintuitive."
A normal distribution has a skewness of zero.
upstream clock:
Any server or reference clock used as a source of time.
µs, us, microsecond:
One millionth of a second, also one thousandth of a millisecond, 0.000,001 seconds, and 1e-6 seconds.



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