NTPsec

A-ntpsec-7-day-stats

Report generated: Mon Jan 5 06:11:25 2026 UTC
Start Time: Mon Dec 29 06:11:23 2025 UTC
End Time: Mon Jan 5 06:11:23 2026 UTC
Report published: Sun Jan 04 10:12:07 PM 2026 PST
Report Period: 7.0 days

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 -4.467 -2.290 -1.367 0.069 1.030 1.479 4.664 2.397 3.769 0.722 0.001 µs -4.821 15.12
Local Clock Frequency Offset -601.868 -591.461 -554.077 -292.084 -201.813 -191.696 -184.616 352.264 399.765 103.477 -322.443 ppb -83.09 408.4

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 0.275 0.417 0.511 0.879 1.417 1.655 2.909 0.906 1.238 0.278 0.910 µs 19.15 66.42

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 108.000 161.000 194.000 325.000 519.000 608.000 1,318.000 325.000 447.000 103.732 337.354 10e-12 19.26 73.1

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 -4.467 -2.290 -1.367 0.069 1.030 1.479 4.664 2.397 3.769 0.722 0.001 µs -4.821 15.12

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 -601.868 -591.461 -554.077 -292.084 -201.813 -191.696 -184.616 352.264 399.765 103.477 -322.443 ppb -83.09 408.4
Temp ZONE0 42.932 43.470 44.008 46.160 47.236 47.236 47.774 3.228 3.766 0.991 46.003 °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 7.000 8.000 8.000 10.000 12.000 12.000 12.000 4.000 4.000 1.161 10.048 nSat 471.9 3792
TDOP 0.490 0.510 0.560 0.790 1.190 1.480 2.320 0.630 0.970 0.202 0.831 40.64 170.2

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 157.131.224.9

peer offset 157.131.224.9 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 157.131.224.9 1.096 2.244 2.845 3.992 4.213 4.338 6.264 1.368 2.094 0.416 3.892 ms 604 5197

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 173.11.101.155

peer offset 173.11.101.155 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 173.11.101.155 -5.117 -3.556 -2.230 -0.124 2.625 4.106 5.636 4.855 7.663 1.506 -0.050 ms -3.835 9.652

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 192.12.19.20

peer offset 192.12.19.20 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.12.19.20 -0.169 1.459 2.533 3.834 4.483 5.104 5.973 1.950 3.644 0.614 3.734 ms 145.5 805.8

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 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) 1.920 2.645 3.223 3.572 3.856 3.992 4.229 0.634 1.346 0.229 3.556 ms 3104 4.563e+04

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) 2.171 2.561 3.222 3.571 3.864 4.012 4.300 0.642 1.451 0.240 3.555 ms 2666 3.73e+04

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 2607:5300:205:200::2502 (zero.txryan.com)

peer offset 2607:5300:205:200::2502 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:5300:205:200::2502 (zero.txryan.com) 1.572 2.221 3.000 3.331 4.046 32.341 32.775 1.046 30.120 3.132 3.695 ms 9.516 89.07

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 2607:5300:205:200::596

peer offset 2607:5300:205:200::596 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:5300:205:200::596 2.082 2.207 3.051 3.351 3.748 3.858 3.884 0.698 1.651 0.273 3.364 ms 1478 1.705e+04

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer offset 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 1.585 2.278 2.802 3.702 3.893 4.066 5.057 1.091 1.788 0.321 3.632 ms 1122 1.18e+04

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 50.116.42.84

peer offset 50.116.42.84 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 50.116.42.84 1.553 2.187 2.932 3.350 3.871 4.531 5.507 0.939 2.343 0.340 3.358 ms 728.9 6734

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 52.10.183.132

peer offset 52.10.183.132 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 52.10.183.132 2.034 2.454 3.136 3.553 3.873 4.115 4.703 0.736 1.661 0.263 3.528 ms 1960 2.48e+04

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 66.220.9.122

peer offset 66.220.9.122 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 66.220.9.122 0.113 1.683 2.370 3.454 4.155 4.524 5.058 1.785 2.841 0.526 3.405 ms 179.2 1060

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) -103.211 -102.118 -101.051 -97.550 -95.171 -94.477 -93.366 5.880 7.641 1.703 -97.648 ms -1.988e+05 1.161e+07

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(1)

peer offset SHM(1) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(1) -4.468 -2.291 -1.368 0.070 1.031 1.480 4.665 2.399 3.771 0.723 0.001 µs -4.819 15.11

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 157.131.224.9

peer jitter 157.131.224.9 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 157.131.224.9 0.081 0.150 0.211 1.010 4.407 13.296 37.316 4.196 13.146 2.487 1.511 ms 5.517 55.06

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 173.11.101.155

peer jitter 173.11.101.155 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 173.11.101.155 0.503 1.147 1.574 2.912 6.772 17.872 57.060 5.198 16.725 3.441 3.553 ms 8.48 103.1

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 192.12.19.20

peer jitter 192.12.19.20 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.12.19.20 0.089 0.147 0.222 1.050 3.559 12.064 23.735 3.337 11.916 2.292 1.516 ms 5.071 42.05

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) 0.121 0.181 0.252 1.272 3.394 16.033 23.305 3.142 15.852 2.340 1.665 ms 4.527 31.73

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) 0.127 0.175 0.247 1.349 4.133 16.043 22.816 3.886 15.868 2.367 1.747 ms 4.581 32.95

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 2607:5300:205:200::2502 (zero.txryan.com)

peer jitter 2607:5300:205:200::2502 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:5300:205:200::2502 (zero.txryan.com) 0.093 0.161 0.241 1.198 4.249 13.270 113.632 4.009 13.109 4.474 1.834 ms 16.3 394.7

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 2607:5300:205:200::596

peer jitter 2607:5300:205:200::596 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:5300:205:200::596 0.213 0.215 0.257 0.959 2.936 5.739 5.795 2.679 5.524 0.920 1.153 ms 3.138 14.07

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer jitter 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.061 0.157 0.237 1.301 3.410 16.780 38.826 3.172 16.623 2.752 1.706 ms 6.762 73.68

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 50.116.42.84

peer jitter 50.116.42.84 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 50.116.42.84 0.088 0.145 0.214 0.850 3.816 13.337 30.922 3.603 13.192 2.627 1.426 ms 5.518 53.51

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 52.10.183.132

peer jitter 52.10.183.132 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 52.10.183.132 0.071 0.136 0.206 0.865 3.743 16.722 27.202 3.538 16.586 2.678 1.495 ms 4.185 30.56

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 66.220.9.122

peer jitter 66.220.9.122 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 66.220.9.122 0.060 0.140 0.221 1.096 3.616 15.092 24.189 3.395 14.952 2.371 1.570 ms 4.542 33.64

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) 0.094 0.197 0.267 0.562 1.276 1.700 2.823 1.008 1.504 0.323 0.639 ms 5.302 18.09

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(1)

peer jitter SHM(1) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(1) 0.042 0.258 0.360 0.812 1.832 2.517 5.122 1.472 2.259 0.471 0.913 µs 5.065 17.37

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -601.868 -591.461 -554.077 -292.084 -201.813 -191.696 -184.616 352.264 399.765 103.477 -322.443 ppb -83.09 408.4
Local Clock Time Offset -4.467 -2.290 -1.367 0.069 1.030 1.479 4.664 2.397 3.769 0.722 0.001 µs -4.821 15.12
Local RMS Frequency Jitter 108.000 161.000 194.000 325.000 519.000 608.000 1,318.000 325.000 447.000 103.732 337.354 10e-12 19.26 73.1
Local RMS Time Jitter 0.275 0.417 0.511 0.879 1.417 1.655 2.909 0.906 1.238 0.278 0.910 µs 19.15 66.42
Server Jitter 157.131.224.9 0.081 0.150 0.211 1.010 4.407 13.296 37.316 4.196 13.146 2.487 1.511 ms 5.517 55.06
Server Jitter 173.11.101.155 0.503 1.147 1.574 2.912 6.772 17.872 57.060 5.198 16.725 3.441 3.553 ms 8.48 103.1
Server Jitter 192.12.19.20 0.089 0.147 0.222 1.050 3.559 12.064 23.735 3.337 11.916 2.292 1.516 ms 5.071 42.05
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.121 0.181 0.252 1.272 3.394 16.033 23.305 3.142 15.852 2.340 1.665 ms 4.527 31.73
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.127 0.175 0.247 1.349 4.133 16.043 22.816 3.886 15.868 2.367 1.747 ms 4.581 32.95
Server Jitter 2607:5300:205:200::2502 (zero.txryan.com) 0.093 0.161 0.241 1.198 4.249 13.270 113.632 4.009 13.109 4.474 1.834 ms 16.3 394.7
Server Jitter 2607:5300:205:200::596 0.213 0.215 0.257 0.959 2.936 5.739 5.795 2.679 5.524 0.920 1.153 ms 3.138 14.07
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.061 0.157 0.237 1.301 3.410 16.780 38.826 3.172 16.623 2.752 1.706 ms 6.762 73.68
Server Jitter 50.116.42.84 0.088 0.145 0.214 0.850 3.816 13.337 30.922 3.603 13.192 2.627 1.426 ms 5.518 53.51
Server Jitter 52.10.183.132 0.071 0.136 0.206 0.865 3.743 16.722 27.202 3.538 16.586 2.678 1.495 ms 4.185 30.56
Server Jitter 66.220.9.122 0.060 0.140 0.221 1.096 3.616 15.092 24.189 3.395 14.952 2.371 1.570 ms 4.542 33.64
Server Jitter SHM(0) 0.094 0.197 0.267 0.562 1.276 1.700 2.823 1.008 1.504 0.323 0.639 ms 5.302 18.09
Server Jitter SHM(1) 0.042 0.258 0.360 0.812 1.832 2.517 5.122 1.472 2.259 0.471 0.913 µs 5.065 17.37
Server Offset 157.131.224.9 1.096 2.244 2.845 3.992 4.213 4.338 6.264 1.368 2.094 0.416 3.892 ms 604 5197
Server Offset 173.11.101.155 -5.117 -3.556 -2.230 -0.124 2.625 4.106 5.636 4.855 7.663 1.506 -0.050 ms -3.835 9.652
Server Offset 192.12.19.20 -0.169 1.459 2.533 3.834 4.483 5.104 5.973 1.950 3.644 0.614 3.734 ms 145.5 805.8
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 1.920 2.645 3.223 3.572 3.856 3.992 4.229 0.634 1.346 0.229 3.556 ms 3104 4.563e+04
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 2.171 2.561 3.222 3.571 3.864 4.012 4.300 0.642 1.451 0.240 3.555 ms 2666 3.73e+04
Server Offset 2607:5300:205:200::2502 (zero.txryan.com) 1.572 2.221 3.000 3.331 4.046 32.341 32.775 1.046 30.120 3.132 3.695 ms 9.516 89.07
Server Offset 2607:5300:205:200::596 2.082 2.207 3.051 3.351 3.748 3.858 3.884 0.698 1.651 0.273 3.364 ms 1478 1.705e+04
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 1.585 2.278 2.802 3.702 3.893 4.066 5.057 1.091 1.788 0.321 3.632 ms 1122 1.18e+04
Server Offset 50.116.42.84 1.553 2.187 2.932 3.350 3.871 4.531 5.507 0.939 2.343 0.340 3.358 ms 728.9 6734
Server Offset 52.10.183.132 2.034 2.454 3.136 3.553 3.873 4.115 4.703 0.736 1.661 0.263 3.528 ms 1960 2.48e+04
Server Offset 66.220.9.122 0.113 1.683 2.370 3.454 4.155 4.524 5.058 1.785 2.841 0.526 3.405 ms 179.2 1060
Server Offset SHM(0) -103.211 -102.118 -101.051 -97.550 -95.171 -94.477 -93.366 5.880 7.641 1.703 -97.648 ms -1.988e+05 1.161e+07
Server Offset SHM(1) -4.468 -2.291 -1.368 0.070 1.031 1.480 4.665 2.399 3.771 0.723 0.001 µs -4.819 15.11
TDOP 0.490 0.510 0.560 0.790 1.190 1.480 2.320 0.630 0.970 0.202 0.831 40.64 170.2
Temp ZONE0 42.932 43.470 44.008 46.160 47.236 47.236 47.774 3.228 3.766 0.991 46.003 °C
nSats 7.000 8.000 8.000 10.000 12.000 12.000 12.000 4.000 4.000 1.161 10.048 nSat 471.9 3792
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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