NTPsec

A-ntpsec-7-day-stats

Report generated: Sun Jan 26 14:03:46 2020 UTC
Start Time: Sun Jan 19 14:03:33 2020 UTC
End Time: Sun Jan 26 14:03:33 2020 UTC
Report published: Sun Jan 26 06:04:21 2020 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 -1,300.000 -800.000 -612.000 14.000 569.000 746.000 1,219.000 1,181.000 1,546.000 375.795 -1.006 ns -4.128 9.754
Local Clock Frequency Offset -870.300 -863.190 -823.090 -720.078 -526.611 -489.655 -483.170 296.479 373.535 92.521 -698.864 ppb -651 5777

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 59.000 83.000 96.000 137.000 200.000 241.000 466.000 104.000 158.000 32.922 141.295 ns 46.54 201.1

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 15.000 24.000 30.000 94.000 218.000 278.000 511.000 188.000 254.000 59.807 103.583 10e-12 3.611 10.77

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 -1,300.000 -800.000 -612.000 14.000 569.000 746.000 1,219.000 1,181.000 1,546.000 375.795 -1.006 ns -4.128 9.754

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 -870.300 -863.190 -823.090 -720.078 -526.611 -489.655 -483.170 296.479 373.535 92.521 -698.864 ppb -651 5777
Temp ZONE0 60.148 60.148 61.224 62.838 64.452 64.452 64.990 3.228 4.304 0.929 62.817 °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 1.000 7.000 7.000 10.000 12.000 12.000 12.000 5.000 5.000 1.327 9.717 nSat 271.6 1837
TDOP 0.510 0.550 0.590 0.810 1.290 1.670 1.720 0.700 1.120 0.234 0.859 28.34 110.9

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. TDOP ranges from 1 to greater than 20. 1 denotes the highest possible confidence level. 2 to 5 is good. Greater than 20 means there will be significant inaccuracy and error.



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 192.168.1.11

peer offset 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.11 -165.491 -66.020 -49.045 -4.309 61.739 85.409 205.053 110.784 151.429 33.775 -0.373 µs -3.645 8.926

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 192.168.1.12

peer offset 192.168.1.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.12 -182.292 -96.834 -80.582 -33.499 35.430 65.195 107.585 116.012 162.029 35.828 -29.063 µs -10.93 30.23

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 2001:470:0:50::2 (clock.fmt.he.net)

peer offset 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) 1.449 2.007 2.207 2.553 2.953 3.295 3.736 0.745 1.288 0.235 2.564 ms 1003 1.026e+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 2001:470:e815::24 (pi4.rellim.com)

peer offset 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::24 (pi4.rellim.com) 2.989 3.587 3.867 4.292 4.729 4.989 5.500 0.862 1.402 0.268 4.298 ms 3459 5.276e+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 216.218.254.202

peer offset 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 216.218.254.202 0.110 2.000 2.208 2.538 2.906 3.199 3.515 0.697 1.200 0.240 2.538 ms 908.6 8966

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 2405:fc00:0:1::123

peer offset 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2405:fc00:0:1::123 5.064 9.100 9.486 11.366 11.890 12.504 19.585 2.404 3.404 0.787 11.274 ms 2410 3.277e+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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer offset 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -11.467 -10.383 -8.787 -1.530 3.433 3.850 4.205 12.220 14.233 3.459 -1.163 ms -7.085 20.76

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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer offset 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -58.516 -52.952 -7.853 3.529 8.016 11.457 13.927 15.869 64.409 10.307 1.300 ms -7.53 41.36

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) -80.610 -64.043 -60.437 -52.450 -45.574 -43.418 -40.235 14.864 20.625 4.500 -52.559 ms -2077 2.684e+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 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) -1,300.000 -800.000 -613.000 15.000 570.000 747.000 1,220.000 1,183.000 1,547.000 376.605 -0.986 ns -4.128 9.747

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 192.168.1.11

peer jitter 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.11 0.010 0.033 0.055 0.208 8.669 9.838 58.369 8.613 9.805 2.998 1.761 ms 1.93 29.82

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 192.168.1.12

peer jitter 192.168.1.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.12 0.009 0.029 0.052 0.208 8.661 9.734 232.988 8.608 9.705 6.127 1.821 ms 26.98 1014

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 2001:470:0:50::2 (clock.fmt.he.net)

peer jitter 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 0.131 0.218 0.299 1.548 9.239 13.861 99.410 8.939 13.643 4.377 3.173 ms 8.507 178.5

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 2001:470:e815::24 (pi4.rellim.com)

peer jitter 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.148 0.280 0.397 1.912 11.417 117.630 186.440 11.020 117.350 16.504 5.303 ms 5.64 51.72

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 216.218.254.202

peer jitter 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 216.218.254.202 0.117 0.195 0.329 1.844 9.272 13.235 42.339 8.943 13.040 3.648 3.193 ms 3.342 29.37

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 2405:fc00:0:1::123

peer jitter 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2405:fc00:0:1::123 0.079 0.272 0.409 2.772 10.281 15.755 157.457 9.873 15.483 6.683 4.298 ms 13.95 305.5

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer jitter 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.157 0.255 0.403 2.105 11.142 45.443 221.717 10.739 45.188 12.479 4.662 ms 9.2 130.4

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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer jitter 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.083 0.277 0.393 2.401 15.292 53.273 221.388 14.898 52.996 15.897 6.009 ms 6.458 69.91

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 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) 0.063 0.315 0.460 1.196 3.585 6.664 18.033 3.125 6.350 1.221 1.584 ms 3.482 17.69

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) 24.000 54.000 73.000 144.000 306.000 414.000 1,039.000 233.000 360.000 75.822 160.852 ns 6.457 25.41

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 -870.300 -863.190 -823.090 -720.078 -526.611 -489.655 -483.170 296.479 373.535 92.521 -698.864 ppb -651 5777
Local Clock Time Offset -1,300.000 -800.000 -612.000 14.000 569.000 746.000 1,219.000 1,181.000 1,546.000 375.795 -1.006 ns -4.128 9.754
Local RMS Frequency Jitter 15.000 24.000 30.000 94.000 218.000 278.000 511.000 188.000 254.000 59.807 103.583 10e-12 3.611 10.77
Local RMS Time Jitter 59.000 83.000 96.000 137.000 200.000 241.000 466.000 104.000 158.000 32.922 141.295 ns 46.54 201.1
Server Jitter 192.168.1.11 0.010 0.033 0.055 0.208 8.669 9.838 58.369 8.613 9.805 2.998 1.761 ms 1.93 29.82
Server Jitter 192.168.1.12 0.009 0.029 0.052 0.208 8.661 9.734 232.988 8.608 9.705 6.127 1.821 ms 26.98 1014
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 0.131 0.218 0.299 1.548 9.239 13.861 99.410 8.939 13.643 4.377 3.173 ms 8.507 178.5
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.148 0.280 0.397 1.912 11.417 117.630 186.440 11.020 117.350 16.504 5.303 ms 5.64 51.72
Server Jitter 216.218.254.202 0.117 0.195 0.329 1.844 9.272 13.235 42.339 8.943 13.040 3.648 3.193 ms 3.342 29.37
Server Jitter 2405:fc00:0:1::123 0.079 0.272 0.409 2.772 10.281 15.755 157.457 9.873 15.483 6.683 4.298 ms 13.95 305.5
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.157 0.255 0.403 2.105 11.142 45.443 221.717 10.739 45.188 12.479 4.662 ms 9.2 130.4
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.083 0.277 0.393 2.401 15.292 53.273 221.388 14.898 52.996 15.897 6.009 ms 6.458 69.91
Server Jitter SHM(0) 0.063 0.315 0.460 1.196 3.585 6.664 18.033 3.125 6.350 1.221 1.584 ms 3.482 17.69
Server Jitter SHM(1) 24.000 54.000 73.000 144.000 306.000 414.000 1,039.000 233.000 360.000 75.822 160.852 ns 6.457 25.41
Server Offset 192.168.1.11 -165.491 -66.020 -49.045 -4.309 61.739 85.409 205.053 110.784 151.429 33.775 -0.373 µs -3.645 8.926
Server Offset 192.168.1.12 -182.292 -96.834 -80.582 -33.499 35.430 65.195 107.585 116.012 162.029 35.828 -29.063 µs -10.93 30.23
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) 1.449 2.007 2.207 2.553 2.953 3.295 3.736 0.745 1.288 0.235 2.564 ms 1003 1.026e+04
Server Offset 2001:470:e815::24 (pi4.rellim.com) 2.989 3.587 3.867 4.292 4.729 4.989 5.500 0.862 1.402 0.268 4.298 ms 3459 5.276e+04
Server Offset 216.218.254.202 0.110 2.000 2.208 2.538 2.906 3.199 3.515 0.697 1.200 0.240 2.538 ms 908.6 8966
Server Offset 2405:fc00:0:1::123 5.064 9.100 9.486 11.366 11.890 12.504 19.585 2.404 3.404 0.787 11.274 ms 2410 3.277e+04
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -11.467 -10.383 -8.787 -1.530 3.433 3.850 4.205 12.220 14.233 3.459 -1.163 ms -7.085 20.76
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -58.516 -52.952 -7.853 3.529 8.016 11.457 13.927 15.869 64.409 10.307 1.300 ms -7.53 41.36
Server Offset SHM(0) -80.610 -64.043 -60.437 -52.450 -45.574 -43.418 -40.235 14.864 20.625 4.500 -52.559 ms -2077 2.684e+04
Server Offset SHM(1) -1,300.000 -800.000 -613.000 15.000 570.000 747.000 1,220.000 1,183.000 1,547.000 376.605 -0.986 ns -4.128 9.747
TDOP 0.510 0.550 0.590 0.810 1.290 1.670 1.720 0.700 1.120 0.234 0.859 28.34 110.9
Temp ZONE0 60.148 60.148 61.224 62.838 64.452 64.452 64.990 3.228 4.304 0.929 62.817 °C
nSats 1.000 7.000 7.000 10.000 12.000 12.000 12.000 5.000 5.000 1.327 9.717 nSat 271.6 1837
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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