NTPsec

NTP4: SecureSync, Rubidium, NTP (Classic)
Twelve Hour - July 30, 2026 23:00 UTC

Report generated: Thu Jul 30 23:02:38 2026 UTC
Start Time: Thu Jul 30 11:02:38 2026 UTC
End Time: Thu Jul 30 23:02:38 2026 UTC
Report Period: 0.5 days

Return to It's About Time

Section Time Frame NTP Server
Local Clock Time/Frequency Offsets One Hour NTP0: x86 SBC, NTPSec, NTP-disciplined (stratum 2)
Local RMS Time Jitter Three Hour NTP1: RPi4B, Uputronics M8, NTPSec
Local RMS Frequency Jitter Six Hour NTP2: CM4, Bollar ZED-F9T, NTPSec
Local Clock Time Offset Histogram Twelve Hour NTP3: CM5, TimeHat LEA-M8T, NTPSec
Local Temperatures One Day NTP4: SecureSync, Rubidium, NTP (Classic)
Local Frequency/Temp Two Day NTP5: RPi3B+, Uputronics MAX-M8Q, NTPSec
Local GPS Three Day NTP6: CM4, TimeBeat OTC Mini, PTP
Server Offsets Seven Day NTP7: LeoNTP, Standalone GNSS, Firmware
Server Jitters Fourteen Day (Updated Daily)
Summary One Month (Updated Daily)
NTPQ Stats
GNSS Performance

NTP4 is a Safran SecureSync 1200 appliance with a Rubidium oscillator and u-blox timing GNSS receiver. It is used as a highly stable atomic reference clock for the network.

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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 -282.106 -24.744 -10.000 0.000 1.998 23.243 230.998 11.998 47.987 15.165 -0.454 µs 2.377 183.8
Local Clock Frequency Offset 9.962 9.968 9.973 10.118 10.332 10.660 10.714 0.359 0.692 0.116 10.117 ppm 2.582 12.4

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 0.955 0.956 0.960 0.976 16.272 61.209 132.395 15.312 60.253 11.602 3.400 µs 6.51 52.75

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 0.050 0.077 0.130 0.318 11.211 48.553 66.967 11.081 48.476 7.853 2.336 ppb 5.376 34

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 -282.106 -24.744 -10.000 0.000 1.998 23.243 230.998 11.998 47.987 15.165 -0.454 µs 2.377 183.8

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 9.962 9.968 9.973 10.118 10.332 10.660 10.714 0.359 0.692 0.116 10.117 ppm 2.582 12.4
Temp BOARD 58.000 58.000 58.000 58.880 59.880 60.750 60.880 1.880 2.750 0.596 59.012 °C
Temp CPU 58.000 58.000 58.880 59.250 60.120 61.120 61.380 1.240 3.120 0.478 59.294 °C
Temp OSC 48.480 48.540 48.620 48.830 49.490 50.270 50.460 0.870 1.730 0.303 48.887 °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 18.000 19.000 21.000 23.000 25.000 26.000 27.000 4.000 7.000 1.555 22.760 nSat 0.1066 2.56
TDOP 0.180 0.180 0.190 0.190 0.200 0.200 0.210 0.010 0.020 0.005 0.193 0.6893 2.996

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 10.0.50.100

peer offset 10.0.50.100 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 10.0.50.100 -322.490 -311.929 -294.705 13.804 38.876 40.517 41.778 333.581 352.446 93.973 -10.754 µs -2.6 8.125

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 10.0.50.20

peer offset 10.0.50.20 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 10.0.50.20 -344.972 -328.110 -301.648 15.118 29.902 33.210 33.552 331.550 361.320 97.750 -23.274 µs -2.446 7.368

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 10.0.50.200

peer offset 10.0.50.200 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 10.0.50.200 -73.124 -44.918 -21.487 25.181 52.897 62.356 75.353 74.384 107.274 23.096 21.513 µs -0.892 4.318

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 10.0.50.30

peer offset 10.0.50.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 10.0.50.30 -312.856 -306.470 -272.561 40.476 58.147 60.873 61.323 330.708 367.343 95.084 5.980 µs -2.529 7.871

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 10.0.50.40

peer offset 10.0.50.40 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 10.0.50.40 -331.466 -321.457 -295.938 6.731 31.816 33.459 36.421 327.754 354.916 90.440 -16.599 µs -2.681 8.706

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 10.0.50.50

peer offset 10.0.50.50 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 10.0.50.50 -290.636 -257.431 -237.275 75.296 99.329 101.990 103.133 336.604 359.421 95.382 42.216 µs -2.463 7.583

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.



Refclock Offset 127.127.45.0

peer offset 127.127.45.0 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock Offset 127.127.45.0 -19.000 -17.000 -7.000 -0.001 1.999 2.000 230.999 8.999 19.000 12.366 0.080 µs 13.78 222.9

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

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local serial GPS 200 ms; local PPS 20µs.

Clock Offset is field 5 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 10.0.50.100

peer jitter 10.0.50.100 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 10.0.50.100 0.954 1.666 2.341 9.343 31.377 54.709 187.576 29.036 53.043 17.011 16.436 µs 5.192 49.06

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 10.0.50.20

peer jitter 10.0.50.20 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 10.0.50.20 1.660 2.280 3.067 13.507 40.899 114.186 188.139 37.832 111.906 18.867 19.280 µs 3.938 30.23

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 10.0.50.200

peer jitter 10.0.50.200 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 10.0.50.200 8.051 8.530 10.937 27.230 59.691 83.638 242.163 48.754 75.108 18.752 30.156 µs 4.871 50.58

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 10.0.50.30

peer jitter 10.0.50.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 10.0.50.30 1.483 2.482 3.032 9.881 39.828 59.660 172.481 36.796 57.178 17.240 16.973 µs 4.118 32.57

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 10.0.50.40

peer jitter 10.0.50.40 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 10.0.50.40 1.730 2.113 2.907 10.716 42.908 98.135 170.003 40.001 96.022 18.442 17.868 µs 3.378 21.82

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 10.0.50.50

peer jitter 10.0.50.50 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 10.0.50.50 4.324 5.840 7.363 20.445 54.964 142.210 186.917 47.601 136.370 21.895 25.067 µs 4.105 27.25

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.



Refclock RMS Jitter 127.127.45.0

peer jitter 127.127.45.0 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock RMS Jitter 127.127.45.0 0.954 0.954 0.954 0.954 1.195 44.145 209.406 0.241 43.191 12.186 2.242 µs 11.55 150.4

The RMS Jitter of a local refclock. 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 9.962 9.968 9.973 10.118 10.332 10.660 10.714 0.359 0.692 0.116 10.117 ppm 2.582 12.4
Local Clock Time Offset -282.106 -24.744 -10.000 0.000 1.998 23.243 230.998 11.998 47.987 15.165 -0.454 µs 2.377 183.8
Local RMS Frequency Jitter 0.050 0.077 0.130 0.318 11.211 48.553 66.967 11.081 48.476 7.853 2.336 ppb 5.376 34
Local RMS Time Jitter 0.955 0.956 0.960 0.976 16.272 61.209 132.395 15.312 60.253 11.602 3.400 µs 6.51 52.75
Refclock Offset 127.127.45.0 -19.000 -17.000 -7.000 -0.001 1.999 2.000 230.999 8.999 19.000 12.366 0.080 µs 13.78 222.9
Refclock RMS Jitter 127.127.45.0 0.954 0.954 0.954 0.954 1.195 44.145 209.406 0.241 43.191 12.186 2.242 µs 11.55 150.4
Server Jitter 10.0.50.100 0.954 1.666 2.341 9.343 31.377 54.709 187.576 29.036 53.043 17.011 16.436 µs 5.192 49.06
Server Jitter 10.0.50.20 1.660 2.280 3.067 13.507 40.899 114.186 188.139 37.832 111.906 18.867 19.280 µs 3.938 30.23
Server Jitter 10.0.50.200 8.051 8.530 10.937 27.230 59.691 83.638 242.163 48.754 75.108 18.752 30.156 µs 4.871 50.58
Server Jitter 10.0.50.30 1.483 2.482 3.032 9.881 39.828 59.660 172.481 36.796 57.178 17.240 16.973 µs 4.118 32.57
Server Jitter 10.0.50.40 1.730 2.113 2.907 10.716 42.908 98.135 170.003 40.001 96.022 18.442 17.868 µs 3.378 21.82
Server Jitter 10.0.50.50 4.324 5.840 7.363 20.445 54.964 142.210 186.917 47.601 136.370 21.895 25.067 µs 4.105 27.25
Server Offset 10.0.50.100 -322.490 -311.929 -294.705 13.804 38.876 40.517 41.778 333.581 352.446 93.973 -10.754 µs -2.6 8.125
Server Offset 10.0.50.20 -344.972 -328.110 -301.648 15.118 29.902 33.210 33.552 331.550 361.320 97.750 -23.274 µs -2.446 7.368
Server Offset 10.0.50.200 -73.124 -44.918 -21.487 25.181 52.897 62.356 75.353 74.384 107.274 23.096 21.513 µs -0.892 4.318
Server Offset 10.0.50.30 -312.856 -306.470 -272.561 40.476 58.147 60.873 61.323 330.708 367.343 95.084 5.980 µs -2.529 7.871
Server Offset 10.0.50.40 -331.466 -321.457 -295.938 6.731 31.816 33.459 36.421 327.754 354.916 90.440 -16.599 µs -2.681 8.706
Server Offset 10.0.50.50 -290.636 -257.431 -237.275 75.296 99.329 101.990 103.133 336.604 359.421 95.382 42.216 µs -2.463 7.583
TDOP 0.180 0.180 0.190 0.190 0.200 0.200 0.210 0.010 0.020 0.005 0.193 0.6893 2.996
Temp BOARD 58.000 58.000 58.000 58.880 59.880 60.750 60.880 1.880 2.750 0.596 59.012 °C
Temp CPU 58.000 58.000 58.880 59.250 60.120 61.120 61.380 1.240 3.120 0.478 59.294 °C
Temp OSC 48.480 48.540 48.620 48.830 49.490 50.270 50.460 0.870 1.730 0.303 48.887 °C
nSats 18.000 19.000 21.000 23.000 25.000 26.000 27.000 4.000 7.000 1.555 22.760 nSat 0.1066 2.56
Summary as CSV file

Our production NTP servers share the same mast-mounted Tallysman Accutenna® TW3972 Triple Band GNSS Antenna + L-band Correction Services antenna using a Tallysman TW164 1-to-4 Port Smart Power GNSS Signal Splitter. No external NTP servers are contacted and all servers, with the exception of NTP6, the LeoNTP 1200, poll each other. Internal NTP clients poll NTP4 or NTP6.

The LeoNTP 1200 is a black-box appliance that doesn't support timing reporting. Its status can be checked by viwing the Server Jitter & Offset from any of the other servers. It can be found at NTP7 or leontp.bollar.com (10.0.50.100). The LeoNTP link above will take you to the Server Jitter between the LeoNTP and the currently selected server.

NTPQ Stats

NTPQ Statistics are not not available for this NTP server.'

GNSS Performance

GNSS Performance is not available for this NTP server.'

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.
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 FIsher-Pearson moment of skewness. There are other different ways to calculate Skewness Wikipedia describes Skewness best: "The qualitative interpretation of the skew is complicated and unintuitive."
A normal distribution has a skewness of zero.
Kurtosis, Kurt:
The kurtosis of a random variable X is the fourth standardized moment and is a dimension-less ratio. ntpviz uses standard Kurtosis. There are other different ways to calculate 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".
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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