From SpinetiX Support Wiki
The following NTP information is displayed within HMP Control Center:
- Server IP.
- A static measure representing the number of servers up to a reference time server (usually an atomic clock).
- peer - this is the server used for the time synchronization;
- candidate - this is a server whose time is consistent with the HMP and may be used in case the peer is no longer available;
- reject - the server is not used, because its stratum is too low or it has been configured as "Monitor only" in the Time Sources;
- oulier - the server is too different from the peer to be used for synchronization;
- initializing - during transition phase or when it cannot be reached;
- unreachable - the server cannot be reached.
- How often the server has been reached as a percentage within the last 8 attempts; it should be as close as possible to 100%.
- Time offset
- The time difference in milliseconds between the HMP time and the NTP server time.
- The time delay in milliseconds between the moment the HMP has send the request and got the answer from the NTP server; it should be as small as possible.
- When repeatedly reading the time, the time offset may vary almost randomly and the difference (second derivation) of these time offsets is called jitter or dispersion. Note that a small value is needed for synchronized content.
- Poll interval
- The time interval between requests towards the NTP server. It will start with the minimum value and gradually increase up to the maximum value; for internal NTP servers (min, max) = (16s, 256s) and for public ones (min, max) = (64s, 1024s).
After the NTP statistics, the information regarding the local clock calibration is displayed. The correction is displayed in ppm (part per million); for instance 1ppm would mean that the internal clock will drift with 32 seconds in a year.
- In case some of your NTP server can't be reached ("Status" column remains always "Initializing"), it may be behind a firewall or just wrongly configured. Check the NTP server configuration with your system administrator.
- The values in the column "Time offset" should be as close to 0 as possible, it this is not the case, then it might be necessary to either check the network configuration or change the NTP server.
- The NTP server might be rejected if the dispersion value is hight, at least higher than the time offset.