Subject : Java Glossary

A free program with versions for Windows and Linux to implement NTP (Network Time Protocol). The current version is 4.2.8p10. Last revised/verified: 2017-05-16 This replaces the inaccurate Windows W32tm.exe method that uses the stripped down SNTP (Simple Network Time Protocol) protocol instead of the full NTP.

rem Using w32tm.exe to resync the Windows clock with SNTP
rem This must be run as administrator.
rem Start the service (need be done only once per boot)
sc.exe start W32Time >nul:
rem probe an NTP clock on the net with SNTP
w32tm.exe /resync >nul:
rem -30-

It is very easy to install. You answer a few questions, and it sets everything up for you including starting services and composing the conf file.

There is no sign in its running or probing. I find this somewhat disconcerting.

Configuration

You control it with a configuration file X:\Program Files (x86)\NTP\etc\ntp.conf like this:

Configuring the Polling Interval

The polling interval is built-in and variable. You don’t have to do anything to control it. If you want to take manual control, open the configuration file and add a line like this:

server [IP-OF-YOUR-SERVER] minpoll 6 maxpoll 6

The default polling value after restart of NTP is the value specified by minpoll. The default values for minpoll and maxpoll are 6 (2^6 = 64 seconds) and 7 (2^7 = 128 seconds) respectively. The recommendation for Windows is to set minpoll and maxpoll to 6. The smallest and largest allowable polling values are 4 (16 seconds) and 17 (1.5 days) respectively.

Meinberg did not actually write the NTP software for Windows. It’s just the standard NTP package maintained by the NTP project at www.ntp.org and support.ntp.org At Meinberg, they support the NTP project by sponsoring, testing, submitting bug reports, and eventually providing patches. They also pick up the source code release, build the binaries for Windows, and put them into a GUI (Graphic User Interface) setup program to simplify installation under Windows.

Meinberg also make radio-controlled clocks some of which fit inside your PC. You would use one for an accurate corporate or network time server that does not depend on time servers on the net. They may use GLONASS or GPS (Global Positioning System) synchronisation.