10.4 Network Time Protocol (NTP)
The public domain software package called NTP (Network Time Protocol) is an implementation of the same
named TCP/IP network protocol. NTP has been initiated in the 1980’s by Dave L. Mills who was trying to
achieve a high accuracy time synchronization for computers across the network. The protocol and related al-
gorithms have been specified in several RFCs. Since then NTP has continuously been optimitzed and is at
present time widely used around the world. The protocol supports an accuracy of time down to nanoseconds.
However, the maximun achievable accuracy also depends on the operating system and the network performance.
Currently there are two versions of NTP which can be used intermixed: NTP v3 is the latest released version
which runs very stable on many operating systems. NTP v4 has some improvements over NTP v3 and has better
support for some operating systems. Additionally, there’s also a simplified version of the protocol called SNTP
(Simple Network Time Protocol). SNTP uses the same TCP/IP packet structure like NTP but due to the simpler
algorithms, it provides only very reduced precision. The NTP package contains a background program (daemon
or service) which synchronizes the computer’s system time to one or more external reference time sources which
can be either other devices on the network, or a radio clock which is connected to the computer.
Additionally, the NTP distribution contains programs which can be used to control or monitor the time syn-
chronization status, and a complete set of documentation in HTML format.
More information about the Network Time Protocol can be found at:
https://www.meinbergglobal.com/english/info/ntp.htm
66
Date: 22nd June 2020
microSync
