NTP is a computer network protocol which is used to synchronise
time on computers across a network. NTP stands for Network Time
Protocol. Dr David Mills of the University of Delaware invented
it over 25 years ago. He saw a growing need to synchronise time
on computers. Now, many distributed computer processes and
applications rely on precise system time. Transaction
processing, event logging, CCTV and DVR applications all rely on
accurate time stamping. NTP has a hierarchical structure. At the
highest level, or stratum, are precise hardware clocks, which
can synchronise to highly accurate external time references,
such as GPS or national radio time and frequency broadcasts.
These hardware clock devices are known as stratum 0 devices. A
stratum 1 time server obtains time directly from a hardware
clock and is the most accurate reference in the NTP hierarchy.
All lower stratum devices obtain time from the stratum above
over a network. As the network introduces timing discrepancies,
lower stratum devices are a fa