Understanding NTP Server Synchronization

Posted 2024-03-19 06:52:27

How Does an NTP Server Work?
An NTP server synchronizes clocks by communicating with multiple referenced time sources over the internet and then averaging the timestamps it receives to determine the correct time. It will then synchronize the system clocks of computers, servers, networking equipment and any other NTP client devices on the local network to this averaged time.

The main mechanism used by NTP is a hierarchical, distributed, and self-organizing system that can select accurate time sources, such as atomic clocks located at national laboratories, and then propagate this information across the internet to the computer workstations around the world.

Sources of Timestamped Reference Time
There are a variety of time sources that an NTP Server can use as a reference to determine accurate timestamps for synchronization purposes:

- Atomic Clocks: Highly precise cesium or rubidium atomic clocks located at national physics laboratories provide the most accurate reference time and serve as primary NTP time sources at the top of the timing hierarchy.

- GPS Satellites: Precise timekeeping from GPS satellites in orbit provides another common reference source used by many NTP servers situated with a clear view of the sky and GPS antenna.

- Radio Clocks: Land-based time signal radio stations such as WWVB or DCF77 broadcast extremely precise timing signals that can be received by special radio clock hardware to provide another level of reference input.

- Parent Servers: NTP servers situated higher up in the timing hierarchy can be configured as parent servers to provide reference time to lower level child NTP servers further downstream.