Any network administrator will tell you how important time synchronization is for a modern computer network. Computers rely on the time for nearly everything, especially in today’s age of online trading and global communication where accuracy is essential.
Failing to ensure that computers are accurately synced together could lead to all manner of problems: data loss, security vulnerabilities, unable to conduct time sensitive transactions and difficulties debugging can all be caused by a lack of, or not adequate enough, time synchronization.
But ensuring every computer on a network has the exact same time is simple thanks to two technologies: the atomic clock and the NTP server (Network Time Protocol).
Atomic clocks are extremely accurate chronometers. They can keep time and not drift by as much of a second in thousands of years and it is this accuracy that has made possible technologies and applications such as satellite navigation, online trading and GPS.
Time synchronization for computer networks is controlled by the network time server, commonly referred to as the NTP server after the time synchronization protocol they use, Network Time Protocol.
When it comes to choosing a time server, there are really only two real type – the radio reference NTP time server and the GPS NTP time server.
Radio reference time servers receive the time from long wave transmission broadcast by physics laboratories like NIST in North America or NPL in the UK. These transmissions can often be picked up throughout the country of origin (and beyond) although local topography and interference from other electrical devices can interfere with the signal.
GPS time servers, on the other hand, use the satellite navigation signal transmitted from GPS satellites. The GPS transmissions are generated by atomic clocks onboard the satellites so they are a highly accurate source of time just like the atomic clock generated time broadcast by the physics laboratories.
Apart from the disadvantage of having to have a roof top antenna (GPS works by line of sight so a clear view of the sky is essential), GPS is obtainable literally everywhere on the planet.
As both types of time server can provide an accurate source of reliable time the decision of which type of time server should be based on the availability of long wave signals or whether it is possible to install a rooftop GPS antenna.