This section provides an overview for time servers as well as their applications and principles. Also, please take a look at the list of 10 time server manufacturers and their company rankings.
Table of Contents
A time server, also known as an NTP server, is a server that transmits the current time over the Internet.
NTP (Network Time Protocol) is a protocol used to retrieve and correct time data between servers on a network, and to provide accurate current time to client PCs.
The client PCs use this protocol to communicate with the time server to obtain the current time. In addition, not only client PCs but also routers and other network devices on the network obtain time data from time server in order to synchronize their operations with the correct time.
If a device on a network communicates with another device based on its own time, the time difference between the two devices could cause serious problems.
For this reason, time server now provide extremely accurate time based on data from atomic clocks.
A quartz crystal is the traditional device used to mark time accurately. Applying a voltage to this element produces a periodic oscillation. This vibration is used to mark time. This is incorporated into PC hardware boards as a real-time clock device (RTC).
However, in the case of the commonly used quartz crystal oscillator (oscillation frequency of 32.768 kHz), a deviation of one time per million seconds occurs, which accumulates and results in a large difference from the real time. In the world of inter-computer communication, computers operate in synchronization with each other according to their own time data, and such an error is unacceptable.
This is why time servers are used to maintain more accurate time.
The time servers obtains accurate time from an atomic clock and provides this data over the network to client PCs and various network devices upon their request. This enables each client PC, etc. to synchronize with the accurate time and execute their processes with extremely high accuracy by correcting the time data held by themselves.
Traditionally, the definition of a second was based on the speed of the earth's rotation, which turned out to be not very accurate, and is now defined by an electronic clock using cesium. The details are quite esoteric, but in essence, one second is defined as 9,192,631,770 times the duration of the period that a cesium-133 atom radiates as it transits between two distances and that is what is meant by "one second".
Incidentally, this is defined as the basic unit in the International System of Units (SI).
NTP is operated in a hierarchical structure for the purpose of load balancing. Stratum is numbered 0, 1, 2, and so on, and the larger the number, the further away from the original time servers, and thus the larger the error.
Stratum 0 is the atomic clock and Stratum 1 is the NICT time servers, and Stratum 1 uses the extremely accurate time from the atomic clock to correct its own RTC time.
According to NICT, the Stratum1 time servers has been enhanced to handle simultaneous access from PCs and as a result, it can handle more than 1 million requests per second.
*Including some distributors, etc.
Sort by Features
Sort by Area
Number of Employees
Newly Established Company
Company with a History
This is the version of our website addressed to speakers of English in Canada. If you are a resident of another country, please select the appropriate version of Metoree for your country in the drop-down menu.