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NTP Servers

PC Time
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Synchronised Time
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GPS Surge
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LF/GPS Over Fibre

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Email:
Sales@TimeTools.co.uk
Info@TimeTools.co.uk

UK:
Tel: 01902 897400
Fax: 0870 123 1844

International:
Tel: +44 1902 897400
Fax: +44 870 123 1844

TimeTools Limited.
Unit 34,
Wombourne Enterprise Park,
Bridgnorth Road,
Wombourne,
South Staffordshire.
WV5 0AL
UK

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NTP Server
NTP Time Server
Time Server
Atomic Clock
Digital Wall Clock

What is NTP?

Products

TimeTools SR and SC range of stratum 1 network time servers provides a highly accurate and reliable solution to any network time sync requirement.

SR Series Rack-
Mountable NTP Servers

SC Series Compact NTP
Servers

Radio and GPS time synchronisation systems for PC's provide cost-effective solution to PC time synchronisation.

MLS Radio PC Time
Server

MPS Radio PC Time
Server

T1000 GPS Time
Server

T2000 GPS Time
Server

TimeTools Ethernet NTP digital wall clocks provide accurate synchronised time display solution.

Ethernet NTP Digital
Wall Clock

NTP stands for Network Time Protocol. NTP is used throughout the internet as a standard means of achieving and maintaining the synchronization of computers and network infrastructure. This article attempts to describe, clearly and simply, what NTP is and why a NTP server is an essential part of a modern computer network.

A NTP server is basically a device that receives precise time from an external hardware clock and provides a network with an accurate timing reference. Accurate time is maintained internally and passed to network time clients on demand. Any network device can contact a NTP server to request time and to synchronize its system clock. In this way networks of computers can synchronize time to an accurate reference.

NTP is essentially a hierarchical protocol. It has a series of levels or 'stratums'. Each stratum is synchronized to the level above in the hierarchy. At the top level, a stratum 1 server obtains accurate time from an external hardware clock. It is the most accurate time reference, since it synchronizes directly to a external time reference.

Lower stratum time servers synchronize to the stratum above and provide consistently less accuracy. Using a hierarchical system, in this manner, has the advantage of allowing multiple time servers to take workload away from the most accurate references and prevents them from becoming swamped.

There are a number of external reference clock time sources available, the most common being GPS. Each GPS satellite has an onboard atomic clock that can provide extremely accurate timing information. National radio time and frequency broadcasts are also a good source of accurate time.

Many time servers also contain precise crystal oscillators that can be used as backup timing references. A backup timing reference provides extended holdover while external references are unavailable. A number of difference types of oscillator are available, the most accurate, and expensive, being Rubidium. However, good price / performance alternatives are available. An OCXO, Oven-Controlled Crystal Oscillator, is a oscillator that is housed in a very small constant temperature oven. Since the greatest cause of drift in crystals is temperature variation, OCXO's attempt to minimize drift by maintaining a constant temperature. TCXO, Temperature-Controlled Crystal Oscillators, work on a similar principle. However, rather than maintain a constant temperature, they speed up or slow down slightly to compensate for any temperature variation.

Modern operating systems provide integrated NTP client software, which allow the system time synchronization to a time server. LINUX and UNIX operating systems have a freely available GNU public licence NTP client available. Microsoft incorporates the 'Windows Time' service in the latest Windows operating systems, which has NTP functionality. Additionally, Novell also provides netware loadable modules (NLM) for synchronization of Netware servers.

Many modern computing applications are distributed systems operating across a large number of individual machines. Without synchronization of cooperating devices many problems can arise. Event logging may not provide a true representation of when a specified event occurred. Transaction time stamps may not be accurate and may be out of sync if generated by more than one machine. Many other applications are time critical and require precise synchronization of network devices.