Time server – Using NTP for Synchronisation

A time server is a generic term for a device that receives and distributes time.  Time servers are available across the Internet or dedicated devices can be bought that offer higher accuracy and more security.

Whilst many manufacturers produce time server devices and other synchronisation tools they all have one thing in common in that they all utilise Network Time Protocol (NTP).

Whilst NTP is not the only time synchronisation software available it is used in the vast majority of synchronisation tools with some 99% of time synchronisation being conducted using NTP. NTP is a protocol used by everyone from NASA to NASDAQ and owes much of its dominance or the time synchronisation market to the dedicated team that continue to update, upgrade and develop NTP (many of whom do not get paid).

NTP is in fact almost as old as the Internet itself having been unveiled as early as 1979. It was developed by Professor David Mills and his team from Delaware University who continue to update and develop it alongside hundreds of dedicated hobbyists referred to as the Internet timekeepers.

NTP is now on version 4 and versions of NTP are included as standard with most operating systems allowing any Windows or Linux computer to run as a time server. However, for those serious about time synchronisation or wanting to keep a network secure there is no real substitute than a dedicated time server that can distribute time sent directly from an atomic clock using NTP.

Time server – Synchronisation Methods

A time server is an essential piece of equipment responsible for ensuring all devices on a computer network are running the same time. Most time servers are dedicated devices that receive a time signal, normally UTC (Coordinated Universal Time), and distribute it to all devices on a network.

Most time servers use the Internet protocol NTP (Network Time Protocol) to synchronise all devices and are often referred to as NTP servers. NTP distributes a single time source throughout the network which is normally a UTC source (Coordinated Universal Time).

There are several places a time server can receive a time signal from. The internet is an obvious source for many although online time sources are not very accurate, can be too far away to give any useful precision, and more importantly are not secure being as they are external to the firewall.

As a dedicated time server is an external device they are extremely secure and impossible for malicious users to tamper with. Dedicated time server can receive a time signal from two sources the GPS network (Global Positioning System) , a highly accurate method and available everywhere on the globe with a good view of the sky; or the specialist long wave radio transmissions broadcast by national physics laboratories.

In Europe the two main radio transmissions are the UK’s MSF signal broadcast by NPL (National Physical Laboratory) in Cumbria, England and the German DCF-77 broadcast near Frankfurt.

These long wave signals are also highly accurate and can be picked up in most neighbouring countries too. The USA has a similar system called WWVB,  transmitted by the National Institute for Standards and Technology (NIST) from Boulder, Colorado.

Free time server check tool

How accurate is the time you receive?

Unfortunately many Internet time servers are wholly inaccurate, however, this free and easy to use tool by Galleon Systems lets you check a server accuracy and reliability. Free to download and complete with instructions – an essential tool for anybody relying on the Internet for UTC time.

To download please visit Galleons NTP server site:

Galleon’s NTP server checker:

Time Server – Suppliers

Here is a list of links to  some of the most reputable time server manufacturers and suppliers from all over the world by country of origin.

UK
France
Germany
Italy
Spain
Poland
North America
Middle East

Galleon’s Time Servers

One of the World’s leading suppliers of time servers are Galleon Systems based in the UK and Europe.

Their time servers provide:

* Automatic update of time with no user intervention required.

* Simple Installation

* Customised products: As the specialist supplier, with the widest product range of dedicated Time Servers in the World if we haven’t got the time synchronisation product you want contact us because we can modify the standard products to your specific requirements.

* Full product range, From Dedicated Rack Mount NTP Time Servers that synchronize the time of thousands of computers across a network to simple Atomic Clocks that connect to a single PC.

* Cost Effective by being a specialist in Time synchronisation, Galleon offers a full product range so you buy the correct product for you needs, not one designed for a Multinational corporation.

* Reliable, Galleon Atomic Clocks and NTP Time Servers are used by organizations world-wide and provide reliable time synchronization 24 hours a day 365 days a year.

* 3 Year warranty. Galleon offers a 3 year warranty on ServerARC, ServerGPS, WorkstationARC and WorkstationGPS NTP Time Server products

* Lifetime Technical support. At Galleon we believe that technical support should be free for as long as you want to use a Galleon product for.

* MSF and GPS: Uses the NPL MSF time signal or GPS satellites time. The MSF time signal provides the strongest radio time signal in the UK and can be received up to about a range of 937.5 miles. GPS satellites time can be received anywhere in the world. You can have both time sources linked to your Galleon NTP Time Server for redundancy in the event that one time source is not available.

Please given Galleon a call, before you LOSE TRACK OF TIME:

+44 (0)121 608 4433

Time Server – The need for a reliable time source

A time server is a necessary part of any computer network. Time servers receive an authoritative time source that they then distribute amongst all devices on a network. Most time servers use a protocol such as NTP (Network Time Protocol) to distribute the single time source to all devices.

The accuracy of a time server depends entirely on the accuracy of the time source that it uses. Most networks require a UTC time source (coordinated universal time). UTC is a global timescale based on International atomic clock time (TAI) and used throughout the globe. Utilising UTC means that a computer network can be synchronised to the exact same time as a network on the other side of the globe allowing precise communications and time sensitive transactions to take place.

A time server can receive a UTC time source from only three places: the Internet, via a radio transmission or the GPS network.

The internet is by far the most commonly used source of UTC time. There are over a thousand time servers all claiming to relay UTC time. However, in surveys, less than half of these internet time sources are accurate and those that are, can be too far away to provide and real use as a timing source.

Using an internet timing source will also leave a computer network vulnerable. The hole left in the firewall to access the timing source can be used by malicious users and the built-in security method of NTP, authentication, can not ne utilised from across the Internet.

Fortunately, the two other methods of receiving UTC time offer both secure and reliable methods of receiving UTC time. The GPS network is available anywhere where there is a clear view of the sky whilst although not every country has a national time and frequency transmission, these longwave signals can be picked up by a radio referenced network time server from within a building.

The Time Server – References and Strata

A time server is a computer server that reads the time from an accurate clock and distributes this information to its clients across a computer network.

The reference used by a time server is normally a UTC (coordinated universal time) time source. UTC is a global time scale adopted all over the world and based on the time told by atomic clocks The most common source for UTC time is now the GPS system (global positioning system).

The most widely-used protocol for distributing and synchronising time is Network Time Protocol (NTP) which has been around almost as long as the Internet itself, having been developed in 1985 by Professor David Mills.

NTP receives the time from the time server and then checks or clocks on its networks to see if they need advancing or retreat.

To prevent overload of networks requesting timing information, NTP is hierarchical.  The term “stratum” is used to label the nearness to a stratum 0 server – that atomic clock. The higher the stratum number the further away the server is. A GPS time server is normally a stratum 1 device as it receives time from a stratum 0 device. However, stratum 2 and stratum 3 devices can still synchronise with each other.

Common Time Server Questions

What is a time server?

A time server is a device that utilises a single time source and distributes it amongst a network. This enables all machines on a LAN (or WAN) to be synchronised together.

What is NTP?

Network Time Protocol is a protocol (a set of instructions) designed to distribute the time from a time server top a network.

Why do I need a time server?

It may well be that you don’t. Many small networks survive and operate perfectly without the need of a time server. However, if computers are required to do time sensitive transactions or applications then a time server is essential. Without proper synchronisation all sorts of unforeseen problems can arise and many of the online transactions that we take for granted such as seat reservation, Internet shopping, the stock exchange and even sending emails are reliant on perfect time synchronisation.

What is the best time reference to use?

A single global timescale based on the time told by atomic clocks has been developed called UTC (Coordinated Universal Time). UTC is utilised by networks all over the world. In using UTC you are in affect synchronising your network with every other network in the world that utilises UTC.

Where to I get UTC time from?

The most common and easiest location to receive UTC time is from across the Internet although Internet time sources are notoriously inaccurate. They also provide little security. Apart from the fact the time server is outside your firewall, NTP can’t authenticate these signals. Authentication is a security measure used by NTP to prevent malicious attacks that masquerade as a time server.
The most secure methods for receiving UTC time is by using either the GPS network (global positioning system), whose satellites transmit the timing information or alternatively by using specialist national time and frequency long-wave transmissions although these are not available everywhere.

NTP Server – Why the Need for a Dedicated Time Server

Just as your computer is only as good as the software it is running, a time server is only as useful as the timing source it uses. Time servers are similar to other servers in that they are located on a network but the primary function of a time server is to supply timing information rather than storing or routing data.

For computers a time stamp is the only point of a reference a computer can use to establish a sequence of events. Timestamps are used in everything from sending an email to debugging a system and ensuring your network is secure.

Nearly all time servers rely on NTP (Network Time Protocol) to synchronise devices once a timing source is selected Whilst it is not the only protocol designed for synchronisation it is by far the most widely used, primarily because it has been under constant development since its inception nearly three decades ago.

A NTP server works by receiving a time reference from an authoritative source, normally a UTC time source. UTC (Coordinated Universal Time) is an International timescale based on the time told by atomic clocks.

Unfortunately many administrators opt to use an Internet timing source to run their time server with. However, several studies of Internet timing references discovered that nearly two thirds were inaccurate by over several seconds (almost an eternity in the world of NTP) and those that weren’t were often too far away from a client to provide reliable accuracy.

Probably the most accurate and widely used method of retrieving a reliable time reference is to use a dedicated GPS Time Server, many national physics laboratories also broadcast the time told by their atomic clocks via long wave radio. These signals can be received by a time server if it is equipped with a radio receiver although not every country broadcasts one and the transmissions are susceptible to interference and local topography.

Once this secure UTC time reference is received the time server can then distribute the time across the network. The timestamp itself is represented as a single ascending number. The number is the amount of seconds from a prime epoch (start number) normally 01 January 1900. The time server checks the system clocks on its clients and advances or retracts the time until all machines on the network are synchronised.