Category: Time Synchronisation

Why Bother Using a NTP Time Server?

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Keeping computers synchronized on a network is vitally important, especially if the network in question deals with time sensitive transactions. And failing to keep a network synchronized can cause havoc leading to errors, vulnerabilities and endless problems with debugging.

However with the amount of online time servers available from reputable places such as NIST or Microsoft it is often queried as to why computer networks need to be synchronised to an external NTP time server.

These dedicated NTP devices are often seen as an unnecessary expense and many network administrators simply forgo them and connect to an online time server, after-all, it does the same job doesn’t it?

Actually there are two major reasons why NTP time servers are not only important but essential for most computer networks and to overlook them could be costly in many ways.

Let me explain. The first reason why an external NTP server is important is accuracy. It’s not that internet time sources are generally inaccurate (although many are) but there is the question of distance the time reference has to travel. Furthermore, in times when the connection is lost -whether it’s because of a local connection fault or the time server itself goes down – the network will start to drift until the connection is restored.

Secondly and perhaps most important is the security issues involved in using an Internet time source. The main problem is that if your connection to a time server through the then a open port (UDP 123 fro NTP requests) has to be left open, And as with any open port that can used as a gateway for malicious software and users.

The reason dedicated NTP time servers are essential for computer networks is that they work completely independently and external to the network’s firewall. Instead of accessing a time source across the Internet they use either GPS or radio transmissions to get the time. And in doing so they can provide accurate time all the time without fear of losing a connection or allowing a nasty Trojan through the firewall.

When Time is Money Accuracy Matters

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We live in a fast paced world where time matters. In some industries even a second can make all the difference. Millions of dollars are exchanged hands in the stock exchange each second and share prices can rise or plummet.

Getting the right price at the right time is essential for trading in such a fast paced money market and perfect network time synchronization is the essential to be able to make that happen.

Ensuring every machine that deals in stocks, shares and bonds has the correct time is vital if people are going to trade in the derivatives market but when traders are sat in different parts of the world how can this possibly be achieved.

Fortunately Coordinated Universal Time (UTC), a global timescale developed after the development of atomic clocks, allows the same time to govern every trader, regardless of where they are in the world.

As UTC is based on atomic clock time and is kept accurate by a constellation of these clocks, it is high reliable and accurate. And industries like the stock exchange use UTC to govern the time on their computer networks.

Computer network time synchronization is achieved in computer networks by using the NTP server (Network Time Protocol). NTP servers receive a source of UTC from an atomic clock reference. This is either from the GPS network or through specialist radio transmissions (it is available through the internet too but is not as reliable).

Once received, the NTP server distributes the highly accurate time throughout the network, continually checking each device and workstation to ensure the clock is as precise as possible.

These network time servers can keep entire networks of hundreds and thousands of machines in perfect synchronization – to within a few milliseconds of UTC!

Time Synchronization on Windows 7

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Windows 7, the latest operating system from Microsoft is also their first operating system that automatically synchronizes the PC clock to an internet source of UTC time (Coordinated Universal Time). From the moment a Windows 7 computer is switched on and is connected to the Internet it will request time signals from the Microsoft time service – time.windows.com.

While for many home users this will save them the hassle of setting and correcting their clock as it drifts, for business users it may be problematic as internet time sources are not secure and receiving a time source through the UDP port on the firewall could lead to security breaches and as Internet time sources can’t be authenticated by NTP (Network Time Protocol) the signals can be hijacked by malicious users.

This internet time source can be deactivated by opening the clock and date dialogue box, and opening the Internet Time tab, clicking the ’Change’ setting button and unchecking the ‘Synchronize with an Internet time server< option.’

Whilst this will unsure no unwanted traffic will be coming through your firewall it will also mean that the Windows 7 machine will not be synchronised to UTC and its timekeeping will be reliant on the motherboard clock, which will eventually drift.

To synchronize a network of Windows 7 machines to an accurate and secure source of UTC then the most practical and simplest solution is to plug in a dedicated NTP time server. These connect directly to a router or switch and enable the safe receiving of an atomic clock time source.

NTP time servers use the highly accurate and secure GPS signal (Global Positioning System) available everywhere on the planet or more localized long wave radio signals transmitted by several national physics laboratories such as NIST and NPL.

Choosing a Time Source for UTC Synchronization

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Ensuring a computer network is time synchronized is vital in modern computer networks. Synchronization, not just between different machines on a network, but also each computer network that communicates with other networks needs to be synchronized with them too.

UTC (Coordinated Universal Time) is a global timescale that allows networks on other sides of the globe to be synchronized together. Synchronizing a network to UTC is relatively straightforward thanks to NTP (Network Time Protocol) the software protocol designed for this very purpose.

Most operating systems, including the latest Microsoft incarnation Windows 7, have a version of NTP (often in a simplified form known as SNTP), that allows a single time source to be used to synchronize every computer and device on a network.

Selecting a source for this time reference is the only real difficulty in synchronizing a network. There are three main locations where UTC time can accurately be received from:

Internet Time

There are many sources of internet time and the latest version of Windows (Windows 7) automatically synchronizes to Microsoft’s time server time.windows.com, so if Internet time is adequate Windows 7 users need not alter their settings. However, for computer networks where security is an issue then internet time sources can leave a system vulnerable as the time has to be received through the firewall forcing a UDP port to be left open. This can be utilised by malicious users. Furthermore, there is no authentication with an internet time source so the timecode could be hijacked before it arrives at your network.

GPS Time

Available literally everywhere on the globe, GPS provides a 24-hour, 365 days-a-year source of UTC time. Delivered externally to the firewall via the GPS satellite signal, time synchronization with GPS is accurate and secure.

Radio Transmissions

Usually broadcast by national physics laboratories such as NIST in the US and the UK’s NPL, the time signals are received via longwave and are also external to the firewall so are secure and accurate.

A dedicated NTP time server can receive both radio and GPS time signal guaranteeing accuracy and security.

IBM takes over London Congestion Charge with Galleon Time Servers

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Computer giants IBM have taken over the running of London’s congestion charge scheme this week and like their predecessors, Capita, they will be synchronizing the system with Galleon Systems time servers.

Essential for the running of the London congestion charge scheme and ensuring all the 400 cameras are synchronized to the exact same time, the blue-chip company have chosen Galleon Systems as their supplier of network time servers to control the congestion charging system.

Having supplied Capita the former controllers of the congestion charging scheme with its NTS network time servers to accurately synchronize the camera system, Galleon Systems are now supplying IBM with its mission critical hardware too.

Galleon Systems range of network time servers can synchronize networks with millisecond accuracy and receive an accurate and secure atomic clock time source from the GPS network (Global Positioning System) or the radio time signal broadcast by national physics laboratories like NPL.

The London congestion scheme may not be popular with many who have to pay the daily charge but the scheme has been recognised worldwide as an effective method of reducing city congestion and similar schemes to the London congestion zone are being implemented in cities across the globe.

Galleon Systems are the UK’s leading supplier of network time servers and NTP (Network Time Protocol) time synchronisation equipment, having been providing network timing solutions for over a decade.

The Way an Atomic Clock Works

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Atomic clocks are the most accurate chronometers we have. They are millions of times more accurate than digital clocks and can keep time for hundreds of millions of years without losing as much as a second. Their use has revolutionised the way we live and work and they have enabled technologies such as satellite navigation systems and global online commerce.

But how do they work? Strangely enough, atomic clocks work in the same way as ordinary mechanical clocks. But rather than have a coiled spring and mass or pendulum they use the oscillations of atoms. Atomic clocks are not radioactive as they do not rely on atomic decay instead they rely on the tiny vibrations at certain energy levels (oscillations) between the nucleus of an atom and the surrounding electrons.

When the atom receives microwave energy at exactly the right frequency, it changes energy state, this state is constant an unchanging and the oscillations can be measured just like the ticks of a mechanical clock. However, while mechanical clocks tick every second, atomic clocks ‘tick’ several billion times a second. In the case of caesium atoms, most commonly used in atomic clocks, they tick 9,192,631,770 per second – which is now the official definition of a second.

Atomic clocks now govern the entire global community as a universal timescale UTC (Coordinated Universal Time) based on atomic clock time has been developed to ensure synchronization. UTC atomic clock signals can be received by network time servers, often referred to as NTP Servers, that can synchronize computer networks to within a few milliseconds of UTC.

How Computers Keep Abreast of Time

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Time governs our lives and keeping abreast of it is vital if we want to get to work on time, make it home for dinner or watch our favourite shows of an evening.

It is also crucial for computer systems. Computers use time as a point of reference, indeed, time is the only point of reference it can use to distinguish between two events and it is crucial that computers operating in networks are synchronized together.

Time synchronization is when all computers that are connected together run the same time. Time synchronization, however, is not simple to implement, primarily because computers are not good time keepers.

We are all used to the time being displayed on the bottom right hand of our computer desktops but this time is normally generated by the onboard crystal oscillator (normally quartz) on the motherboard.

Unfortunately these onboard clocks are prone to drift and a computer clock may lose or gain a second or so each day. While this may not sound like much, it can soon accumulate and with some networks consisting of hundreds and even thousands of machines, if they are all running different times its not hard to imagine the consequences; emails may arrive before they are sent, data may fails to backup, files will get lost and the networks will be amass of confusion and nearly impossible to debug.

To ensure synchronization throughout a network all devices must connect to a single time source. NTP (Network Time Protocol) has been devised for this very purpose and can distribute a time source to all devices and ensure that any drift is countered.

For true accuracy the single time source should be a source of UTC (Coordinated Universal Time) which is a global timescale that is used across continents and pays no heed to timezones, this allows networks on opposite sides of the Earth to be synchronized together.

A source of UTC should also be governed by an atomic clock as any drift in the time will mean that your network will be out of sync with UTC. By far the easiest, most efficient, secure, accurate and reliable method of receiving an atomic clock source of UTC is to use a dedicated NTP time server. NTP servers receive the UTC time from either the GPS network (Global Positioning System) or from radio transmission broadcast by national physics laboratories such as NIST or NPL.

Seven Reasons why your Network needs a Time Server

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Time servers, often referred to as NTP time servers after the protocol (Network Time Protocol) used to distribute time are an increasingly important part of any computer network. The NTP server receives a timing signal from an accurate source (such as an atomic clock) and then distributes it to all devices on the network.

However, despite the increasing importance of these time synchronisation devices, many network administrators still fail to accurately synchronise their networks and can leave their entire computer system vulnerable.

Here are seven reasons why a NTP time server is a crucial piece of equipment for YOUR network:

• Security: NTP servers use an external source of time and don’t rely on an open firewall port. An unsynchronized server will also be vulnerable to malicious users who can take advantage of time differences.

• Error logging: failing to adequately synchronize a computer network may mean that it is near impossible to trace errors or malicious attack, especially if the times on the log files from different machine do not match.

• Legal Protection: Not being able to prove the time can have legal implications if somebody has committed fraud or other illegal activity against your company.

• Accuracy: NTP Time Servers ensure that all networked computers are synchronized automatically to the exact time throughout your network so everybody in your company can have access to the exact time.

• Global Harmony: A global timescale known as UTC (Coordinated Universal Time) has been developed to ensure that systems across the globe can run the exact same time. By utilising a NTP server not only will every device on you network be synchronised together but your network will be synchronised with every other network on Earth that is hooked up to UTC.

• Control: With a NTP server you have control of the configuration. You can allow automatic changes each spring and autumn for daylight saving time or set your server time to be locked to UTC time only – or indeed, any time zone you choose.

• Automatic update of time. No user intervention required, a NTP time server will account for leap seconds and time zones ensuring trouble free synchronisation.

Benefits of Accurate Network Time Synchronization

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Your computer probably does hundreds and thousands of tasks a day. If that is part of a network then the number of tasks could be millions. From sending emails to saving data, and everything else your computer is tasked to do, they are all logged by the computer or server.

Computers use timestamps to logo processes and indeed, timestamps are used as the only method a computer has to indicate when and if a task or application has been conducted. Timestamps are normally a 16 or 32 bit integer (one long number) that counts back the seconds from a prime epoch – normally 01 January 1970.

So for every task you computer does it will be stamped with the number of seconds from 1970 that the transaction was conducted. These timestamps are the only piece of information a computer system has to ascertain what tasks have been completed and what tasks have yet to be instigated.

The problem with computer networks of more than one machine is that the clocks on individual devices are not accurate enough for many modern time sensitive applications. Computer clocks are prone to drift they are typically based on inexpensive crystal oscillator circuits and can often drift by over a second a day.

This may not seem much but in today’s time sensitive world a second can be a long time indeed especially when you take into account the needs of industries like the stock exchange where a second can be the difference in price of several percent or online seat reservation, where a second can make the difference between an available seat and one that is sold.

This drift is also accumulative so within only a few months the computer systems could be over a minute out of sync and this can have dramatic effects on time sensitive transactions and can result in all sorts of unexpected problems from emails not arriving as a computer thinks they have arrived before they have been sent to data not being backed up or lost completely.

A NTP time server or network time server are increasingly becoming crucial pieces of equipment for the modern computer network. They receive an accurate source of time from an atomic clock and distribute it to all devices on the network. As atomic clocks are incredibly accurate (they won’t drift by a second even in a 100,000 years) and the protocol NTP (Network Time Protocol) continually checks the devices time against the master atomic clock time – it means the computer network will be able to run perfectly synchronised with each device within a few milliseconds of the atomic clock.

Life Without the Atomic Clock

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When we consider the most important inventions of the last 100 years, very few people will think of an atomic clock. In fact, if you ask somebody to come up with a top ten of inventions and innovations its doubtful if the atomic clock would figure at all.

Its probably not hard to imagine what people think of as the most life-changing inventions: the Internet, mobile phones, satellite navigation systems, media players etc.

However, nearly all theses technologies rely on accurate and precise time and they would not function without it. The atomic clocks lies at the heart of many of the modern innovations, technologies and applications associated with them.

Let’s take the Internet as an example. The Internet is, in its simplest form, a global network of computers, and this network spans time zones and countries. Now consider some of the things we use the Internet for: online auctions, Internet banking or seat reservation for example. These transactions could not be possible with precise and accurate time and synchronisation.

Imagine booking a seat on an airline at 10am and then another customer tries to book the same seat after you on a computer with a slower clock. The computer only has the time to go on so will consider the person who booked after you to have been the first customer because the clock says so! This is the reason any Internet network that requires time sensitive transactions is connected to a NTP server to receive and distribute an atomic clock time signal.

And for other technologies the atomic clock is even more crucial. Satellite navigation (GPS) is a prime example. GPS (Global Positioning System) works by triangulating atomic clock signals from satellites. Because of the high velocity of radio waves an inaccuracy of 1 second could see a sat-nav device out by 100,000 km.

Other technologies too from mobile phone networks to air traffic control systems are completely reliable on atomic clocks demonstrating how underrated this technology is.