Understanding your Network Time Server

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Network time servers are responsible for providing a network’s time. Of course, all computers have their own onboard clocks built into the motherboards, but these devices are only cheap oscillators and are prone to drift. When you have a network of hundreds or even thousands of PCs and devices, if there was no synchronisation to a single network time source, all the machines could be relaying completely different times, often several minutes apart.

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Keeping Time with Network Time Protocol

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When it comes to network time synchronisation, Network Time Protocol (NTP) is by far the most widely used software protocol. Whether it’s for keeping a network of hundreds or thousands of machines synchronised, or keeping a single machine running true, NTP offers the solution. Without NTP, and the NTP server, many of the tasks we perform on the internet, from shopping to online banking, simply wouldn’t be possible.

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Using GPS for Accurate and Secure Time for any Network

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Perhaps the safest and most accurate means of obtaining a time source is by utilising the time codes transmitted by the GPS (Global Positioning System). All that is required for picking up these GPS signals is a GPS NTP server, which will not only receive the time code, but also distribute it around the network, check for drift and maintain stable and precise time on all machines.

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Receiving GPS Time for Network Synchronisation

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To synchronise a computer network or other technology systems to GPS time, all that is required is a GPS network time server. GPS network time servers are simple to install, simple to use and can maintain accuracy for all sorts of technologies. Used by organisations as diverse as stock exchanges, air traffic control and banking systems, GPS time servers provide an efficient and cost effective solution to maintain network synchronicity.

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The Cost of Inaccurate Network Time

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When a network loses time, you are at risk of losing far more than just what time of day it is. Time is an essential aspect of network security and any errors in a network time server can lead to catastrophic result. However, the solution for ensuring network security is fairly simple and relatively inexpensive – the NTP time server.

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Increased Accuracy of Dual NTP Server Systems

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The NTP time server has revolutionised the synchronisation of computer networks over the last twenty years. NTP (Network Time Protocol) is the software  that  is responsible for distributing time from the time server to the entire network, adjusting machines for drift and assuring accuracy.

NTP can reliable maintain system clocks to within a few millimetres of UTC (Coordinated Universal Time) or whatever timescale it is fed with.

However NTP can only be as reliable as the time source that it receives and as UTC  is the global civil timescale it depends on where the UTC source comes from.

National time and frequency transmissions from physics labs like NIST in the USA or NPL in the UK are extremely reliable sources of UTC and NTP time servers are designed specifically for them. However, the time signals are not guaranteed, they can drop off throughout the day and are susceptible to interference; they are also regularly turned of for maintenance.

For most applications a few hours of your network relying on crystal oscillators will probably not cause too much problems in synchronisation. However, GPS (Global Positioning System) is far more reliable source for UTC time in that a GPS satellite is always overhead. They do require a line-of-sight reception which means an antenna has to go on the roof or outside an open window.

For applications where accuracy and reliability are essential the safest solution is to invest in a dual system NTP time server, these device can receive both the radio transmissions such  as MSF, DCF-77 or WWVB and the GPS signal.

On a dual system NTP server, NTP will take both time sources and to synchronise a network to ensuring increased accuracy and reliability.

GPS Time Server and its Accuracy from space

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The GPS network (Global Positioning System), is commonly known as a satellite navigation system. It however, actually relays a ultra-precise time signal from an onboard atomic clock.

It is this information that is received by satellite navigation devices that can then triangulate the position of the receiver by working out how long the signal has taken to arrive from various satellites.

These time signals, like all radio transmissions travel at the speed of light (which is close to 300,000km a second). It is therefore highly important that these devices are not just accurate to a second but to a millionth of a second otherwise the navigation system would be useless.

It is this timing information that can be utilized by a GPS time server as a base for network time. Although this timing information is not in a UTC format (Coordinated Universal Time), the World’s global timescale, it easily converted because of its origin from an atomic clock.

A GPS time server can receive the signal from a GPS aerial although this does need to have a good view of the sky as the satellites relay their transmissions via line-of-sight.
Using a dedicated GPS time server a computer network can be synchronised to within a few milliseconds of NTP (milli=1000th of a second) and provide security and authentication.

Following the increase use of GPS technology over the last few years, GPS time servers are now relatively inexpensive and are simple and straight forward systems to install.

Next Generation of Accurate Atomic Clocks Starts Ticking as NIST scientists unveil new strontium clock

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Those chronological pioneers at NIST have teamed up with the University of Colorado and have developed the world’s most accurate atomic clock to date. The strontium based clock is nearly twice as accurate as the current caesium clocks used to govern UTC (Coordinated Universal Time) as it loses just a second every 300 million years.

Strontium based atomic clocks are now being seen as the way forward in timekeeping as higher levels of accuracy are attainable that are just not possible with the caesium atom. Strontium clocks, like their predecessors work by harnessing the natural yet highly consistent vibration of atoms.

However, these new generations of clocks use laser beams and extremely low temperatures close to absolute zero to control the atoms and it is hoped it is a step forward to creating a perfectly precise clock.

This extreme accuracy may seem a step too far and unnecessary but the uses for such precision are many fold and when you consider the technologies that have been developed that are based on the first generation of atomic clocks such as GPS navigation, NTP server synchronisation and digital broadcasting a new world of exciting technology based on these new clocks could just be around the corner.

While currently the world’s global timescale, UTC, is based on the time told by a constellation of caesium clocks (and incidentally so is t he definition of a second as just over 9 billion caesium ticks), it is thought that when the Consultative Committee for Time and Frequency at the Bureau International des Poids et Mesures (BIPM) next meets it will discuss whether to make these next generation of atomic clocks the new standard.

However, strontium clocks are not the only method of highly precise time. Last year a quantum clock, also developed at NIST managed accuracy of 1 second in 1 billion years. However, this type of clock can’t be directly monitored and requires a more complex scheme to monitor the time.

Receiving the Time and Finding the Correct Time Source

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So you have decided to synchronize your network to UTC (Coordinated Universal Time), you have a time server that utilizes NTP (Network Time Protocol) now the only thing to decide on is where to receive the time from.

NTP servers do not generate time they simply receive a secure signal from an atomic clock but it is this constant checking of the time that keeps the NTP server accurate and in turn the network that it is synchronizing.

Receiving an atomic clock time signal is where the NTP server comes into its own. There are many sources of UTC time across the Internet but these are not recommended for any corporate use or for whenever security is an issue as internet sources of UTC are external to the firewall and can compromise security – we will discuss this in more detail in future posts.

Commonly, there are two types of time server. There are those that receive an atomic clock source of UTC time from long wave radio broadcasts or those that use the GPS network (Global Positioning System) as a source.

The long wave radio transmissions are broadcast by several national physics laboratories. The most common signals are the USA’s WWVB (broadcast by NIST – National Institute for Standards and Time), the UK’s MSF (broadcast by the UK National Physical Laboratory) and the German DCF signal (Broadcast by the German National Physics Laboratory).

Not every country produces these time signals and the signals are vulnerable to interference from topography. However, in the USA the WWVB signal is receivable in most areas of North America (including Canada) although the signal strength will vary depending on local geography such as mountains etc.

The GPS signal on the other hand is available literally everywhere on the planet as along as the GPS antenna attached to the GPS NTP server can have a clear view of the sky.

Both systems are a truly reliable and accurate method of UTC time and using either will allow synchronization of a computer network to within a few milliseconds of UTC.

The Body Clock Natures Own NTP Server

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Developing new methods of telling the time accurately and precisely has developed to a new obsession amongst chronologists in the twenty first century. Since the development of the first atomic clocks in the 1950’s with millisecond accuracy the race was started with organisation such as the US’s NIST (National Institute for Standards and Time) and the UK’s NPL (National Physical Laboratory) developing increasingly accurate atomic clocks.

Atomic clocks are used as the time source for high technologies and applications such as satellite navigation and air traffic control, they are also the source for time signals used by NTP servers to synchronise computer networks.

An NTP server works by continually adjusting the computers system clock to ensure it matches the time relayed by the atomic clock. In doing this the NTP server can keep a computer network to within a few milliseconds of atomic clock controlled UTC (Coordinated Universal Time).

However, as remarkable this technology may seem it appears Mother Nature has already been doing the very same thing with our own body clocks.

The human body clock is only just being understood by medical science (the study of which is called Chronobiology) but what is known is that the body clock extremely important in the functioning of our day to day lives; it is also highly accurate and works in a very similar way to the NTP server.

Whilst a NTP time server receives a time signal from an atomic clock and adjust the system clocks on computers to match, our body clocks do the very same thing. The body clock runs in a circadian rhythm in other words a 24 hour clock. When the sun rises in the morning part of the brain that governs the body clock called the suprachiasmatic nucleus – which is located in the brain’s hypothalamus, automatically corrects for the sun’s movement.

In this way the human body clock adjusts for the darker winters and lighter months of the summer which is why you may find it more difficult to wake in the winter. The body clock adjusts itself every day to ensure it is synchronised to the rotation of the sun just as a NTP time server synchronises a computer’s system clock to ensure it is running accurately  to its timing source – the atomic clock.