Archive for the ‘ntp server’ Category

Time Server Synchronisation The basics

Monday, February 2nd, 2009

NTP (Network Time Protocol) is an internet based protocol designed to synchronise the clocks on a computer network. It is the main time synchronisation software used in computer networks and is also packaged with most operating systems.

An NTP server is a dedicated device that receives a single time source then distributes it amongst all devices on a network. The protocol NTP monitors the drift of the internal clocks on a network and corrects for them.

An NTP server can receive a time source from either a national physical laboratory such as the UK’s National Physical Laboratory (NPL), however, these time signals are broadcast via long wave radio and have finite range.

GPS NTP servers are designed to receive the time source generated by the atomic clocks onboard GPS satellites (Global Positioning System). GPS is available anywhere on the planet as a time source as long as there is a clear view of the sky.

Without correct synchronisation all sorts of potential problems can occur such as leaving a computer system vulnerable to fraud, malicious users and hackers. An unsynchronised computer network may also lose data and be difficult to audit.

A global timescale called UTC (Coordinated Universal Time) has been developed to ensure the entire world uses the same timescale. The NTP server utilise UTC ensuring the computer network is telling the same time as every other computer network.

Five Reasons Why Your Business Needs an NTP Server (Part 1)

Tuesday, January 27th, 2009

Most businesses these days rely on a computer network. Computers in most organisations conduct thousands of tasks a second, from controlling production lines; ordering stock; preparing financial records and communicating with computers on other networks – often from the other side of the world.

Computers use just one thing to keep track of all these tasks: time. Timestamps are the computers only reference for when an event or task occurs in relation to other events. They receive time in the form of timestamps and they measure time in periods of milliseconds (thousandth of a second) as they may conduct hundreds of processes each second.

A global timescale known as UTC (Coordinated Universal Time) has been developed to ensure computers from different organisations all over the world can synchronise together. So what happens if the clocks on computers don’t coincide with each other or with UTC?

The consequences of running a network with computers that are not synchronised can be disastrous. Here are five reasons why all businesses need adequate network synchronisation using a NTP server (Network Time Protocol) or other network time server device.

1. Tasks fail to happen:

When computers are running at different times, events on different machines can fail to happen as often a PC may assume an event on another machines has already happened if the time for that event has passed according to its own clock. And what is worse, when one task fails it has a knock-on effect with other tasks failing to happen and in turn causing further tasks to fail.

2. Loss of Data:

When tasks fail to happen it soon gets noticed but when networks are not synchronised data that is meant to be kept can quite easily be lost and it can go unnoticed for quite a while. Data can be lost because storage as and retrieval is also reliant on time stamps.

NTP Server 5 Steps to Network Synchronisation

Wednesday, January 21st, 2009

Synchronising a network is often considered a headache by network administrators who fear that getting it wrong can lead to disastrous results and while there is no deny that a lack of synchronisation can cause unforeseen problems particularly with time sensitive transactions and security, perfect synchronisation is simple if these steps are followed:

1. Use a dedicated NTP server. The NTP server is a device that receives a single time source then distributes it amongst a network of computers using the protocol NTP (Network Time Protocol) one of the oldest Internet based protocols and by far the most widely used time synchronisation software. NTP is often packaged with modern operating systems such as Windows or Linux although there is no substitute for a dedicated NTP device.

2. Always use a UTC time source (Coordinated Universal Time). UTC is based on GMT (Greenwich Meantime) and International Atomic Time (TAI) and is highly accurate. UTC is used by computer networks all over the world ensuring that commerce and trade are all using the same timescale.

3. Use a secure an accurate time signal. Whilst time signals are available all over the Internet they are unpredictable in their accuracy and while some may offer decent enough precision an Internet time server is outside a networks firewall which if left open to receive a timecode will cause vulnerabilities in the security of the network. Either GPS (global positioning system) or a dedicated radio signal such as those transmitted by national physics laboratories (such as MSF – UK, WWVB - USA, DCF –Germany) offer secure and reliable methods of receiving a secure and accurate time signal.

4. Organise a network into stratum, levels. Strata ensure that the NTP server is not inundated with time requests and that the network bandwidth doesn’t become congested. A stratum tree is organised by a few select machines being stratum 2 devices in that they receive a time signal from the NTP server (stratum 1 device) these in turn distribute the time to other devices (stratum 3) and so on.

5. Ensure all machines are utilising UTC and the NTP server tree. A common error in time synchronisation is to not ensure all machines are properly synchronised, just one machine running inaccurate time can have unforeseen consequences.

The NTP Server Time Synchronisation Made Easy

Friday, January 16th, 2009

Time synchronisation is often described as a ‘headache’ by network administrators. Keeping computers on a network all running the same time is increasingly important in modern network communications particularly if a network has to communicate with another network running independently.

For this reason UTC (Coordinated Universal Time) has been developed to ensure all networks are running the same accurate timescale. UTC is based on the time told by atomic clocks so it is highly precise, never losing even a second. Network time synchronisation is however, relatively straight forward thanks to the protocol NTP (Network Time Protocol).

UTC time sources are widely available with over a thousand online stratum 1 servers available on the Internet. The stratum level describes how far away a time server is to an atomic clock (an atomic clock that generates UTC is known as a stratum 0 device). Most time servers available on the Internet are in fact not stratum 1 devices but stratum in that they get their time from a device that in turn receives the UTC time signal.

For many applications this can be accurate enough but as these timing sources are on the Internet there is very little you can do to ensure both their accuracy and their precision. In fact even if an Internet source is highly accurate the distance away form it can cause delays int eh time signal.

Internet time sources are also unsecure as they are situated outside of the firewall forcing the network to be left open for the time requests. For this reason network administrators serious about time synchronisation opt to use their own external stratum 1 server.

These devices, often called a NTP server, receive a UTC time source from a trusted and secure source such as a GPS satellite then distribute it amongst the network. The NTP server is far more secure than an Internet based time source and are relatively inexpensive and highly accurate.

NTP Server Time synchronisation for Dummies

Wednesday, January 14th, 2009

Time synchronisation is extremely important for modern computer networks. In some industries time synchronisation is absolutely vital especially when you are dealing with technologies such as air traffic control or marine navigation where hundreds of lives could be put at risk by lack of precise time.

Even in the financial world, correct time synchronisation is vital as millions can be added or wiped off share prices every second. For this reason the entire world adheres to a global timescale known as coordinated universal time (UTC). However, adhering to UTC and keeping UTC precise are two different things.

Most computer clocks are simple oscillators that will slowly drift either faster or slower. Unfortunately this means that no matter how accurate they are set on Monday they will have drifted by Friday. This drift may be only a fraction of a second but it soon won’t take long for the originally UTC time to be over a second out.

In many industries this may not mean a matter of life and death of the loss of millions in stocks and shares but lack of time synchronisation can have unforeseen consequences such as leaving a company less protected from fraud. However, receiving and keeping true UTC time is quite straight forward.

Dedicated network time servers are available that uses the protocol NTP (Network Time Protocol) to continually check the time of a network against a source of UTC time. These devices are often referred to as an NTP server, time server or network time server. The NTP server constantly adjusts all devices on a network to ensure that the machines are not drifting from UTC.

UTC is available from several sources including the GPS network. This is an ideal source of UTC time as it is secure, reliable and available everywhere on the planet. UTC is also available via specialist national radio transmissions which are broadcast from national physics laboratories although they are not available everywhere.

NTP Server History Acquiring Precision

Monday, January 12th, 2009

When we take a glance at our watches or the office clock we often take for granted that the time we are given is correct. We may notice if our watches are ten minutes fast or slow but take little heed if they are a second or two out.

Yet for thousands of years mankind has strode to get ever increasingly accurate clocks the benefits of which are plentiful today in our age of satellite navigation, NTP servers, the Internet and global communications.

To understand how accurate time can be measured it is first important to understand the concept of time itself. Time as it has been measured on Earth for millennia is a different concept to time itself which as Einstein informed us was part of the fabric of the universe itself in what he described as a four dimensional space-time.

Yet we have historically measured time based not on the passing of time itself but the rotation of our planet in relation to the Sun and the Moon. A day is divided into 24 equal parts (hours) each of which is divided into 60 minutes and the minute is divided into 60 seconds.

However, it has now been realised that measuring time this way can not be considered accurate as the Earth’s rotation varies from day to day. All sorts of variable such as tidal forces, hurricanes, solar winds and even the amount of snow at the poles effects the speed of the Earth’s rotation. In fact when the dinosaurs first started roaming the Earth, the length of a day as we measure it now would have only been 22 hours.

We now base our timekeeping on the transition of atoms using atomic clocks with a second based on 9,192,631,770 periods of the radiation emitted by the hyperfine transition of a unionized caesium atom in the ground state. Whilst this may sound complicated it really is just an atomic ‘tick’ that never alters and therefore can provide a highly accurate reference to base our time on.

Atomic clocks use this atomic resonance and can keep time that is so accurate a second isn’t lost in even a billion years. Modern technologies all take advantage of this precision enabling many of the communications and global trade we benefit from today with the utilisation of satellite navigation, NTP servers and air traffic control changing the way we live our lives.

The NTP Server and the Atomic Clock Reason for Precision

Saturday, January 10th, 2009

In an age of atomic clocks and the NTP server time keeping is now more accurate then ever with ever increasing precision having allowed many of the technologies and systems we now take for granted.

Whilst timekeeping has always been a preoccupation of mankind, it has only been in the last few decades that true accuracy has been possible thanks to the advent of the atomic clock.

Before atomic time, electrical oscillators like those found in the average digital watch were the most accurate measure of time and whilst electronic clocks like these are far more precise than their predecessors – the mechanical clocks, they can still drift by up to a second a week.

But why does time need to be so precise, after all, how important can a second be? In the day-to-day running of our lives a second isn’t that important and electronic clocks (and even mechanical ones) provide adequate timekeeping for our needs.

In our day-to-day lives a second makes little difference but in many modern applications a second can be an age.

Modern satellite navigation is one example. These devices can pinpoint a location anywhere on earth to within a few metres. Yet they can only do this because of the ultra-precise nature of the atomic clocks that control the system as the time signal sent from the navigation satellites travels at the speed of light which is nearly 300,000 km a second.

As light can travel such a vast distance in a second any atomic clock governing a satellite navigation system that was just one second out it would the positioning would be inaccurate by thousands of miles, rendering the positioning system useless.

There are many other technologies that require similar accuracy and also many of the ways we trade and communicate. Stocks and shares fluctuate up and down every second and global trade requires that everybody all over the world has to communicate using the same time.

Most computer networks are controlled by using a NTP server (Network Time Protocol). These devices allow computer networks to all use the same atomic clock based timescale UTC (coordinated universal time). By utilising UTC via a NTP server, computer networks can be synchronised to within a few milliseconds of each other.

NTP Server running a network (Part 2)

Thursday, January 8th, 2009

Organising Strata

Stratum levels describe the distance between a device and the reference clock. For instance an atomic clock based in a physics laboratory or GPS satellite is a stratum 0 device. A stratum 1 device is a time server that receives time from a stratum 0 device so any dedicated NTP server is stratum 1. Devices that receive the time from the time server such as computers and routers are stratum 2 devices.

NTP can support up to 16 stratum levels and although there is a drop-off in accuracy the further away you go stratum levels are designed to allow huge networks to all receive a time from a single NTP server without causing network congestion or a blockage in the bandwidth.

When using a NTP server it is important to not overload the device with time requests so the network should be divided with a select number of machines taking requests from the NTP server (the NTP server manufacturer can recommend the number of requests it can handle). These stratum 2 devices can ten be used as time references for other devices (which become stratum 3 devices) on very large networks these can then be used as time references themselves.

Happy Christmas from all at Galleon Systems

Thursday, December 25th, 2008

Here at Galleon Systems, one of Europe’s leading suppliers of NTP server systems, we would like to wish all our customers, suppliers and even our competitors a Merry Christmas and a Happy New Year. We hope 2009 is a successful year for you all.

Atomic Clock Synchronisation using MSF

Wednesday, December 24th, 2008

Accurate time using Atomic Clocks is available across Great Britain and parts of northern Europe using the MSF Atomic Clock time signal transmitted from Cumbria, UK; it provides the ability to synchronize the time on computers and other electrical equipment.

The UK MSF signal is operated by NPL – the National Physical Laboratory. MSF has high transmitter power (50,000 watts), a very efficient antenna and an extremely low frequency (60,000 Hz). For comparison, a typical AM radio station broadcasts at a frequency of 1,000,000 Hz. The combination of high power and low frequency gives the radio waves from MSF a lot of bounce, and this single station can therefore cover most of Britain and some of continental Europe.

The time codes are sent from MSF using one of the simplest systems possible, and at a very low data rate of one bit per second. The 60,000 Hz signal is always transmitted, but every second it is significantly reduced in power for a period of 0.2, 0.5 or 0.8 seconds: • 0.2 seconds of reduced power means a binary zero • 0.5 seconds of reduced power is a binary one. • 0.8 seconds of reduced power is a separator. The time code is sent in BCD (Binary Coded Decimal) and indicates minutes, hours, day of the year and year, along with information about daylight savings time and leap years.

The time is transmitted using 53 bits and 7 separators, and therefore takes 60 seconds to transmit. A clock or watch can contain an extremely small and relatively simple antenna and receiver to decode the information in the signal and set the clock’s time accurately. All that you have to do is set the time zone, and the atomic clock will display the correct time.

Dedicated time servers that are tuned to receive the MSF time signal are available. These devices connect o a computer network like any other server only these receive the timing signal and distribute it to other machines on the network using NTP (Network Time Protocol).