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.
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.
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.
As British summer time officially ended last weekend, with the clocks going back to bring the UK back to GMT (Greenwich Mean Time), the debate about the annual clock changing has started again. The Coalition Government has proposed plans to change the way Britain keeps time by shifting the clocks forward another hour, and in effect reverting to Central European Time (ECT)..
ECT, would mean that Britain would remain an hour ahead of GMT in the winter and two hours ahead in the summer, providing lighter evenings but darker mornings, especially for those north of the border.
However, any proposed plans have stiff opposition from the Scottish Government who suggest that by altering the clocks, many areas in Scotland wouldn’t see daylight during winter until about 10am, meaning many children would have to go to school in the dark.
Other opponents, include traditionalists, argue that GMT has been the basis for British time for over a century, and that any change would be simply … unBritish.
However, a change to ECT would make things easier for businesses that trade with Europe, keeping British workers on a similar timescale to their European neighbours.
Whatever the outcome of the proposed changes to GMT, little will change when it comes to technology and computer networks as they already keep the same timescale all over the globe: UTC (Coordinated Universal Time).
UTC is a global timescale kept true by an array of atomic clocks and is used by all sorts of technologies such as computer networks, CCTV cameras, bank telling machines, air traffic control systems and stock exchanges.
Based on GMT, UTC remains the same the world over, enabling global communication and the transfer of data across time zones without error. The reason for UTC is obvious when you consider the amount of trade that goes on across borders. With industries such as the stock exchange, where stocks and shares fluctuate in price continuously, split second accuracy is essential for global traders. The same is true for computer networks, as computers use time as the only reference as to when an event has taken place. Without adequate synchronisation, a computer network may lose data and international transactions would become impossible.
Most technologies keep synchronised to UTC by using NTP time servers (Network Time Protocol), which continually check system clocks across whole networks to ensure that they all are synced to UTC.
NTP time servers receive atomic clock signals, either by GPS (Global Positioning Systems) or by radio signal broadcast by national physics laboratories such as NIST in the United States or NPL in the UK. These signals provide millisecond accuracy for technologies, so no matter what time zone a computer network is, and no matter where it is in the world, it can have the same time as every other computer network across the globe that it has to communicate with.
Time synchronisation is something easily taken for granted in this day and age. With GPS NTP servers, satellites beam down time to technologies, which keeps them synced to the world’s time standard UTC (Coordinated Universal Time).
Before UTC, before atomic clocks, before GPS, keeping time synchronised was not so easy. Throughout history, humans have always kept track of time, but accuracy was never that important. A few minutes or an hour or so difference, made little difference to people’s lives throughout the medieval and regency periods; however, come the industrial revolution and the development of railways, factories and international commerce, accurate timekeeping became crucial.
Greenwich Mean Time (GMT) became time standard in 1880, taking over from the world’s first time standard railway time, developed to ensure accuracy with railway timetables. Soon, all businesses, shops and offices wanted to keep their clocks accurate to GMT, but in an age before electrical clocks and telephones, this proved difficult.
Enter the Greenwich Time Lady. Ruth Belville was a businesswoman from Greenwich, who followed in her father’s footsteps in delivering time to businesses throughout London. The Belville’s owned a highly accurate and expensive pocket watch, a John Arnold chronometer originally made for the Duke of Sussex.
Every week, Ruth, and her father before her, would take the train to Greenwich where they would synchronise the pocket watch to Greenwich Mean Time. The Belvilles would then travel around London, charging businesses to adjust their clocks their chronometer, a business enterprise that lasted from 1836 to 1940 when Ruth finally retired at the age of 86.
BY this time, electronic clocks had began to take over traditional mechanical devices and were more accurate, needing less synchronisation, and with the telephone speaking clock introduced by the General Post Office (GPO) in 1936, timekeeping services like the Belville’s became obsolete.
Today, time synchronisation is far more accurate. Network time servers, often using the computer protocol NTP (Network Time Protocol), keep computer networks and modern technologies true. NTP time servers receive an accurate atomic clock time signal, often by GPS, and distribute the time around the network. Thanks to atomic clocks, NTP time servers and the universal timescale UTC, modern computers can keep time to within a few milliseconds of each other.
Accurate time is one of the most important aspects to keeping a computer network secure and safe. Places such as stock exchanges, banks and air traffic control rely on secure and accurate time. As computers rely on time as their only reference for when events happen, a slight error in a time code could lead to all sorts of errors, from millions being wiped off share prices to aeroplane flight paths being incorrect.
And time doesn’t just need to be accurate for these organizations, but secure too. A malicious user who interferes with a timestamp could cause all sorts of trouble, so ensuring time sources are both secure and accurate is vital.
Security is increasingly important for all sorts of organisations. With so much trade and communication conducted over the internet, using a source of accurate and secure time is as important a part of network security as anti-virus and firewall protection.
Despite the need for accuracy and security, many computer networks still rely on online time servers. Internet sources of time are not only unreliable, with inaccuracies commonplace, and distance and latency affecting the precision, but an Internet time server is also unsecure and able to be hijacked by malicious users.
But an accurate, reliable and completely secure source of time is available everywhere, 365 days a year—GPS.
While commonly thought of as a means of navigation, GPS actually provides an atomic clock time code, direct from the satellite signals. It is this time code that navigation systems use for calculating position but it is just as effective to provide a secure time stamp for a computer network.
Organizations that rely on accurate time for safety and security all use GPS, as it is a continuous signal, that never goes down, is always accurate and can’t be interfered with by third parties.
To utilise GPS as a source of time, all that is required is a GPS time server. Using an antenna, the time server receives the GPS signal, while NTP (Network Time Protocol) distributes it around the network.
With a GPS time server, a computer network is able to maintain accuracy to within a few milliseconds of the atomic clock time signal, which is translated into UTC time (Coordinated Universal Time) thanks to NTP, ensuring the network is running the same accurate time as other networks also synchronised to a UTC time source.
The stock market has been in the news a lot lately. As global uncertainty about national debts rise, the markets are in flux, with prices changing incredibly quickly. On a trading floor, every second counts and precise time is essential for global buying and selling of commodities, bonds and shares.
The international stock exchanges such as the NASDAQ and London Stock Exchange all require accurate and precise time. With traders buying and selling shares for customers across the globe, a few seconds of inaccuracy could cost millions as share prices fluctuate.
NTP servers linked to atomic clock timing signals ensure that the stock exchange keeps an accurate and precise time. As computers across the globe all receive the stock prices, as and when they change, these two use NTP server systems to maintain time.
The global timescale UTC (Coordinated Universal Time) is used as the basis for atomic clock timing, so no matter where a trader is on the globe, the same timescale prevents confusion and errors when dealing with stocks and shares.
Because of the billions of pounds worth of stocks and shares that are bought and sold on trading floors every day, security is essential. NTP servers work externally to networks, getting their time from sources such as GPS (Global Positioning System) or radio signals put out by organisations like the National Physical Laboratory (NPL) or the National Institute for Standards and Time (NIST).
The stock exchanges can’t use a source of internet because of the risk this could pose. Hackers and malicious users could tamper with the time source, leading to mayhem and cost millions and perhaps billions if the wrong time was spread around the exchanges.
The precision of internet time is limited too. Latency over distance can create delays, which could lead to errors, and if the time source ever went down, the stock markets could hit trouble.
It is not only stock markets that need precise and accurate time, computer networks across the globe concerned about security use dedicated NTP servers like Galleon Systems’ NTS 6001. Providing accurate time from both GPS and radio signals from NPL and NIST, the NTS 6001 ensure accurate, precise and secure time every day of the year.
Computer hacking is a common subject in the news. Some of the biggest companies have fallen victim to hackers, and for a myriad of reasons. Protecting computer networks from invasion from malicious users is an expensive and sophisticated industry as hackers use many methods to invade a system.
Various forms of security exist to defend against unauthorised access to computer networks such as antivirus software and firewalls.
One area often overlooked, however, is where a computer network gets it source of time from, which can often be a vulnerable aspect to a network and a way in for hackers.
Most computer networks use NTP (Network Time Protocol) as a method of keeping synchronised. NTP is excellent at keeping computers at the same time, often to within a few milliseconds, but is dependent on a single source of time.
Because computer networks from different organisations need to communicate together, having the same source of time makes sense, which is the reason most computer networks synchronise to a source of UTC (Coordinated Universal Time).
UTC, the world’s global timescale, is kept true by atomic clocks and various methods of utilising UTC are available.
Quite often, computer networks use an internet time source to obtain UTC but this is often when they run into security issues.
Using internet time sources leave a computer network open to several vulnerabilities. Firstly, to allow access to the internet time source, a port needs keeping open in the system firewall (UDP 123). As with any open port, unauthorised users could take advantage of this, using the open port as a way into the network.
Secondly, if the internet time source itself if tampered with, such as by BGP injection (Border Gateway Protocol) this could lead to all sorts of problems. By telling internet time servers it was a different time or date, major havoc could ensue with data getting lost, system crashes—a type of Y2K effect!
Finally, internet time servers can’t be authenticated by NTP and can also be inaccurate. Vulnerable to latency and affected to distance, errors can also occur; earlier this year some reputable time servers lost several minutes, leading to thousands of computer networks receiving the wrong time.
To ensure complete protection, dedicated and external time servers, such as Galleon’s NTS 6001 are the only secure method of receiving UTC. Using GPS (or a radio transmission) an external NTP time server can’t be manipulated by malicious users, is accurate to a few milliseconds, can’t drift and is not susceptible to timing errors.
Security is an essential aspect for any computer network. With so much data now available online, giving ease of access to permitted users, it is important to prevent unauthorised access. Failure to secure a computer network can lead to all sorts of problems for a business, such as data theft, or the network crashing and preventing authorised users from working.
Most computer networks have a firewall, which controls access. A firewall is perhaps the first line of defence in preventing unauthorised access, as it can screen and filter traffic attempting to get on to the network.
All traffic attempting to gain access to the network has to pass through the firewall; however, not all unauthorised attempts to gain access to a network is from people, malicious software is often used to gain access to data or disrupt a compute network, and often these programs can get past this first line of defence.
Different forms of malicious software can gain access to computer networks, and include:
- Computer Viruses and Worms
These can change or replicate existing files and programs. Computer viruses and worms often steal data and send it to unauthorised users.
Trojans appear as harmless software but contains viruses or other malicious software hidden in the program and are often downloaded by people thinking they are normal and benign programs.
Computer programs that spy on the network, reporting to unauthorised users. Often spyware can run undetected for a long time.
A botnet is a collection of computers taken over and used to perform malicious tasks. A computer network can fall victim to a botnet or unwillingly become part of one.
Computer networks are attacked in other ways too, such as bombarding the network with access requests. These targeted attacks, called denial-of-service attacks (DDoS attack), can prevent normal use as the network slows down as it tries to deal with all attempts at access.
Protecting Against Threats
Besides the firewall, antivirus software forms the next line of defence against malicious programs. Designed to detect these types of threats, these programs remove or quarantine malicious software before they can do damage to the network.
Antivirus software is essential for any business network and needs regular updating to make sure the program is familiar with all the latest types of threats.
Another essential method for ensuring security is to establish accurate synchronisation of the network. Making sure all machines are running the exact same time will prevent malicious software and users from taking advantage of time lapses. Synchronising to a NTP server (Network Time Protocol) is a common method of ensuring synchronised time. While many NTP servers exist online, these are not very secure as malicious software can hijack the time signal and enter the computer firewall via the NTP port.
Furthermore, online NTP servers can also be attacked leading to the incorrect time being sent to computer networks that access the time from them. A more secure method of getting precise time is to use a dedicated NTP server that works externally to the computer network and receives the time from a GPS (Global Positioning System) source.
Development in clock accuracy seems to increase exponentially. From the early mechanical clocks, there were only accurate to about half an hour a day, to electronic clocks developed at the turn of the century that only drifted by a second. By the 1950’s, atomic clocks were developed that became accurate to thousandths of a second and year on year they have becoming ever more precise.
Currently, the most accurate atomic clock in existence, developed by NIST (National Institute for Standards and Time) loses a second every 3.7 billion years; however, using new calculations researchers suggest they can now come up with a calculation that could lead to an atomic clock that would be so accurate it would lose a second only every 37 billion years (three times longer than the universe has been in existence).
This would make the atomic clock accurate to a quintillionth of a second (1,000,000,000,000,000,000th of a second or 1x 1018). The new calculations that could aid the development of this sort of precision has been developed by studying the effects of temperature on the miniscule atoms and electrons that are used to keep the atomic clocks ‘ticking’. By working out the effects of variables like temperature, the researchers claim to be able to improve the accuracy of atomic clock systems; however, what possible uses does this accuracy have?
Atomic clock accuracy is becoming ever relevant in our high technology world. Not only do technologies like GPS and broadband data streams rely on precise atomic clock timing but studying physics and quantum mechanics requires high levels of accuracy enabling scientists to understand the origins of the universe.
To utilise an atomic clock time source, for precise technologies or computer network synchronisation, the simplest solution is to use a network time server; these devices receive a time stamp direct from an atomic clock source, such as GPS or radio signals broadcast by the likes of NIST or NPL (National Physical Laboratory).
These time servers use NTP (Network Time Protocol) to distribute the time around a network and ensure there is no drift, making it possible for your computer network to be kept accurate to within milliseconds of an atomic clock source.