Archive for June, 2011

Leap Second Argument Rumbles On

Wednesday, June 29th, 2011

The argument about the use of the Leap Second continues to rumble on with astronomers again calling for the abolition of this chronological ‘fudge.’

Galleon's NTS 6001 GPS

The Leap Second is added to Coordinated Universal Time to ensure the global time, coincides with the movement of the Earth. The problems occur because modern atomic clocks are far more precise than the rotation of the planet, which varies minutely in the length of a day, and is gradually slowing down, albeit minutely.

Because of the differences in time of the Earth’s spin and the true time told by atomic clocks, occasional seconds need adding to the global timescale UTC—Leap Seconds. However, for astronomers, leap seconds are a nuisance as they need to keep track of both the Earth’s spin—astronomical time—to keep their telescopes fixed on studied objects, and UTC, which they need as atomic clock source to work out the true astronomical time.

Next year, however, a group of astronomical scientists and engineers, plan to draw attention to the forced nature of Leap Seconds at the World Radiocommunication Conference. They say that as the drift caused by not including leap seconds would take such a long time—probably over a millennia, to have any visible effect on the day, with noon gradually shifting to afternoon, there is little need for Leap Seconds.

Whether Leap Seconds remain or not, getting an accurate source of UTC time is essential for many modern technologies. With a global economy and so much trade conducted online, over continents, ensuring a single time source prevents the problems different time-zones could cause.

Making sure everybody’s clock reads the same time is also important and with many technologies millisecond accuracy to UTC is vital—such as air traffic control and international stock markets.

NTP time servers such as Galleon’s NTS 6001 GPS, which can provide millisecond accuracy using the highly precise and secure GPS signal, enable technologies and computer networks to function in perfect synchronicity to UTC, securely and without error.

A Guide to Securing Computer Networks in Business

Thursday, June 23rd, 2011

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

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.

  • Spyware

Computer programs that spy on the network, reporting to unauthorised users. Often spyware can run undetected for a long time.

  • Botnet

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.

Other threats

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.


Summer Solstice The Longest Day

Monday, June 20th, 2011

June 21 marks the summer solstice for 2011. The summer solstice is when the Earth’s axis is most inclined to the sun, providing the most amount of sunshine for any day of the year. Often known as Midsummer’s day, marking the exact middle of the summer, periods of daylight get shorter following the solstice.

For the ancients, the summer solstice was an important event. Knowing when the shortest and longest days of the year were important to enable early agricultural civilisations to establish when to plant and harvest crops.

Indeed, the ancient monument of Stonehenge, in Salisbury, Great Britain, is thought to have been erected to calculate such events, and is still a major tourist attraction during the solstice when people travel from all over the country to celebrate the event at the ancient site.

Stonehenge is, therefore, one of the oldest forms of timekeeping on Earth, dating back to 3100BC. While nobody knows exactly how the monument was built, the giant stones were thought to have been transported from miles away—a mammoth task considering the wheel hadn’t even been invented back then.

The building of Stonehenge shows that timekeeping was as important to the ancients as it is to us today. The need for acknowledging when the solstice occurred is perhaps the earliest example of synchronisation.

Stonehenge probably used the setting and rising of the sun to tell the time. Sundials also used the sun to tell the time way before the invention of clocks, but we have come a long way from using such primitive methods in our timekeeping now.

Mechanical clocks came first, and then electronic clocks which were many times more accurate; however, when atomic clocks were developed in the 1950’s, timekeeping became so accurate that even the Earth’s rotation couldn’t keep up and an entirely new timescale, UTC (Coordinated Universal Time) was developed that accounted for discrepancies in the Earth’s spin by having leap seconds added.

Today, if you wish to synchronise to an atomic clock, you need to hook up to a NTP server which will receive an UTC time source from GPS or a radio signal and allow you to synchronise computer networks to maintain 100% accuracy and reliability.

Stonehenge–Ancient timekeeping

Cyber Attacks and the Importance Time Server Security

Wednesday, June 15th, 2011

The media is full of stories of cyber terrorism, state sponsored cyber warfare and internet sabotage. While these stories may seem like they come from a science fiction plot, but the reality is that with so much of the world now dependent on computers and the internet, cyber attacks are a real concern for governments and businesses alike.

Crippling a website, a government server or tampering with systems like air-traffic control can have catastrophic effects—so no wonder people are worried. Cyber attacks come in so many forms too. From computer viruses and trojans, that can infect a computer, disabling it or transferring data to malicious users; distributed denial of service attacks (DDoS) where networks become clogged up preventing normal use; to border gateway protocol (BGP) injections, which hijack server routines causing havoc.

As precise time is so important for many technologies, with synchronisation crucial in global communication, one vulnerability that can be exploited is the online time server.

By sabotaging a NTP server (Network Time Protocol) with BGP injections, servers that rely on them can be told it’s a completely different time than it is; this can cause chaos and result in a myriad of problems as computers rely solely on time to establish if an action has or hasn’t taken place.

Securing a time source, therefore, is essential for internet security and for this reason, dedicated NTP time servers that operate externally to the internet are crucial.

Receiving time from the GPS network, or radio transmissions from NIST (National Institute for Standards and Time) or the European physical laboratories, these NTP servers can’t be tampered with by external forces, and ensure that the network’s time will always accurate.

All essential networks, from stock exchanges to air traffic controllers, utilise external NTP servers for these security reasons; however, despite the risks, many businesses still receive their time code from the internet, leaving them exposed to malicious users and cyber attacks.

Dedicated GPS Time Server--immune to cyber attacks

Atomic Clocks now Accurate to a Quintillionth of a Second?

Wednesday, June 8th, 2011

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.

Network Time Server

Keeping Track of Global Time

Wednesday, June 1st, 2011

So much business these days is conducted across borders, countries and continents. Global trade and communication is an important aspect for all sorts of industries, trades and businesses.

Of course, communicating across borders often means communicating across time zones too, and this poses problems for both people and computers. When those in United States start work, Europeans are half way through their day, while those in the Far East have gone to bed.

Knowing the time in several countries is, therefore, important for many people, but fortunately, many solutions exist to help.

Modern operating systems like Windows 7 have facilities that allow you to show several time zones on the computer clock, while web pages and apps such as: offer an easy way to work out the different time across time zones.

Many offices use multiple analogue and digital wall clocks to provide staff with easy access to the time in important trade countries, sometimes these use atomic clock receivers to maintain perfect accuracy, but what about computers? How do they deal with different time zones?

The answer lies in the global timescale UTC (Coordinated Universal Time). UTC was developed following the invention of atomic clocks. Kept precise by a constellation of these super-accurate clocks, UTC is the same across the globe enabling computers to communicate effectively without the differences in time zones affecting functionality.

To ensure preciseness in communication, computer networks need an accurate source of UTC as system clocks are nothing more than quartz oscillators, which can drift by several seconds a day—a long time for computer communication.

A software protocol, NTP (Network Time Protocol) ensures that this time source is distributed around the network, maintaining its accuracy.

NTP servers receive the source of UTC, often from sources such as GPS or radio referenced signals broadcast by NPL in the UK (National Physical Laboratory—transits the MSF signal from Cumbria) or NIST in the USA (National Institute of Standards and Time—transmits the WWVB signal from Colorado).

With UTC and NTP time servers, computer networks across the globe can communicate precisely and error-free enabling trouble free computing and truly global communication.

NTP server