The worst part of a power cut is running around the house setting all the clocks and timers back to the correct time, it can take ages and you will always forget one, however, as long as you have a wrist watch it should be quite easy to get your clocks all telling the same time. But what time is your wrist watch set too and who regulates that time?
Complete precision and accuracy in time telling is not essential for our day-to-day lives and neither is synchronisation, our computer may be a few minutes slower than our wall clock but it will make little difference when we send an email.
However, what if the person we sent the email to has a computer clock that is even slower? They may end up sending a reply before they have technically received it. Computers are easily fooled if timestamps run backwards – remember the millennium bug!
For this reason it is important for computers, particularly those that deal with time sensitive or financial applications, to be telling the same time; otherwise global stocks could be bought whilst already sold-out or an airline seat, already purchased could be bought again by a buyer with a slower computer clock.
The regulation of time didn’t start until after the development of atomic clocks when the oscillation of the caesium atom became the standard definition of a second (9,192,631,770 a second).
The time told by these atomic clocks was so accurate a new timescale was developed called International Atomic Time (TAI). However, it was discovered that the traditional method of telling time, based on the revolution of the Earth (ie 24 hours in a day) and this new timescale soon became out of sync with each other as the gravity from the moon alters the revolution of the Earth, slowing it down.
This difference in the Earths spin is only minute but enough people argued (mainly astronomers) that if it was not compensated for, night would eventually creep into day (albeit in many thousands of years) and it would be difficult to keep track of the celestial bodies.
A compromise was called for and the new timescale, Universal Coordinated Time (UTC) was developed that accounted for the slowing of the Earth’s spin by adding leap seconds every year or so.
UTC has meant that modern technologies and applications such as the Global Positioning System, satellite communication, live television broadcasts and global trading have become possible.
Computer networks can receive UTC time and keep all their devices synchronised to it by using a NTP server (Network Time Protocol). NTP servers can receive UTC time from an atomic clock source via the Internet, a national radio transmission or through the GPS network.
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Keeping Time: Network Synchronisation
Technology and the Importance of Time
It is a question that has perplexed philosophers and scientists since the dawn of man, ‘what exactly is time?’ and it has only been in our recent history that we have started to discover answers, thanks to Einstein and his work on special and general relativity.
We now know time is not the abstract concept we first thought it was, we also know it is not constant and is relative to different observers throughout the universe with the speed of light being the only constant in the universe.
In other words if the speed of light has to be the same for everybody then someone travelling at close to such a speed would find time slow down.
Fortunately as all humans live within the boundaries of the planet Earth it means the passing of time is very similar for us all (or so minutely different as to be impossible to measure). However, technologies such as satellites and GPS systems have to take into account this altering state of time otherwise they would become wholly inacurate.
As humans have progressed, telling the time with ever increasing accuracy has become more and more important. Historically, knowing the time was not so imperative. People needed to know the correct day to plant crops or when sunrise and sunset happened but accuracy was not a preoccupation.
However, since the invention of the mechanical clock followed at the turn of the twentieth century by electronic clocks, humans have started to rely on more and more accuracy for their technologies.
Seafaring, aviation and now space travel mean that humans have sought more and more accuarte ways of keeping time.
In the 1950’s atomic clocks were developed which were so accurate it was discovered that the revolution of the Earth, something we had based our timescale on for centuries, was no where near as accurate as these new clocks.
Now technologies such as the Internet, the Global Positioning System and satellite communication requires absolute precision as light can travel 300,000 km every second meaning accuracies of a split second could mean our satellite navigation systems could be out by thousands of miles and computer trading would be nigh on impossible.
Fortunately a global time scale, UTC (Coordinated Universal Time), has been developed and is based on the time told by atomic clocks. This allows systems all over the world to be synchronised to the exact same time.
Computer networks use the NTP protocol (Network Time Protocol) to receive a UTC timing reference and synchronise all machines on a network to that time.
NTP servers can receive a time reference over the Internet (although not very secure) from a national radio transmission (as long as the receiver is within range of a suitable transmission) or from the GPS network (via a rooftop GPS antenna).
Richard N Williams is a technical author and a specialist in the telecommunications and network time synchronisation industry helping to develop dedicated NTP clocks. Please visit us for more information about NTP and other network time server solutions
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Configuring Windows as a Ntp Server
Microsoft Windows has a built in time synchronisation facility called windows time (w32time.exe). Windows time is based on Network Time Protocol (NTP) an Internet protocol designed to synchronise computers on a network.
Using Windows Time service it is possible to configure the operating system to run as NTP time server, allowing you to synchronise all network devices to that time. Inn some older versions of Windows such Windows 2000 a stripped-down version of NTP called SNTP (Simplified Network Time Protocol) exists but is perfectly adequate for most timing applications.
Windows Time should be present in the service list. To locate Windows Time simply find the following subkey in the registry:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Time
NOTE: editing registry entries can cause irreversible problems it is strongly advised to create a backup before editing any entries to the registry.
Windows can easily set the system clock to use UTC (Coordinated Universal Time, the World’s time standard) by accessing an Internet source (either: time.windows.com or time.nist.gov). To achieve this, a user merely has to double click the clock on their desktop and adjust the settings in the Internet Time tab.
It must be noted however, that Microsoft and other operating system manufacturers strongly advise that external timing references should be used as Internet sources can’t be authenticated.
To configure the Windows Time service to use an external time source, click Start, Run and type regedit then click OK.
Locate the following subkey:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParametersType
In the right pane, right-click Type then click Modify, in edit Value type NTP in the Value data box then click OK.
Locate the following subkey:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeConfigAnnounceFlags.
In the right pane, right-click AnnounceFlags and click Modify. The ‘AnnounceFlags' registry entry indicates whether the server is a trusted time reference, 5 indicates a trusted source so in the Edit DWORD Value box, under Value Data, type 5, then click OK.
Network Time Protocol (NTP) is an Internet protocol used for the transfer of accurate time, providing time information along so that a precise time can be obtained
To enable the Network Time Protocol; NTPserver, locate and click:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeTimeProvidersNtpServer
In the right pane, right-click Enabled, then click Modify.
In the Edit DWord Value box, type 1 under Value data, then click OK.
Now go back and click on
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParametersNtpServer
In the right pane, right-click NtpServer, then Modify, in the Edit DWORD Value under Value Data type In the right pane, right-click NtpServer, then Modify, in the Edit DWORD Value under Value Data type the Domain Name System (DNS), each DNS must be unique and you must append 0x1 to the end of each DNS name otherwise changes will not take effect.
Now click Ok.
Locate and click the following
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeTimeProvidersNtpClientSpecialPollInterval
In the right pane, right-click SpecialPollInterval, then click Modify.
In the Edit DWORD Value box, under Value Data, type the number of seconds you want for each poll, ie 900 will poll every 15 minutes, then click OK.
To configure the time correction settings, locate:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Timeconfig
In the right pane, right-click MaxPosPhaseCorrection, then Modify, in the Edit DWORD Value box, under Base, click Decimal, under Value Data, type a time in seconds such as 3600 (an hour) then click OK.
Now go back and click:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Timeconfig
In the right pane, right-click MaxNegPhaseCorrection, then Modify.
In the Edit DWORD box under base, click Decimal, under value data type the time in seconds you want to poll such as 3600 (polls in one hour)
Exit Registry Editor
Now, to restart windows time service, click Start, Run (or alternatively use the command prompt facility) and type:
net stop w32time && net start w32time
And that’s it your time server should be now up and running.
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The Web Design Myths
If your site has been around for a while, you'd probably have been visited by the "Web Design Police" (people who have a lot of time on their hands). In fact, depending on your site, you might have been visited by different branches of these people, both advocating opposite policies. I recently received an email from one of my visitors who had apparently been "helped" by some of these people, and thought that an article on two of the myths of web design is appropriate.
1. The Myth of "Content is King, No Animation/Sound/Java/etc"
The adage that "Content is King" applies to all websites, and I am not disputing that. It is also true that when you add sound, animation, Java applets and lots of graphics, your web page takes a long time to load, and some of your visitors may not bother to wait for it to load; they'll just go away.
However, putting those two together does not actually mean that all pages with animation, sound and applets are necessarily bad. The trick is to know when they're appropriate and to make the download speed as fast as it is reasonably possible under the circumstances. I will mention a few ways of reducing your graphics and animation file sizes later in this article.
When is it appropriate? Sometimes applets are needed for some sort of processing - for example, the Sesame Street website has a Java applet that shows Elmo (a Sesame Street character) dancing, and the child using it can use the mouse pointer to "tickle" Elmo and he'll respond according to where he is tickled. The applet takes forever to load on a 56K modem, but you cannot say that it is out of place: the site caters to young children who are there to play. In this case, the applet is an appropriate solution. Likewise, animation and sound might be appropriate for sites that feature online comics, online gaming, etc.
In fact, if yours is a website that sells website design services, that is, you want people to pay you to design their website, it is in your interest not to make your site too plain. Many potential customers see your site as an example of what their site can become. There's no point claiming "Content is King" at this time - they won't be around long enough to hear your claim. Such sites need a certain amount of colour, graphics, etc, although of course making it take too long to load would also be a deterrent to your potential clients.
Like all things, how you design your site depends on your topic and your target audience. Keep that cardinal rule in mind and you'll be fine.
2. The Myth of "Good Web Design is in the Graphics"
On the other end of the scale are the people who believe a good website must have much colour, graphics, animation and sound. You might meet them, for example, in the form of newcomers or pundits who either do not have much real world web experience or who only surf on T1 connections.
My first encounter with such people came in the form of an old friend who exhibited his personal website proudly to me. At the centre of his home page was a large animated graphic that was a few hundred kilobytes in size. That graphic had little function on that page - it did not provide any informative value: it was neither a logo, nor was it a photo of himself, or an image map, or anything at all. It was purely decorative. At that time (many years ago), I was using a 14.4K modem and that page took ages to load.
Now don't get me wrong. Decorative graphics on a page are fine. They make a page more pleasant to look at, and hence more likely to be read. But you should at least make them as small as possible. While I'm hesitant to give a hard and fast rule about how big such graphics should be, a decorative graphic that is a few hundred kilobytes in size is definitely too big to be tolerated.
3. Some Page Design Tips
If your concern is that your page should look good without being too slow to load, here are a few commonly used tricks that you may want to consider:
Do not put too much text in one big block. Separate them out into paragraph and put white space between paragraphs. This makes your text look more readable.
Like colored pages? That's okay, but in general, if the readability of your text is important to you, a white background with black text works best.
If you must have a colored background, make sure you try out your page by viewing it in resolutions like 256 colors to see whether the page looks alright. A colored page that looks fine on your 32 bit color resolution system may have dithering that makes your text difficult to read on lesser settings.
If you check the websites of big companies (Microsoft, Yahoo, etc), you will find that they still prefer a white background with black text for their main text. These companies probably have more resources for testing the usability of their website than you have, so it may not be wise to scoff at their design too quickly.
http://www.thedesignbuild.com
http://www.webdesign.reprintarticlesite.com
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Certification Programmes in Networking
MCSE boot camp training is for those who want to build a career in the field of networking. A boot camp training process covers the main topics very quickly but effectively. The course is of very short duration, that is, of only two to three weeks. MCSE or Microsoft Certified Systems Engineer is one of the best-known and opening Microsoft certification. MCSE certifies a person as being able to handle the networking problems and can analyze the networking requirements to run the business. The certification not only validates your expertise with products launched by Microsoft, but also demonstrates your skills and capabilities to present and potential employers and peers.
Windows 2000 and Windows server 2003 are the two different product platforms of MCSE past 2007, these lines were not a part of the MCSE, and each of them requires a different set of exams.
For MCSE boot camp 2003, candidate must pass six core-designed exams (one client operating system exams, one design exam, and four networking exams) and one elective exam.
For the windows 2000 MCSE boot camp training, a candidate is required to clear five core exams (four operating system and one design exam). There are four compulsory or core examinations to be cleared by the candidate for MCSE NT 4.0 boot camp (retired). The syllabus of the examinations includes Networking essentials, Windows NT Server, Windows NT server in the enterprise and Windows NT workstation, plus two electives. The basic subjects of the exams are Microsoft SQL Server, network security, computer networking, Microsoft Exchange Server, other topics of networking and specific Microsoft products.
The individuals also prefer CISCO career certifications like CCNA, CCNP, and CCNE etc. Various institutions organize CISCO boot camp training program that provide, for training for these specific courses.
There are three levels of certification: Associate, Professional and Expert. The certification of CCNA cab be gained by passing two tests (ICND1 and ICND2), or one single test (CCNA 640-802), the two test option is more advantageous, allowing the candidate to focus on certain subjects. The certificate is valid for three years.
CCNA imparts trainee knowledge of networking like ability to install, configure and trouble shoot local and wide area networks. On the other hand, CCNP certifications have the demonstrated knowledge and expertise required to manage the routers and switches that form the medium sized networks (between 100 and 500 nodes). All the MCSE, CISCO and CCNP Boot Camp training programs are required to gain expertise in the networking field.
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