SORTING OUT THE INTERNET
10 million host computers, 40 million users, why is there not complete chaos

There you are, on the microsoft page one minute, click the mouse, now you are examining another page at another destination(or downloading software). You examine the URL and see "de" at the end. Surely this means that the site you are now on is stored on a page in Germany. Another click and you find that you are on a page in the UK, perhaps back on theUKOnline computer pages.

In a matter of a few minutes you could well have circulated the globe many times. Not only you but many millions like you. In fact there about 40 million people using the WEB these days, flitting between ten million host computers. As there is no actual central authority overseeing the Internet, there should be utter chaos with all this information whizzing about. Happily, the Internet is really quite well organised, into what is called a 'package switched network' working in a similar way to a huge Post Office.

All messages sent on the Net are broken up into small chunks of data ranging from 296 bytes up to a maximum of 1,064 bytes. Each packet of data has a delivery address and will take various routs along the Net until it reaches it's goal. If one communication link is busy it will take another, perhaps longer route, until the data eventually gets through.

Clicking on a URL (Uniform Resource Locator) address link for Information causes your WEB Browser to examine the address for the computer, called the host, on the Internet where this information lies. On a typical URL this is the section between the first two "/" 's. If we take an address such as http://www.ukonline.co.uk/contents/members/ this would be www.ukonline.co.uk.

Once the host name has been extracted by the Browser, a messager will be sent to a computer called the DNS (Domain Name Server)with your Internet Service Provider. The host name is then searched for in the DNS database and its address retrieved. This is a numeric address, "understood" by the Internet, not un-alike the structure of your home address in that it identifies the country, town street and house number.

After the DNS conversion a message is sent over the Internet stating you request for a particular page of information on the selected host. Along with your request for information is sent a temporary address assigned to you.

The main telecommunication systems, of the major UK Internet service providers, are connected together at Telehouse in the London Docklands. In a system called Linx, all the telecommunication lines come together allowing the free flow of messages between the various British networks. If your information request is in another country, the request is passed on to other countries equivalent of Linx until the host is contacted.

Communication computers, called routers, working like telephone exchanges pass on your request down the line towards the destination computer. The process works very much like postal sorting offices, knowing roughly where the host computer is by the type of address. This sorting office analogy works in that as a letter, posted in London to my address in Tredegar, moves from London to a sorting office in Cardiff, then on to another office in the town of Tredegar, and then delivered to my house by the postman. Similarly, as each line of the mail address sends the letter on to the next sorting office, the packet of information is sent to the another router that brings it closer to its destination.

Each router will have a knowledge of how messages have moves through various connections, and so will choose, what it considers, is the best route for your message package.

On arriving at its destination your requested page is located. As your request contains your return address, this is used when sending packages of information back to your PC where it arrives a few second later. Of course the speed will depend on how busy the lines and router are. All of the requested page will be sent back, in data packets, unless you send a 'stop' message. When this happens the computer forgets about you and if you reconnect you will have to go through the whole process again.

Although it may appear that you are moving from one computer URL to the next as if they were "daisy chained" together, this is not the case. You are sent the page from the host computer which contains another URL and when you click on it you go through the process all over again to the new URL's destination.