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INFORMATION IS POWER
Computer problems are like black holes—except that instead of absorbing light, they absorb time.

Have you ever spent an hour, an afternoon or several days trying to figure out why a file won’t download or why your computer always locks up when you do this or that? It’s frustrating.

It’s even more frustrating, though, to find out that just a little background information on the workings of a particular program or piece of hardware would have made the solution to your problem immediately evident. But basic nuts-and-bolts information about using computers is surprisingly hard to find.

Take the Internet, for example. You probably use it regularly, maybe every day, but do you know what’s going on behind the scenes?

Well, the Internet happens to be the topic of this month’s column. For future columns, I invite you to send suggestions for basic computing topics you would like to see covered in CyberNews. You can e-mail them to me at "hoylej{at}ada.org".

THE INTERNET
The Internet is a worldwide collection of interconnected computers, servers and networks. All of these individual components, in one way or another, tie into a group of high-speed, high-capacity networks known as the Internet backbone. The backbone networks carry the bulk of Internet traffic and are owned by major Internet service providers, or ISPs, including GTE, MCI and Sprint.

When you connect to the Internet from work or home, you create a network connection with your ISP, which leases access to the backbone. Data are then passed back and forth, via the ISP, between your computer and computers on other networks through routers and the backbone. Routers are hardware links that allow data to be passed among networks.

The secret to routing data among all of the individual networks that make up the Internet is the Transmission Control Protocol/Internet Protocol, or TCP/IP, network protocol. A protocol is simply a set of rules that govern the exchange of information between computers. TCP/IP acts as an envelope that contains data and facilitates their journey over the Internet. The TCP breaks up data into small chunks, called packets, that can easily and quickly traverse the Internet. The TCP also assigns a sequence number to each packet so that the packets can be reassembled into data when they reach their destination.

The IP embeds destination information, called an IP address, into each TCP packet. Every computer hooked into the Internet must have a unique IP address, which is generally assigned by an ISP.

Using the IP address, routers forward packets through the quickest route available, over the backbone and to their final destination. The packets do not have to be sent in order or even along the same route; the destination computer uses the TCP information to reassemble the packets into recognizable data.

Other higher-level protocols work with TCP/IP to provide specific services. All that these protocols do is repackage data so they can be shared easily between specific programs.

One of the most common higher-level protocols used on the Internet is Hypertext Transfer Protocol. This is the protocol that powers the World Wide Web, which will be the subject of next month’s CyberNews.

Joe Hoyle, electronic media editor, ADA Publishing, a division of ADA Business Enterprises, Inc., "hoylej{at}ada.org".

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