Basic Structure of the Internet

The best view of the Internet comes with following a packet from your PC. When you log into a web site, you actually send a command to a distant server telling it to download a page of data to your PC. Your web browser packages that command into a packet labeled with the address of the server storing the page that you want. Your PC sends the packet to your modem (or terminal adapter), which transmits it across your telephone or other connection to your Internet Service Provider or ISP.

The ISP actually operates as a message forwarder. At the ISP, your message gets combined with those from other PCs and sent through a higher speed connection (at least you should hope it is a high speed connection) to yet another concentrator that eventually sends your packet to one of five regional centers (located in New York, Chicago, San Francisco, Los Angeles, and Maryland). There the major Internet carriers exchange signals, routing the packets from your modem to the carrier that haul them to their destination based on their Internet address.

One of the weaknesses of today's Internet is its addressing. All of the Internet addresses are global. From the address itself, neither you nor a computer can tell where that address is or, more importantly, how to connect to it. The routers in the Internet regional centers maintain tables to help quickly send packets to the proper address. Without such guidance, packets wander throughout the world looking for the right address. Worse, the current Internet naming convention which assigns 32-bit addresses, doesn't have the breadth necessary to accommodate all future applications of the Internet. Some experts believe that the Internet will simply run out of available addresses sometime around the turn of the century-whether the shortfall occurs before or after the millennium depends on how pessimistic an expert you ask.

Internet addresses are separate and distinct from the domain names used as Uniform Resource Locators (URLs) through which you specify Web pages. The domain names give you a handle with a natural-language look. Internet addresses are, like everything in computing, binary codes.

Even domain names are running short. Finding a clever and meaningful name for a web site is a challenge that's ever increasing. Believing that one of the problems in the shortage of URLs has been the relatively few suffixes available, one of the coordinating agencies for Internet names, the International Ad Hoc Committee, proposed seven additional suffixes in addition to the six already in use in the U.S. and the national suffixes used around the world (.US for United States, .CA for Canada, and so on).