The backbone of the Internet consists of a powerful set of telephone lines including T3 lines, capable of transferring data at a very fast rate of about 45 megabytes per second. The lines link metropolitan cities and include national access points or feeds. If you imagine a geographic map, they are equivalent major highways, explaining why the Internet is often referred to as the Information Superhighway. The backbone of the Internet is operated and maintained by various companies and organizations working cooperatively without centralized ownership. Redundancy is built into the backbone of the Internet so that if one or more major lines go down, traffic can be rerouted, much like a traffic detour when a highway is temporarily under construction. While this might slow Internet traffic, it will not break the Internet.

While T3 lines provide the backbone for the Internet, smaller tributaries provide local support by establishing dedicated lines that link into the Internets backbone at national access points. Revisiting the map analogy, these can be equated with boulevards and major streets that lead to freeways. These secondary lines are leased and maintained by various Internet Service Provider (ISP) co-ops using routers to direct traffic. But how does a discreet communication get from your computer to a website? Its all about addressing and data packets.

Every computer connected to the Internet is assigned a unique Internet Protocol (IP) address. When you point- and-click on a link, your browser sends out a request that is addressed to the website that houses the content you want. Routers along the way read the data packets address and relay it along the best route available. When the data packet arrives at the website, the server reads the request and sends the requested page back to your computer via a return address in the data packet: this is your computers IP address. The data packet is routed back to you (in actuality, several data packets) and your browser interprets the content and displays the page for you. In essence the Internet is akin to a highway filled with rushing data packets versus cars.

The first whisperings of an Internet-like network reach all the way back to Leonard Kleinrocks, Information Flow in Large Communication Nets (1961), and J.C.R. Licklider / W. Clarks, On- Line Man Computer Communication (1962). Licklider then headed up the U.S. Advanced Research Projects Agency (ARPA) to develop these designs into what was to become the Internet, initially dubbed the ARPANET. The U.S. Department of Defense (DoD) funded the project in 1969, interested in developing a non- centralized, redundant communication system that could survive a nuclear attack. The rest, as they say, is history.

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