November 9, 2001
Connect to Internet ‘city’ road system
Editors note: This is one of several columns that I wrote for the Columbia Missourian. They were originally called Your Digital World
The Internet.
It’s arguably the biggest innovation in computing and society in recent history. But some people have different perceptions of what it is. For instance, many people confuse the Internet with the World Wide Web.
If the Web isn’t the Internet, then what is it? First, a bit of history. In the 1970s the U.S. military was concerned about having its communications and computer network crippled by nuclear strikes. What they wanted was a de-centralized network, which meant that if many big computer centers (read cities), were taken out then the remaining stations would still be able to communicate.
What they got was ARPAnet, the precursor to the Internet.
To imagine what the Internet looks like let’s peek into my apartment. I have two computers, Gina and Macs. They are connected to a router, which does what it sounds like, it takes information which is supposed to go to Macs and sends it down the right wire, and does the same for Gina. It’s a network. The Internet is just a network writ large.
Think of the Internet as a large city. Each house, apartment and office building contains users that are all connected by the streets and highways in the city. In this analogy the side streets that handle limited traffic would be the modem lines on the Internet. The larger streets, like Broadway and Providence Road would represent the faster connections, like DSL or cable access. Even larger are the highways like Interstate 70 that are high-speed fiber-optic lines, (which coincidentally often run under or parallel to major highways), that can handle huge volumes of traffic. The entire transportation infrastructure from dirt roads to six-lane freeways is the Internet.
So if the Internet’s topology, (the way it’s mapped), is like a complex series of roads, it’s important to understand the way data is sent on the network.
Unlike the roads where you drive past houses, the Internet goes from house to house along the digital roads. For instance when I e-mail this column to my editor it goes through 17 different servers to get to his inbox.
But what happens if a nuclear attack takes one of those out?
I head for the hills and ask my editor for a later deadline. But, with all the information zooming on the Internet pieces of data can get lost, or the servers can go down. The designers of ARPAnet countered the lost server problem by creating a packet system. The sentence “See spot run” might be sent to a computer as “See” “spot” “run.” If one or more packets gets lost or garbled during transmission, then the receiver asks for them again. So in our Internet as the city analogy, everyone communicates by a giant game of “Telephone.” If someone stops playing the game as the message is traveling and part of the message has to be re-sent one person might decide whom he or she should pass it on to instead. The router in my house does the same thing, the routers on the Internet do the same thing, and they look for live servers whenever a packet hits a dead or busy one.
Everything that people use the Internet for such as the Web, instant messaging and e-mail, aretypes of data being sent.
Still confuzzled about the Internet, send me an e-mail.
Filed under: Technology
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