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What is the Internet?

Brief tutorial that describes this wonderful thing called Internet
What is the Internet?

I got this question out of many of my students. It’s quite difficult to give a scientifically correct definition. Actually, this article is meant to give a quick look at the Internet, rather than analyzing its technological features.

Ok, first, a little bit of history. In the times of the Cold War, America and the USSR where “at war”. Nuclear holocaust was in the mind of every living American. This was partially due to the launch of the Sputnik satellite the soviets put on orbit. The Department of Defense wanted a network that could easily adapt to changes and that could interconnect distant locations. The latter was already achieved; the telephone system was capable of transporting voice over many thousand kilometers. The problem was that if a telecommunications office would be for some reason disabled, all the users attached to that office would not be able to communicate with nobody. So, the smart guys from DoD developed the first Internet, if we can call it like that: ARPA Net. This early Internet could communicate important information among different locations around the US. Most important, the system could “find” another way, in case a communication link came down.

Finally, the Cold War was over. Still, the system remained operational. Soon, universities connected to this network. Soon, the growth became almost uncontrollable and the Internet developed to the form in witch we can fin it today.

It’s important to say two things: nobody is controlling the Internet and nobody is “producing” it. As strange as it may seem, the last phrase is unfortunately in a lot of people’s minds. Actually, some of my students asked me this. Ok, let’s review each statement.

Nobody is controlling the Internet

This is a two-edged sword. The good about this fact is that one can, for example, build a site without much trouble and with a relatively small budget. No one will ask you why you want that site; you just pay for the name of the site and period. Things are pretty loose. The bad thing about the fact that nobody is controlling the Internet is that relative to our example, you can write all you want in the site that you just bought. If it’s poetry, it’s ok. But if you are explaining, for example, how to make a bomb, then things tend to become a little bit ugly. Nowadays, one can find pretty much everything on the Internet. Ok, let’s see now the second statement about the Internet

Nobody is “producing” the Internet

Ok, to put it briefly, the Internet is one huge network of networks. Let me explain that. Suppose in a city we have an Internet Service Provider (ISP) that connects the majority of the inhabitants. Everyone pays a fee (smaller or greater) to the ISP in order to have access to the Internet. Various ISP’s may run in a city. These ISP pay at their turn to a larger ISP for access to the Internet. So the pyramid goes up until we find the top-level ISP’s, that don’t pay anything to anybody. They just establish connections with another top-level ISP, in order to exchange data. It’s a simple as that. Practically, from a newbie’s point of view, the Internet consists of the following:

• Computers: the computers of all the users that access www.google.com, for example
• Traffic moving devices: these devices make sure that one request to view www.google.com reaches Google and doesn’t go anywhere else.
• Servers: everyone has heard of servers. They simply provide the services that we use every day, like e-mail, web-search, sites and so on.

Keep in mind that the above grouping is only meant for understanding purposes. In real life, things are much more complicated.

Before I end this article, I would like to comment on my first statement (nobody is controlling the Internet). In this big network (witch pretty much resembles a huge city) if you want to go somewhere, you need to know the address, right? Everyone has heard of an IP address, but not everyone knows what an IP address is. An IP address is like one’s postal address. It’s unique and identifies your computer. Everyone connecting to the Internet has an unique IP address. The format is a four dotted decimal notation, for example 82.78.213.112. Now, the reason I discussed about this is that, like every good thing in life, IP addresses are not infinite. Roughly, the total number of IP address is 4.294.967.296. So, if IP addresses are finite, precise control is required. For this purpose an authority has been created in order to allocate IP addresses. Its name is IANA and stands for Internet Assigned Numbers Authority.

Now, let me explain a little bit how one as a home user gets an IP address. Top-level ISP’s buy addresses from IANA. As some of you may have already anticipated, these addresses are not sold in a chaotic fashion. Instead, IANA sells “chunks” of IP addresses in a contiguous fashion, for example one ISP cannot buy 82.78.213.112 and 82.78.213.117, and instead he has to buy the whole “chunk” starting from 82.78.213.1 and ending to 82.78.213.254.

So, as we have seen, the first “golden rule” has changed a little bit. We can rephrase it: the Internet is very loosely controlled.

The most important things to know about the Internet are the following:

• it’s a network of networks
• it’s very loosely controlled
• nobody is “producing” it
• every computer connected to the Internet is identified by an unique address, called the IP address

source:NetMeUp

posted by alex2xlnc @ 2:29 PM