How can we connect?

Today, I had a interesting lesson in my university.
A topic of it was about the Internet.

Do you know how the Internet  connect us?
The Internet different from the Telephone Line.
When we call by phone, we connect a line with a top, and the top connect our line each other.In a word, all lines are converged on the top, and we have to  connect our line with another's through the top.

On the other hand, the Internet has lines which extends as if a cobweb did.
And we can connect our line with a extension of it when we use the Internet.
So the lines are not converged on one place.

To be precise, lines of the Internet are hierarchically converged by providers.
First, providers individually converge end user's lines.
Next, they are converged on a higher provider.
It is just like below.

It continues, and at the end, they are converged on ten highest provider called "tier 1."
They are the largest companies of a provider in the world.
Almost all of them are American's.

Generally, lower providers pay higher providers to connect lines with theirs.
And tier 1 are in habit of not paying each other to connect lines.
So they haven't payed and only gotten money from lowers.
It seems that this system has been criticized by countries which don't have tier 1 .

I think this system is arrogant.
But in fact, lower need them, though lower isn't necessarily needed by them.
It is possible to be enough reasons why they can be such a arrogant.

The countries which have only lower providers have to get sites like the google or the twitter which is strong enough to be needed by tier 1.

You can get more information about this from links below.
http://en.wikipedia.org/wiki/Tier_1_network
http://en.wikipedia.org/wiki/Router


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