Bit of a profound question here. What is it that internet service providers actually provide? What is it that they do that I cannot do myself? It’s not like they’ve got this big machine labelled “internet” somewhere and each provider has a cable hooked in it.
I know providers provide DNS, but it’s not like it’s necessary; I have a DNS running along just fine in my own apartment, and don’t use my provider’s DNS. I have a gateway, a web server, a mail server, an FTP server and a firewall, and it seems to me that the only thing I cannot do myself is that last critical bit, actually connecting to the internet. Why? The internet isn’t centralized, so why can’t I connect on my own?
In short, are we all the victim of the Huge ISP Scam?
Perhaps a better way to look at the question is how do ISPs connect to the Internet?
They have their own ISPs.
Let’s take the example of a small mom-n-pop dialup ISP in East Wanker, Nebraska. They’re connecting people directly to the internet, probably via PPP, or perhaps by having people dial directly into an Internet-connected terminal server (not likely these days.)
So where does their connection come from? They’ll need something bigger than a single phone line to get enough data in and out to handle all their users. So they’ll probably have a T1 or similar, usually rented from the local phone company. And that line will connect to an upstream ISP which is in the business of leasing big lines to mom-n-pop dialups all around Wanker County. And they’ll have some really phat pipes, like multiple T3’s, which will be connected to one of the major backbone providers, or in some cases multiple backbone providers. These are really really big ISPs that maintain some of the highest bandwidth cables all over the world.
The important thing to understand is the hierarchical nature of the business. In order to plug directly into these top-level guys, you’ll need hundreds of thousands of dollars worth of equipment and you’ll have to pay them a hell of a lot of money. And since your lone computer couldn’t possibly saturate that kind of bandwidth anyway, there would be no reason for you to do so – you’ll instead buy a cheap modem (or whatever) and buy service from a downstream provider for a few bucks per month.
OK, so basically we have a bunch of backbone providers that maintain contact with each other, and each backbone provider is connected to a bunch of internet providers who are in turn connected to a bunch of smaller internet providers, and that way, in the end, everybody is connected to everybody else?
Suspected it was something like that.
So, how many of these backbone providers are there? Any relation to the root DNS’s?
There’s no particular one-to-one relationship with the root DNS servers, (and anyone can theoretically set up their own root DNS if they wanted.) But most of them are connected directly to the big backbone networks.
Here is a list of most of the medium-to-biggest sized backbone providers around the country. Take a look at AT&T, Verio, and Exodus for some cool maps.
There’s also ThinkGeek’s 2002 Map of the Internet which has a pretty visual representation of the hierarchical nature of the Internet’s topology.
You know, I think it was just about that time that a little ditty started going through my head. I believe it went a little something like this: *“Arrrrrrgh!!! Get 'em off of me!!! Get 'em off me!!! Argggggh!!! Get 'em off!! Get 'em off!! Arrrrrrrrgh… Arggggggghh!!!” *