Where ISP's get their "internet" from?

People usually get their “internet” (home or business) after they sign some kind of contract with an ISP.

My question is: where ISP’s get the “internet” that they provide from? Do they pay some other internet wholesaler or something? And to take this even further, can anyone, with the right equipment, be his or hers own ISP and provide internet to themselves?

Please, fight my ignorance. Thanks.

The little ones talk to the big ones and the big ones talk to each other. (“peering”)

You still need to communicate with others somehow. That’s the key to the internet, communicating with others. If you get a big benefit from your ‘upstream’, you will probably have to pay your upstream partners money. Once you get big enough that there is a benefit to your partners to supply access to your customers, the fees balance out and you can sign a peering contract where neither of you pay one another, you just mutually share internet traffic.

We act as an ISP at our college and get our Internet from a series of tubes . . . I mean from AT&T and Time Warner cable. Essentially, the big telecoms charge smaller ISPs for the connection.

You get your “internet” in the form of something like a T1 line from somebody like AT&T or one of their many competitors. Then you have to set up your own servers, register your domain, etc. Your cost is going to be several hundred dollars per month.

Keep in mind that what you’ll be getting is completely unfiltered internet traffic. Your server is going to be a target for hackers 24/7/365. Your ISP deals with a lot of stuff long before it gets to your computer, and if you are going to be the ISP then you have to deal with it. This requires a lot more hands on effort than just running an antivirus program on your computer. If you don’t manage the hackers well enough, your server will end up black listed, and other servers on the internet will reject traffic from you, and effectively large sections of the internet don’t work for you.

The only really strange piece of equipment you’ll have is a T1 modem. Other than that, the server is just a computer (typically running some sort of server OS - you don’t want this guy to be running something like XP home). What other computers and networking equipment you put in your system is up to you. You could just have the one server and that’s it if you want.

You can see the internet as a bunch of fiber optic and copper wire connected routers. These cables and routers are maintained by phone companies and ISPs. They own and manage the backbone of the internet. They all have peering and connection agreements with each other and freely exchange data with each other.

Youre too small of an entity to have your own backbone or have any agreement with a big carrier, so you buy access to a carrier’s network thus the internet via an ISP. The ISP then provides some kind of last mile solution to connect your home or business usually via DSL, cable modems, T1s, etc.

Depends on what you mean by ISP.

Your average ISP for instance Bluehost.com might have their own servers somewhere. Others, most of them in fact host their servers in a ‘colocation’ facility. Which is essentially a big warehouse with a massive pipe that hosts lots and lots of servers.

Then if you’re talking about where they get the service from for like DSL or something there are strange and byzantine relationships for that. Like Verizon owns the lines, Covad maintains and operates the lines, and Verizon leases the lines from Covad. So basically in order to get around telecom monopoly stuff you deal with Covad instead of Verizon. That way upstart competitors for Verizon can come up and lease their service from Covad and provide DSL service to your home.

The internet has some massive switching stations that create regional nodes that hold the integrity of the larger internet together.

Most likely from a Tier 1 ISP such as Level 3, Global Crossing, Qwest or the other big ones mentioned (AT&T, Sprint & Verizon)

You can be your own ISP, but it isn’t cost-effective - you’re probably looking at $300/month or more for a T1 circuit to an “upstream provider” and the delivery of traffic. And a T1 line (1.5Mbit/sec, give or take) is slower than most cable modems these days. On the other hand, T1 service is true “all you can eat”, unlike the cable company’s “we have a limit and we’ll cut you off, but we can’t tell you what that limit is” plan.

ISPs connect with each other for “peering” (where neither side pays the other for traffic, but one or both pays for the actual connection) and “transit” (where one pays the other for traffic). It gets rather odd at the top level, since if ISP B won’t peer with ISP A for some reason, then ISP A will need to purchase transit or cut some sort of back-room deal. In one instance, ISP B was also a long-distance telco, and would only provide peering to ISP A if ISP A would also agree to use ISP B’s phone service for long distance.

Peering is better, because you don’t have to pay for traffic. But you have to be a pretty major player to peer with the larger providers. For example, Comcast’s peering policy is here. You’ll need to have a national network running at at least 10Gbit/sec and meet them at 4 places all across the US. Note that peering agreements are often written to demand more than is reasonable and tend to get negotiated down.

I just checked on one of my peering routers and I have over 200 peering connections on it, all at Gigabit or faster speeds.

There are currently ten recognized Tier 1 networks:

AT&T, Global Crossing, L3, NTT, Qwest, Sprint, Tata, Verizon, Savvis, and TeleSonera.

A Tier 1 network is a network that can reach any place on the Internet without having to pay for transit rights. In other words, all Tier 1 providers are fully peered with all other Tier 1 providers.

The next level down, sometimes called Tier 2 networks, are providers that have peering arrangements with some Tier 1 providers, but pay for transit with some of the others. So they can’t reach the entire Internet through peering alone.

And the next level are networks that pay for transit on one or more networks and don’t have peering arrangements with anybody.

Most small ISPs are Tier 3 networks. A few really big ISPs are Tier 2 networks. The Tier 1 networks are not in the business of selling Internet service retail. (Even Verizon’s DSL operation is a customer of their Tier 1 network, which is operated by a different subsidiary.)

mswas said: “The internet has some massive switching stations that create regional nodes that hold the integrity of the larger internet together.”
My question: Is this subject to a terrorist attack? A hacker attack?
Kinda scary if it is. :eek:

Remember, the original ARPANET (the current net’s predecessor) was designed to be resistant to attacks.

If any one of these public interchange points was knocked out (as the one in downtown Manhattan was when the generators ran dry 5 days after 9/11), most traffic would move to other points. Only those sites connected solely at that one site would be affected.

What would be worse would be random packet loss at one of these points. MAE East used to have packet loss (15 years or so ago) which was hugely annoying to a lot of folks. Because packet loss won’t cause traffic to route elsewhere (unless it is severe enough that the net’s internal routing protocols would be affected), traffic will flow along normally until a packet is dropped. Then the computer that sent the dropped packet will time out and re-transmit the packet if it doesn’t receive an acknowledgement that it was received the first time. This delay is what hurts things.

Another risk with a higher probability is a “backhoe incident”. ISPs try to order circuits from more than one carrier to avoid this, but carriers have a habit of purchasing / trading service from other ones, so everything can be in a single cable. In the early 90’s there was one such incident (in the Midwest, as I recall) that took out a large chunk of the Internet, both by directly cutting connections and by forcing traffic onto other paths which became overloaded. That is less likely these days, however.

In simplified terms, when it comes to Internet connection you have three kinds of connections:
Tier 1 network - Able to access any place on the Internet for free. It also provides the fastest connection and best quality. Tier 1 ISPs sell Internet access to Tier 2 ISPs and large companies.

Tier 2 network - Able to access some parts of the Internet for free and pays a Tier 1 network for access to the rest. Tier 2 Internet access is a little slower and has a little less quality. Tier 2 ISPs sell to Tier 3 ISPs and other businesses.

Tier 3 network - Has to pay Tier 1 and/or Tier 2 ISPs for internet access, and then sells Internet access to residential and small business customers.

The questions asked IMO are to tech/complicated to simplify IMO.

Minor quibble. The fastest highest quality connections for the end user are probably on the Tier 3 ISP’s ( also the worst ). The best T3’s are multi-homed with many of the T1 carriers and therefore have direct paths to them and the T2/T3 customers of the T1’s, and have oodle’s ( that’s a technical term :stuck_out_tongue: ) of bandwidth to them all.

“And to take this even further, can anyone, with the right equipment, be his or hers own ISP and provide internet to themselves?”

I would argue that you cannot be your own ISP, you need the provide in the P (as in to others ). I think that what you are asking is more like a case I’ve been in the middle of before. A company gets there links from several ISP’s , there own IP’s and participates in BGP ( thats how ISP’s talk to each other about how to find the IP’s they have ). When you are up to the doing your own BGP level you are part of the Internet in a direct way. Doing BGP doesn’t mean you are a “service provider” of any kind.

Its also possible the OP by “internet” means services like email.

Anyone can be an ISP with the right equipment , know how and $


Are any of these a company based in China? I have to believe that there is at least one Tier 1 network based in China.

Tier 1 networks are not well defined or agreed on.

I check this several times a day … its mostly US centric. It doesn’t match friedo’s list and I know it doesn’t match “the world”. If minor country X has a national ISP by friedo’s definition any backbone carrier who doesn’t peer without payments isn’t Tier-1 ( yea friedo I know thats not what you meant its just not that simple ) [and lets not even get into most T1’s have contracts with other T1’s that could in theory lead to payments].

Since you bring up a point where I would like a bit of ignorance to be fought.

“I have to believe that there is at least one Tier 1 network based in China.”

Did you have a T1 in mind?


Not particularly, I just was thinking that the Chinese government would not like to be “buying” internet service from a Tier 1 provider that is a company based in the USA or India. I’m using the simplified definitions given by Nobody in post 12:
Tier 1 networks sell internet service to Tier 2 providers.