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TechKnowSurge Catalog Videos What’s an Internet Service Provider (ISP)?
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What’s an Internet Service Provider (ISP)?

An Internet Service Provider (ISP) connects end users to the internet's backbone infrastructure, bridging the gap between private homes or businesses and the broader global network. The most significant cost and technical challenge in this process lies in delivering that final connection—known as the last mile—to individual locations using available infrastructure such as DSL, cable, fiber, satellite, or cellular.

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About this video

The internet is a network of interconnected networks, and an Internet Service Provider sits between that global infrastructure and the individual user. ISPs connect to the internet's backbone—the high-capacity lines and systems that form the core of global data transmission—and extend that connectivity outward to homes and businesses. Some organizations connect directly to backbone providers, while most residential and small-business users rely on ISPs to bridge that gap on their behalf. The service an ISP provides is, at its core, a managed pathway between the end user and the broader internet. Building and maintaining backbone infrastructure requires significant capital investment, covering physical cabling, routing rights, and materials across vast distances. However, because that cost is spread across millions of users, the per-user share remains comparatively low. The more economically challenging problem is the last mile—the final stretch of connection from an ISP's local infrastructure to an individual address. Unlike backbone lines that serve enormous numbers of users simultaneously, last-mile infrastructure must ultimately reach a single endpoint, making the cost-to-user ratio far less favorable. To solve this, ISPs rely on whatever physical or wireless infrastructure already serves a given location. Common last-mile solutions include DSL delivered over existing phone lines, broadband over coaxial cable, fiber-optic connections in newer developments, and satellite or cellular options in areas where wired infrastructure is limited or unavailable. The specific technology available to any user depends largely on geography and the existing buildout in their area.

What you'll learn

What's covered

Internet Service Providers

Aligned to

CompTIA Network+
1.6 Compare and contrast network topologies, architectures, and types.
Cisco CCNA
1.2 Describe characteristics of network topology architectures
Cisco CCST Networking
1.3 Differentiate between LAN, WAN, MAN, CAN, PAN, and WLAN
3.2 Differentiate between Wi-Fi, cellular, and wired network technologies
CompTIA A+ Core 1
2.7 Compare and contrast Internet connection types, network types, and their features.

Key terms

Internet Service Provider
ISP
A company that provides end users with access to the internet by connecting them to the internet backbone.
Bandwidth
The maximum rate of data transfer across a network path, typically measured in bits per second.
Wide Area Network
WAN
A network that spans a large geographic area, connecting multiple local area networks.
Last Mile
The final leg of a telecommunications network that connects an ISP to the end user's location, often the most costly segment to deploy.
Internet Backbone
The high-capacity data routes and core infrastructure that carry aggregated internet traffic between major networks and ISPs.
Digital Subscriber Line
DSL
A last-mile connection technology that delivers internet service over existing telephone lines.
Fiber Optic
A network transmission medium that carries data as pulses of light through a glass or plastic strand rather than as electrical signals over copper, enabling very high speeds and immunity to electromagnetic interference. Fiber optic cables are used for high-bandwidth runs such as backbone links, long-distance WAN connections, and data center interconnects.

Transcript

In order to connect to the internet we have to go through an internet service provider. Just like the name sounds, it provides a service of connecting to the internet. So let's take a look at what an ISP actually does.

The Internet as a Network of Networks

When we talked about the internet, we talked about how it's a network of networks. So we have all of these companies that have gotten together to interconnect their networks. Now, this makes it look like a company is just part of a geographical location, but these are all intermixed. They interconnect these different companies together to give us the internet.

But how do we access this? How do we access the internet service provider? Sometimes we go directly to the company that provides what we call the backbone. The backbone is the main connection that's connecting everything together. So sometimes we'll go directly to that main backbone provider, but a lot of times there's other internet service providers that have a connection into the internet, and then we are sitting here in our home and we make a connection into the internet service provider, and they're making the link between us and the internet. So that's the service that they're providing, is a connection through us and to the internet.

The Cost of the Backbone

Let's talk a little bit about cost. We have all of these connections that are running all across the United States and other countries that are providing for these internet services. That is the main highways for the internet. We call it the backbone of the internet, and there's all these lines that are running everywhere.

Well, to lay down these lines, we've got to figure out how we're going to route these lines and where we're going to put them and lay down these lines. And that is really expensive to do. It costs a ton of money to figure out how to string a line up that's that large, the material that goes into it, all the rights of way that you purchase, so that way you can get that communication flowing. It's very expensive. Although, when you consider how many users are paying for it, it actually ends up being a very small cost per user.

The Last Mile

Instead, what we actually run into is our internet service provider. They're the ones that are connecting you to the backbone here. The most expensive part about this is they have to do the same thing for their end users, to figure out how to connect from the ISP to the end house. And now what you're talking about is stringing up a still very expensive line that's right here, but going and feeding to just a single user.

We call this the last mile, because you have some sort of distance here and it's the last mile. We can string up these lines right here, which is miles and miles and miles and miles, and the cost per user is actually fairly small compared to this last mile making it to your house. So we have to utilize what was available to us to get you an internet connection there.

What Comes Into the Home

So what are typical things that come into our home? We have power, we have water, we have a sewer line going out of our house possibly, we have a phone coming into it, and we have a cable perhaps, the cable company, so we have a cable running into it. Some of the newer homes have fiber. We also might have access to satellite now, so maybe we have some sort of dish network satellite, or cellular. So these are the things that might be available to you, might be a connection for that last mile.

Now power is not a great solution for this, because, well, it's just not a great way to transfer data. We can actually get data through the power lines, but it's not the best way to do it. Water and sewer, obviously that's not going to be a great way to get a data connection to it.

So a lot of times we'll use phones with like a DSL, or perhaps we use a cable, like the internet cable, and we use that, and so we set that up. Or maybe it's that you've got a newer connection, it could be fiber. And if those aren't available to you, then maybe you have to use some sort of like satellite or cellular to get that last mile internet connection to your home.

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