From the course: Networking Foundations: Networking Basics

A high-level look at a network

From the course: Networking Foundations: Networking Basics

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A high-level look at a network

- When we talk about a network, we're talking about a collection of interconnected devices. For example, in your organization maybe you have a laptop, that communicates with your corporate email server, well that communication is being done over a network. We might also have networks in our homes. Just last year my wife and I, we built a new home and that gave me the opportunity to go a little overboard with the house wiring and technology. We were able to get a gig fiber internet connection, and we put in wiring, that supports speeds of 10 gigabits per second. For wireless connections, we installed seven wireless access points, nine security cameras that were all powered over the Ethernet network connections, and we purchased several IoT or internet of things, devices. For example, our doorbell, oven, refrigerator, TVs Amazon Alexa, they're all networked together. And we said that a network interconnects devices but what does that look like? Well, we have two primary ways to connect into a network. First we have wired connections. And a common example of a wired connection, is an Ethernet cable, which has an eight conductor connector on each end. This was called an rj45 connector. You might hear these cables called, CAT 5 or CAT 6 cables, that access to the network, might be over a wireless local area network, or wireless land. You might hear that called wifi for short. And that covers a relatively limited geographical region. Or we have cellular services, that support data transmission, and we have widespread coverage of cell signals. And for example, consider a cell phone. Now my cell phone can send and receive data, using cellular service, but if I'm in an environment, that has a wireless LAN, I can connect to that network, using this phone's wireless capabilities. So some devices like the cell phone, they have more than one wireless option. And another way that we can categorize networks, is by their scope. Meaning what area do they cover? Let's consider some common examples. A Personal Area Network or a PAN, is a very small network that interconnects two devices. For example, if you have a gaming system, with a wireless controller, maybe using Bluetooth, well that connection between your controller and your gaming console, that constitutes a PAN. A Local Area Network or a LAN, is usually local to a building, or maybe just an area within that building. And this is what you would find in your home. And this would allow as an example, computers within a department, to share resources such as, that very expensive copier you bought. Or allow all those computers to access, the same set of files, that might be stored on a computer acting as a file server. A Campus Area Network or a CAN, that can interconnect nearby buildings. Each of which have a land within the building. We oftentimes see this in university or business campuses. Some businesses have multiple locations, spread across a large metropolitan area. The great news is, some large cities like Chicago, they have a Metropolitan Area Network or a MAN evadable, which allows a business to connect all of their offices to a MAN, and then those different offices, they can communicate between one another, at a very high speed. And finally, we have a Wide Area Network or a WAN, that interconnects networks over large geographical regions. Maybe we have our corporate offices scattered around the country, maybe around the globe. Well, they can communicate with each other, using these WAN connections. Several years ago, WAN connections, they were fairly slow, they could be really expensive. But today with so many locations around the world, having high speed access to the internet, a WAN connection is often made over the internet. Of course, for security reasons, we can encrypt the data flowing over that internet connection, using a technology called, VPNs or Virtual Private Networks. That allows us to virtually have a private network, which is a more secure network, even though our data is flowing over the public internet.

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