before we get into the fun part of configuring and maintaining network devices will first need to learn how to recognize up
in this section. We're going to be discussing the various types of networking equipment, what it can look like and how to recognize it on a networking diagram.
So let's go ahead and get started
before we get into the details of the various network devices that you may come across. Will need to learn a little bit about the OS I model,
and the OS I model stands for Open systems Interconnection model. And it's a conceptual framework that helps describe the functions of a network.
The OS I model contains seven layers that characterize and standardized communication functions across the network without regard to the actual physical hardware that sets up the networks. It's kind of a framework he can use.
In short, it can give you a basic visual of everything going on in a network which can help you design and troubleshooting networking issues.
So the full seven layers if we start at the very top that are kind of your host layers, and that's gonna be the things that aren't necessarily on network devices, but we've got our application layer
going down session layer and then transport layer, and the three layers that we're going to focus on in this course is the layers one through three or or three through one. So if we start at the bottom of the O. S I model, we've got the layer one, which is the physical layer.
layer where your actual network cables and connections are. That's where the data flows.
Layer two is the data link layer, and this provides the node to node data transfer. They can also handle error correction from Layer one.
This is where you'll see Mac addresses, also known as layer to or physical addresses.
This is where your switching is. Take takes place
and in layer to data is referred to as frames,
and I think it front layer one. It's ah, Data's referred to his bits.
The last layer we need to be familiar with for this course is layer three, which is the network layer. This is where the routers function, and it's where the routing takes place.
Here, you'll see I P addresses Mature, also referred to as layer three addresses and his data goes across the network and layer three. It's referred to as packets
A lot of the time, if you are having conversations with other network engineers and stuff, a lot of people will just refer to everything as packets, and that's okay with the actual technical description of data for each layer. Like you said, it is in layer one is bits, layer to his frames and later three is packets.
There are many different types of network devices, all performing different functions and meeting different needs and requirements. Most of these devices work at the 1st 3 layers of the O. S I model,
here I've got kind of the short list of some of the things we're going to be going over.
So the 1st 1 is, ah, hubs. These air, also known as like dumb network devices of dumb switches. There's not a whole lot of configuration in them, and they basically just allow you give you extra Ethernet ports.
Then we do have ah, switches which typically operate a layer two of the OSI model, although they can't even operate up to layer three and on the right, it is the one the blue box, with the arrows pointing to arrows pointing each direction.
That's what it will look like. Any network map.
And then next we've got routers was work at Layer three, and that's of course, represented by the blue circle, with the two errors pointed in in two arrows pointed out,
there's a few other network devices were going to going over as well. We've got bridges, which helped connect networks servers, which typically provide a service to the network. She could have like a, um,
a file server, apprentice server, those air all on networks, and they provide a service. Those usually worked at those host layers that we talked about before.
Next, we've got our transmission media, and that's the actual physical media that connects devices so we can have, like a twisted pair. Ethernet co axial cable fiber connections and those all work again at layer one.
Just a quick question to see where we're at. Um, what is the network map?
And I know we haven't gone over that yet, but it is pretty self explanatory. A network map is a map of the network
Network maps give you a visual layout of a network, which can help use the network engineer. Plan out a variety of network tasks, including troubleshooting connections, rounding issues, tracking down where network just congestion could be on the network, Um, and determine where the network
equipment actually lives on the network.
With a network map, you can also planned upgrades or changes to the network. It will make it really easy seeing kind of visualize everything in your brain.
Network maps can be a simple as this home network map here,
um, which basically contains on the left. You got your desktop computer, which is plugged into a wireless router.
That wireless router is then connected directly to the Internet,
and it is giving off a wireless signal where your laptop is connected.
So it's pretty simple network map that a lot of people's homes probably look like. They may have other devices gaming councils, TVs and things like that. But that's just a real simple network map. Or they can be
even more complex. On complicated Is this kind of really small enterprise network
Because of top? We've got a server connected to a switch, which goes to a firewall, and then another. Servers are kind of like a D M C or a D military. So
and that goes into our core routing land. You can see you've got four routers, all connected together, and they are those circle devices
to the left branch of the router to it looks like we've got a switch connected to just one PC.
If we go down to the bottom, which looks like rather one looks like kind of this is a really enterprise office area. We've got a few switches that have the redundant connections, and you can see that there are two connections going in between each switch
and then, um, looks like we've got some file servers, printers, Cem,
PCs, things like that.
And if we go up to the right, we've got Router three, which looks like kind of a smaller home office, possibly even a home router. And then you've got a laptop directly connected to it and a PC connected to him.
So there's a lot of information here. It's nothing to worry about. This is just kind of, ah, real quick example of a network map. You can see a lot of information just by glancing right at this. If someone asked you where a driver to is. You can find it right away. Or what's the I P address of route or three? You can look at the map and you can see
all of that information
So in today's video, we went over a brief introduction to the offside model and how it helps described functions of a network and allow engineers to architect of the network.
We introduced a variety of network devices like hubs, routers and switches, which we will be going over in depth in a later video. And we went over some basic network maps and how they could be used to troubleshoot or plan network changes up. Next, we've got network architecture.