[Music] right great livens now we move on to local area networks okay so there is a picture of a typical network but let's jump in and find out some more about networks now we do have different types of networks now remember at its core what is a network a network is where I have two or more Compu devices connected through some sort of media for the purpose of sharing information so I have different types of networks I have the pan Which is organized around the individual a hand in the home environment a land a small area generally in one building then I've got the internet which is a worldwide computer network and the intranet which is the organization's private Network so we need to know the different types of networks we need to know our definition of what a network is and then we need look at some of the basic components of a network some of the hardware now remember we talk about computers we talk about peripherals when it comes to a network we talk about clients and servers so a server is a powerful computer what does this computer do well it provides services to clients within the network and those clients could be a desktop a laptop a tablet a smartphone anything that's connecting to the main server um and making use of those Services however on the other side our server has and as I just mentioned different services like offering file Services email internet web server print server database server so if I use the example of the print server this means that when any of these clients want to print that instruction or that request rather will go through to the server and the server will then manage that print request and send it through to the appropriate printer well how do you know that you're connected to a network first of all so you switch on your PC you log in everything is okay and you maybe go to file explorer and you suddenly see that there are some more drives so if I use this as an example there you can see there's my cat server drive there are the presence of other computers in the network and access to devices especially printers is not directly attached to the computer you'll also usually have an indicator showing network activity in the notification area right so let's go back to the hardware to connect to a network we need a network interface controller this is built in this is a network card and this is usually built into your laptops um some of them are already on the motherboards of your desktop machines but I want you just to look at the term here uh they'll use the term Nic which means stands for network interface controller so we need this to connect to a network um I plug my network cable in there plug it into my network point and then these lights start flashing because there's communication now there are wireless adapters um but both are bolt into many devices that we find these days I mean the mere fact that your phones can connect to wireless means you've you've got an Nic there okay then we have our switches these devices and here's just an example of one they are used to connect computers in a network so that communication can occur and here we have for example a printer we've got some computers we've got a laptop and they're all plugged into the switch from the switch you might have a cable that's running from there through to your server and that's how not only are these devices able to communicate with one another but communicate with the server as well we see the same scenario um playing out to many restaurants airports hotels and yeah you can see they have a network they have a network running there this one has as well okay so these are just some of the basic components that we find in our network uh you might be at home and you might have a router and your rout is providing Wireless act or Wireless connectivity for everyone within the house right that is a network okay now we know what a land is and we know that's our local area network we know that this is in one geographical area um but we do also have wireless lands now they are easier to install easier and more practical between buildings Etc uh but there are disadvantages to them as well so please with your wireless lands just know again at least two of those there are different communication methods remember a network we said is two or more Computing devices connected through some sort of media so that connection can be with cables um UTP unshielded twisted pair shielded twisted pair and I've got a video on this in in my shorts um so go and have a look at that on YouTube the fiber optic cable I've done a video with both of these you've got your STP your shielded Twisted cable so those are your physical cables you've also got your wireless access points um and wireless adapters under your wireless category so you can either communicate with a network via cables or Wireless and just to give you an example this is what an unshielded twisted pair cable looks like as the name implies it's a twisted pair of cables that has no Shield shelding unshielded twisted pair this one shielded twisted pair okay this also indicates and UTP is one of the most common uh network cables out there you have different categories of UTP cable and many of them indicate or refer to um the speed of the data that they can transfer so here you can see cat 5e the data rate can be up to 1,000 megabits per second the cat 6 data up to 1,000 megabits per second um the Cat 5 was only up to 100 megabits per second so um you can see with the cat 6 compared to Cat 5 uh it's a whole times 10 difference between the data that can be moved across per second this is our fiber optic cable and you can see there's our glass fibers so light is moving through these glass fibers that is how the data is moving across and this is why it's able to move so fast so if we look at the difference with our UTP cable it only spans certain distances and you end up getting a bit of signal loss whereas your fiber can go for much longer your UTP cable is affected by electrical sources whereas your fiber is not your UTP uses electrical signals to transmit data whereas your fiber uses light signals this you need to know all right when we talk about data transmission speed just understand which is what I mentioned earlier it's the rate at which data is transferred over the media used so for example 100 megabits per second or 1,000 megabits per second when you see that rating on the cable over here what that means is that it's the maximum speed uh at which data can be transferred on the particular cable okay so when you see these specifications on a wireless adapter uh you're going to buy a PC you're going to buy a laptop and they tell you it's a 802.11g that indicates the speed um that that particular standard has which means your wireless adapter in your laptop will be able to operate or transfer data at that speed um or if it's got that particular it'll transfer it at that speed just understand that your wireless land is going to be slower than your cabled land and this has got to do with the consistency of the signal going through then our network software um this is dealing now with software that controls communication and security in a network most operating systems have built-in networking capabilities but for larger networks they have server editions of the operating system right these are installed on your servers so all this is telling you is that most operating systems that we have today are able not only to have this capability but it allows you then to use that connect it up to a network and there you go okay but you're going to have a special software package when it comes to your service remember all the things that a server has to be able to do as well then we have some of the advantages and disadvantages of a landan again you only need to know like two of these um files are transferred without the use of devices software can be shared hardware can be shared files are stored in a cental location any of those um you can use when it comes to the advantages and then um our disadvantages I mean the main thing is just it's expensive to install and maintain and you need a network administ Ator to manage this entire network now you have additional potential disadvantages efforts Wireless what are they security can be compromised easier the performance can decrease and you can even get signal loss or interference now something new that has been coming up in the grade 11 and 12 sector is dealing with what a network topology is now first of all this term refers to the the layout of devices and their physical or logical connections using cables or Wi-Fi and the first one we get is our bus topology and you can see here I've got one main cable and all the computers are connected to that cable this main cable then acts as a backbone for my network um one of the computers in the network can be set up as the server okay so that is my bus topology there are certain advant and disadvantages to that I'm just um sharing this with you you don't always have to know this it's more just identifying the topologies themselves here's one called the star topology so you can see that star layout here's our switch in the middle so with this one each computer is connected to a central device called a switch that makes the connections between the computers over the network okay so the switch is doing that and you can see the physical difference again it's not always going to be laid out like that but that is what they are referring to we we have some advantages and disadvantages now our ring topology and you can see how that is set up again computers in this network are connected in a circular fashion and data travels in One Direction that means if these two are busy over here I've got to wait for my turn to be able to transfer data and if I'm transferring data from myself to this PC over here it's going to go all all the way past all of these before it gets to that point so each computer is connected directly to the next computer forming a single pathway for signals through the network and then the last one we get is our mesh topology so here every node in other words every machine over here in this network has a direct Point to-point connection to the other node let's see well this what has a direct connection to that one direct connection to that one that one that one that one and that one right um it's reliable because if one of the connections fail it can always maintain or remain intact so the data can still get to its destination by another route okay so these are just the topologies and we've looked at um our advantages and disadvantages now we're just going to touch on our basic network security please when it comes to basic network security we are dealing with the rules to ensure the security of a network preventing unauthorized access to information and network misuse so access to confidential files must be restricted in a school situation it's important that Learners don't have access to test before they are written a username and password um must be created for folks to log in and get gain access to the network resources you need to choose a password known only to you and you need to keep the password secret now when it comes to passwords you need to work on a few guidelines try to make it at least eight characters long have a mixture of uppercase and lowercase letters numbers and special characters don't use anything that's easy to guess don't use passwords that follow a pattern try to change the passwords regularly um and a good example of this is this now I know you won't remember this I know you won't remember this but that's the point it must be difficult okay then lastly we have our ethical use of computers or networks rather um this is where the need for acceptable ethical practices are required this is why we have an acceptable use policy ever noticed how when you go to the shops or you go to the restaurants and they tell you you can use the Wi-Fi and you connect and you limited to a certain speed and a certain um amount of data that you can use that is what we call an acceptable use policy it outlines the rights and responsibilities of users especially in networked environments it lists what the user may or may not do on the network okay now you can go through this to see what should be included in the AUP things like ntic rules restrictions on what may be accessed the amount of data downloaded restrictions on installing hardware and software um these are just some of the guidelines that should be should be adhered to when throwing up an AUP whether it's for a restaurant shop or your school