Network Attached Storage (NAS)

00:00

Another way of sharing files on the network is to use a new as device.

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So now stands for network attached storage.

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And as you can see this in this picture, it looks a little bit just like a normal desktop computer. But actually, all that's inside it is a little bit of electronics, and then a number of hard drives

00:21

on this type of device doesn't plug into directly into your computer. It plugs directly into the network,

00:32

and

00:33

this makes the storage that's available on those hard drives,

00:36

too available to anyone on the network. Anyone that you give provisions, too

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other advantages off a nasty device of these

00:48

they can sometimes support. A feature called Raid and Raid can be used to provide better performance or four tolerance in case of disk failures.

01:00

So what is great rate stands for redundant array of independent discs. There are various raid standards that are defined, and they all require the use of multiple physical drives in order to provide full tolerance

01:14

or better performance, or both.

01:18

So, for example, there's a standard called Raid zero, also known as striping.

01:23

This requires that you haven't least two physical desks you can use many more than two if you want,

01:29

and what this does is it gives you much better read and write performance.

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But it doesn't provide any fault tolerance.

01:34

If I set up a raid zero and any of the discs within that grade zero configuration fail, you lose all the data, so there's no fault tolerance. But there is better performance.

01:47

If you want full tolerance, you can use Raid one, also known as mirroring, and this literally takes the contents of one disc and mirrors it to another disk.

01:57

So if either one of those physical discs actually fail,

02:00

you still have access to your data.

02:02

But this doesn't provide any performance benefit

02:07

now. What if you want both? What if you want full tolerance and you want to performance benefit so you're being a bit greedy.

02:14

Well, then there's right vibe striping with parity.

02:17

This requires at least three physical desks,

02:21

and this provides both full tolerance. If any one of those three disks fail,

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then you still have access to your data,

02:28

and it provides better performance. So when no disks up failed and you just reading and writing to this volume,

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you'll get much better performance than if it was a single dr.

02:38

And once again, like with raid zero,

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it has a minimum of three desks, but you can have many more than three desks within a rate five configuration.

02:53

The term directly attached storage

02:54

can refer either to the internal disks that I installed in your computer

03:00

or external hard disks such as this one that you see in the picture,

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which is typically plugged in through the USB port, FireWire or other parts on your computer.

03:12

The external drive could be a mechanical hard disk, or it could be a solid state discs.

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We've mentioned solid state discs earlier in the course, and remember, they have no moving parts and are much faster than mechanical drives. The only downside of solid state disks is there much more expensive per megabyte than a traditional mechanical hard disk.

03:37

Moving on from that on looking at peer to peer networks using either blue to the USB cables. Or why fight

03:47

so a peer to peer connection is a direct connection between two computing devices.

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This can be a wired connection. So, for example, you can use a crossover patch cable

04:00

or a crossover USB cable, and we'll talk about both of those in a minute

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or it can be wireless.

04:06

Now, with wireless, it could be a Bluetooth connection between two devices.

04:12

And earlier on, we already mentioned that, for example, you can connect your smartphone to your desktop or laptop computer using blue, too,

04:20

and then you could transfer files between them.

04:24

But there's also other variations. There is a version off WiFi known as ad hoc WiFi.

04:30

This sets up a WiFi connection between two devices directly without having to connect to a home router or while its access point.

04:40

There's also a version of this cold wife I direct often deployed on printers.

04:45

There was a legacy technology that was often used for peer to peer connections, and that was using infrared light.

04:51

And this was, for example, used to connect a wireless keyboard to a computer or connect a wireless printer to a computer.

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Um, this kind of technology require relied on transmitting infrared light between the two devices,

05:08

and although it worked fairly well, it did require line of sight between the two devices because this is like the light has to be able to travel from one to the other

05:17

on DDE.

05:18

It did suffer from a form of interference, and that is a light interference. For example, if the

05:25

the wireless keyboard was sitting near a window and the sun was shining brightly in the brights, light from the sun would drive out the infrared light, and you might find that the connection breaks.

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In any case, this is pretty much a legacy technology. Modern computing devices do not support infrared.

05:43

In fact, the only place you really find this still being used is in the remote controls you have at home for your TV and DVD player and so on,

05:51

which still use infrared light for communication.

05:59

And I just want to point this out when people talk of a peer to peer network. Sometimes what they mean by that is a work group or a hug group.

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But that is not the sense in which camp here is referring to peer to peer connections.

06:13

What they're referring to is what we're outline on this slide, a direct connection between two devices.

06:23

So one way of doing a wired connection between two devices directly is to use a crossover patch cable.

06:30

This looks just like a normal patch cable. It has R J 45 plugs at either end,

06:34

but the wires are twisted inside it,

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and what you can do is connect to computers together through their network adapter cards by plugging the cable into the adapter card in each computer.

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As a result, they will then be networked with each other.

06:50

You don't need any intermediate devices like switches or home writers

06:55

on you basically created a little network between the tube.

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So what's going on in the cable? It's simply this, and the reason it's called a crossover is that transmit wires from one side are connected to the received wires on the other side,

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and so now the two computers can transmit and receive information with each other.

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In effect, what you're doing is creating a network. But I've made up of just two devices,

07:27

and now all your network functions will work. Through that connection. You can access shared folders you can access shared printers and so on.

07:40

What if you're one or both of your computers don't have network interface cards? Well, then you have another option,

07:46

and that is a USB crossover cable,

07:48

so most devices will have a USB port, and you can then plug them two together using this USB crossover cable.

07:57

Typically, this requires a little bit of electronics, so in the middle of the cable, there might be a little box that does some translation of the data

08:05

on dhe. Usually it also requires specialized software, and that will typically come with the cable itself.

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But again, the net effect of all of that is, is that you have network to devices directly to each other.

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Simply plug the cable into the USB ports on each machine and then follow the instructions that came with the cable

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and another way of connecting two devices together. But this time without wires is Bluetooth.

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So many devices now support Bluetooth.

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Most laptops do

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smartphones do and tablets to

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desktop computers. It's a little bit more patchy. Some desktop computers might support Bluetooth and others may not.

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But if you want to use Bluetooth, obviously both devices must support blue, too.

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Once the connection's established between the two,

09:03

then you can transfer files between them, such as between a smartphone and a desktop computer.

09:09

You can also use this to connect to certain printers. Some printers, thes days also have built in Bluetooth support.

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So, for example, from your smartphone, you might be able to connect to a Bluetooth printer and send

09:24

documents you want printed from the smartphone to the printer.

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Yet another way of connecting devices together wirelessly is ad hoc WiFi.

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So

09:39

up to now we have talked about WiFi in relation to creating a generalized network.

09:45

And at the heart of this kind of network is either a home router, which is what you typically have on a home network were in corporate environments that have wireless access points. These are kind of like home writers, except that they don't do anything else that our home Ratter does, such as writing or connecting you to the Internet. Instead,

10:03

they only provide one function, and they act as wireless access points

10:07

so that devices can connected them.

10:09

I feel WiFi devices connecting either to a wireless access point or a home router.

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That is what we call infrastructure mode for WiFi.

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In this mode, all devices connect to each other through the access point or harm Ratter. In other words, your wireless devices. They're not directly connecting to each other.

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They're actually, in fact, connecting to the home writer or access point and then threw it, gaining access to the other device that they're trying to talk to.

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However, WiFi also defines another mode. This is called ad hoc mode

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on. This is a peer to peer connection, so this allows two devices to connect directly to each other using WiFi.

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So, for example, you could have two Windows laptops. You could take them out into the middle of a field where there's no other connections available of any kind.

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And you could set up an ad hoc WiFi network between the two devices, and they would then be able to communicate. So again, what you're really doing is creating a kind of mini network that consists of only two devices,

11:16

and this technology, or a simplified version of it, has been implemented by a lot of printer vendor's

11:22

on so many printers now, and the

11:26

will support this mode of communication. But they give it the trade name of Wife I direct

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and connecting to a wife. I direct printer can be a simple as pressing a button on one or both devices or intrigue a code or a pin,

11:41

so this is supported by the latest printers and support for it is also built into many operating system, especially those designed for mobile devices like Android or IOS.

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And, as we've said, what this does is it allows the device to connect directly to another device, such as a smartphone to a printer,

12:09

one last meaning of peer to peer networks that we need to be aware off.

12:13

Um,

12:13

there are networks off

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devices on the Internet

12:20

that connect directly to each other and relay files.

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Some millions of computers on the Internet can be connected to each other. Using these

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peer to peer P to P protocols

12:31

such as Big Torrente is a popular one. You might have heard off

12:35

each computer access a node within a vast peer to peer network.

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Each computer can act both as a receiver off when it wants to receive files,

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and it can then store and forward those files and transmit them to other peers within the network.

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This is a peer to peer network because there's no one computer that is central and controlling everything. Instead, all the different nodes are setting up connections with each other across the Internet, as required

13:05

files are downloaded in fragments. And so when you're downloading a file in this kind of network, a bit of the file might come from one device. One note and another bit of the file might come from another note.

13:18

This type of network is often used to distribute the distribute, Pirated software, Pirated movies and videos.

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And that's why there's a skull and crossbones at the top there.

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When you use one of these networks, you do so at your own risk.

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Anything that you download could be infected with malicious software,

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and it could infect your computer. And then your entire network

13:43

and, apart from anything else, probably done growed. Downloading those Pirated bits off software, movies and so on is probably illegal.

13:56

Finally, in this module, we're going to look at network printing.

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So, firstly, what is meant by local printer is a printer that is plug directly into a computer, typically using the USB cable.

14:11

In the past, we used to use parallel cables and parallel interfaces, but these days all printers connect using the USB came up

14:20

a local printer. Once you have set it up and installed it on a local machine,

14:26

you can then choose to share it on to the network.

14:30

Once you share the printer, other users on the network can connect to the shirt printer and sent print jobs to it

14:37

in a similar way to the way we saw how you could share a folder and uses couldn't connect to the shed fold up.

14:45

This does require, of course, that the shed could be sharing. Computer is actually turned on when you want to connect to it and use it. Shared printer.

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So let's have a look at installing and then sharing a printer. So here are my Windows 10 machine

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would open up a tool called printers and scanners

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and then rub Run the ad a printer wizard

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and I'm going to install a local printer.

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And normally I would carefully choose what port it's connected to. But since this isn't really, I'm just gonna skip through that,

15:26

and I just chose whatever make and model it came up with.

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Remember, it's not a real printer,

15:33

okay, so the printers now set up, and I can go and manage it

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and then go to its properties.

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And here, just like with the folder, there is a sharing tab, and here I can choose to share the printer now the share name de force to the make and model. But you could change that to something more user friendly if you wanted,

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and then we click. Okay,

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so this point, the local printer has been installed and is being shared.

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So I went on, log on at the window seven machine

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and to see what shared resource it exists on the Windows 10 machine,

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I'm gonna click, start and then type in the U. N. C. Part backslash backslash name of the Windows 10 computer.

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And there you see in the window that there's the shared folder that we created earlier. And there's the shirt printer

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I found right. Click on the shared printer, and I choose connect

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the Windows seven machine connects to the Windows 10 machine and downloads the printer drivers if it confined them there.

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And now, on Windows seven, I open up the devices in Printers folder,

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and there is thief or printer. I just connected to I. Can I use it as if it was a local printer on the Windows seven machine. I concerned print jobs to it and so on.

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And now something similar

17:08

but not to be confused with sharing a local print up,

17:12

and that is network printers.

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Unlike local printers that plug directly into a computer using a USB cable,

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a network printer

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connects to the network directly.

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This means either it has a network adapter built into the printer, so you use a normal R J 45 cable and plug that into the network,

17:34

or it connects wirelessly to the network using WiFi.

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But the key point is, it's not directly connected to a computer, and it's not being shared through a computer.

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So the way users now connect to it is not by using the U. N C path of a computer. Because they're not connecting to a computer, they're connecting directly to the printer.

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What they do is they enter its I P address.

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Every device in a T. C. P I. P Network is assigned a unique identify. Unknown is the I. P. Address, so you have to know what that I P addresses, although Windows another pretty good job of trying to figure out the I P address of network printers.

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So here from my Window seven machine, I'm going to try and connect to a network printer

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devices and prentiss folder. I'm gonna add a printer,

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and I'm going to say this is a network device

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and you'll see Windows start searching the network.

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And as it does, it finds a couple of network printers, and there's their I. P address. So Windows has figured out the i p address of the network printer.

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Now I just need to tell it what make and model it is.

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So I just select that from the list,

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and then we give it a name

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and then go ahead and install it

19:06

so it's now listed as a printer that's available to me. So now, once again, I couldn't open that up, but I consent print jobs do it,

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just like if it was a local printer.

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So in module 4.3, we were asked to compare and contrast different methods of sharing and storage.

19:30

The first thing we looked at was downloading files,

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so we looked at two protocols that could be used for that.

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If you go to a Web page and you see a link to download a file, that's probably using http or possibly https

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and the other protocol we looked at his FTP in the most secure versions of that.

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Remember, if you download a file from a Web page and it's using http,

19:56

then the fire is being downloaded unencrypted.

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If it's using https, then the file is encrypted before it's downloaded.

20:04

So depending on the sensitivity of that file, you might want to make sure that one of the other protocol is being used.

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I remember we should looked at in the

20:15

video how you can right click on a link,

20:18

copy the link address pasted into note pad, and then you'd be able to see where that's using. Http or https.

20:26

We also talked about FTP file transfer protocol.

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This is a very old protocol that's part of the TCP I P suite,

20:33

and it's used to connect to a

20:36

another's computer and upload or download files. The computer you connect to has to be set up as an FTP server.

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The big advantage of FTP is it works across multiple operating systems so your Windows machine could connect to a UNIX FTP server and then download upload files.

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But just like with H d. D. P. F. D. P is not secured by default,

21:00

so you can add security to it, either by combining with SSL, in which case it's called F. D. P s

21:07

or combining it with secure Shell, in which case is called sftp

21:14

Again, the choice of which of those you use really depends on the server. The server may not support any of the secure protocols,

21:22

or it may support one of the security protocols, so you're pretty much stuck with choosing whatever the server supports.

21:30

We then went on and looked at storage. So we saw this local storage, such as a internal hard drive or an attached to USB drive.

21:37

And there's hosted storage where you store your fires somewhere on the network, maybe on a file server or maybe in a cloud provider,

21:48

online storage.

21:51

We also looked at peer to peer connections and with saw Bluetooth can be used for that as well as wife. I direct.

21:57

And we also saw that

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sometimes when people talk about peer to peer, where they're talking about P to P networks like

22:07

BitTorrent, which

22:08

are often used for sharing Pirated software, movies and so on.

22:14

Finally, we looked at printing, setting up a local printer and then sharing it on connecting to it from another computer,

22:21

and we also looked at the concept of network printers that plug directly to the network