1 00:00:04,750 --> 00:00:06,910 IP discipline, networking. 2 00:00:07,030 --> 00:00:12,610 Hello, everyone, and welcome back to the course, as this is the first section of that course here, 3 00:00:12,610 --> 00:00:20,050 we're going to actually offer some videos and lectures that are talking about the essentials, about 4 00:00:20,050 --> 00:00:21,850 the networking concepts. 5 00:00:21,850 --> 00:00:25,960 And we're going to focus strongly on the discipline diaper stack. 6 00:00:26,230 --> 00:00:32,740 It is very important for us to mention that this section and all the sections of the above are based 7 00:00:32,740 --> 00:00:36,850 on the Internet protocol, version four and version six. 8 00:00:38,230 --> 00:00:45,350 So if you don't know what this is, basically Internet protocol version four is the database of all 9 00:00:45,370 --> 00:00:55,300 IP addresses that are possible to be taken in Internet and IP version six is created due to the fact 10 00:00:55,300 --> 00:01:02,320 that IP Version four already is started running out of IP addresses, even though there were billions 11 00:01:02,340 --> 00:01:04,930 possible other races with the IP version four. 12 00:01:05,570 --> 00:01:12,280 But now, since they are taken to the export of Internet, now, we're also using the IP version six 13 00:01:12,760 --> 00:01:13,900 IP address type. 14 00:01:14,230 --> 00:01:22,090 So the IP in the IP set of protocols are designed to work together to provide an end to end transmission 15 00:01:22,090 --> 00:01:26,600 of messages across different interconnected networks. 16 00:01:26,920 --> 00:01:35,020 So usually we say that the protocol works in the transport layer while the IP protocol works on the 17 00:01:35,020 --> 00:01:35,860 network layer. 18 00:01:36,040 --> 00:01:41,760 So the DP is responsible for creating connections through a data flow. 19 00:01:41,950 --> 00:01:50,980 And this is because this process guarantees that the data delivered to the destination is without any 20 00:01:50,980 --> 00:01:56,470 errors and it is delivered basically in the same order in which we send it out. 21 00:01:56,650 --> 00:02:04,180 On the other side, IP is responsible for sending and receiving data blocks, so they move the IP users 22 00:02:04,180 --> 00:02:08,230 to find the right IP address or the right roll to a system. 23 00:02:08,470 --> 00:02:15,850 But it pretty much doesn't guarantee that the that the data actually is reaching the right destination. 24 00:02:16,030 --> 00:02:20,230 And for that reason, we're usually using the TCAP and IP at the same time. 25 00:02:20,320 --> 00:02:23,470 So actually, let's talk about the similarities about that. 26 00:02:23,500 --> 00:02:31,990 Espin they basically both of the protocols are used to solve the transmission over data generated in 27 00:02:31,990 --> 00:02:36,260 the network and aim to be transmitted internally or externally. 28 00:02:36,460 --> 00:02:43,080 The union basically of those protocols is then to ensure that information always arrives on the best 29 00:02:43,090 --> 00:02:45,590 road and on the correct destination. 30 00:02:45,940 --> 00:02:53,980 So let's talk now about the protocol stack and the different layers incorporated within this protocol 31 00:02:53,980 --> 00:02:54,510 stack. 32 00:02:54,550 --> 00:02:59,230 So basically the protocol stack his exactly four layers. 33 00:02:59,560 --> 00:03:01,870 The first one is called the application layer. 34 00:03:01,870 --> 00:03:09,190 And this layer pretty much manages the high level protocols, including representation, coding and 35 00:03:09,190 --> 00:03:10,960 some that will control issues. 36 00:03:11,140 --> 00:03:14,120 It handles everything that is related to applications. 37 00:03:14,410 --> 00:03:22,150 So an example for application, there would be telnet, which we always use, for example, to connect 38 00:03:22,150 --> 00:03:28,900 to certain devices that are, for example, connected to a router which actually has an IP address. 39 00:03:30,130 --> 00:03:33,430 And let's say to that router, you can connect more than one device. 40 00:03:33,430 --> 00:03:33,740 Right. 41 00:03:34,450 --> 00:03:37,830 So these devices are going to be at the application layer. 42 00:03:38,290 --> 00:03:39,760 Then you have the transport layer. 43 00:03:39,970 --> 00:03:47,320 And this layer basically handles the quality of the service, the reliability, the control or the flow 44 00:03:47,320 --> 00:03:48,490 and the errors as well. 45 00:03:48,520 --> 00:03:56,980 So one of those protocols is exactly that GCP protocol, which aims to provide a reliable network communication 46 00:03:56,980 --> 00:03:58,920 and some order of the connections. 47 00:03:59,380 --> 00:04:06,940 So the transport there could be either with Tsipi protocol, which gives unordered connection to a device 48 00:04:06,940 --> 00:04:13,660 on or UDP where there is no order connection, which means that when we send messages, there is no 49 00:04:13,660 --> 00:04:19,050 guarantee that they are going to be received in the same order that the data they've been sent. 50 00:04:19,180 --> 00:04:21,220 Next one is the network layer. 51 00:04:21,430 --> 00:04:29,740 And basically the purpose of the network layer is to send packets from the source to any network and 52 00:04:29,740 --> 00:04:37,210 make this packet to reach a destination regardless of the route that they actually use in order to get 53 00:04:37,210 --> 00:04:37,570 there. 54 00:04:37,720 --> 00:04:41,350 And the final layer is called the network access there. 55 00:04:41,480 --> 00:04:45,550 And this is also called the host to host the network layer. 56 00:04:46,120 --> 00:04:50,860 It includes the one and the W8 and protocols. 57 00:04:51,130 --> 00:04:55,210 They are also known as link layer or data link layers. 58 00:04:55,540 --> 00:05:02,950 So we can say that the network assessment is basically the interface layer to the current. 59 00:05:03,060 --> 00:05:04,420 Network hardware. 60 00:05:04,590 --> 00:05:10,710 So if we check the next diagram, we can actually see the different layers and what they basically control. 61 00:05:10,950 --> 00:05:17,880 So on the top level, as you can see, we have the application layer with the SMTP or the Telnet commands 62 00:05:18,180 --> 00:05:19,440 in order to assess devices. 63 00:05:19,450 --> 00:05:25,380 Then we have the transport layer, then the network layer, which is the IP address basically. 64 00:05:25,650 --> 00:05:31,610 And finally we have the network layer, which is, for example, the wireless or the one that's C. 65 00:05:32,190 --> 00:05:37,240 So the network layer is basically when you connect to the Internet, then we get a network, which is 66 00:05:37,240 --> 00:05:43,410 the IP addresses, then we get the transport of that IP address and finally we reach our application. 67 00:05:43,650 --> 00:05:45,460 This is basically how it works. 68 00:05:45,480 --> 00:05:52,120 Everything that is related to connecting to some service on the web or locally. 69 00:05:52,170 --> 00:05:56,810 And usually the IP address is the most important protocol in the network. 70 00:05:57,330 --> 00:06:04,290 And even though is the most important, as we already said, the IP address does not provide any reliability, 71 00:06:04,530 --> 00:06:06,660 flow, control or error recovery. 72 00:06:06,990 --> 00:06:13,730 And is it because IP is simply a way in order to name a device or service on the Web or locally? 73 00:06:14,100 --> 00:06:24,150 So the protocol that is basically responsible for the reliability and the recovery is the Tsipi protocol 74 00:06:24,450 --> 00:06:28,960 or the UDP protocol, both of them, they're used in the transport layer. 75 00:06:29,370 --> 00:06:36,640 So when you want to send some data over a network, this is called sending an IP diagram. 76 00:06:36,870 --> 00:06:45,540 So this basic unit or this diagram is transmitted from one site through the pipe network to another 77 00:06:45,540 --> 00:06:45,960 site. 78 00:06:46,470 --> 00:06:55,110 Also, the application layer is basically the layer where the user interacts with the computer, where 79 00:06:55,110 --> 00:07:01,800 actually the services or the action occurs with the actual system that we use. 80 00:07:02,100 --> 00:07:10,230 And even though it forces some browsers over Internet, we actually do use them in order to connect 81 00:07:10,230 --> 00:07:13,570 to the application layer or to communicate with the application layer. 82 00:07:13,770 --> 00:07:19,200 So we log into the browser and then we communicate with the actual through service that is somewhere 83 00:07:19,200 --> 00:07:21,330 around the world on their site. 84 00:07:21,330 --> 00:07:29,460 If we want to access a remote document, we can use the HTP protocol, which is basically everything 85 00:07:29,700 --> 00:07:32,760 that we've seen the beginning of the name of each website. 86 00:07:32,950 --> 00:07:41,460 Each time we request a communication of this type, the browser actually interacts with the application 87 00:07:41,460 --> 00:07:41,810 layer. 88 00:07:42,180 --> 00:07:50,250 So it actually serves as an interface between the user application and the protocol stack and finally 89 00:07:50,250 --> 00:07:53,130 provides a communication with the lower layers.