1 00:00:00,830 --> 00:00:02,030 Data transmission. 2 00:00:03,220 --> 00:00:09,160 Let's briefly look at how data is transferred from one node to another using the IPS data encapsulation 3 00:00:09,160 --> 00:00:09,730 model. 4 00:00:09,760 --> 00:00:14,230 In this diagram, you are seeing the simple Ethernet network with the three nodes. 5 00:00:14,230 --> 00:00:16,270 One, two, two, three. 6 00:00:16,870 --> 00:00:24,160 So here in this example, the node at here, actually let's name this the typhoons. 7 00:00:25,460 --> 00:00:26,190 Computer. 8 00:00:27,430 --> 00:00:33,340 And here let's actually make this oxly.com and. 9 00:00:34,230 --> 00:00:36,060 Or for example. 10 00:00:36,960 --> 00:00:38,010 iPhones. 11 00:00:39,840 --> 00:00:41,040 Network, right? 12 00:00:41,280 --> 00:00:42,540 Yeah, in our laptop. 13 00:00:44,890 --> 00:00:45,140 Here. 14 00:00:45,970 --> 00:00:46,660 So. 15 00:00:47,760 --> 00:00:56,980 And for example, with the IP address, 192.168 .0. 101 named Typhoons. 16 00:00:56,980 --> 00:01:06,910 Computer Typhoons computer wants to send the data using the IP protocol to the node at the with the 17 00:01:06,940 --> 00:01:08,020 IP address here. 18 00:01:08,320 --> 00:01:09,340 Telecom. 19 00:01:09,370 --> 00:01:15,130 The IP address 192.168 .0. 108. 20 00:01:16,640 --> 00:01:18,460 And the switch device. 21 00:01:18,470 --> 00:01:20,300 This is the switch device of us. 22 00:01:21,440 --> 00:01:26,750 Forwards Ethernet frames between all nodes on the network. 23 00:01:27,230 --> 00:01:33,080 The switch doesn't need an IP address because it operates only at the link layer. 24 00:01:33,350 --> 00:01:35,860 Remember what the what link layer is this? 25 00:01:35,870 --> 00:01:37,430 This is the layer one. 26 00:01:39,860 --> 00:01:42,620 So the switch device. 27 00:01:43,550 --> 00:01:49,620 Doesn't need an IP address because it operates only at the link layer. 28 00:01:49,640 --> 00:01:53,360 And here I will write that down. 29 00:01:53,360 --> 00:02:00,500 What what is take place takes place to send the data between two nodes. 30 00:02:00,530 --> 00:02:01,700 The first step. 31 00:02:02,360 --> 00:02:04,460 The operating. 32 00:02:05,620 --> 00:02:06,220 System. 33 00:02:06,220 --> 00:02:07,810 Actually, let me copy this. 34 00:02:07,810 --> 00:02:08,250 Here. 35 00:02:08,260 --> 00:02:08,770 Yeah. 36 00:02:10,690 --> 00:02:11,920 And make topper. 37 00:02:11,950 --> 00:02:13,000 The first step. 38 00:02:13,000 --> 00:02:13,840 Step one. 39 00:02:14,560 --> 00:02:15,460 Step one. 40 00:02:16,260 --> 00:02:20,970 The operating system network stack. 41 00:02:21,760 --> 00:02:25,390 So the operating system network stack node. 42 00:02:27,280 --> 00:02:35,140 Encapsulates the application and transport layer data and builds an IP packet with a source address 43 00:02:35,140 --> 00:02:41,890 of 192.168 .0. 101. 44 00:02:42,640 --> 00:02:45,580 Remember, this is the Typhoon's computer IP address. 45 00:02:46,640 --> 00:03:00,110 And the destination address here I read wrote that as a to the destination address of 192.168 .0. 108. 46 00:03:01,040 --> 00:03:03,380 And the step two after that. 47 00:03:03,380 --> 00:03:06,380 Step two is, um. 48 00:03:07,090 --> 00:03:15,700 The operating system can at this point encapsulate the IP data as an Ethernet frame. 49 00:03:17,790 --> 00:03:25,650 Encapsulate IP IP data as an Ethernet frame. 50 00:03:30,560 --> 00:03:34,310 So the operating system can at this point, as I said. 51 00:03:35,210 --> 00:03:42,740 Encapsulate IP data as an Ethernet frame, but it might not know the Mac address of the target node 52 00:03:42,740 --> 00:03:49,910 and it can request the Mac address for a particular IP address using the address resolution protocol. 53 00:03:49,940 --> 00:03:58,820 ARP, which sends a request to all nodes on the network to find that the Mac address for the destination 54 00:03:58,850 --> 00:04:01,850 IP address and a step three. 55 00:04:01,910 --> 00:04:11,210 Step three is once the node at Typhoon's computer receives an address resolution protocol response, 56 00:04:11,210 --> 00:04:13,970 it can build the frame right as here. 57 00:04:14,910 --> 00:04:19,980 So the setting source address of the local MAC address of here. 58 00:04:20,010 --> 00:04:24,300 1155774A1B, b. 59 00:04:24,480 --> 00:04:26,310 And the destination address. 60 00:04:26,310 --> 00:04:30,630 So the destination address is actually this and here. 61 00:04:31,960 --> 00:04:41,260 Our address resolution Protocol just figured out our typhoon's computer Mac address and tells us that 62 00:04:41,260 --> 00:04:44,740 our source MAC address is Typhoon's computer Mac address. 63 00:04:44,740 --> 00:04:46,930 And the destination is this. 64 00:04:49,080 --> 00:04:51,450 And the step four is. 65 00:04:55,830 --> 00:04:59,370 Actually a sharp response. 66 00:04:59,790 --> 00:05:08,580 Step three was area response and the step four is that then the lastly, the switch forwards the frame 67 00:05:08,580 --> 00:05:18,790 to the destination node, which unpacks the IP packet and verifies that the destination IP address matches. 68 00:05:18,810 --> 00:05:28,560 Then the IP payload is extracted and the passes up to the stack to be received by the waiting application.