1 00:00:00,450 --> 00:00:05,939 Oh, I would, you know, I say it stands for open systems interconnection. 2 00:00:06,120 --> 00:00:11,160 It is a conceptual framework used to describe the functions of a networking system. 3 00:00:11,970 --> 00:00:18,900 Yes, I mean, it characterises computing functions into a universal set of rules and requirements in 4 00:00:18,900 --> 00:00:23,360 order to support interoperability between different products and software. 5 00:00:23,610 --> 00:00:28,890 And obviously, a reference model, the communication between a computing system and split into seven 6 00:00:28,890 --> 00:00:35,850 different abstractions, then the physical datalink network in their transport layer, session, presentation 7 00:00:35,850 --> 00:00:36,720 and application. 8 00:00:37,170 --> 00:00:39,060 So let's have a look here, as you can see. 9 00:00:39,390 --> 00:00:41,730 So here are then seven layers we have. 10 00:00:41,730 --> 00:00:47,040 We have the application there, the end user and they are actually could be FTB by us as such. 11 00:00:47,040 --> 00:00:53,940 Then we have that presentation there, the syntax there, which is SLAC and as such, a map app to be. 12 00:00:54,060 --> 00:01:00,360 And you can see that the presentation, like the FTB, exists in the presentation and application. 13 00:01:01,430 --> 00:01:07,040 We have the session there for sink and seemed to board empty eye sockets when, when, so and so on 14 00:01:07,970 --> 00:01:08,750 transport layer. 15 00:01:09,050 --> 00:01:16,000 So here is responsible for the TCB and Whitby exists in the transport into kitchens. 16 00:01:16,400 --> 00:01:21,580 We have the network, the packets, IBC and VIP IPsec GMP. 17 00:01:21,980 --> 00:01:29,690 We have the datalink that frames Ethernet P.P.P or in Table B. We have switch and bridge, so you can 18 00:01:29,690 --> 00:01:31,250 see it is inside the datalink. 19 00:01:31,550 --> 00:01:36,650 We have the physical finally, which is the physical structure, the court's five US wireless hub speakers 20 00:01:36,680 --> 00:01:37,190 and so on. 21 00:01:37,640 --> 00:01:37,900 OK. 22 00:01:38,300 --> 00:01:43,700 By the way, the doctors will be here inside this layer or categorised inside this lab. 23 00:01:44,780 --> 00:01:46,270 Now, let's start with the physical damage. 24 00:01:46,730 --> 00:01:52,980 Now this is the lowest layer of the US model, which is concerned with electrically or optically transmitting 25 00:01:53,000 --> 00:01:58,250 role and structure database across the network from the physical layer of the sanding device to the 26 00:01:58,250 --> 00:02:00,140 physical layer of the receiving device. 27 00:02:00,420 --> 00:02:07,220 OK, so from singing to receiving, it can include specifications such as voltage bin layout cabling 28 00:02:07,220 --> 00:02:13,460 and radio frequencies, and the physical layer one might find physical resources such as it workups, 29 00:02:13,760 --> 00:02:18,380 cabling repeaters, network adapters automatic now for the datalink now. 30 00:02:19,330 --> 00:02:26,320 At the data lab, directly connected knots are used to perform not to note that transfer where it is 31 00:02:26,320 --> 00:02:35,580 backwards into print so that it can now also correct that may be that may have occurred at the physical 32 00:02:35,580 --> 00:02:40,910 level, and the datalink layer encompasses two up layers of its own. 33 00:02:40,960 --> 00:02:48,250 So the first media access control, which is the Mac, provides flow control and multiplexing for device 34 00:02:48,250 --> 00:02:51,940 transmission over into the second, which is the NLC. 35 00:02:51,940 --> 00:02:58,480 Biological control provides flow and it'll control over the physical medium, as well as identifies 36 00:02:58,480 --> 00:03:07,030 the protocols for the little plan that Blair is responsible for receiving frames from the datalink layer 37 00:03:07,240 --> 00:03:13,240 and delivering them to their intended destinations among based on the addresses contained inside the 38 00:03:13,240 --> 00:03:13,510 frame. 39 00:03:14,170 --> 00:03:19,630 Then, interlayer finds this nation by using logical addresses such as IP, the Internet Protocol and 40 00:03:19,660 --> 00:03:26,530 if their daughters are crucial component used to quite literally around information where it needs to 41 00:03:26,530 --> 00:03:27,550 go between networks. 42 00:03:28,800 --> 00:03:36,580 And by the way, they're wrong to categorize in this clip or in this in the transport that it makes 43 00:03:36,600 --> 00:03:42,900 the delivery and error checking of data because it regulates the size sequencing and ultimately the 44 00:03:42,900 --> 00:03:45,240 transfer of data between systems and hosts. 45 00:03:45,810 --> 00:03:53,880 One of the most common examples of the transport layer is the TCB or the transmitter to ensure the transmission 46 00:03:53,880 --> 00:03:55,530 control protocol or the UDP. 47 00:03:55,650 --> 00:03:57,300 So this would be and would be are here. 48 00:03:58,570 --> 00:04:05,290 The session live session now controls the conversations between different computers, obsession or connection 49 00:04:05,290 --> 00:04:08,140 between machines is set up, made and determined. 50 00:04:08,670 --> 00:04:14,650 Terminated at layer five, which is a decision that so essential services also include authentication 51 00:04:14,650 --> 00:04:15,820 and reconnections. 52 00:04:16,750 --> 00:04:17,920 Well, the presentation now. 53 00:04:18,950 --> 00:04:25,850 The layout, the presentation now formats or translate data for application layer based on the syntax 54 00:04:25,850 --> 00:04:28,430 or semantics that the application access. 55 00:04:28,790 --> 00:04:35,720 So because of this at times also called the syntax down, this snare can also handle the encryption 56 00:04:35,720 --> 00:04:37,730 and decryption required by the application. 57 00:04:39,630 --> 00:04:45,120 And finally, we have the application now, which is a display on both the end user and the application 58 00:04:45,120 --> 00:04:48,390 now interact directly with the software application. 59 00:04:48,690 --> 00:04:57,960 This lab sees network services provided to end user applications such as what browser or Office 365 60 00:04:58,530 --> 00:05:04,380 365 application that identifies communication partners, resource availability and.