1 00:00:01,120 --> 00:00:03,050 We want standardization. 2 00:00:03,160 --> 00:00:10,560 The reason why I can take a copper ethernet cable such as this which has a RJ 45 connector. 3 00:00:10,780 --> 00:00:15,040 Now we won't get into the details it's actually got a different name but most of us refer to this as 4 00:00:15,040 --> 00:00:17,390 an RJ 45 connector. 5 00:00:17,410 --> 00:00:25,060 I want to be able to take this and plug it into an HP laptop plug it into it to Shiba laptop plug it 6 00:00:25,060 --> 00:00:26,740 into an ISIS laptop. 7 00:00:27,720 --> 00:00:33,840 We won't worry about pronunciation for now but the moral of the story is I can take this cable and plug 8 00:00:33,840 --> 00:00:40,770 it into different laptops because of this interface has been standardized and different vendors have 9 00:00:40,770 --> 00:00:47,980 agreed to create the equipment to the specification or to the standard that makes life a lot easier. 10 00:00:48,180 --> 00:00:51,900 In the old old days vendors just did what they wanted to. 11 00:00:51,990 --> 00:00:56,490 They developed their own protocols and their own specifications which wasn't good for customers. 12 00:00:56,490 --> 00:01:01,440 It was great for the vendor because if he bought the equipment you were locked into that vendor. 13 00:01:01,440 --> 00:01:03,810 We don't want that as a customer as a customer. 14 00:01:03,810 --> 00:01:08,660 We want to be able to buy equipment from different vendors and they should all be able to work together. 15 00:01:08,760 --> 00:01:17,850 So because of standardization and because of the industry agreeing on specific models this cable can 16 00:01:17,850 --> 00:01:21,080 plug into different vendor devices without any problems. 17 00:01:21,090 --> 00:01:24,800 We take that for granted today but it was not always the case. 18 00:01:30,290 --> 00:01:33,820 Now the first thing I want you to realize is and you probably know this already. 19 00:01:33,860 --> 00:01:36,620 Nothing in life is as simple as it seems. 20 00:01:36,740 --> 00:01:43,400 And people often have different viewpoints and debate often very heatedly about what is right and what 21 00:01:43,400 --> 00:01:44,240 is wrong. 22 00:01:44,240 --> 00:01:48,860 Don't get stuck in those debates for the CCMA exam. 23 00:01:48,920 --> 00:01:53,870 Just know that there are different models different viewpoints. 24 00:01:53,960 --> 00:01:57,820 But there's one model that you need to know for the exam for the real world. 25 00:01:57,830 --> 00:02:00,670 Have your opinion and go with your opinion. 26 00:02:00,680 --> 00:02:06,230 There were different competing groups that were clashing about what was important and which protocols 27 00:02:06,230 --> 00:02:09,430 should win the so-called protocol wars. 28 00:02:09,500 --> 00:02:16,400 So we had the ISI Group with their protocols we had the TTP IP group with their protocols TTP IP is 29 00:02:16,400 --> 00:02:17,450 one basically. 30 00:02:17,450 --> 00:02:24,440 So for a long time we used the so-called over side model to discuss TTP IP protocols. 31 00:02:24,440 --> 00:02:27,740 But the TTP IP protocols is what we use in the real world. 32 00:02:27,740 --> 00:02:29,100 We use IP version 4. 33 00:02:29,120 --> 00:02:37,250 We use TTP we use UDP we use IP version 6 TTP UDP once again we use IP protocols in the real world. 34 00:02:37,730 --> 00:02:44,090 So there's this disconnect if you like between the OS side model and the protocols that are actually 35 00:02:44,090 --> 00:02:45,750 used in the real world. 36 00:02:45,770 --> 00:02:52,410 So now in the new version of the CCMA we have what these called if you like a hybrid model can combined 37 00:02:52,430 --> 00:02:57,640 model of os sy and TTP IP model so don't get confused. 38 00:02:57,650 --> 00:03:01,270 There was originally a four layer TTP IP model. 39 00:03:01,280 --> 00:03:08,390 We have a seven layer OS model but now we've ended up in summary with a five layer TPP IP model. 40 00:03:08,510 --> 00:03:16,140 Five layers but we refer to the top layer as a layer 7 because it originated from the same model. 41 00:03:16,190 --> 00:03:21,500 So I'm going to talk about some of the details now but in summary make sure that when you study for 42 00:03:21,500 --> 00:03:25,160 the exam you understand that there's a TCB IP model. 43 00:03:25,250 --> 00:03:30,320 But today we talk about five layers instead of the original four layers that were discussed in the original 44 00:03:30,320 --> 00:03:36,950 or if C or request for comments requests for comments or a way that people discuss new protocols and 45 00:03:36,950 --> 00:03:38,990 agree on what a protocol should be. 46 00:03:38,990 --> 00:03:41,710 A protocol is basically a way to communicate. 47 00:03:41,750 --> 00:03:46,640 So if I'm communicating with you in English we've agreed a certain way to communicate. 48 00:03:46,670 --> 00:03:52,610 If I suddenly switch to another language and say two hundred funda you won't necessarily understand 49 00:03:52,610 --> 00:03:59,180 what I'm saying because that language uses a different communication stack if you like or a different 50 00:03:59,180 --> 00:04:01,400 way to communicate versus English. 51 00:04:01,400 --> 00:04:05,780 We have to agree on the protocol or language that we're going to discuss. 52 00:04:05,780 --> 00:04:11,810 So RF sees allow us to agree on what protocol will be implemented by different vendors so that it's 53 00:04:11,810 --> 00:04:15,860 kind of standardized in the old old days we didn't have standardized protocols. 54 00:04:15,860 --> 00:04:20,840 Every vendor did what they wanted but that was a total mess because she had different networks that 55 00:04:20,840 --> 00:04:22,600 couldn't communicate with each other. 56 00:04:22,670 --> 00:04:27,740 These days we want to have one network such as the internet that allows us all to communicate with one 57 00:04:27,740 --> 00:04:34,100 another and that works because we've agreed on standards in the industry so different vendors Cisco 58 00:04:34,490 --> 00:04:40,550 HP Juniper etc. will create equipment that can talk to each other based on the standard. 59 00:04:41,270 --> 00:04:47,950 So in summary you need to know TCB IP model which today consists of five models for this currency CCMA 60 00:04:48,650 --> 00:04:52,670 reflects the real world more than say previous models. 61 00:04:52,670 --> 00:04:59,450 We have the OEM model which consists of seven layers don't get hung up on the individual layers and 62 00:04:59,450 --> 00:05:02,090 I'm going to show you this practically using Packet Tracer. 63 00:05:02,300 --> 00:05:08,420 Understand how the layers work you may get questions saying Okay so at which lay of the oversized model 64 00:05:08,420 --> 00:05:13,850 do you find HDP which is a protocol used for surfing the Internet. 65 00:05:14,630 --> 00:05:18,680 If you go to Web sites such as Facebook dot com you'll be using HDP. 66 00:05:18,830 --> 00:05:22,780 Actually today it's a s which is encrypted HDP it's more secure. 67 00:05:23,030 --> 00:05:29,210 That is an example of what we would call a layer 7 protocol but you also need to understand in networking 68 00:05:29,540 --> 00:05:35,870 that we'll discuss devices such as hubs and we'll say hubs or layer 1 devices hubs aren't really used 69 00:05:35,870 --> 00:05:41,030 today but I'm going to discuss them just to give you an understanding because when you use a wireless 70 00:05:41,030 --> 00:05:46,060 network things kind of change with Wi-Fi sex or the latest release of Wi-Fi. 71 00:05:46,520 --> 00:05:51,270 But previously everything acted as a pure hub in the air. 72 00:05:51,290 --> 00:05:54,260 In other words only one person could communicate at a time. 73 00:05:54,410 --> 00:06:00,800 Wi-Fi still like a hub because it's a shared medium that is shared so you need to understand the principles 74 00:06:00,800 --> 00:06:01,270 of hubs. 75 00:06:01,280 --> 00:06:08,120 Even though we don't use them physically today as in connecting cables to a hub but the air in wireless 76 00:06:08,120 --> 00:06:10,020 networks is kind of like a hub. 77 00:06:10,100 --> 00:06:14,040 We have switches which are called Layer 2 devices. 78 00:06:14,060 --> 00:06:18,910 Actually some people would debate where the switches are a thing but we won't get into that. 79 00:06:18,920 --> 00:06:21,040 We have bridges which are layer to devices. 80 00:06:21,050 --> 00:06:26,320 We have routers which are layer three devices and we have what are called Layer 3 switches. 81 00:06:26,390 --> 00:06:31,710 So notice I'm using terms here a one device layer two device Layer 3 device. 82 00:06:31,710 --> 00:06:38,790 We have a layer 4 protocol which could be DCP or UDP and then we have Layer 7 applications such as HDP 83 00:06:39,180 --> 00:06:43,180 FCP TFT P telnet SS H etc.. 84 00:06:43,350 --> 00:06:46,650 Don't get hung up on those you need to know those protocols. 85 00:06:46,650 --> 00:06:54,750 You need to know where they fit in the so-called TTP IP model or side model it'll come to you as we 86 00:06:55,050 --> 00:06:59,440 do a whole bunch of laps and I'm gonna show you the protocols practically in Packet Tracer. 87 00:06:59,430 --> 00:07:05,400 You'll see where those different protocols reside or set if you like in the model.