1 1 00:00:00,720 --> 00:00:02,100 Copper media. 2 2 00:00:02,100 --> 00:00:05,320 In this lesson, we're going to talk about copper media. 3 3 00:00:05,320 --> 00:00:07,060 Now, when we talk about copper media, 4 4 00:00:07,060 --> 00:00:10,350 there are subcategories inside of this larger category 5 5 00:00:10,350 --> 00:00:11,550 of copper media, 6 6 00:00:11,550 --> 00:00:13,870 and each one is going to have different specifications 7 7 00:00:13,870 --> 00:00:15,170 and uses. 8 8 00:00:15,170 --> 00:00:16,320 Now in this lesson, 9 9 00:00:16,320 --> 00:00:19,430 we're going to talk about three main types of copper media. 10 10 00:00:19,430 --> 00:00:22,360 These are coaxial cables, twisted pair cables, 11 11 00:00:22,360 --> 00:00:23,950 and serial cables. 12 12 00:00:23,950 --> 00:00:25,980 Now, when I talk about copper media, 13 13 00:00:25,980 --> 00:00:29,000 the first and oldest one is coaxial cable. 14 14 00:00:29,000 --> 00:00:31,200 Also known as co-ax. 15 15 00:00:31,200 --> 00:00:33,730 This is going to have an inner insulated conductor 16 16 00:00:33,730 --> 00:00:37,230 or center wire that's going to pass all of our data over it. 17 17 00:00:37,230 --> 00:00:39,540 This is known as our center core. 18 18 00:00:39,540 --> 00:00:41,280 Now we also have this outer shell 19 19 00:00:41,280 --> 00:00:42,900 that is a braided metal shield 20 20 00:00:42,900 --> 00:00:45,390 to help shield it from any data transmission leakage 21 21 00:00:45,390 --> 00:00:47,480 coming from inside the cable outward, 22 22 00:00:47,480 --> 00:00:50,130 and it provides protection from the outside in 23 23 00:00:50,130 --> 00:00:52,120 against electromagnetic interference 24 24 00:00:52,120 --> 00:00:54,610 because of this braided metal shielding. 25 25 00:00:54,610 --> 00:00:57,480 Now on the outside, we have this plastic jacket 26 26 00:00:57,480 --> 00:01:00,340 and then there's a metallic shield and an insulator 27 27 00:01:00,340 --> 00:01:02,990 and inside that insulator, we have that center core 28 28 00:01:02,990 --> 00:01:05,010 where all the data's going to pass through. 29 29 00:01:05,010 --> 00:01:08,490 Now, where might you find coaxial cables in modern networks? 30 30 00:01:08,490 --> 00:01:10,920 Well, there's really two main places. 31 31 00:01:10,920 --> 00:01:12,810 First, we're going to have RG-6, 32 32 00:01:12,810 --> 00:01:15,310 which is commonly used by your local cable company 33 33 00:01:15,310 --> 00:01:17,280 to connect their service to your home. 34 34 00:01:17,280 --> 00:01:20,100 It's a very thick version of a coaxial cable. 35 35 00:01:20,100 --> 00:01:21,900 Now, once you get inside your home, 36 36 00:01:21,900 --> 00:01:24,720 you're going to use what's known as an RG-59, 37 37 00:01:24,720 --> 00:01:26,690 and this is going to carry composite video 38 38 00:01:26,690 --> 00:01:29,910 between two nearby devices or connect an outlet 39 39 00:01:29,910 --> 00:01:31,380 to a cable modem. 40 40 00:01:31,380 --> 00:01:34,580 Now, if you have cable TV or satellite TV in your house, 41 41 00:01:34,580 --> 00:01:37,270 you're probably using RG-59 cables 42 42 00:01:37,270 --> 00:01:39,280 running from the cable or satellite box 43 43 00:01:39,280 --> 00:01:42,630 to your TV or to the outlet jack on the wall. 44 44 00:01:42,630 --> 00:01:46,270 This is commonly referred to as a coaxial cable or co-ax, 45 45 00:01:46,270 --> 00:01:48,770 and it's the most common one you're going to find. 46 46 00:01:48,770 --> 00:01:51,730 Now, how does a coaxial cable connect to your device? 47 47 00:01:51,730 --> 00:01:54,460 Well, there's two commonly used type of connectors 48 48 00:01:54,460 --> 00:01:56,400 when it comes to coaxial cables. 49 49 00:01:56,400 --> 00:01:59,760 These are known as an F-type and a BNC connector. 50 50 00:01:59,760 --> 00:02:01,830 Now most coaxial cables these days 51 51 00:02:01,830 --> 00:02:04,000 are going to have an F-type connector. 52 52 00:02:04,000 --> 00:02:06,540 This is basically a screw-on type of connector 53 53 00:02:06,540 --> 00:02:09,410 that attaches to the cable box or to the wall jack. 54 54 00:02:09,410 --> 00:02:11,380 This is commonly used in cable TV, 55 55 00:02:11,380 --> 00:02:14,150 and cable modems for consumer applications. 56 56 00:02:14,150 --> 00:02:15,890 Now the second type of connector we have 57 57 00:02:15,890 --> 00:02:18,020 is known as a BNC connector, 58 58 00:02:18,020 --> 00:02:21,130 also called a Bayonet Neill Concelman connector, 59 59 00:02:21,130 --> 00:02:23,320 or a British Naval Connector. 60 60 00:02:23,320 --> 00:02:25,960 Now usually network professionals will simply refer 61 61 00:02:25,960 --> 00:02:29,000 to all of these as a BNC connector though. 62 62 00:02:29,000 --> 00:02:31,660 Now BNC connectors used to be used really heavily 63 63 00:02:31,660 --> 00:02:32,560 in networking, 64 64 00:02:32,560 --> 00:02:35,060 especially in the early days of computer networks. 65 65 00:02:35,060 --> 00:02:38,030 In fact, if you ever come across an old 10BASE-2 66 66 00:02:38,030 --> 00:02:40,820 or 10BASE-5 network from the early days of ethernet, 67 67 00:02:40,820 --> 00:02:43,030 somewhere around the 1970s or eighties, 68 68 00:02:43,030 --> 00:02:45,300 this was the standard connector used by them. 69 69 00:02:45,300 --> 00:02:47,410 It was a BNC connector. 70 70 00:02:47,410 --> 00:02:50,600 So if all of these things are so old and obsolete, 71 71 00:02:50,600 --> 00:02:52,500 why am I even mentioning them? 72 72 00:02:52,500 --> 00:02:54,360 Well, because a lot of my students 73 73 00:02:54,360 --> 00:02:57,000 will go on to work in jobs for the Department of Defense 74 74 00:02:57,000 --> 00:02:59,100 or one of their military subcontractors. 75 75 00:02:59,100 --> 00:03:02,080 And they still use a lot of BNC connectors 76 76 00:03:02,080 --> 00:03:05,120 as well as RG-6 and RG-59 cabling 77 77 00:03:05,120 --> 00:03:06,900 for some of their older network devices, 78 78 00:03:06,900 --> 00:03:08,770 because they simply haven't upgraded them yet 79 79 00:03:08,770 --> 00:03:10,830 and they still work for some of their older command 80 80 00:03:10,830 --> 00:03:11,990 and control systems. 81 81 00:03:11,990 --> 00:03:13,950 So you may come across them 82 82 00:03:13,950 --> 00:03:15,450 while you're working in the field. 83 83 00:03:15,450 --> 00:03:17,000 It's important for you to realize 84 84 00:03:17,000 --> 00:03:18,750 what these things look like. 85 85 00:03:18,750 --> 00:03:20,950 You have to realize that you don't have to fully screw on 86 86 00:03:20,950 --> 00:03:22,480 one of these BNC connectors 87 87 00:03:22,480 --> 00:03:24,370 like you would an F-type connector. 88 88 00:03:24,370 --> 00:03:27,000 Instead, a BNC connector is going to be used 89 89 00:03:27,000 --> 00:03:28,500 by pushing the connector in 90 90 00:03:28,500 --> 00:03:30,510 and then twisting it about a half a turn 91 91 00:03:30,510 --> 00:03:32,170 to lock it in place. 92 92 00:03:32,170 --> 00:03:34,353 Now, there is a newer style coaxial cable 93 93 00:03:34,353 --> 00:03:37,540 that is being used in modern applications as well. 94 94 00:03:37,540 --> 00:03:39,820 This one is known as twinaxial. 95 95 00:03:39,820 --> 00:03:42,930 Now a twinaxial cable is similar to a coaxial cable, 96 96 00:03:42,930 --> 00:03:45,050 but instead of having just one conductor, 97 97 00:03:45,050 --> 00:03:48,320 there's going to be two inner conductors to carry the data. 98 98 00:03:48,320 --> 00:03:50,740 Twinaxial cables are used for very short range, 99 99 00:03:50,740 --> 00:03:53,110 high speed connections between devices. 100 100 00:03:53,110 --> 00:03:56,830 For example, there's a use case for using an SFP plus 101 101 00:03:56,830 --> 00:03:59,970 direct attached copper cable between two different switches 102 102 00:03:59,970 --> 00:04:02,400 that are shorter than about seven meters apart. 103 103 00:04:02,400 --> 00:04:04,850 Now, if you decide to use twinaxial cable for this, 104 104 00:04:04,850 --> 00:04:06,630 you can avoid using fiber cables 105 105 00:04:06,630 --> 00:04:08,360 and it'll save you a bit of money 106 106 00:04:08,360 --> 00:04:09,560 if your networking devices 107 107 00:04:09,560 --> 00:04:11,550 will support this type of connection. 108 108 00:04:11,550 --> 00:04:13,920 In this application, you're going to be able to get speeds 109 109 00:04:13,920 --> 00:04:15,530 of up to 10 gigabits per second, 110 110 00:04:15,530 --> 00:04:17,210 over that twinaxial cable. 111 111 00:04:17,210 --> 00:04:20,850 And it uses a lot less energy than traditional copper cables 112 112 00:04:20,850 --> 00:04:22,890 to achieve this level of speed. 113 113 00:04:22,890 --> 00:04:24,440 That said, personally, 114 114 00:04:24,440 --> 00:04:27,550 I've never had to use twinaxial cables in my life. 115 115 00:04:27,550 --> 00:04:30,760 And instead I've either relied on the twisted pair cable 116 116 00:04:30,760 --> 00:04:33,370 or a fiber optic cable between my switches 117 117 00:04:33,370 --> 00:04:35,210 for my high-speed trunks. 118 118 00:04:35,210 --> 00:04:37,790 Now the second type of copper cable you may run into 119 119 00:04:37,790 --> 00:04:39,810 is known as a serial cable. 120 120 00:04:39,810 --> 00:04:42,840 These cables usually have a series of straight copper wires 121 121 00:04:42,840 --> 00:04:45,510 inside a single cable or plastic jacket. 122 122 00:04:45,510 --> 00:04:48,200 Normally they're going to be terminated with a DB-9 123 123 00:04:48,200 --> 00:04:50,120 or DB-25 connector, 124 124 00:04:50,120 --> 00:04:52,580 which is a D shaped subminiature connector 125 125 00:04:52,580 --> 00:04:55,640 with nine or twenty-five pins at the end of it. 126 126 00:04:55,640 --> 00:04:59,090 These cables are also known as an RS-232 cable, 127 127 00:04:59,090 --> 00:05:01,030 since that's the signaling method that's used 128 128 00:05:01,030 --> 00:05:03,600 when transmitting data over these cables. 129 129 00:05:03,600 --> 00:05:06,510 These cables are very old and they're not commonly used 130 130 00:05:06,510 --> 00:05:09,580 in modern networks, but you may come across one 131 131 00:05:09,580 --> 00:05:12,150 if you're working with an older network connectivity method, 132 132 00:05:12,150 --> 00:05:14,190 such as an external ISDN modem 133 133 00:05:14,190 --> 00:05:17,040 or a T1 or an E1 modem connection. 134 134 00:05:17,040 --> 00:05:19,100 Our third type of copper cable we have 135 135 00:05:19,100 --> 00:05:21,360 is known as twisted pair cable. 136 136 00:05:21,360 --> 00:05:24,020 Now twisted pair is going to be the most popular 137 137 00:05:24,020 --> 00:05:26,360 local area network cabling technology 138 138 00:05:26,360 --> 00:05:28,440 that we're going to use in our networks today. 139 139 00:05:28,440 --> 00:05:30,640 If you're plugging in a network cable to your laptop 140 140 00:05:30,640 --> 00:05:31,560 or your desktop, 141 141 00:05:31,560 --> 00:05:35,160 you're usually doing this using a copper twisted pair cable. 142 142 00:05:35,160 --> 00:05:36,460 Inside this cable, 143 143 00:05:36,460 --> 00:05:38,760 there are eight individually insulated wires 144 144 00:05:38,760 --> 00:05:41,220 that are going to be inside of this cable sheath. 145 145 00:05:41,220 --> 00:05:43,870 And each of those is twisted up into a pair, 146 146 00:05:43,870 --> 00:05:46,710 which is why we call it twisted pair cable. 147 147 00:05:46,710 --> 00:05:48,350 Now, if you open up this cable, 148 148 00:05:48,350 --> 00:05:50,370 you can see there are going to be four pairs, 149 149 00:05:50,370 --> 00:05:53,610 each twisted with two wires in each of those pairs. 150 150 00:05:53,610 --> 00:05:56,400 Now the twist here is really important. 151 151 00:05:56,400 --> 00:05:59,120 The more twists you have within an inch of the cable 152 152 00:05:59,120 --> 00:06:01,070 the better the protection that cable has 153 153 00:06:01,070 --> 00:06:04,050 from electromagnetic interference or EMI. 154 154 00:06:04,050 --> 00:06:05,500 If you have less twists 155 155 00:06:05,500 --> 00:06:07,210 and the cable becomes more susceptible 156 156 00:06:07,210 --> 00:06:09,270 to more electromagnetic interference, 157 157 00:06:09,270 --> 00:06:11,140 and this will also mean you have slower speeds 158 158 00:06:11,140 --> 00:06:12,430 for your cable. 159 159 00:06:12,430 --> 00:06:13,720 This becomes really important 160 160 00:06:13,720 --> 00:06:15,660 because the more interference you have, 161 161 00:06:15,660 --> 00:06:18,030 the worse your data transmission rate is going to be 162 162 00:06:18,030 --> 00:06:20,740 because you have to retransmit your data more often. 163 163 00:06:20,740 --> 00:06:23,050 This is going to slow down your overall throughput 164 164 00:06:23,050 --> 00:06:25,030 and bandwidth in your network. 165 165 00:06:25,030 --> 00:06:26,350 As we go through this lesson, 166 166 00:06:26,350 --> 00:06:28,370 we're going to start to discuss the different categories 167 167 00:06:28,370 --> 00:06:31,540 of cable, going from CAT 5 up to CAT 8. 168 168 00:06:31,540 --> 00:06:32,920 And the common theme here 169 169 00:06:32,920 --> 00:06:34,860 is that the higher the category number, 170 170 00:06:34,860 --> 00:06:37,480 the more twist you're going to find per inch of cable, 171 171 00:06:37,480 --> 00:06:39,240 and therefore the higher speed 172 172 00:06:39,240 --> 00:06:40,820 that particular cable category 173 173 00:06:40,820 --> 00:06:42,840 is going to be able to achieve. 174 174 00:06:42,840 --> 00:06:45,460 Now, when we're dealing with the twisted pair cabling, 175 175 00:06:45,460 --> 00:06:48,300 you're going to hear it broken down into one of two types, 176 176 00:06:48,300 --> 00:06:51,030 either UTP or STP. 177 177 00:06:51,030 --> 00:06:53,620 UTP stands for unshielded twisted pair 178 178 00:06:53,620 --> 00:06:56,650 and STP stands for shielded twisted pair. 179 179 00:06:56,650 --> 00:06:57,500 On this screen, 180 180 00:06:57,500 --> 00:07:00,810 you can see an example of an unshielded twisted pair cable. 181 181 00:07:00,810 --> 00:07:03,720 Now notice the wires are twisted and they're covered 182 182 00:07:03,720 --> 00:07:05,810 in this plastic jacket on the outside 183 183 00:07:05,810 --> 00:07:07,700 that's going to protect it from the elements. 184 184 00:07:07,700 --> 00:07:11,110 Now with UTP, you're going to find a much cheaper cable. 185 185 00:07:11,110 --> 00:07:12,720 When you start using STP, 186 186 00:07:12,720 --> 00:07:14,560 it's going to be a little bit harder to use, 187 187 00:07:14,560 --> 00:07:16,690 and it's going to cost a little bit more. 188 188 00:07:16,690 --> 00:07:18,120 When you're dealing with UTP, 189 189 00:07:18,120 --> 00:07:20,890 there is no metal being used in the part of the shielding 190 190 00:07:20,890 --> 00:07:23,160 and therefore UTP is going to be cheaper 191 191 00:07:23,160 --> 00:07:24,510 because it's all plastic, 192 192 00:07:24,510 --> 00:07:28,200 except for those thin copper wires inside of our four pairs 193 193 00:07:28,200 --> 00:07:30,220 making up those eight wires. 194 194 00:07:30,220 --> 00:07:32,630 Now, because of it's low cost, and it's easy to use, 195 195 00:07:32,630 --> 00:07:35,610 unshielded twisted pair cabling is the media of choice 196 196 00:07:35,610 --> 00:07:38,050 for most local area networks these days. 197 197 00:07:38,050 --> 00:07:39,870 UTP can be bent very easily 198 198 00:07:39,870 --> 00:07:41,390 as you're pushing it through conduit, 199 199 00:07:41,390 --> 00:07:43,140 throughout your ceilings and your walls 200 200 00:07:43,140 --> 00:07:45,570 and you can install it with very low cost tools 201 201 00:07:45,570 --> 00:07:48,420 in just a few days of training in most cases. 202 202 00:07:48,420 --> 00:07:51,760 The second type of twisted pair cable is known as STP 203 203 00:07:51,760 --> 00:07:53,690 or shielded twisted pair. 204 204 00:07:53,690 --> 00:07:56,070 Now STP is just like UTP, 205 205 00:07:56,070 --> 00:07:59,400 except each twisted pair inside that cable sheath 206 206 00:07:59,400 --> 00:08:01,790 is going to be wrapped with some metal foil. 207 207 00:08:01,790 --> 00:08:02,710 And there's also going to be this 208 208 00:08:02,710 --> 00:08:04,400 braided metallic shield wrapping 209 209 00:08:04,400 --> 00:08:06,630 around all four of those pairs. 210 210 00:08:06,630 --> 00:08:09,030 This means the wires in an STP cable 211 211 00:08:09,030 --> 00:08:12,310 are going to be twisted up in pairs just like they were in UTP. 212 212 00:08:12,310 --> 00:08:14,580 But the difference is, they have this metal shielding 213 213 00:08:14,580 --> 00:08:17,360 that else minimize EMI between the inner twisted pairs 214 214 00:08:17,360 --> 00:08:18,420 even more. 215 215 00:08:18,420 --> 00:08:20,840 And there's also this outer braiding shield 216 216 00:08:20,840 --> 00:08:23,720 to minimize EMI from the outside environment too. 217 217 00:08:23,720 --> 00:08:26,830 Essentially we're taking the best things from UTP 218 218 00:08:26,830 --> 00:08:30,130 and all that shielding from using a coaxial cable 219 219 00:08:30,130 --> 00:08:32,510 and putting it into one device. 220 220 00:08:32,510 --> 00:08:34,710 Now, because of all this extra metal though, 221 221 00:08:34,710 --> 00:08:37,450 this is going to make shielded twisted pairs cost more 222 222 00:08:37,450 --> 00:08:40,380 than an equivalent category of unshielded twisted pair. 223 223 00:08:40,380 --> 00:08:44,350 Other than that, STP and UTP operate about the same 224 224 00:08:44,350 --> 00:08:46,830 with the exception of the EMI interference 225 225 00:08:46,830 --> 00:08:49,060 that's going to be less with STP. 226 226 00:08:49,060 --> 00:08:51,040 Now, both STP and UTP 227 227 00:08:51,040 --> 00:08:53,670 both have the same amount of distance limitations. 228 228 00:08:53,670 --> 00:08:55,550 Either of them can go about a hundred meters, 229 229 00:08:55,550 --> 00:08:57,640 which is around 300 feet. 230 230 00:08:57,640 --> 00:09:00,630 Both also use the same type of connectors to terminate them. 231 231 00:09:00,630 --> 00:09:03,510 And the wires on the inside are exactly the same 232 232 00:09:03,510 --> 00:09:05,450 with the exception of that metal shielding 233 233 00:09:05,450 --> 00:09:08,360 being wrapped around them in the case of STP. 234 234 00:09:08,360 --> 00:09:09,950 Now, speaking of connectors, 235 235 00:09:09,950 --> 00:09:11,840 let's talk about the two connector types 236 236 00:09:11,840 --> 00:09:13,840 that's used with twisted pair cabling. 237 237 00:09:13,840 --> 00:09:16,990 These are RJ45 and RJ11. 238 238 00:09:16,990 --> 00:09:19,810 Now, RJ45 is the most commonly used connector 239 239 00:09:19,810 --> 00:09:20,960 in our networks. 240 240 00:09:20,960 --> 00:09:24,370 The RJ45 connector is a plastic eight pin connector, 241 241 00:09:24,370 --> 00:09:25,810 and it looks like a fatter version 242 242 00:09:25,810 --> 00:09:28,010 of a traditional landline phone jack. 243 243 00:09:28,010 --> 00:09:31,850 Now, RJ45 is used all the time in ethernet based networks, 244 244 00:09:31,850 --> 00:09:35,070 including ones with CAT 5, CAT 6, CAT 7, 245 245 00:09:35,070 --> 00:09:36,680 or CAT 8 cables. 246 246 00:09:36,680 --> 00:09:40,150 If you're using an RJ45 connector with a CAT 5 cable, 247 247 00:09:40,150 --> 00:09:43,030 it's only going to have to use four of the eight pins. 248 248 00:09:43,030 --> 00:09:45,370 The other four are reserved for future use, 249 249 00:09:45,370 --> 00:09:47,070 but they can be used for other applications, 250 250 00:09:47,070 --> 00:09:49,750 such as power over ethernet and things like that. 251 251 00:09:49,750 --> 00:09:51,580 Ever since we moved to gigabit ethernet 252 252 00:09:51,580 --> 00:09:53,680 with 1000BASE-T and higher 253 253 00:09:53,680 --> 00:09:55,540 all four pairs and their eight pins 254 254 00:09:55,540 --> 00:09:57,600 are going to be used for data transfer. 255 255 00:09:57,600 --> 00:09:59,480 We're going to talk more about the different categories 256 256 00:09:59,480 --> 00:10:01,260 and speeds in just a moment. 257 257 00:10:01,260 --> 00:10:02,810 The second type of connector that we use 258 258 00:10:02,810 --> 00:10:05,740 with twisted pair cables is known as RJ11. 259 259 00:10:05,740 --> 00:10:08,310 Now, RJ11 is a six pin connector. 260 260 00:10:08,310 --> 00:10:10,750 And when used in an RJ11 configuration, 261 261 00:10:10,750 --> 00:10:13,640 only two of those pins are actually going to be used. 262 262 00:10:13,640 --> 00:10:16,320 Commonly, you're going to find this in phone systems 263 263 00:10:16,320 --> 00:10:18,820 to connect your phone to a landline jack. 264 264 00:10:18,820 --> 00:10:21,650 Now, one of these pins is going to be reserved for the ring, 265 265 00:10:21,650 --> 00:10:23,450 and one is going to be reserved for the signal 266 266 00:10:23,450 --> 00:10:25,600 inside of these phone systems. 267 267 00:10:25,600 --> 00:10:28,500 If you're using a DSL modem for your internet connectivity, 268 268 00:10:28,500 --> 00:10:30,110 or you're providing VoIP services 269 269 00:10:30,110 --> 00:10:31,970 through an analog telephone adapter, 270 270 00:10:31,970 --> 00:10:34,090 you may come across an RJ11. 271 271 00:10:34,090 --> 00:10:35,953 But otherwise they're not very common 272 272 00:10:35,953 --> 00:10:38,570 inside our local area networks. 273 273 00:10:38,570 --> 00:10:40,210 When creating one of these phone lines, 274 274 00:10:40,210 --> 00:10:42,890 you can simply use CAT 5 or similar cabling, 275 275 00:10:42,890 --> 00:10:45,010 and then put an RJ11 connector on the end 276 276 00:10:45,010 --> 00:10:47,250 instead of an RJ45. 277 277 00:10:47,250 --> 00:10:49,380 Now, as I said, in most networks, 278 278 00:10:49,380 --> 00:10:51,910 you're going to be using an RJ45 connector 279 279 00:10:51,910 --> 00:10:54,440 at the end of an unshielded twisted pair cable, 280 280 00:10:54,440 --> 00:10:56,520 because these are the most common thing 281 281 00:10:56,520 --> 00:10:58,582 you're going to run across in the field. 282 282 00:10:58,582 --> 00:11:01,820 Now you may be wondering, I keep saying, RJ. 283 283 00:11:01,820 --> 00:11:03,490 What does RJ stand for? 284 284 00:11:03,490 --> 00:11:06,090 Like RJ45 and RJ11? 285 285 00:11:06,090 --> 00:11:08,540 Well, it stands for Registered Jack. 286 286 00:11:08,540 --> 00:11:10,370 Basically, they are the standardized 287 287 00:11:10,370 --> 00:11:12,430 telecommunication network interfaces 288 288 00:11:12,430 --> 00:11:14,420 that are used to carry voice or data, 289 289 00:11:14,420 --> 00:11:17,150 and they specify the standards that the device needs to meet 290 290 00:11:17,150 --> 00:11:19,780 in order to connect to the phone or data network. 291 291 00:11:19,780 --> 00:11:21,880 There are lots of different variants out there, 292 292 00:11:21,880 --> 00:11:24,420 but RJ11 is used for phone networks 293 293 00:11:24,420 --> 00:11:26,900 and RJ45 is used for data networks 294 294 00:11:26,900 --> 00:11:28,890 as the two most popular ones out there. 295 295 00:11:28,890 --> 00:11:32,290 And these are the only two you need to know for the exam. 296 296 00:11:32,290 --> 00:11:35,600 All right, let's talk about bandwidth and throughput. 297 297 00:11:35,600 --> 00:11:38,420 Bandwidth is your theoretical measure of how much data 298 298 00:11:38,420 --> 00:11:41,690 could be transferred from a source to its destination. 299 299 00:11:41,690 --> 00:11:43,940 Throughput on the other hand is the actual measure 300 300 00:11:43,940 --> 00:11:46,550 of how much data is successfully transferred 301 301 00:11:46,550 --> 00:11:48,850 from a source to its destination. 302 302 00:11:48,850 --> 00:11:51,860 Now notice these terms are very closely related 303 303 00:11:51,860 --> 00:11:54,420 and you'll often hear people use them interchangeably 304 304 00:11:54,420 --> 00:11:55,870 when you're working in the field. 305 305 00:11:55,870 --> 00:11:59,130 But technically there is a subtle difference here. 306 306 00:11:59,130 --> 00:12:01,730 As we talk about the different cables and categories, 307 307 00:12:01,730 --> 00:12:04,700 we're going to be talking about them in terms of bandwidth, 308 308 00:12:04,700 --> 00:12:06,580 which is their theoretical measure 309 309 00:12:06,580 --> 00:12:08,470 of how much data could be transferred 310 310 00:12:08,470 --> 00:12:10,550 from the source to a destination, 311 311 00:12:10,550 --> 00:12:13,070 as opposed to what you may see in your own networks 312 312 00:12:13,070 --> 00:12:14,830 under real world conditions. 313 313 00:12:14,830 --> 00:12:17,430 That real-world conditions and the things you're seeing, 314 314 00:12:17,430 --> 00:12:19,250 that is throughput. 315 315 00:12:19,250 --> 00:12:20,770 All right, for the exam, 316 316 00:12:20,770 --> 00:12:22,970 you need to know several different categories 317 317 00:12:22,970 --> 00:12:26,550 of twisted pair of cabling, specifically CAT 3, 318 318 00:12:26,550 --> 00:12:30,660 CAT 5, CAT 5e, CAT 6, CAT 6a, 319 319 00:12:30,660 --> 00:12:32,510 CAT 7 and CAT 8. 320 320 00:12:32,510 --> 00:12:35,550 For each cable type, you need to know its category number, 321 321 00:12:35,550 --> 00:12:36,900 it's ethernet standard, 322 322 00:12:36,900 --> 00:12:38,970 the bandwidth or transmission speed it uses 323 323 00:12:38,970 --> 00:12:41,820 and the maximum distance it can operate. 324 324 00:12:41,820 --> 00:12:44,070 Now, when I mentioned an ethernet standard, 325 325 00:12:44,070 --> 00:12:45,420 this is going to be a designation 326 326 00:12:45,420 --> 00:12:47,230 given to a particular category 327 327 00:12:47,230 --> 00:12:49,310 and allows us to really easily understand 328 328 00:12:49,310 --> 00:12:52,180 the bandwidth and the cable type that's going to be used. 329 329 00:12:52,180 --> 00:12:54,860 For example, just looking at that standard number, 330 330 00:12:54,860 --> 00:12:57,190 you can tell if it's copper or fiber. 331 331 00:12:57,190 --> 00:12:59,490 So let's start out with CAT 3. 332 332 00:12:59,490 --> 00:13:01,690 First, we have 10BASE-T, 333 333 00:13:01,690 --> 00:13:03,670 which is our first ethernet cable type 334 334 00:13:03,670 --> 00:13:05,810 that operated over twisted pair cabling 335 335 00:13:05,810 --> 00:13:09,010 and it was starting to be used all the way back in the 1980s 336 336 00:13:09,010 --> 00:13:11,770 and became popular throughout the eighties and nineties. 337 337 00:13:11,770 --> 00:13:14,010 The maximum speed of a CAT 3 cable, 338 338 00:13:14,010 --> 00:13:17,970 which is known as a 10BASE-T is 10 megabits per second. 339 339 00:13:17,970 --> 00:13:20,230 Now like most twisted pair cables, 340 340 00:13:20,230 --> 00:13:22,520 CAT 3 can only go up to a hundred meters 341 341 00:13:22,520 --> 00:13:25,020 or around 300 feet in distance. 342 342 00:13:25,020 --> 00:13:27,730 Now notice the standard here is written as a number, 343 343 00:13:27,730 --> 00:13:31,260 the word base, and then a letter, in this case T. 344 344 00:13:31,260 --> 00:13:33,910 This makes designation of it very quick and easy 345 345 00:13:33,910 --> 00:13:36,620 so you can see the speed, 10 megabits per second, 346 346 00:13:36,620 --> 00:13:38,250 and the cable type being used. 347 347 00:13:38,250 --> 00:13:40,170 T for twisted pair. 348 348 00:13:40,170 --> 00:13:42,040 For all the twisted pair cables, 349 349 00:13:42,040 --> 00:13:45,190 you're going to see there are base-T or base-TX. 350 350 00:13:45,190 --> 00:13:47,340 When we get to the fiber cables later on, 351 351 00:13:47,340 --> 00:13:49,860 we're going to see that they're going to use that base notation, 352 352 00:13:49,860 --> 00:13:51,830 but they'll have different letters at the end. 353 353 00:13:51,830 --> 00:13:53,320 And those letters are going to change 354 354 00:13:53,320 --> 00:13:55,660 based upon the type of fiber being used, 355 355 00:13:55,660 --> 00:13:58,360 whether it's a single mode or multimode fiber. 356 356 00:13:58,360 --> 00:14:01,750 So when we talk about a CAT 3 or 10BASE-T network, 357 357 00:14:01,750 --> 00:14:04,987 remember this was originally the ethernet network, 358 358 00:14:04,987 --> 00:14:07,660 and it is the slowest one we're going to cover. 359 359 00:14:07,660 --> 00:14:11,090 Next, we have CAT 5 with 100BASE-TX, 360 360 00:14:11,090 --> 00:14:13,150 which was called fast ethernet. 361 361 00:14:13,150 --> 00:14:15,580 Now fast ethernet operates at a hundred megabits 362 362 00:14:15,580 --> 00:14:16,413 per second, 363 363 00:14:16,413 --> 00:14:19,710 which is why it is called 100BASE-TX network. 364 364 00:14:19,710 --> 00:14:23,320 Now the TX here stands for twisted pair, fast ethernet, 365 365 00:14:23,320 --> 00:14:25,250 and is the only twisted pair network, 366 366 00:14:25,250 --> 00:14:28,620 that uses something other than a T in the base notation. 367 367 00:14:28,620 --> 00:14:30,920 Again, just like CAT 3 cables, 368 368 00:14:30,920 --> 00:14:34,030 CAT 5 cables, or 100BASE-TX cables 369 369 00:14:34,030 --> 00:14:36,250 can only go up to a hundred meters in length 370 370 00:14:36,250 --> 00:14:39,220 before their signal must be repeated using a switch, 371 371 00:14:39,220 --> 00:14:42,690 a router or some kind of a repeater device. 372 372 00:14:42,690 --> 00:14:47,080 Next, we have CAT 5e, which is known as 1000BASE-T. 373 373 00:14:47,080 --> 00:14:50,330 Now a 1000BASE-T network or gigabit ethernet 374 374 00:14:50,330 --> 00:14:53,360 is going to operate at 1000 megabits per second, 375 375 00:14:53,360 --> 00:14:56,240 which is also known as one gigabit per second. 376 376 00:14:56,240 --> 00:15:00,100 Again, our distance here is limited to only 100 meters. 377 377 00:15:00,100 --> 00:15:04,180 Next we have CAT 6 which can operate either 1000BASE-T 378 378 00:15:04,180 --> 00:15:06,120 or 10GBASE-T. 379 379 00:15:06,120 --> 00:15:09,610 Now, if CAT 6 is going to be used with a 1000BASE-T network, 380 380 00:15:09,610 --> 00:15:12,360 it can operate at 1000 megabits per second 381 381 00:15:12,360 --> 00:15:15,900 or one gigabit per second, just like CAT 5e did, 382 382 00:15:15,900 --> 00:15:18,490 and it goes up to 100 meters in length. 383 383 00:15:18,490 --> 00:15:20,710 Now CAT 6 can also go faster 384 384 00:15:20,710 --> 00:15:23,100 and it can go up to 10 gigabits per second, 385 385 00:15:23,100 --> 00:15:25,330 using a 10GBASE-T network. 386 386 00:15:25,330 --> 00:15:27,510 But when you use this higher speed, 387 387 00:15:27,510 --> 00:15:31,850 you can only go 55 meters instead of the full 100 meters. 388 388 00:15:31,850 --> 00:15:33,960 Next, we have CAT 6a 389 389 00:15:33,960 --> 00:15:36,270 which was an improvement over CAT 6. 390 390 00:15:36,270 --> 00:15:40,030 CAT 6a will allow you to operate 10GBASE-T networks 391 391 00:15:40,030 --> 00:15:42,130 at that full 10 gigabits per second, 392 392 00:15:42,130 --> 00:15:44,310 all the way up to a hundred meters. 393 393 00:15:44,310 --> 00:15:46,170 Next we have CAT 7, 394 394 00:15:46,170 --> 00:15:49,730 and CAT 7 is going to operate 10GBASE-T as well, 395 395 00:15:49,730 --> 00:15:52,030 giving you that full 10 gigabits per second 396 396 00:15:52,030 --> 00:15:53,760 at up to a hundred meters. 397 397 00:15:53,760 --> 00:15:57,330 Oddly enough, CAT 7 was actually released over six years 398 398 00:15:57,330 --> 00:15:59,210 before CAT 6a was, 399 399 00:15:59,210 --> 00:16:03,050 but it could use either a traditional RJ45 style connector 400 400 00:16:03,050 --> 00:16:05,320 or a different connector known as TERA, 401 401 00:16:05,320 --> 00:16:06,760 T-E-R-A, 402 402 00:16:06,760 --> 00:16:09,810 and therefore it was able to reach 10 gigabit speeds, 403 403 00:16:09,810 --> 00:16:11,930 much faster over the hundred meters 404 404 00:16:11,930 --> 00:16:14,050 before CAT 6 could be modified 405 405 00:16:14,050 --> 00:16:16,510 into the newer CAT 6a standard. 406 406 00:16:16,510 --> 00:16:18,420 All that said, for the exam, 407 407 00:16:18,420 --> 00:16:20,900 I just need you to remember that both CAT 6a 408 408 00:16:20,900 --> 00:16:24,690 and CAT 7 are both considered 10GBASE-T networks 409 409 00:16:24,690 --> 00:16:27,920 and can operate up to a maximum of 100 meters 410 410 00:16:27,920 --> 00:16:30,720 at a speed of 10 gigabits per second. 411 411 00:16:30,720 --> 00:16:32,590 Finally, we have CAT 8 412 412 00:16:32,590 --> 00:16:35,320 which can operate 40GBASE-T networks, 413 413 00:16:35,320 --> 00:16:38,180 which is able to provide 40 gigabits per second, 414 414 00:16:38,180 --> 00:16:40,820 but only up to 30 meters. 415 415 00:16:40,820 --> 00:16:42,930 All right, let's summarize with a chart 416 416 00:16:42,930 --> 00:16:44,740 and see if we can find the easy way 417 417 00:16:44,740 --> 00:16:47,310 to memorize all of these different facts and figures. 418 418 00:16:47,310 --> 00:16:50,250 Starting with CAT 3 and going up to CAT 7, 419 419 00:16:50,250 --> 00:16:52,810 we can just start multiplying by 10 each time 420 420 00:16:52,810 --> 00:16:55,160 to get our bandwidth and our ethernet standards. 421 421 00:16:55,160 --> 00:16:57,730 So we go from 10 megabits per second 422 422 00:16:57,730 --> 00:16:59,390 to a hundred megabits per second, 423 423 00:16:59,390 --> 00:17:01,220 to a thousand megabits per second 424 424 00:17:01,220 --> 00:17:03,230 to 10 gigabits per second. 425 425 00:17:03,230 --> 00:17:04,930 for CAT 8, you just have to remember 426 426 00:17:04,930 --> 00:17:07,230 that it switches by multiplier of four, 427 427 00:17:07,230 --> 00:17:09,640 getting us up to 40 gigabits per second. 428 428 00:17:09,640 --> 00:17:12,400 Now for the distance, this is also pretty easy 429 429 00:17:12,400 --> 00:17:15,610 because it's almost always going to be 100 meters. 430 430 00:17:15,610 --> 00:17:17,210 Now, there are only two exceptions. 431 431 00:17:17,210 --> 00:17:18,980 So if you can remember the exceptions 432 432 00:17:18,980 --> 00:17:23,010 are CAT 6 at 55 meters and CAT 8 at 30 meters. 433 433 00:17:23,010 --> 00:17:24,090 Then you just need to remember 434 434 00:17:24,090 --> 00:17:26,560 the rest are all going to be 100 meters. 435 435 00:17:26,560 --> 00:17:29,170 Now let's talk about length for just a minute here, 436 436 00:17:29,170 --> 00:17:31,100 because you're going to get questions on the exam 437 437 00:17:31,100 --> 00:17:32,120 where the answer comes down 438 438 00:17:32,120 --> 00:17:34,210 to how long the cable is going to be. 439 439 00:17:34,210 --> 00:17:35,690 Now they will usually come straight out 440 440 00:17:35,690 --> 00:17:36,890 and ask you a question like 441 441 00:17:36,890 --> 00:17:39,500 what's the maximum length of a CAT 5e cable. 442 442 00:17:39,500 --> 00:17:41,330 That would be way too easy. 443 443 00:17:41,330 --> 00:17:43,410 So instead, they're usually going to incorporate 444 444 00:17:43,410 --> 00:17:45,650 it into some kind of troubleshooting question. 445 445 00:17:45,650 --> 00:17:48,840 For example, you might get something that looks like this. 446 446 00:17:48,840 --> 00:17:50,550 You working as a network technician 447 447 00:17:50,550 --> 00:17:52,050 and a user in the corner office 448 448 00:17:52,050 --> 00:17:53,540 is complaining that they're having intermittent 449 449 00:17:53,540 --> 00:17:56,800 network connectivity issues when using a CAT 5e cable 450 450 00:17:56,800 --> 00:17:58,440 and connect it to the LAN. 451 451 00:17:58,440 --> 00:18:00,090 Their office is 85 meters 452 452 00:18:00,090 --> 00:18:02,510 from the closest intermediate distribution frame. 453 453 00:18:02,510 --> 00:18:04,240 Which of the following might be the source 454 454 00:18:04,240 --> 00:18:05,960 of their connectivity issues? 455 455 00:18:05,960 --> 00:18:07,920 Then you might get some options like, 456 456 00:18:07,920 --> 00:18:09,590 the connection is set to half-duplex 457 457 00:18:09,590 --> 00:18:10,740 instead of full duplex, 458 458 00:18:10,740 --> 00:18:13,300 or the connection may have exceeded the maximum distance 459 459 00:18:13,300 --> 00:18:14,730 for a CAT 5e cable, 460 460 00:18:14,730 --> 00:18:18,110 or the connection is using WPA instead of WPA2, 461 461 00:18:18,110 --> 00:18:20,500 or the connection needs to be set to encrypted 462 462 00:18:20,500 --> 00:18:21,950 instead of un-encrypted. 463 463 00:18:21,950 --> 00:18:23,480 The answer here would be that the connection 464 464 00:18:23,480 --> 00:18:26,595 may have exceeded the maximum distance for a CAT 5e cable. 465 465 00:18:26,595 --> 00:18:28,520 But wait a minute, Jason, 466 466 00:18:28,520 --> 00:18:30,820 didn't you just say the maximum cable length 467 467 00:18:30,820 --> 00:18:31,990 was a hundred meters 468 468 00:18:31,990 --> 00:18:34,920 and this question said we were only 85 meters away. 469 469 00:18:34,920 --> 00:18:37,270 What the heck is going on here? 470 470 00:18:37,270 --> 00:18:41,090 Well, yes, the maximum cable length is a hundred meters, 471 471 00:18:41,090 --> 00:18:44,690 but that's often the maximum, not the minimum. 472 472 00:18:44,690 --> 00:18:46,590 Oftentimes in the real world, 473 473 00:18:46,590 --> 00:18:47,880 you're going to see that you can't get 474 474 00:18:47,880 --> 00:18:49,950 a full a hundred meters in cable length 475 475 00:18:49,950 --> 00:18:51,310 from these types of cables 476 476 00:18:51,310 --> 00:18:53,500 because there's interference from fluorescent lights 477 477 00:18:53,500 --> 00:18:55,500 and other sources of EMI. 478 478 00:18:55,500 --> 00:18:59,130 Also, the question said that the IDF was 85 meters away. 479 479 00:18:59,130 --> 00:19:01,880 Not that the cable length was 85 meters. 480 480 00:19:01,880 --> 00:19:04,630 So if the IDF is 85 meters away, 481 481 00:19:04,630 --> 00:19:06,050 you're still going to have to run that cable 482 482 00:19:06,050 --> 00:19:09,250 from the patch panel up from the IDF into the ceiling, 483 483 00:19:09,250 --> 00:19:11,410 and then from the ceiling over to the office 484 484 00:19:11,410 --> 00:19:13,920 and from the office ceiling down to the wall drop 485 485 00:19:13,920 --> 00:19:15,130 and then from the wall drop, 486 486 00:19:15,130 --> 00:19:17,720 you have a patch cable connecting to the computer. 487 487 00:19:17,720 --> 00:19:19,530 All of this is going to add length 488 488 00:19:19,530 --> 00:19:21,160 because going up and down to the ceiling 489 489 00:19:21,160 --> 00:19:23,230 might be another four or five meters. 490 490 00:19:23,230 --> 00:19:25,720 You might also have to go from that patch cable 491 491 00:19:25,720 --> 00:19:28,010 might be a 15 or 20 meter cable 492 492 00:19:28,010 --> 00:19:30,280 going from one side of the office to the other. 493 493 00:19:30,280 --> 00:19:32,120 You can't just assume that there's a straight line 494 494 00:19:32,120 --> 00:19:34,260 from the IDF to the corner office, 495 495 00:19:34,260 --> 00:19:36,320 because it might not be true. 496 496 00:19:36,320 --> 00:19:39,280 For this reason, I usually recommend keeping your cable runs 497 497 00:19:39,280 --> 00:19:40,930 under 70 meters in length 498 498 00:19:40,930 --> 00:19:42,970 when you're going from the IDF to the office 499 499 00:19:42,970 --> 00:19:44,440 that you want to run the jack to. 500 500 00:19:44,440 --> 00:19:47,550 This allows for the ups, downs, overs and arounds 501 501 00:19:47,550 --> 00:19:48,840 that you're going to actually have to do 502 502 00:19:48,840 --> 00:19:50,370 when you're running that cable. 503 503 00:19:50,370 --> 00:19:52,600 Now, would I expect you to get this question right 504 504 00:19:52,600 --> 00:19:54,330 if I asked it to you right now? 505 505 00:19:54,330 --> 00:19:56,460 Well, no, because we haven't even covered 506 506 00:19:56,460 --> 00:19:58,190 all the things covered in this question, 507 507 00:19:58,190 --> 00:20:00,960 like the intermediate distribution frame, patch panels, 508 508 00:20:00,960 --> 00:20:02,420 and other key components. 509 509 00:20:02,420 --> 00:20:04,850 But I wanted to give you an idea of how these questions 510 510 00:20:04,850 --> 00:20:07,670 are going to be worded and work together to combine concepts 511 511 00:20:07,670 --> 00:20:10,670 across different domains, into a single question. 512 512 00:20:10,670 --> 00:20:12,110 This question, for example, 513 513 00:20:12,110 --> 00:20:14,530 covered concepts from three different objectives, 514 514 00:20:14,530 --> 00:20:16,610 across three different domains. 515 515 00:20:16,610 --> 00:20:17,443 All right, 516 516 00:20:17,443 --> 00:20:19,260 so now that we've talked about the different cable types, 517 517 00:20:19,260 --> 00:20:21,040 their categories and the connections, 518 518 00:20:21,040 --> 00:20:23,290 we need to talk about how to actually wire these cables 519 519 00:20:23,290 --> 00:20:26,400 into the connectors to allow us to connect these things 520 520 00:20:26,400 --> 00:20:28,960 to our devices, using the right pinouts. 521 521 00:20:28,960 --> 00:20:31,650 On the exam, it would be completely fair of them 522 522 00:20:31,650 --> 00:20:33,560 to ask you to create a straight-through cable 523 523 00:20:33,560 --> 00:20:36,650 or a crossover cable, because one of the exam objectives 524 524 00:20:36,650 --> 00:20:38,210 states that you should be able to troubleshoot 525 525 00:20:38,210 --> 00:20:40,010 common cable connectivity issues 526 526 00:20:40,010 --> 00:20:42,970 using the appropriate tools, such as a cable stripper, 527 527 00:20:42,970 --> 00:20:45,120 cable crimper, and cable tester. 528 528 00:20:45,120 --> 00:20:47,150 So to ensure you're ready for that, 529 529 00:20:47,150 --> 00:20:50,170 we need to talk a bit more about the way the ends are wired 530 530 00:20:50,170 --> 00:20:52,310 and the proper sequence for the pinouts 531 531 00:20:52,310 --> 00:20:53,720 of these connectors. 532 532 00:20:53,720 --> 00:20:56,150 Now I just mentioned a term that you should be familiar with 533 533 00:20:56,150 --> 00:20:58,030 from backing your A-plus studies. 534 534 00:20:58,030 --> 00:20:59,850 But like I promised before, 535 535 00:20:59,850 --> 00:21:01,990 I'm going to do a quick refresher of this term 536 536 00:21:01,990 --> 00:21:04,630 to make sure everybody's on the same page. 537 537 00:21:04,630 --> 00:21:07,100 Now that term is a straight-through cable. 538 538 00:21:07,100 --> 00:21:10,390 A straight-through cable is also known as a patch cable. 539 539 00:21:10,390 --> 00:21:13,120 This type of cable contains the exact same pinouts 540 540 00:21:13,120 --> 00:21:14,770 on both ends of the cable. 541 541 00:21:14,770 --> 00:21:16,910 This is why it's known as a straight-through, 542 542 00:21:16,910 --> 00:21:19,520 because pin one on one side goes straight on through 543 543 00:21:19,520 --> 00:21:21,960 to pin one on the other side of the cable. 544 544 00:21:21,960 --> 00:21:24,470 Now, to keep everyone consistent when we make cables, 545 545 00:21:24,470 --> 00:21:26,260 you're going to find there's a standard pinout 546 546 00:21:26,260 --> 00:21:30,100 known as a 568A and a 568B standard. 547 547 00:21:30,100 --> 00:21:33,250 Now 568B is the standard that's preferred 548 548 00:21:33,250 --> 00:21:35,450 for wiring jacks inside your buildings. 549 549 00:21:35,450 --> 00:21:38,060 And most people are going to use a 568B 550 550 00:21:38,060 --> 00:21:42,070 to 568B wiring scheme for straight-through patch cables. 551 551 00:21:42,070 --> 00:21:43,810 Now, what does that look like? 552 552 00:21:43,810 --> 00:21:46,220 Well, if we count our pins from one to eight, 553 553 00:21:46,220 --> 00:21:49,290 we're going to have a color scheme of orange white, orange, 554 554 00:21:49,290 --> 00:21:53,970 green white, blue, blue white, green, brown white, brown. 555 555 00:21:53,970 --> 00:21:56,240 That is going from pins one to eight. 556 556 00:21:56,240 --> 00:21:59,180 So both sides of our cable will match up 557 557 00:21:59,180 --> 00:22:02,140 and this will create a straight-through patch cable. 558 558 00:22:02,140 --> 00:22:06,640 These patch cables are used to connect a DTE to a DCE. 559 559 00:22:06,640 --> 00:22:09,210 Now, what is a DTE and a DCE? 560 560 00:22:09,210 --> 00:22:12,230 Well, a DTE is a data terminal equipment, 561 561 00:22:12,230 --> 00:22:15,210 which includes things like laptops and desktops, servers, 562 562 00:22:15,210 --> 00:22:16,250 and routers. 563 563 00:22:16,250 --> 00:22:18,530 These are all considered end point devices 564 564 00:22:18,530 --> 00:22:21,400 that connect to a piece of data communications equipment 565 565 00:22:21,400 --> 00:22:23,040 or DCE. 566 566 00:22:23,040 --> 00:22:26,840 Now a DCE is things like a switch, a modem, a hub, 567 567 00:22:26,840 --> 00:22:28,050 or a bridge. 568 568 00:22:28,050 --> 00:22:31,250 If you're connecting a DTE to a DCE, 569 569 00:22:31,250 --> 00:22:36,250 or a DCE to a DTE, you can use a straight-through cable. 570 570 00:22:36,280 --> 00:22:38,650 Basically any terminal device can connect 571 571 00:22:38,650 --> 00:22:42,190 to any communication device using one of these patch cables. 572 572 00:22:42,190 --> 00:22:45,170 But if I wanted to connect a switch to another switch, 573 573 00:22:45,170 --> 00:22:47,590 since they're both data communication equipment, 574 574 00:22:47,590 --> 00:22:49,750 I have to use a different type of cable 575 575 00:22:49,750 --> 00:22:51,980 known as a crossover cable. 576 576 00:22:51,980 --> 00:22:55,280 Anytime you connect a DTE to a DTE, 577 577 00:22:55,280 --> 00:22:56,760 a terminal to a terminal 578 578 00:22:56,760 --> 00:22:59,370 or a DCE to a DCE, 579 579 00:22:59,370 --> 00:23:01,750 communication equipment to communication equipment, 580 580 00:23:01,750 --> 00:23:03,940 you have to use a crossover cable. 581 581 00:23:03,940 --> 00:23:06,810 So if I connect a computer to a laptop, 582 582 00:23:06,810 --> 00:23:08,990 that's going to need a crossover cable. 583 583 00:23:08,990 --> 00:23:11,820 If I'm connecting a computer to a switch, I don't need one. 584 584 00:23:11,820 --> 00:23:13,700 I can use a patch cable. 585 585 00:23:13,700 --> 00:23:17,270 So, what makes a crossover cable so special? 586 586 00:23:17,270 --> 00:23:18,600 Well across over cable 587 587 00:23:18,600 --> 00:23:20,550 is going to take your send and receive pins 588 588 00:23:20,550 --> 00:23:23,560 from that cable and swap those on the other end 589 589 00:23:23,560 --> 00:23:26,450 when you create your connector and you pin it out. 590 590 00:23:26,450 --> 00:23:30,170 So on one end, you're going to need to have a 568B, 591 591 00:23:30,170 --> 00:23:33,720 and on the other end, you're going to have a 568A. 592 592 00:23:33,720 --> 00:23:36,370 This is used to connect a workstation to a workstation 593 593 00:23:36,370 --> 00:23:38,210 or a switch to a switch. 594 594 00:23:38,210 --> 00:23:41,330 Now in general, you should always use a crossover cable 595 595 00:23:41,330 --> 00:23:43,620 when you're going from a switch to a switch. 596 596 00:23:43,620 --> 00:23:45,540 For the exam, I want you to remember 597 597 00:23:45,540 --> 00:23:49,050 that a switch to a switch requires a crossover cable. 598 598 00:23:49,050 --> 00:23:51,170 The reason I'm making a big deal about this 599 599 00:23:51,170 --> 00:23:54,220 is that in the real world, this isn't always the case. 600 600 00:23:54,220 --> 00:23:56,430 Now this is because most modern switches 601 601 00:23:56,430 --> 00:23:58,790 have something known as MDIX, 602 602 00:23:58,790 --> 00:24:02,020 which stands for medium dependent interface crossover. 603 603 00:24:02,020 --> 00:24:04,890 Essentially MDIX is an automated way 604 604 00:24:04,890 --> 00:24:07,950 to electronically simulate using a crossover cable 605 605 00:24:07,950 --> 00:24:10,590 even if you're using a straight-through patch cable. 606 606 00:24:10,590 --> 00:24:13,740 Essentially your modern switch, if it supports MDIX 607 607 00:24:13,740 --> 00:24:16,180 will allow you to use a patch or straight-through cable, 608 608 00:24:16,180 --> 00:24:19,540 and it will switch the pinout electronically inside itself 609 609 00:24:19,540 --> 00:24:20,830 to make it work. 610 610 00:24:20,830 --> 00:24:24,090 But for the exam, you should always assume a switch 611 611 00:24:24,090 --> 00:24:27,890 is going to be an older device that does not support MDIX, 612 612 00:24:27,890 --> 00:24:30,140 unless the question specifically states 613 613 00:24:30,140 --> 00:24:32,480 that the switch is using MDIX. 614 614 00:24:32,480 --> 00:24:34,930 Now we'll talk about this more when we go to troubleshooting 615 615 00:24:34,930 --> 00:24:37,740 way in the end of this course, but for right now, 616 616 00:24:37,740 --> 00:24:38,960 I wanted to bring this up 617 617 00:24:38,960 --> 00:24:41,310 because it's something that is going to come back and bite you 618 618 00:24:41,310 --> 00:24:42,770 if you don't remember it. 619 619 00:24:42,770 --> 00:24:44,670 Remember when there are two switches 620 620 00:24:44,670 --> 00:24:46,100 and they're not communicating 621 621 00:24:46,100 --> 00:24:48,890 it's usually because somebody is putting a patch cable there 622 622 00:24:48,890 --> 00:24:50,290 or a straight-through cable there 623 623 00:24:50,290 --> 00:24:52,430 instead of doing a crossover cable 624 624 00:24:52,430 --> 00:24:55,380 and that switch doesn't support MDIX. 625 625 00:24:55,380 --> 00:24:57,450 If your switch doesn't support MDIX, 626 626 00:24:57,450 --> 00:24:59,400 you have to use a crossover cable 627 627 00:24:59,400 --> 00:25:01,350 to make those devices talk. 628 628 00:25:01,350 --> 00:25:04,150 All right, let's look at the pinout a little bit closer, 629 629 00:25:04,150 --> 00:25:06,770 and this time let's look at our 568A 630 630 00:25:06,770 --> 00:25:09,330 and 568B wiring standards. 631 631 00:25:09,330 --> 00:25:12,010 Remember, 568B is the standard we use 632 632 00:25:12,010 --> 00:25:13,710 for all our interior wiring 633 633 00:25:13,710 --> 00:25:17,250 and for both ends of a straight-through cable or wall jack. 634 634 00:25:17,250 --> 00:25:19,640 But if we want to do a crossover cable, 635 635 00:25:19,640 --> 00:25:21,940 we're going to use 568B on one end 636 636 00:25:21,940 --> 00:25:24,090 and 568A on the other end. 637 637 00:25:24,090 --> 00:25:27,350 When you do this, you're going to start with 568B on one end, 638 638 00:25:27,350 --> 00:25:30,820 and then switch out pins one, two, three, and six 639 639 00:25:30,820 --> 00:25:31,850 on the other end, 640 640 00:25:31,850 --> 00:25:33,940 so that we have our transmit and receive pins 641 641 00:25:33,940 --> 00:25:37,240 in a different place when we create that crossover cable. 642 642 00:25:37,240 --> 00:25:39,360 Essentially your orange and your green pairs 643 643 00:25:39,360 --> 00:25:41,190 are going to swap places. 644 644 00:25:41,190 --> 00:25:43,000 Now, do you have to memorize this? 645 645 00:25:43,000 --> 00:25:45,010 Yes, unfortunately you do. 646 646 00:25:45,010 --> 00:25:47,500 In the real world, you really don't have to even memorize 647 647 00:25:47,500 --> 00:25:49,230 because you can carry your smartphone with you 648 648 00:25:49,230 --> 00:25:50,710 or a small chart in your pocket. 649 649 00:25:50,710 --> 00:25:52,140 And whenever you're going to make a cable, 650 650 00:25:52,140 --> 00:25:54,370 you could pull it out of your wallet and look at it. 651 651 00:25:54,370 --> 00:25:57,890 But for the exam, you need to know this pattern. 652 652 00:25:57,890 --> 00:26:00,550 As I said before, they may give you a question that says, 653 653 00:26:00,550 --> 00:26:04,240 wire up the correct pinout for a 568B connector. 654 654 00:26:04,240 --> 00:26:05,880 Then you're going to have to drag and drop 655 655 00:26:05,880 --> 00:26:07,760 the color of the wire to the right pin 656 656 00:26:07,760 --> 00:26:09,480 as part of a simulation. 657 657 00:26:09,480 --> 00:26:11,080 Or they can be really mean 658 658 00:26:11,080 --> 00:26:12,800 and just ask you to create a patch cable, 659 659 00:26:12,800 --> 00:26:14,170 or a crossover cable. 660 660 00:26:14,170 --> 00:26:16,340 And you're going to have to drag and drop the right wires 661 661 00:26:16,340 --> 00:26:19,270 into the right spots in an RJ45 connector 662 662 00:26:19,270 --> 00:26:21,800 from pins one to eight, for both sides. 663 663 00:26:21,800 --> 00:26:23,880 If that happens, you are really going to hope 664 664 00:26:23,880 --> 00:26:25,240 you have memorized the color schemes 665 665 00:26:25,240 --> 00:26:28,870 for both 568B and 568A, right? 666 666 00:26:28,870 --> 00:26:30,560 Now, the last thing we need to talk about 667 667 00:26:30,560 --> 00:26:32,040 in terms of copper cabling 668 668 00:26:32,040 --> 00:26:34,890 is the concept of plenum versus non plenum. 669 669 00:26:34,890 --> 00:26:37,070 So, what does plenum mean? 670 670 00:26:37,070 --> 00:26:39,300 Well, plenum cable is a special coating 671 671 00:26:39,300 --> 00:26:42,190 that's put on an unshielded or shielded twisted pair cable, 672 672 00:26:42,190 --> 00:26:44,530 and it provides a fire-retardant chemical layer 673 673 00:26:44,530 --> 00:26:47,320 to the outer insulating jacket of that cable. 674 674 00:26:47,320 --> 00:26:49,380 Now, if you have a plenum rated cable, 675 675 00:26:49,380 --> 00:26:51,420 this means it's more fire resistant, 676 676 00:26:51,420 --> 00:26:54,330 and it also minimizes the amount of dangerous fumes 677 677 00:26:54,330 --> 00:26:56,940 that are released if the cable catches on fire. 678 678 00:26:56,940 --> 00:26:58,480 If you're going to be running cables in a place 679 679 00:26:58,480 --> 00:27:01,320 that you physically can't see such as the ceiling, 680 680 00:27:01,320 --> 00:27:04,700 the walls, a raised floor, or near air ducts, 681 681 00:27:04,700 --> 00:27:07,210 you must use plenum cable per the laws 682 682 00:27:07,210 --> 00:27:09,150 and county requirements in your state 683 683 00:27:09,150 --> 00:27:11,000 or in the county in which you live. 684 684 00:27:11,000 --> 00:27:13,040 Now, plenum cable is a bit more expensive 685 685 00:27:13,040 --> 00:27:14,370 than non plenum cable, 686 686 00:27:14,370 --> 00:27:17,980 but it is a major safety issue to not use plenum cable. 687 687 00:27:17,980 --> 00:27:20,570 So you simply have to use plenum cable 688 688 00:27:20,570 --> 00:27:22,720 anytime you're going to put a cable in a place 689 689 00:27:22,720 --> 00:27:25,000 that your users can't visibly see. 690 690 00:27:25,000 --> 00:27:26,090 Now, on the other hand, 691 691 00:27:26,090 --> 00:27:27,820 if you're running a cable from a wall jack 692 692 00:27:27,820 --> 00:27:29,820 to the back of your desktop or laptop, 693 693 00:27:29,820 --> 00:27:32,630 you don't need to spend the extra money on plenum cable. 694 694 00:27:32,630 --> 00:27:33,720 For these connectors, 695 695 00:27:33,720 --> 00:27:35,430 it's okay to save a little bit of money 696 696 00:27:35,430 --> 00:27:37,940 by using these non plenum rated cables. 697 697 00:27:37,940 --> 00:27:40,820 Non plenum rated cables are also known as PVC, 698 698 00:27:40,820 --> 00:27:42,230 and they can either be shielded 699 699 00:27:42,230 --> 00:27:44,520 or unshielded twisted pair cables. 700 700 00:27:44,520 --> 00:27:46,560 Now on the exam, remember, 701 701 00:27:46,560 --> 00:27:49,210 plenum is for anything you cannot see, 702 702 00:27:49,210 --> 00:27:52,170 but again, you cannot put non plenum cables 703 703 00:27:52,170 --> 00:27:55,920 in your ceilings, walls, raised floors or air ducks. 704 704 00:27:55,920 --> 00:27:58,220 This is a big, big no-no, 705 705 00:27:58,220 --> 00:27:59,720 and it's a very dangerous thing 706 706 00:27:59,720 --> 00:28:02,120 for the safety of your networks and your people.