1 1 00:00:00,680 --> 00:00:02,090 Transceivers. 2 2 00:00:02,090 --> 00:00:04,530 So at this point we've already discussed copper cables 3 3 00:00:04,530 --> 00:00:06,070 and fiber optic cables, 4 4 00:00:06,070 --> 00:00:08,130 but what's really the difference between these two 5 5 00:00:08,130 --> 00:00:10,070 and when should use each one? 6 6 00:00:10,070 --> 00:00:12,780 Well, when we compare copper versus fiber optic, 7 7 00:00:12,780 --> 00:00:15,460 we really need to compare it in four main areas, 8 8 00:00:15,460 --> 00:00:18,180 the speed of the bandwidth, the distance it can cover, 9 9 00:00:18,180 --> 00:00:19,990 how good it is against EMI 10 10 00:00:19,990 --> 00:00:22,210 and what kind of security it can give you. 11 11 00:00:22,210 --> 00:00:24,080 Now, when we deal with fiber optic cabling, 12 12 00:00:24,080 --> 00:00:26,010 it has a lot of advantages. 13 13 00:00:26,010 --> 00:00:27,870 It has a higher bandwidth than copper. 14 14 00:00:27,870 --> 00:00:30,250 It can cover a much larger distances than copper, 15 15 00:00:30,250 --> 00:00:33,200 it's immune to EMI because it's not using electricity 16 16 00:00:33,200 --> 00:00:35,270 and instead is using light to pass the data. 17 17 00:00:35,270 --> 00:00:38,100 And also it has better security because it's much harder 18 18 00:00:38,100 --> 00:00:40,860 to tap into and to be able to read those signals 19 19 00:00:40,860 --> 00:00:43,710 without using extremely expensive equipment. 20 20 00:00:43,710 --> 00:00:47,120 So for all these reasons, fiber is really great, 21 21 00:00:47,120 --> 00:00:50,110 but copper has a couple of benefits too. 22 22 00:00:50,110 --> 00:00:52,270 Copper cabling is less expensive. 23 23 00:00:52,270 --> 00:00:53,850 It's really easy to install, 24 24 00:00:53,850 --> 00:00:56,780 and the tools to work with it are really really inexpensive 25 25 00:00:56,780 --> 00:00:58,050 and really cheap. 26 26 00:00:58,050 --> 00:01:02,200 In fact, you can go on Amazon and get 100 RJ-45 connectors, 27 27 00:01:02,200 --> 00:01:03,620 a crimper and a tester 28 28 00:01:03,620 --> 00:01:06,330 for all less than about $10 in America. 29 29 00:01:06,330 --> 00:01:08,820 If you try to do the same thing for fiber optic cabling, 30 30 00:01:08,820 --> 00:01:11,530 it'll cost you several 100 dollars to get the pieces 31 31 00:01:11,530 --> 00:01:13,090 to build your own cable. 32 32 00:01:13,090 --> 00:01:15,990 So when you look at fiber versus copper cabling, 33 33 00:01:15,990 --> 00:01:18,150 I want you to remember that fiber is used 34 34 00:01:18,150 --> 00:01:20,580 when you need to cover a really long distance. 35 35 00:01:20,580 --> 00:01:24,010 Remember fiber optic cables can go up to 40 kilometers 36 36 00:01:24,010 --> 00:01:26,200 or more, and they carry much higher speeds 37 37 00:01:26,200 --> 00:01:27,650 than copper cables. 38 38 00:01:27,650 --> 00:01:29,940 Fiber optic cabling can even reach speeds 39 39 00:01:29,940 --> 00:01:32,220 of 60 to 70 terabytes or more. 40 40 00:01:32,220 --> 00:01:34,740 It can be extremely fast. 41 41 00:01:34,740 --> 00:01:38,330 Copper on the other hand can go relatively short distances. 42 42 00:01:38,330 --> 00:01:40,910 If you're dealing with CAT 3 through CAT 7 cables, 43 43 00:01:40,910 --> 00:01:43,500 you'll remember we can't go higher than a 100 meters 44 44 00:01:43,500 --> 00:01:45,310 without losing our signal. 45 45 00:01:45,310 --> 00:01:47,590 Copper cabling is also much slower. 46 46 00:01:47,590 --> 00:01:50,370 Today it's common to find speeds up to 10 gigabits 47 47 00:01:50,370 --> 00:01:53,160 per second, and distance is limited to a 100 meters, 48 48 00:01:53,160 --> 00:01:55,180 if you're using a CAT 7 cable. 49 49 00:01:55,180 --> 00:01:57,450 Now, if you use the newest cable CAT 8, 50 50 00:01:57,450 --> 00:02:00,800 you can reach speeds of 25 to 40 gigabits per second, 51 51 00:02:00,800 --> 00:02:04,090 but you can only go 30 meters before the signal starts 52 52 00:02:04,090 --> 00:02:05,950 deteriorating and you start losing it 53 53 00:02:05,950 --> 00:02:07,820 due to single attenuation. 54 54 00:02:07,820 --> 00:02:11,070 This way, your connection will start slowing or failing. 55 55 00:02:11,070 --> 00:02:14,330 Now 10 gigabits per second is pretty fast over copper, 56 56 00:02:14,330 --> 00:02:16,320 if we want to stick with CAT 7 cabling, 57 57 00:02:16,320 --> 00:02:19,480 and this is pretty fast for most home and office networks 58 58 00:02:19,480 --> 00:02:20,760 that you might be using. 59 59 00:02:20,760 --> 00:02:23,200 But if you're going to be using a long-haul circuit, 60 60 00:02:23,200 --> 00:02:26,100 or you need something faster than 10 gigabits per second, 61 61 00:02:26,100 --> 00:02:28,210 you definitely want to consider using fiber, 62 62 00:02:28,210 --> 00:02:29,960 because its benefits are going to outweigh 63 63 00:02:29,960 --> 00:02:32,220 the limitations of copper cabling. 64 64 00:02:32,220 --> 00:02:33,740 So as you can see, 65 65 00:02:33,740 --> 00:02:35,540 sometimes you're going to want to use copper, 66 66 00:02:35,540 --> 00:02:37,540 and sometimes you're going to want to use fiber. 67 67 00:02:37,540 --> 00:02:39,240 If you're dealing with your local area network, 68 68 00:02:39,240 --> 00:02:41,110 you're probably going to be using copper. 69 69 00:02:41,110 --> 00:02:43,160 You start dealing with a man or a win, 70 70 00:02:43,160 --> 00:02:45,150 you might be moving up to fiber. 71 71 00:02:45,150 --> 00:02:47,980 So let's say I decide to use a fiber cable to cover 72 72 00:02:47,980 --> 00:02:50,150 a 30 mile distance, going across the city 73 73 00:02:50,150 --> 00:02:51,910 between two office buildings. 74 74 00:02:51,910 --> 00:02:54,080 That is considered my long-haul circuit 75 75 00:02:54,080 --> 00:02:56,890 or a Wing Connection for this particular network. 76 76 00:02:56,890 --> 00:02:59,880 Now, once that fiber reaches my building across town, 77 77 00:02:59,880 --> 00:03:01,750 I need to connect my network to it. 78 78 00:03:01,750 --> 00:03:04,230 But if it's like most office networks, 79 79 00:03:04,230 --> 00:03:06,230 it's going to be made up of copper cabling 80 80 00:03:06,230 --> 00:03:08,880 and all the switches are going to support copper cables 81 81 00:03:08,880 --> 00:03:11,400 like CAT 6 or CAT 7 as well. 82 82 00:03:11,400 --> 00:03:14,020 So now that the fiber has gotten to my building, 83 83 00:03:14,020 --> 00:03:17,360 how can I transfer that fiber back into my copper network 84 84 00:03:17,360 --> 00:03:19,920 so I can operate with the rest of my lane? 85 85 00:03:19,920 --> 00:03:22,430 Well, that's the idea of where media converters 86 86 00:03:22,430 --> 00:03:23,600 come into play. 87 87 00:03:23,600 --> 00:03:27,100 A media converter or a transceiver is used to convert media 88 88 00:03:27,100 --> 00:03:30,500 from one format to another, like going fiber to copper 89 89 00:03:30,500 --> 00:03:32,100 or copper to fiber. 90 90 00:03:32,100 --> 00:03:34,920 These are considered a layer one device because all they do 91 91 00:03:34,920 --> 00:03:37,500 is take a signal in convert it and repeat it 92 92 00:03:37,500 --> 00:03:38,950 out the other side. 93 93 00:03:38,950 --> 00:03:41,110 For example, if I have a media converter 94 94 00:03:41,110 --> 00:03:42,800 that takes in a fiber connection, 95 95 00:03:42,800 --> 00:03:45,360 like an ST connector stick and twist, 96 96 00:03:45,360 --> 00:03:48,400 I can then take that in transmit that fiber 97 97 00:03:48,400 --> 00:03:51,550 to this transceiver, and then I can convert it 98 98 00:03:51,550 --> 00:03:55,020 and send it out the other side as an RJ 45 connector. 99 99 00:03:55,020 --> 00:03:57,690 That way I can then connect it to a CAT 5, 100 100 00:03:57,690 --> 00:04:00,620 six or seven cable and go into a switch. 101 101 00:04:00,620 --> 00:04:03,830 This is the idea of using a media converter or transceiver. 102 102 00:04:03,830 --> 00:04:06,270 Essentially we can take input from fiber 103 103 00:04:06,270 --> 00:04:07,930 and send the output to copper. 104 104 00:04:07,930 --> 00:04:09,790 And we'll receive information from the copper 105 105 00:04:09,790 --> 00:04:12,240 side of the network, we can convert it and send it back out 106 106 00:04:12,240 --> 00:04:13,940 the fiber side too. 107 107 00:04:13,940 --> 00:04:17,060 Basically media converters and transceivers are just used 108 108 00:04:17,060 --> 00:04:20,580 to convert copper to fiber optic, fiber optic to copper, 109 109 00:04:20,580 --> 00:04:22,790 but we can also use them for coaxial the fiber 110 110 00:04:22,790 --> 00:04:25,610 or fiber to coaxial or any other layer one, 111 111 00:04:25,610 --> 00:04:27,680 to layer one conversion you may need to do 112 112 00:04:27,680 --> 00:04:29,160 within your networks. 113 113 00:04:29,160 --> 00:04:31,110 These transceivers are simply a device 114 114 00:04:31,110 --> 00:04:33,240 that send and receive data. 115 115 00:04:33,240 --> 00:04:35,630 Transceivers are transmit receivers. 116 116 00:04:35,630 --> 00:04:39,340 They can operate either bi-directional or full-duplex modes. 117 117 00:04:39,340 --> 00:04:41,860 Now we haven't talked a lot about bi-directional versus 118 118 00:04:41,860 --> 00:04:43,420 duplex communication yet. 119 119 00:04:43,420 --> 00:04:46,320 So let's stop and cover that for a moment here. 120 120 00:04:46,320 --> 00:04:48,450 If a communication is bi-directional, 121 121 00:04:48,450 --> 00:04:51,030 that means it has to take turns when communicating. 122 122 00:04:51,030 --> 00:04:54,130 So if you use a walkie-talkie as a kid in the old days, 123 123 00:04:54,130 --> 00:04:55,950 you might be familiar with this concept. 124 124 00:04:55,950 --> 00:04:58,600 You'd pick up the walkie-talkie and you'd press the button 125 125 00:04:58,600 --> 00:04:59,860 and you'd say something. 126 126 00:04:59,860 --> 00:05:02,610 Now, while you were talking, your buddy on the other side 127 127 00:05:02,610 --> 00:05:04,510 had the other walkie-talkie, but they couldn't 128 128 00:05:04,510 --> 00:05:06,260 key up and talk at the same time, 129 129 00:05:06,260 --> 00:05:08,840 because it's using bi-directional communication. 130 130 00:05:08,840 --> 00:05:12,130 One person talks, and the other person has to listen. 131 131 00:05:12,130 --> 00:05:13,750 This way we take turns. 132 132 00:05:13,750 --> 00:05:16,800 This is also known as half-duplex because only one side 133 133 00:05:16,800 --> 00:05:18,730 of the connection can use all the bandwidth 134 134 00:05:18,730 --> 00:05:20,200 at any given time. 135 135 00:05:20,200 --> 00:05:23,280 So when your friend is talking, you have to listen. 136 136 00:05:23,280 --> 00:05:25,720 If you're talking, your friend has to listen. 137 137 00:05:25,720 --> 00:05:28,070 You both can't talk at the same time. 138 138 00:05:28,070 --> 00:05:30,770 This is a half-duplex communication. 139 139 00:05:30,770 --> 00:05:33,270 Now, the other way we can communicate is using something 140 140 00:05:33,270 --> 00:05:34,900 called full-duplex. 141 141 00:05:34,900 --> 00:05:37,580 Full-duplex mode allows both devices to communicate 142 142 00:05:37,580 --> 00:05:40,840 at the same time and they have access to the bandwidth 143 143 00:05:40,840 --> 00:05:42,090 and they share it. 144 144 00:05:42,090 --> 00:05:43,760 This is like, if you were going to pick up the phone 145 145 00:05:43,760 --> 00:05:47,120 and call me both you and I can talk simultaneously, 146 146 00:05:47,120 --> 00:05:48,660 you can talk and I can listen, 147 147 00:05:48,660 --> 00:05:50,470 or I can talk and you can listen. 148 148 00:05:50,470 --> 00:05:52,830 This would happen just like half-duplex mode. 149 149 00:05:52,830 --> 00:05:55,080 But if I said something you don't like, 150 150 00:05:55,080 --> 00:05:57,950 you can actually shout over me because we have the ability 151 151 00:05:57,950 --> 00:05:59,710 to talk at the same time. 152 152 00:05:59,710 --> 00:06:02,840 This is why it's called full-duplex communication. 153 153 00:06:02,840 --> 00:06:04,960 With the walkie-talkie, we couldn't do that 154 154 00:06:04,960 --> 00:06:06,550 because we were using bi-directional, 155 155 00:06:06,550 --> 00:06:08,260 half-duplex communication, 156 156 00:06:08,260 --> 00:06:10,860 but with the full-duplex capability of a telephone, 157 157 00:06:10,860 --> 00:06:13,790 we can both talk and listen at the same time. 158 158 00:06:13,790 --> 00:06:14,950 Now with that said, 159 159 00:06:14,950 --> 00:06:17,740 let's go back to our discussion of transceivers. 160 160 00:06:17,740 --> 00:06:20,270 You actually find that in a lot of large networks, 161 161 00:06:20,270 --> 00:06:22,130 you're going to end up using these transceivers 162 162 00:06:22,130 --> 00:06:24,620 or transmit receivers a lot. 163 163 00:06:24,620 --> 00:06:29,180 For example, we have a thing called the GBIC module, GBIC. 164 164 00:06:29,180 --> 00:06:31,650 This is going to exist in our routers and our switches. 165 165 00:06:31,650 --> 00:06:34,830 Now a GBIC is a standard hot-pluggable gigabit ethernet 166 166 00:06:34,830 --> 00:06:37,430 transceiver that can take in copper or fiber 167 167 00:06:37,430 --> 00:06:38,550 as its connector. 168 168 00:06:38,550 --> 00:06:40,000 Now, in addition to GBIC, 169 169 00:06:40,000 --> 00:06:42,210 we also have some newer variants of these. 170 170 00:06:42,210 --> 00:06:44,080 For instance, we have an SFP 171 171 00:06:44,080 --> 00:06:46,330 or a small form-factor pluggable. 172 172 00:06:46,330 --> 00:06:49,710 An SFP is a smaller module than a GBIC, and it's basically 173 173 00:06:49,710 --> 00:06:52,860 a compact and hot-pluggable optical module 174 174 00:06:52,860 --> 00:06:55,230 that's used with fiber connections and it could be plugged 175 175 00:06:55,230 --> 00:06:57,240 in or out of that switch or router 176 176 00:06:57,240 --> 00:06:59,110 without turning off the device. 177 177 00:06:59,110 --> 00:07:03,320 Now, an SFP is a transceiver and it supports up to 4.25 178 178 00:07:03,320 --> 00:07:05,330 gigabytes per second of speed. 179 179 00:07:05,330 --> 00:07:09,340 Sometimes you're going to hear an SFP called a mini GBIC 180 180 00:07:09,340 --> 00:07:12,700 because it's about half the size of a standard GBIC module. 181 181 00:07:12,700 --> 00:07:16,480 The next transceiver you might find is known as an SFP+ 182 182 00:07:16,480 --> 00:07:19,990 or small form-factor pluggable plus module. 183 183 00:07:19,990 --> 00:07:24,450 It's essentially a faster version of an SFP instead of 4.25 184 184 00:07:24,450 --> 00:07:26,770 gigabytes per second, we're going to be able to support 185 185 00:07:26,770 --> 00:07:28,240 10 gigabytes per second. 186 186 00:07:28,240 --> 00:07:31,700 So it's about twice as fast as a regular SFP. 187 187 00:07:31,700 --> 00:07:34,460 Now moving into faster and faster modules, 188 188 00:07:34,460 --> 00:07:38,990 we have a QSFP or a Quad Small Form-factor Plugable. 189 189 00:07:38,990 --> 00:07:42,360 Again, this is another type of optical module transceiver, 190 190 00:07:42,360 --> 00:07:46,830 just like SFP, just like SFP+, and just like GBIC. 191 191 00:07:46,830 --> 00:07:47,900 The big difference here 192 192 00:07:47,900 --> 00:07:50,120 is that it's going faster and faster. 193 193 00:07:50,120 --> 00:07:53,620 This time we can go about 40 gigabytes per second. 194 194 00:07:53,620 --> 00:07:56,240 Then we have QSFP+, 195 195 00:07:56,240 --> 00:07:59,800 this is a Quad Small Form-factor pluggable plus. 196 196 00:07:59,800 --> 00:08:03,050 As you might've guessed, it is just like a QSFP, 197 197 00:08:03,050 --> 00:08:04,540 but it's faster. 198 198 00:08:04,540 --> 00:08:08,980 It's another optical module, just like QSFP, SFP+, 199 199 00:08:08,980 --> 00:08:10,730 SFP and GBIC. 200 200 00:08:10,730 --> 00:08:13,160 But it's going to operate at faster speeds. 201 201 00:08:13,160 --> 00:08:16,790 This one can go up to 41.2 gigabytes per second. 202 202 00:08:16,790 --> 00:08:21,240 Now there's also newer variants of QSFP like QSFP 28, 203 203 00:08:21,240 --> 00:08:23,760 which operates up to 100 gigabytes per second. 204 204 00:08:23,760 --> 00:08:28,520 And QSFP 56, which operates up to 200 gigabytes per second. 205 205 00:08:28,520 --> 00:08:30,080 Now, at the end of the day, though, 206 206 00:08:30,080 --> 00:08:32,540 these are all just different types of transceivers 207 207 00:08:32,540 --> 00:08:35,470 converting the light that travels over a fiber optic cable 208 208 00:08:35,470 --> 00:08:38,390 into an electrical one or zero that our copper network 209 209 00:08:38,390 --> 00:08:41,170 switches and cables are going to be able to utilize. 210 210 00:08:41,170 --> 00:08:43,560 All of these pluggable modules are installed directly 211 211 00:08:43,560 --> 00:08:44,980 into a switch or router. 212 212 00:08:44,980 --> 00:08:47,690 But sometimes you need to run a fiber optic cable 213 213 00:08:47,690 --> 00:08:50,190 for a single workstation or a single server 214 214 00:08:50,190 --> 00:08:52,010 because it's beyond the a 100 meter limit 215 215 00:08:52,010 --> 00:08:55,320 of your traditional CAT 5, six or seven cables. 216 216 00:08:55,320 --> 00:08:57,000 Now you can do that as well. 217 217 00:08:57,000 --> 00:09:00,070 You simply need to use a media converter or transceiver 218 218 00:09:00,070 --> 00:09:02,910 to convert the copper cable to fiber on one end, 219 219 00:09:02,910 --> 00:09:05,430 then you run your fiber cable and on the other end, 220 220 00:09:05,430 --> 00:09:08,020 you put another media converter to go from fiber 221 221 00:09:08,020 --> 00:09:09,380 back to copper. 222 222 00:09:09,380 --> 00:09:11,490 This essentially converts an electrical signal 223 223 00:09:11,490 --> 00:09:12,700 to an optical signal, 224 224 00:09:12,700 --> 00:09:14,780 that can be pushed over a long distance, 225 225 00:09:14,780 --> 00:09:16,580 and then converting it back on the other side 226 226 00:09:16,580 --> 00:09:18,000 into an electrical signal, 227 227 00:09:18,000 --> 00:09:19,940 to push it back into a copper cable 228 228 00:09:19,940 --> 00:09:21,670 where it can reach your network adapter 229 229 00:09:21,670 --> 00:09:23,570 and go back into your computer. 230 230 00:09:23,570 --> 00:09:26,260 So if you ever need to switch the physical format 231 231 00:09:26,260 --> 00:09:29,610 of your networks to cross a greater distance, have no fear. 232 232 00:09:29,610 --> 00:09:32,950 You can convert that CAT 7 cable into a fiber optic cable 233 233 00:09:32,950 --> 00:09:35,330 simply by using a stand-alone media converter 234 234 00:09:35,330 --> 00:09:37,960 or transceiver, send it over a couple of miles 235 235 00:09:37,960 --> 00:09:40,230 across your campus or across your city. 236 236 00:09:40,230 --> 00:09:42,290 And then reconvert it on the other side 237 237 00:09:42,290 --> 00:09:44,723 with another media converter or transceiver.