1 1 00:00:00,660 --> 00:00:02,360 Fiber cable issues. 2 2 00:00:02,360 --> 00:00:03,990 In this lesson, we're going to discuss 3 3 00:00:03,990 --> 00:00:06,650 the various fiber cable issues you may experience 4 4 00:00:06,650 --> 00:00:08,240 such as incorrect transceivers, 5 5 00:00:08,240 --> 00:00:09,900 transmit and receive being reversed, 6 6 00:00:09,900 --> 00:00:11,650 or dirty optical cables. 7 7 00:00:11,650 --> 00:00:13,560 Now, first, we might experience issues 8 8 00:00:13,560 --> 00:00:15,260 with incorrect transceivers. 9 9 00:00:15,260 --> 00:00:17,610 A transceiver is a transmitter and receiver 10 10 00:00:17,610 --> 00:00:19,170 in a single device. 11 11 00:00:19,170 --> 00:00:20,360 Transceivers are going to be used 12 12 00:00:20,360 --> 00:00:22,890 to convert a network connection from one type to another, 13 13 00:00:22,890 --> 00:00:25,650 and they work at layer one of the OSI model. 14 14 00:00:25,650 --> 00:00:26,970 In your routers and switches, 15 15 00:00:26,970 --> 00:00:29,700 it's common to use a transceiver for your fiber connections, 16 16 00:00:29,700 --> 00:00:32,050 but if you're going to be using the wrong transceiver, 17 17 00:00:32,050 --> 00:00:34,300 this connection simply won't work. 18 18 00:00:34,300 --> 00:00:36,780 Many transceivers are considered hot pluggable, 19 19 00:00:36,780 --> 00:00:38,240 and they can be taken out, replaced 20 20 00:00:38,240 --> 00:00:40,200 without shutting down the associate router, 21 21 00:00:40,200 --> 00:00:42,210 switch or SAN device. 22 22 00:00:42,210 --> 00:00:44,610 If a transceiver fails and you need to replace it, 23 23 00:00:44,610 --> 00:00:45,990 this becomes quite easy 24 24 00:00:45,990 --> 00:00:48,270 since you can simply unplug the bad transceiver 25 25 00:00:48,270 --> 00:00:49,870 and plug in your replacement. 26 26 00:00:49,870 --> 00:00:51,100 But you need to ensure 27 27 00:00:51,100 --> 00:00:52,670 you're using the correct transceiver, 28 28 00:00:52,670 --> 00:00:54,530 otherwise, you're going to have problems. 29 29 00:00:54,530 --> 00:00:57,180 If you put in the wrong type of SFP transceiver, 30 30 00:00:57,180 --> 00:00:58,400 you're going to have data loss 31 31 00:00:58,400 --> 00:01:00,620 line:15% and a loss of connectivity over time. 32 32 00:01:00,620 --> 00:01:02,460 line:15% Remember, transceivers are designed 33 33 00:01:02,460 --> 00:01:04,080 line:15% to support a certain type of connection 34 34 00:01:04,080 --> 00:01:05,750 line:15% and a certain type of cable. 35 35 00:01:05,750 --> 00:01:08,550 line:15% If you're using a long wave SFP transceiver, 36 36 00:01:08,550 --> 00:01:10,920 line:15% but then connect a short wave fiber cable to them, 37 37 00:01:10,920 --> 00:01:12,330 line:15% that's not going to work. 38 38 00:01:12,330 --> 00:01:14,840 line:15% Therefore, if you have a device that's no longer working 39 39 00:01:14,840 --> 00:01:16,950 line:15% and you recently changed out your transceiver, 40 40 00:01:16,950 --> 00:01:18,400 line:15% you should go back and double-check 41 41 00:01:18,400 --> 00:01:20,350 line:15% that you're using the right model for your device 42 42 00:01:20,350 --> 00:01:22,130 line:15% and your associate cabling. 43 43 00:01:22,130 --> 00:01:24,080 Next, we can sometimes have issues 44 44 00:01:24,080 --> 00:01:27,000 when our transmit and receive ends are being reversed. 45 45 00:01:27,000 --> 00:01:28,280 Now, while this may occur 46 46 00:01:28,280 --> 00:01:30,400 in a twisted pair network occasionally, 47 47 00:01:30,400 --> 00:01:32,140 this is really going to be the biggest issue 48 48 00:01:32,140 --> 00:01:34,270 inside your fiber-based networks. 49 49 00:01:34,270 --> 00:01:36,290 Remember, most of our fiber connections 50 50 00:01:36,290 --> 00:01:38,720 are going to consist of two individual cables, 51 51 00:01:38,720 --> 00:01:40,120 one for transmission of data 52 52 00:01:40,120 --> 00:01:42,010 and one for receiving that data. 53 53 00:01:42,010 --> 00:01:43,810 For example, if you're connecting a switch 54 54 00:01:43,810 --> 00:01:46,170 to a workstation using a network interface card 55 55 00:01:46,170 --> 00:01:47,970 that has ST connections on it, 56 56 00:01:47,970 --> 00:01:50,470 one of those is going to be labeled TX for transmit. 57 57 00:01:50,470 --> 00:01:52,990 The other one is going to be RX for receive. 58 58 00:01:52,990 --> 00:01:54,720 Now, if you connect the transmit cable 59 59 00:01:54,720 --> 00:01:55,970 to the RX connection, 60 60 00:01:55,970 --> 00:01:58,240 and the receive cable to the TX connection, 61 61 00:01:58,240 --> 00:01:59,750 you're not going to get a valid link 62 62 00:01:59,750 --> 00:02:01,300 or connection to that switch. 63 63 00:02:01,300 --> 00:02:04,270 If this happens, you can quickly identify and fix this 64 64 00:02:04,270 --> 00:02:07,210 by simply disconnecting the TX and RX port cables 65 65 00:02:07,210 --> 00:02:09,050 and swapping those cables. 66 66 00:02:09,050 --> 00:02:10,450 Then, when you do that, 67 67 00:02:10,450 --> 00:02:13,280 you can check the LED link activity lights on your NIC, 68 68 00:02:13,280 --> 00:02:15,890 and you're going to see the link is now online and available 69 69 00:02:15,890 --> 00:02:17,880 as indicated by a solid orange light 70 70 00:02:17,880 --> 00:02:19,050 or a blinking orange light 71 71 00:02:19,050 --> 00:02:21,820 if the network is actively communicating again. 72 72 00:02:21,820 --> 00:02:24,350 Finally, we have dirty optical cables. 73 73 00:02:24,350 --> 00:02:26,380 Dirty fiber optic cables and connectors 74 74 00:02:26,380 --> 00:02:28,070 can cause major performance issues 75 75 00:02:28,070 --> 00:02:30,440 or connection problems inside your network. 76 76 00:02:30,440 --> 00:02:32,850 A dirty fiber just means something is interfering 77 77 00:02:32,850 --> 00:02:35,240 with the clear optical connection between the cable, 78 78 00:02:35,240 --> 00:02:36,900 the connector, and the connection port 79 79 00:02:36,900 --> 00:02:38,380 for the fiber connection. 80 80 00:02:38,380 --> 00:02:40,050 Even something as small as some dust, 81 81 00:02:40,050 --> 00:02:41,570 or dirt, or your fingerprints 82 82 00:02:41,570 --> 00:02:43,180 can really severely block the light 83 83 00:02:43,180 --> 00:02:44,950 being sent down that cable. 84 84 00:02:44,950 --> 00:02:47,180 Now, remember, multi-mode fibers 85 85 00:02:47,180 --> 00:02:50,200 are only 50 to 62 microns in diameter, 86 86 00:02:50,200 --> 00:02:51,400 so it really doesn't take much 87 87 00:02:51,400 --> 00:02:53,210 to block these connections. 88 88 00:02:53,210 --> 00:02:55,410 If you find yourself with a dirty optical cable 89 89 00:02:55,410 --> 00:02:56,243 or connector, 90 90 00:02:56,243 --> 00:02:57,440 you really just need to clean it 91 91 00:02:57,440 --> 00:03:00,220 using a dry cleaning or wet cleaning method. 92 92 00:03:00,220 --> 00:03:02,570 Dry cleaning involves simply using light pressure 93 93 00:03:02,570 --> 00:03:04,730 while rubbing the end face of a fiber cable 94 94 00:03:04,730 --> 00:03:07,150 or connector using a dry cleaning cloth 95 95 00:03:07,150 --> 00:03:08,530 in one direction. 96 96 00:03:08,530 --> 00:03:10,650 This will usually be used when you need to clean dust 97 97 00:03:10,650 --> 00:03:12,680 or dirt off the face of a connector. 98 98 00:03:12,680 --> 00:03:15,670 This same technique can be used for a fiber connection port 99 99 00:03:15,670 --> 00:03:18,310 on a switch or network interface card too. 100 100 00:03:18,310 --> 00:03:20,130 Wet cleaning involves lightly moistening 101 101 00:03:20,130 --> 00:03:21,650 a piece of lint-free cloth 102 102 00:03:21,650 --> 00:03:23,400 with a fiber optic cleaning solution, 103 103 00:03:23,400 --> 00:03:25,160 and then wiping the end face of the cable 104 104 00:03:25,160 --> 00:03:27,040 in one direction as well. 105 105 00:03:27,040 --> 00:03:28,080 This cleaning solution 106 106 00:03:28,080 --> 00:03:31,330 should be 91% or higher isopropanol alcohol 107 107 00:03:31,330 --> 00:03:33,050 if you're using a solution. 108 108 00:03:33,050 --> 00:03:35,350 Now, wet cleaning is considered more invasive 109 109 00:03:35,350 --> 00:03:36,220 than dry cleaning, 110 110 00:03:36,220 --> 00:03:39,010 but it is useful when trying to remove oil residues 111 111 00:03:39,010 --> 00:03:41,530 or films off those cables and connectors, 112 112 00:03:41,530 --> 00:03:43,990 such as if somebody has put their fingerprints on them. 113 113 00:03:43,990 --> 00:03:45,180 You're going to have to use wet cleaning 114 114 00:03:45,180 --> 00:03:46,870 to get those fingerprints off. 115 115 00:03:46,870 --> 00:03:49,300 Now, if you start receiving a large amount of errors 116 116 00:03:49,300 --> 00:03:50,640 over a fiber connection, 117 117 00:03:50,640 --> 00:03:52,530 or your performance begins to slow down, 118 118 00:03:52,530 --> 00:03:53,910 it could be the indication 119 119 00:03:53,910 --> 00:03:56,150 that you need to clean a dirty fiber. 120 120 00:03:56,150 --> 00:03:58,070 This can also be quantitatively determined 121 121 00:03:58,070 --> 00:03:59,880 if you're using a fiber light meter, 122 122 00:03:59,880 --> 00:04:01,550 because you can compare the decibel reading 123 123 00:04:01,550 --> 00:04:03,450 from your baseline of a clean fiber 124 124 00:04:03,450 --> 00:04:04,963 versus this dirty fiber. 125 125 00:04:06,040 --> 00:04:08,281 (upbeat music)