1 00:00:00,210 --> 00:00:01,043 In this lesson, 2 00:00:01,043 --> 00:00:03,870 we're going to discuss Power over Ethernet issues. 3 00:00:03,870 --> 00:00:05,790 Power over Ethernet is a technology 4 00:00:05,790 --> 00:00:08,400 that allows network cables to carry both electrical power 5 00:00:08,400 --> 00:00:10,650 and data over a single line. 6 00:00:10,650 --> 00:00:12,330 Power over Ethernet is really useful 7 00:00:12,330 --> 00:00:14,880 for devices like IP cameras, VoIP phones, 8 00:00:14,880 --> 00:00:16,470 and Wi-Fi access points 9 00:00:16,470 --> 00:00:18,180 because it enables them to receive power 10 00:00:18,180 --> 00:00:20,760 and data through the same copper network cable. 11 00:00:20,760 --> 00:00:23,430 By using a single cable for both data and power, 12 00:00:23,430 --> 00:00:24,870 we can simplify our cabling 13 00:00:24,870 --> 00:00:26,910 and reduce the need for additional power sources 14 00:00:26,910 --> 00:00:28,800 for our endpoint devices. 15 00:00:28,800 --> 00:00:31,140 Now, Power over Ethernet comes in two varieties, 16 00:00:31,140 --> 00:00:33,450 known as Power over Ethernet, or PoE, 17 00:00:33,450 --> 00:00:36,630 and Power over Ethernet Plus, or PoE+. 18 00:00:36,630 --> 00:00:39,000 PoE and PoE+ are actually governed 19 00:00:39,000 --> 00:00:41,310 by different IEEE standards though. 20 00:00:41,310 --> 00:00:43,320 Power over Ethernet, or PoE, 21 00:00:43,320 --> 00:00:47,430 is defined by the IEEE 802.3af standard. 22 00:00:47,430 --> 00:00:49,500 Now, this PoE standard was the first one 23 00:00:49,500 --> 00:00:50,730 to be widely adopted, 24 00:00:50,730 --> 00:00:53,550 and it has the ability to provide up to 15.4 watts 25 00:00:53,550 --> 00:00:56,520 of DC power to each of your endpoint devices. 26 00:00:56,520 --> 00:00:58,950 With PoE though, there's actually some power loss 27 00:00:58,950 --> 00:01:00,270 that occurs as the power moves 28 00:01:00,270 --> 00:01:01,920 from the Power over Ethernet switch 29 00:01:01,920 --> 00:01:03,690 across the copper network cabling 30 00:01:03,690 --> 00:01:05,400 and over to the endpoint device. 31 00:01:05,400 --> 00:01:07,620 So the actual minimum guaranteed power available 32 00:01:07,620 --> 00:01:10,860 to your endpoint device is only going to be 12.95 watts 33 00:01:10,860 --> 00:01:12,840 of DC power instead. 34 00:01:12,840 --> 00:01:15,780 Now, Power over Ethernet Plus, or PoE+, 35 00:01:15,780 --> 00:01:19,860 is defined by the IEEE 802.3at standard. 36 00:01:19,860 --> 00:01:22,980 This PoE+ standard was developed as an enhanced version 37 00:01:22,980 --> 00:01:25,590 of the older Power over Ethernet standard. 38 00:01:25,590 --> 00:01:27,120 Now, one of the biggest changes from PoE 39 00:01:27,120 --> 00:01:29,640 to PoE+ was the increasing the amount 40 00:01:29,640 --> 00:01:31,830 of power available for your endpoint devices 41 00:01:31,830 --> 00:01:35,670 because PoE+ can now provide up to 30 watts of DC power 42 00:01:35,670 --> 00:01:37,710 to each of your endpoint devices. 43 00:01:37,710 --> 00:01:39,930 Similar to PoE though, there is power loss 44 00:01:39,930 --> 00:01:41,610 that occurs over the network cable, 45 00:01:41,610 --> 00:01:43,710 so the actual minimum guaranteed power available 46 00:01:43,710 --> 00:01:44,910 at the endpoint device 47 00:01:44,910 --> 00:01:48,630 is only going to be 25.5 watts of DC power. 48 00:01:48,630 --> 00:01:51,100 Now, despite the advantages of using something like PoE 49 00:01:51,100 --> 00:01:53,250 and PoE+, there are some issues 50 00:01:53,250 --> 00:01:55,380 that arise when you implement Power over Ethernet 51 00:01:55,380 --> 00:01:56,910 in your enterprise networks, 52 00:01:56,910 --> 00:01:58,530 including things like errors associated 53 00:01:58,530 --> 00:02:00,210 with the power budget being exceeded 54 00:02:00,210 --> 00:02:02,520 and the incorrect standard being selected. 55 00:02:02,520 --> 00:02:05,610 Now, first, we have the power budget exceeded error. 56 00:02:05,610 --> 00:02:08,340 The power budget exceeded error occurs when the power demand 57 00:02:08,340 --> 00:02:10,050 from the connected endpoint device 58 00:02:10,050 --> 00:02:11,880 exceeds the power supply capacity 59 00:02:11,880 --> 00:02:13,530 of the Power over Ethernet switch 60 00:02:13,530 --> 00:02:15,390 or power ejection device. 61 00:02:15,390 --> 00:02:17,940 Each PoE switch or injector is going to be designed 62 00:02:17,940 --> 00:02:20,550 with a maximum power capacity that it can deliver. 63 00:02:20,550 --> 00:02:23,280 This capacity is known as the power budget. 64 00:02:23,280 --> 00:02:25,110 Now, this power budget is the sum of all 65 00:02:25,110 --> 00:02:26,700 of the DC power available to all 66 00:02:26,700 --> 00:02:29,130 of your endpoint devices connected to that switch, 67 00:02:29,130 --> 00:02:30,600 not just the amount of power available 68 00:02:30,600 --> 00:02:32,280 on a single switch port. 69 00:02:32,280 --> 00:02:34,350 Now, whenever the cumulative power requirement for all 70 00:02:34,350 --> 00:02:36,690 of your connected endpoint devices gets exceeded, 71 00:02:36,690 --> 00:02:38,490 your network is going to start to have issues 72 00:02:38,490 --> 00:02:40,980 with your PoE-supported endpoint devices. 73 00:02:40,980 --> 00:02:43,530 For example, those devices may randomly begin 74 00:02:43,530 --> 00:02:46,650 to restart themselves, or they may refuse to power on, 75 00:02:46,650 --> 00:02:49,680 or they may behave erratically in some way. 76 00:02:49,680 --> 00:02:52,020 To resolve the power budget exceeded error, 77 00:02:52,020 --> 00:02:53,940 you should first check the power requirements for each 78 00:02:53,940 --> 00:02:55,860 of your connected endpoint devices. 79 00:02:55,860 --> 00:02:57,870 Then you need to add up the power requirements 80 00:02:57,870 --> 00:03:00,660 for all of those connected devices and compare that value 81 00:03:00,660 --> 00:03:02,400 with the total power budget available 82 00:03:02,400 --> 00:03:04,260 for your Power over Ethernet source, 83 00:03:04,260 --> 00:03:06,750 such as your PoE-enabled network switch. 84 00:03:06,750 --> 00:03:08,430 Then, if the total you calculate 85 00:03:08,430 --> 00:03:10,650 exceeds your available power budget, you need 86 00:03:10,650 --> 00:03:13,200 to start considering removing some non-essential devices 87 00:03:13,200 --> 00:03:15,000 to reduce the required power levels, 88 00:03:15,000 --> 00:03:17,250 or you need to upgrade your PoE source, 89 00:03:17,250 --> 00:03:18,570 like your network switch to one 90 00:03:18,570 --> 00:03:20,940 that has a higher overall power budget. 91 00:03:20,940 --> 00:03:23,640 Second, we have an incorrect standard error. 92 00:03:23,640 --> 00:03:24,960 As discussed earlier, 93 00:03:24,960 --> 00:03:27,060 Power over Ethernet comes in two varieties 94 00:03:27,060 --> 00:03:31,050 that rely on the two different standards of PoE and PoE+. 95 00:03:31,050 --> 00:03:33,360 If you're trying to run a PoE+ endpoint device 96 00:03:33,360 --> 00:03:35,340 that's expecting to receive a maximum of 30 watts 97 00:03:35,340 --> 00:03:38,700 of DC power, but you're connecting it to an older PoE switch 98 00:03:38,700 --> 00:03:41,850 that only can provide 15.4 watts of DC power, 99 00:03:41,850 --> 00:03:44,370 this will start to cause issues for that endpoint device 100 00:03:44,370 --> 00:03:46,560 and it will fail to work properly. 101 00:03:46,560 --> 00:03:49,140 Now, if you have a mismatch between the PoE device standard 102 00:03:49,140 --> 00:03:51,090 that you need to use and the PoE standard 103 00:03:51,090 --> 00:03:53,220 that your PoE enabled switch can provide, 104 00:03:53,220 --> 00:03:54,090 this will also lead 105 00:03:54,090 --> 00:03:56,370 to an incorrect standard error occurring. 106 00:03:56,370 --> 00:03:58,290 To resolve an incorrect standard error, 107 00:03:58,290 --> 00:03:59,940 you should first check the PoE standard 108 00:03:59,940 --> 00:04:01,950 that's being supported by both the endpoint device 109 00:04:01,950 --> 00:04:03,780 and the PoE-enabled switch. 110 00:04:03,780 --> 00:04:05,880 Then you should ensure there is compatibility 111 00:04:05,880 --> 00:04:07,650 between those two devices. 112 00:04:07,650 --> 00:04:09,780 For example, I've used some endpoint devices 113 00:04:09,780 --> 00:04:12,420 like VoIP phones that can be powered by either a PoE 114 00:04:12,420 --> 00:04:14,970 or PoE+ enabled network device. 115 00:04:14,970 --> 00:04:17,100 In this case, the VoIP phone could be configured 116 00:04:17,100 --> 00:04:19,019 to use either of those two standards, 117 00:04:19,019 --> 00:04:21,240 but I've also used some video-based phone 118 00:04:21,240 --> 00:04:22,680 that will only support receiving power 119 00:04:22,680 --> 00:04:24,990 from a PoE+ enabled network device 120 00:04:24,990 --> 00:04:27,570 because those endpoint devices require the maximum 121 00:04:27,570 --> 00:04:29,640 of 30 watts of DC power to be able 122 00:04:29,640 --> 00:04:31,920 to power on and operate efficiently. 123 00:04:31,920 --> 00:04:34,590 If you connected one of these PoE+ only client devices 124 00:04:34,590 --> 00:04:36,270 to a regular PoE switch, 125 00:04:36,270 --> 00:04:38,100 the device will either not function properly, 126 00:04:38,100 --> 00:04:39,990 or it simply won't power up 127 00:04:39,990 --> 00:04:41,880 because you're using that older PoE connection 128 00:04:41,880 --> 00:04:44,070 and it's not providing enough power. 129 00:04:44,070 --> 00:04:45,240 Now, if you have a mismatch 130 00:04:45,240 --> 00:04:46,073 where your network switch 131 00:04:46,073 --> 00:04:48,360 can't support the newer PoE+ standard, 132 00:04:48,360 --> 00:04:49,680 you can either replace that switch 133 00:04:49,680 --> 00:04:52,170 with a newer one that does support PoE+, 134 00:04:52,170 --> 00:04:54,900 or you can use Power over Ethernet injectors 135 00:04:54,900 --> 00:04:57,870 that match the PoE+ standard to provide more power 136 00:04:57,870 --> 00:04:59,700 to your endpoint devices. 137 00:04:59,700 --> 00:05:01,530 Now, a Power over Ethernet injector, 138 00:05:01,530 --> 00:05:04,320 also known as a PoE injector, is simply a device 139 00:05:04,320 --> 00:05:05,520 that adds electrical power 140 00:05:05,520 --> 00:05:07,470 to a standard Ethernet data cable, 141 00:05:07,470 --> 00:05:08,850 so you can provide both power 142 00:05:08,850 --> 00:05:12,060 and data to a PoE-capable endpoint device. 143 00:05:12,060 --> 00:05:14,610 So remember, Power over Ethernet is a technology 144 00:05:14,610 --> 00:05:16,920 that allows network cables to carry both data 145 00:05:16,920 --> 00:05:19,380 and electrical power at the same time. 146 00:05:19,380 --> 00:05:21,150 Power over Ethernet issues can occur 147 00:05:21,150 --> 00:05:22,980 when either the power budget is exceeded 148 00:05:22,980 --> 00:05:24,990 or the incorrect standard is being used 149 00:05:24,990 --> 00:05:26,370 between the endpoint devices 150 00:05:26,370 --> 00:05:28,830 and the network devices that are providing the power. 151 00:05:28,830 --> 00:05:31,530 When a Power over Ethernet issue occurs, you can expect 152 00:05:31,530 --> 00:05:32,430 that your endpoint device 153 00:05:32,430 --> 00:05:34,290 will either restart itself randomly, 154 00:05:34,290 --> 00:05:35,730 won't work properly at all, 155 00:05:35,730 --> 00:05:39,030 or it'll simply not power on when you try to boot it up. 156 00:05:39,030 --> 00:05:40,290 Therefore, it's important for you 157 00:05:40,290 --> 00:05:42,510 to understand the symptoms, potential causes, 158 00:05:42,510 --> 00:05:44,250 and the troubleshooting methodologies that are used 159 00:05:44,250 --> 00:05:47,010 to identify and resolve these Power over Ethernet issues 160 00:05:47,010 --> 00:05:48,010 within your network.