Free CCNA Training Course | Part 6 - Power Over Ethernet

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We've got a quick and to the point video for you today, and it's all about power. Imagine you need to connect a few desk phones, wireless access points and security cameras to your network. They will require power, of course, but you don't necessarily want to put a big power socket next to each device. They take up a lot of space. They can look a bit ugly and the cabling can get messy. Fortunately, we have an alternative, which is power over Ethernet. That is where we supply power over a regular network cable. Any device that connects to our network that we can power using power over Ethernet is called a power device, or PD. The generally smaller devices like this phone that only require a few watts of power to stop. We simply connect the network cable to the back of our phone, and we'll see that it starts booting up automatically . No extra power needed. Cisco originally introduced powered interfaces over 20 years ago. It was called Cisco inline power, and it could deliver up to seven watts of power per port. The maximum port speed for this standard was 100 Meg. This was a Cisco only technology, so if you wanted it, you needed to have a Cisco switch. It was a pretty good idea, though. So since then, the EA has released several standards that any vendor can use. The original Pope standard was 80, 2.3 a f, which is now known as type one p o e. It uses two powered YS and provides 15.4 watts of power per port. Type one power is still used quite commonly, and he's really good for powering small appliances like desk phones and small wireless access points. You probably know that we measure power in Watts. Like any power solution, there is a little power loss as power runs over the cable. It's no different with network cables. So type one power supply is a 15.4 watts at the port, but only guarantees 12.95 watts at the power device. Just to explain this terminology a bit. Any device that supplies power is called a PC or power sourcing equipment. Any device that consumes the power is called a PD or power device. There are some other devices that simply need more power in order to run. These include things like a four in one security camera, tablets, LCD screens and plenty more soap plus was developed. This supplies 30 watts of power per port. But why stop there? We now have two additional POW plus plus standards called type three and type four. And they can deliver 61 hundred watts per port. Cisco have their own versions of these call ups and UPO Plus. Most notably, these standards power up to two pairs of wires in the network cable. These higher powered standards are good for teleconferencing solutions. Kiosk terminals, small switches, laptops and small TV screens. Each of these standards is a power class power devices can change their power class over time if needed. For example, a device may need only type one to power up later on. It might need to turn on a screen, so it might signal a switch that needs a change to type two, three or four. The next question is, does it matter what kind of cabling we use? Yeah, a bit. It obviously has to be copper cabling. You simply can't supply power over fiber. Also, it should be no longer than 100 meters long, and ideally it needs to be cat five or better. But here's the really big question, is Pope safe? Well, it is a much smaller amount of power than you would have in your average wall socket. Also, it uses DC power, not AC, which makes it much safer at small power levels. Additionally, the Tripoli Standard says that iPSC will only supply power to a device that requests it. So if you plug in a device that doesn't have a need for power, it won't get fried. So it was relatively safe. It is still power, so you still should use appropriate caution. Don't go looking your network cables or anything like that, although to be fair, if you're the kind of person that leaks power cables, you're probably in the wrong industry. OK, we have a few quiz questions, but they're pretty easy in this video, I'm sure you're happy for a break. We've been talking about using switches as power sourcing equipment. This is the nicer solution, but there are other options. For example, this play injector. This is a separate device that combines the network signal from the switch with power from some other power source. So if you have a switch, it doesn't support power. This might be a suitable alternative. one common use of this power injector would be to power an outdoor wireless access point, which are often too far away from the switch for regular power to work. Similar to an injector, you can also get a splitter. This is where you have something providing power, but the device doesn't natively support being powered through power. For example, a Raspberry Pi, it has a power source that's separate to the networking device, so a split up will separate the power from the data, allowing you to plug in both cables separately. The advantage to this is that you don't need a wall socket to power all your devices, even if they don't support Bowie. But please remember, there isn't a bottomless pit of power available to you. Each switch has a power budget. The power budget is the maximum amount of power that it can supply with poetry, for example, ones which I've use in past is a small twelve port switch and has a power budget of about 100 watts. This means I could enable power on only six ports or I could have power plus on up to three ports. Or some combination thereof that is less than 100 watts. So keep this in mind when you're buying a new switch. Generally, you can get the which is datasheet like the one shown here from the switch vendor, which gives you this information. I think the interesting takeaway from this is how the power budget is calculated. Let's say you have a desk phone connected to an interface. You enable play on the interface, which can supply up to 15.4 watts. However, a simple desk phone is unlikely to draw all 15 watts. It may draw only five watts when calculating your power budget. Work with the amount of power that the interface can supply. What I mean is assume that the phone will consume all 15.4 watts of power. If you had that switch with a budget of 100 watts, you wouldn't assume that you could run two phones at five watts each. You need to assume that you can only have six phones at 15.4 watts each. This is because each connected device may start drawing more power than you expect up to the limit of that port. Also, when looking at data sheets, they may provide two values the total power of the switch consumes and the power budget. For example, a switch may consume up to 830 watts of power. Remember, though, that it needs to consume some power itself just to turn on run. So while it may consume up to 830 watts of power, 720 watts, maybe for power, while 110 watts may be for the switch itself. Some switches allow you to add a second power supply, depending on the model adding a second power supply will increase your total power budget. So our 830 watts, which may then consume up to 1550 watts of power, still 110 watts for the switch itself, but now 14 140 watts of power, a budget that makes sense. And here are the last two quiz questions. I really hope these quizzes have been helpful to you and you've been learning from them. We've reached the end of our section on layer two technology and switching in the next section, we're going to look at layer three and routing, starting with a basic review on IP addresses and the routing table. Please join me there.
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Channel: Network Direction
Views: 1,364
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Keywords: Network direction, Networking, Ccna, Free, Cisco, 200-301, primer, Poe, Power over ethernet, Powered device, PD, Watts, 802.3af, Cisco Inline Power, Type-1, 15.4W, 802.3at, 802.3bt, UPoE, UPoE+, Power class, Power sourcing equipment, PSE, PoE injector, PoE splitter, Power budget
Id: -RAPwEMHM58
Channel Id: undefined
Length: 8min 28sec (508 seconds)
Published: Tue Oct 12 2021
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