WEBVTT 0:00:03.280000 --> 0:00:07.800000 Welcome to this video, which is titled Wi-Fi components, which is what 0:00:07.800000 --> 0:00:10.140000 we're going to talk about right here. 0:00:10.140000 --> 0:00:15.880000 So certainly for the Cisco CCNA exam, as well as just daily life, if you're 0:00:15.880000 --> 0:00:19.200000 going to work in the world of Wi-Fi, you have to be able to recognize 0:00:19.200000 --> 0:00:23.840000 what the common components are that are used in the world of Wi-Fi. 0:00:23.840000 --> 0:00:27.660000 You're going to hear a lot of terminology about this component is used 0:00:27.660000 --> 0:00:29.840000 here, this component is talking to this component. 0:00:29.840000 --> 0:00:33.460000 And if you don't know what the terms are, you can't really visualize what's 0:00:33.460000 --> 0:00:37.320000 going on. So let's start out with some Wi-Fi terminology. 0:00:37.320000 --> 0:00:40.500000 So starting out with Wi-Fi clients. 0:00:40.500000 --> 0:00:46.780000 Technically, if you read any of the 802.11 documents, and if you have 0:00:46.780000 --> 0:00:50.000000 a hard time sleeping one night, I'd recommend you break open any of those 0:00:50.000000 --> 0:00:51.980000 IEEE 802.11 documents. 0:00:51.980000 --> 0:00:54.760000 They're very long, very dry. 0:00:54.760000 --> 0:00:59.340000 But the technical term for a Wi -Fi client is called a station. 0:00:59.340000 --> 0:01:02.580000 All right, so a client is a station, they're synonymous. 0:01:02.580000 --> 0:01:05.080000 So this is an endpoint for data. 0:01:05.080000 --> 0:01:09.140000 So Wi-Fi station is something that will be creating data and then sending 0:01:09.140000 --> 0:01:13.840000 it out wirelessly, or it will be receiving data and then consuming that 0:01:13.840000 --> 0:01:16.840000 data wirelessly. 0:01:16.840000 --> 0:01:21.880000 So Wi-Fi data is not meant to pass through a client. 0:01:21.880000 --> 0:01:25.560000 It's meant to terminate on a client or start on a client, but a Wi-Fi 0:01:25.560000 --> 0:01:29.860000 client, a station technically does not pass Wi-Fi data through from one 0:01:29.860000 --> 0:01:31.180000 point to the other. 0:01:31.180000 --> 0:01:32.820000 That's not a Wi-Fi client. 0:01:32.820000 --> 0:01:36.640000 Now there are some differentiators, lots of different differentiators 0:01:36.640000 --> 0:01:40.520000 between different Wi-Fi clients, such as the power source. 0:01:40.520000 --> 0:01:44.740000 So my laptop is a Wi-Fi client. 0:01:44.740000 --> 0:01:49.720000 Your smartphone is a Wi-Fi client, but I can guarantee you the power of 0:01:49.720000 --> 0:01:53.520000 my laptop because it's plugged into an AC outlet has a lot more power 0:01:53.520000 --> 0:01:56.920000 than the power of your little battery in your cell phone. 0:01:56.920000 --> 0:02:00.840000 And that actually translates to meaningful Wi-Fi stuff. 0:02:00.840000 --> 0:02:04.400000 Something that has more power means its radio is stronger. 0:02:04.400000 --> 0:02:08.840000 It can push out a signal further and its signal can be read and is more 0:02:08.840000 --> 0:02:11.500000 clear to other Wi-Fi receivers. 0:02:11.500000 --> 0:02:14.800000 Whereas something that's like battery operated that's smaller, it's going 0:02:14.800000 --> 0:02:17.780000 to have a hard time pushing out its signal wirelessly because it just 0:02:17.780000 --> 0:02:21.400000 doesn't have the juice to push it out there to create that electromagnetic 0:02:21.400000 --> 0:02:28.720000 radiation. The quantity and types of antennas. 0:02:28.720000 --> 0:02:36.900000 So as Wi-Fi standards have evolved over time, one of the ways that they 0:02:36.900000 --> 0:02:43.740000 have found to increase data rates is to add more antennas because, so 0:02:43.740000 --> 0:02:44.720000 let's just think about this here. 0:02:44.720000 --> 0:02:48.540000 So when you're transmitting, when you're transmitting wirelessly, what 0:02:48.540000 --> 0:02:51.860000 happens is your antenna, wherever it is like in a laptop, is typically 0:02:51.860000 --> 0:02:56.740000 embedded somewhere on the periphery of the screen, like on the outer edges, 0:02:56.740000 --> 0:02:58.680000 like up here could be by antenna. 0:02:58.680000 --> 0:03:01.620000 This might have some antennas here or from all three of these might have 0:03:01.620000 --> 0:03:04.140000 antennas in the background behind the screen that's usually where they're 0:03:04.140000 --> 0:03:10.920000 placed. Now when I'm transmitting something wirelessly, I have a Wi-Fi 0:03:10.920000 --> 0:03:14.240000 transmitter. Just think of it as a radio that can transmit out inside 0:03:14.240000 --> 0:03:21.480000 my laptop. That thing will feed electrical energy across a cable to my 0:03:21.480000 --> 0:03:26.040000 antennas. So inside here, there's some antennas with some like copper 0:03:26.040000 --> 0:03:28.380000 cabling or some copper connectors. 0:03:28.380000 --> 0:03:32.480000 We can't see any of this stuff to the transmitter inside my laptop. 0:03:32.480000 --> 0:03:36.880000 So I'm transmitting, I'm sending alternating current and I'm manipulating 0:03:36.880000 --> 0:03:40.320000 that alternating current making, going faster, slower, stronger or weaker 0:03:40.320000 --> 0:03:44.700000 to my radios, which is just basically a wire basically. 0:03:44.700000 --> 0:03:46.860000 They're a little bit more complicated than that. 0:03:46.860000 --> 0:03:51.180000 But by sending that current alternating up to the wire in my antennas, 0:03:51.180000 --> 0:03:56.620000 it's radiating out the electromagnetic radiation, the radio frequency. 0:03:56.620000 --> 0:03:59.360000 So that's the process of transmitting. 0:03:59.360000 --> 0:04:05.060000 And so the more antennas I have, the more I can transmit out. 0:04:05.060000 --> 0:04:10.340000 But in reality, the more antennas you have is not really for the benefit 0:04:10.340000 --> 0:04:11.540000 of transmitting. 0:04:11.540000 --> 0:04:15.560000 It's more beneficial in the receiving direction because when I'm receiving 0:04:15.560000 --> 0:04:20.000000 what's happening, over the air, all around me is electromagnetic radiation, 0:04:20.000000 --> 0:04:23.180000 probably passing through my body and your body right now. 0:04:23.180000 --> 0:04:27.400000 It goes through almost everything except metal and some other things. 0:04:27.400000 --> 0:04:34.220000 So as the electromagnetic radiation hits my antennas, it actually induces 0:04:34.220000 --> 0:04:41.160000 it causes an alternating current to start up in the copper of my antennas 0:04:41.160000 --> 0:04:45.400000 right here. And that alternating current is then fed to my receiver and 0:04:45.400000 --> 0:04:48.280000 my receiver can decode that as ones or zeros. 0:04:48.280000 --> 0:04:53.700000 So the more antennas I have, the easier it is for me to pick up that electromagnetic 0:04:53.700000 --> 0:04:58.400000 radiation as it's permeating my laptop and hitting my antennas. 0:04:58.400000 --> 0:05:01.200000 It's easier for me to receive a signal. 0:05:01.200000 --> 0:05:05.400000 So this is also one differentiating factor among clients. 0:05:05.400000 --> 0:05:08.600000 Some clients, once again, like a smartphone, will typically just have 0:05:08.600000 --> 0:05:10.460000 one Wi-Fi antenna in it. 0:05:10.460000 --> 0:05:15.060000 Other clients like your laptops or your desktop PCs may have three or 0:05:15.060000 --> 0:05:23.120000 more. The more antennas you have, the faster you can send and receive. 0:05:23.120000 --> 0:05:26.960000 And the quantities and types of transceivers as well. 0:05:26.960000 --> 0:05:31.540000 A transceiver is a combination of two words, transmitter and receiver. 0:05:31.540000 --> 0:05:34.900000 So in your car, you have a receiver, right? 0:05:34.900000 --> 0:05:37.220000 That's how you listen to the radio when you're driving to and from work 0:05:37.220000 --> 0:05:38.400000 you have a receiver. 0:05:38.400000 --> 0:05:40.900000 And I suppose if you were a MacGyver or something, you could turn that 0:05:40.900000 --> 0:05:45.860000 into a transmitter, but it's purpose built just to receive information. 0:05:45.860000 --> 0:05:48.960000 It's not really built for you to talk through it. 0:05:48.960000 --> 0:05:54.160000 Well, transceivers can do both transmitting and receiving. 0:05:54.160000 --> 0:05:59.220000 And the higher end clients can have two, three, four transceivers, which 0:05:59.220000 --> 0:06:02.600000 once again, the more you have, the more you can transmit, the more you 0:06:02.600000 --> 0:06:06.540000 can receive. Ultimately, the faster your Wi-Fi can go. 0:06:06.540000 --> 0:06:13.920000 All right, so that's what a Wi-Fi client is. 0:06:13.920000 --> 0:06:17.920000 Another type of thing is called a Wi-Fi access point. 0:06:17.920000 --> 0:06:20.860000 You've probably heard of this, an AP or an access point. 0:06:20.860000 --> 0:06:24.400000 This is a consolidation point for the clients. 0:06:24.400000 --> 0:06:30.060000 So all the clients will associate to the access point. 0:06:30.060000 --> 0:06:33.780000 They will send their Wi-Fi data to the access point. 0:06:33.780000 --> 0:06:37.080000 The access point will then take it from there and put it onto the wired 0:06:37.080000 --> 0:06:40.440000 LAN and send it off into the wired world. 0:06:40.440000 --> 0:06:44.020000 So it bridges the wireless and wired domains. 0:06:44.020000 --> 0:06:46.980000 Now, we're some differentiators among access point. 0:06:46.980000 --> 0:06:48.260000 There's a lot of differentiators. 0:06:48.260000 --> 0:06:50.200000 A lot of them are what we just saw with the clients. 0:06:50.200000 --> 0:06:55.620000 One thing is some access points are centrally managed and others are individually 0:06:55.620000 --> 0:06:59.420000 managed. So if I get a light weight, if I get an access point that's called 0:06:59.420000 --> 0:07:03.960000 a lightweight access point, that typically means that the access point 0:07:03.960000 --> 0:07:06.300000 itself has no GUI. 0:07:06.300000 --> 0:07:08.140000 It has no command line. 0:07:08.140000 --> 0:07:11.540000 There's no way for me to connect to it and configure it directly. 0:07:11.540000 --> 0:07:15.040000 I have to get some other controlling software, some other controlling 0:07:15.040000 --> 0:07:19.100000 device, which can connect to that access point and manage it. 0:07:19.100000 --> 0:07:23.500000 So the access point is managed externally by another device. 0:07:23.500000 --> 0:07:27.100000 Whereas an individually managed or an autonomous access point, like a 0:07:27.100000 --> 0:07:30.200000 lot of the original ones were, they have their own GUIs. 0:07:30.200000 --> 0:07:34.160000 They have their own command line. 0:07:34.160000 --> 0:07:38.120000 So like when you go to Best Buy or Amazon or something and you buy an 0:07:38.120000 --> 0:07:40.980000 access point for your house, typically speaking, what you're going to 0:07:40.980000 --> 0:07:45.780000 be getting is an autonomous or standalone access point where you can control 0:07:45.780000 --> 0:07:50.360000 it because it presents a GUI to you where you can configure it. 0:07:50.360000 --> 0:07:53.900000 Just like Wi-Fi clients, different access points have different quantities 0:07:53.900000 --> 0:07:56.560000 and types of transceivers. 0:07:56.560000 --> 0:08:01.900000 Some transceivers are meant to be done just on a 2.4 gigahertz spectrum. 0:08:01.900000 --> 0:08:05.820000 Other transceivers operate purely on the 5 gigahertz spectrum. 0:08:05.820000 --> 0:08:10.120000 Quantied types of antennas, whether it's made for indoor or outdoor usage 0:08:10.120000 --> 0:08:14.940000 or both. Your typical access point that you buy for your home use will 0:08:14.940000 --> 0:08:16.500000 be an indoor access point. 0:08:16.500000 --> 0:08:19.660000 If you took that thing and you set it outside while it's raining, it's 0:08:19.660000 --> 0:08:21.580000 toast. You'd have to buy another one. 0:08:21.580000 --> 0:08:24.820000 But there are other access points that are purposely built for the outdoors 0:08:24.820000 --> 0:08:28.820000 to withstand harsh environments like snow and rain and sleet and hail 0:08:28.820000 --> 0:08:32.580000 and whatever else might be thrown at them. 0:08:32.580000 --> 0:08:36.560000 Enhanced and proprietary features. 0:08:36.560000 --> 0:08:40.400000 Clearly, different vendors that create access points, a lot of times will 0:08:40.400000 --> 0:08:44.340000 put their own special proprietary features in them as a selling point 0:08:44.340000 --> 0:08:48.580000 to try to get you to buy theirs as opposed to their competition. 0:08:48.580000 --> 0:08:55.840000 Let's say I decide that I have a company, it doesn't even have to be that 0:08:55.840000 --> 0:09:00.040000 big, but I've got a company, I've decided I'm going to put 10 access points 0:09:00.040000 --> 0:09:04.920000 around my company to give Wi-Fi connectivity to all the clients out there. 0:09:04.920000 --> 0:09:11.200000 Well, I could certainly buy 10 lightweight access points, but that's not 0:09:11.200000 --> 0:09:15.220000 really scalable because I'd have to unpack each one, connect to the GUI 0:09:15.220000 --> 0:09:19.280000 of each one, configure each one, put it on the ceiling or on the wall 0:09:19.280000 --> 0:09:21.580000 and do that 10 different times. 0:09:21.580000 --> 0:09:24.500000 And then later on, if I decide, oh, I need to make a change, I want to 0:09:24.500000 --> 0:09:27.340000 enable the feature or enable the security protocol. 0:09:27.340000 --> 0:09:30.500000 I'd have to connect to each one of those individually and do that. 0:09:30.500000 --> 0:09:35.040000 It's much more scalable if all the access points I purchase are lightweight 0:09:35.040000 --> 0:09:41.040000 access points because those talk back to a Wi-Fi controller. 0:09:41.040000 --> 0:09:46.720000 The Wi-Fi controller configures and manages and monitors all of my lightweight 0:09:46.720000 --> 0:09:50.180000 access points, so it's a central point of management. 0:09:50.180000 --> 0:09:54.120000 Probably wouldn't have this in your house, although you could, but definitely 0:09:54.120000 --> 0:09:57.140000 in a business environment is where you're going to find controllers and 0:09:57.140000 --> 0:09:58.820000 lightweight access points. 0:09:58.820000 --> 0:10:04.160000 They also control Wi-Fi access for the clients. 0:10:04.160000 --> 0:10:05.380000 What's that talking about? 0:10:05.380000 --> 0:10:09.880000 Well, in a standalone or autonomous access point, you know, the typical 0:10:09.880000 --> 0:10:13.040000 kind that you buy for your house, one of the things you can configure 0:10:13.040000 --> 0:10:15.320000 in there is the security. 0:10:15.320000 --> 0:10:18.060000 You know, what kind of security you're going to do, what the password 0:10:18.060000 --> 0:10:21.460000 is going to be that clients need to connect to the Wi-Fi, maybe some other 0:10:21.460000 --> 0:10:23.540000 enhanced security stuff. 0:10:23.540000 --> 0:10:27.260000 Well, when an access point is a lightweight access point, it's typically 0:10:27.260000 --> 0:10:28.800000 not enforcing all that. 0:10:28.800000 --> 0:10:32.500000 So when a client connects to it, that access point will just pass along 0:10:32.500000 --> 0:10:36.460000 the client information to the controller, and the controller will determine, 0:10:36.460000 --> 0:10:39.900000 yes, that client is allowed on, and they'll report back to the access 0:10:39.900000 --> 0:10:43.780000 point saying, you're good, let him on, or the controller might say, nope, 0:10:43.780000 --> 0:10:47.560000 they supplied the wrong credentials, don't let them onto the Wi-Fi. 0:10:47.560000 --> 0:10:51.580000 So where are some differentiators among controllers? 0:10:51.580000 --> 0:10:54.620000 Well, number one, the quantity of Wi-Fi clients they support. 0:10:54.620000 --> 0:10:59.500000 Some controllers can literally support tens of thousands of Wi-Fi clients. 0:10:59.500000 --> 0:11:02.700000 The features are available on them. 0:11:02.700000 --> 0:11:07.200000 Whether they are appliance or cloud-based, what that means is, like this, 0:11:07.200000 --> 0:11:09.920000 right here, look at this picture, this is a controller you can actually 0:11:09.920000 --> 0:11:11.180000 hold in your hands. 0:11:11.180000 --> 0:11:13.920000 You can touch it, you can feel it, you can put on your desk, that's considered 0:11:13.920000 --> 0:11:18.280000 an appliance. So when we talk about this term network appliance, whether 0:11:18.280000 --> 0:11:22.220000 it be a controller or a firewall or something else, an appliance is basically 0:11:22.220000 --> 0:11:26.480000 a generic term that says, it's a physical thing that's got a box, it's 0:11:26.480000 --> 0:11:32.480000 got a housing, and it was purpose-built to accomplish a specific objective, 0:11:32.480000 --> 0:11:35.480000 like a Wi-Fi controller that's an appliance would look like that. 0:11:35.480000 --> 0:11:39.460000 You can't use that for routing purposes or for switching purposes, it 0:11:39.460000 --> 0:11:42.100000 wasn't built for that, it was built to be a controller. 0:11:42.100000 --> 0:11:47.700000 Whereas some controllers are in the cloud where you just pay for the service 0:11:47.700000 --> 0:11:53.500000 of the controller, you can do something on your access points, your access 0:11:53.500000 --> 0:11:56.620000 point now how to get out to the internet, to the IP address where that 0:11:56.620000 --> 0:12:00.060000 controller lives in the cloud, but you don't actually touch it, you don't 0:12:00.060000 --> 0:12:03.840000 feel it's not appliance, it's all software-based. 0:12:03.840000 --> 0:12:07.600000 And the type and quantity of uplink interfaces, because the controller 0:12:07.600000 --> 0:12:10.960000 itself will have some back interfaces that connect to the wired LAN. 0:12:10.960000 --> 0:12:14.580000 So as we're going to go through here, we're going to see in a lot of environments 0:12:14.580000 --> 0:12:18.600000 where a lightweight access point is connected to a controller, when your 0:12:18.600000 --> 0:12:24.600000 Wi-Fi client sends data wirelessly to the access point, the access point 0:12:24.600000 --> 0:12:28.040000 will actually tunnel that data all the way to the controller, and then 0:12:28.040000 --> 0:12:33.400000 it will be the controller's job to dump that data out onto the wired LAN, 0:12:33.400000 --> 0:12:35.120000 out onto the switch. 0:12:35.120000 --> 0:12:39.220000 So the controller has to have some uplink interfaces to do that. 0:12:39.220000 --> 0:12:44.360000 So that concludes this video on an overview of Wi-Fi components.