1 1 00:00:00,910 --> 00:00:04,020 In the last video, we talked about why we use networks. 2 2 00:00:04,020 --> 00:00:05,540 And the whole purpose is to get data 3 3 00:00:05,540 --> 00:00:08,700 from one place to another, from one machine to another. 4 4 00:00:08,700 --> 00:00:11,440 Now whether that's carrying voice, video or data, 5 5 00:00:11,440 --> 00:00:13,920 it's going to have to get across the network somehow. 6 6 00:00:13,920 --> 00:00:16,190 Now what comprises our networks? 7 7 00:00:16,190 --> 00:00:18,670 Well, that's what we're going to answer in this video. 8 8 00:00:18,670 --> 00:00:19,560 We're going to talk about 9 9 00:00:19,560 --> 00:00:21,240 all of the different network components, 10 10 00:00:21,240 --> 00:00:23,880 things like clients and servers, hubs, 11 11 00:00:23,880 --> 00:00:26,000 wireless access points, switches, 12 12 00:00:26,000 --> 00:00:28,490 routers, media and WAN links. 13 13 00:00:28,490 --> 00:00:30,640 Now some of those terms probably look familiar 14 14 00:00:30,640 --> 00:00:31,810 and others may not. 15 15 00:00:31,810 --> 00:00:33,340 So we're going to go through each one of them 16 16 00:00:33,340 --> 00:00:34,980 individually in this lesson, 17 17 00:00:34,980 --> 00:00:37,270 the first one we have is clients. 18 18 00:00:37,270 --> 00:00:39,340 And these are the devices that our end user 19 19 00:00:39,340 --> 00:00:41,080 is going to access the network with. 20 20 00:00:41,080 --> 00:00:43,440 This can be something like a workstation, a laptop, 21 21 00:00:43,440 --> 00:00:47,080 a tablet, a smartphone, a smart TV, a server, 22 22 00:00:47,080 --> 00:00:49,210 or any other terminal device. 23 23 00:00:49,210 --> 00:00:51,830 Even your wifi enabled thermostat like a nest, 24 24 00:00:51,830 --> 00:00:53,770 this is considered a client. 25 25 00:00:53,770 --> 00:00:56,170 This can be any device that connects to the network. 26 26 00:00:56,170 --> 00:00:57,960 And we're going to use this big bucket term 27 27 00:00:57,960 --> 00:01:00,730 called client to describe all of them. 28 28 00:01:00,730 --> 00:01:03,690 The next component we have is what's known as a server. 29 29 00:01:03,690 --> 00:01:05,950 Now a server is something that provides resources 30 30 00:01:05,950 --> 00:01:07,610 to the rest of your network. 31 31 00:01:07,610 --> 00:01:09,410 Now, if you're at work, you're probably familiar 32 32 00:01:09,410 --> 00:01:12,030 with an email server or a file server, right? 33 33 00:01:12,030 --> 00:01:13,090 And there's different servers 34 34 00:01:13,090 --> 00:01:14,260 that provide different functions. 35 35 00:01:14,260 --> 00:01:16,420 You may have a web server or an email server 36 36 00:01:16,420 --> 00:01:18,163 or a file server or a chat server 37 37 00:01:18,163 --> 00:01:19,990 a or print server and all sorts 38 38 00:01:19,990 --> 00:01:21,830 of other different kinds of servers. 39 39 00:01:21,830 --> 00:01:23,420 These can be dedicated hardware, 40 40 00:01:23,420 --> 00:01:25,450 or they can be a specialized type of software 41 41 00:01:25,450 --> 00:01:27,540 that the device uses, and that takes it 42 42 00:01:27,540 --> 00:01:30,050 and allows it to act like a server for us. 43 43 00:01:30,050 --> 00:01:31,250 We'll talk more about these 44 44 00:01:31,250 --> 00:01:32,840 as we go through the different models, 45 45 00:01:32,840 --> 00:01:34,600 whether it's going to be a client server model 46 46 00:01:34,600 --> 00:01:36,950 or a peer to peer model, but for right now, 47 47 00:01:36,950 --> 00:01:39,480 I just want you to be familiar with the term server. 48 48 00:01:39,480 --> 00:01:42,320 The next component we're going to discuss is called a hub. 49 49 00:01:42,320 --> 00:01:44,700 Now, a hub is a piece of old technology 50 50 00:01:44,700 --> 00:01:46,620 that we really don't use in our networks anymore, 51 51 00:01:46,620 --> 00:01:49,670 but we're still going to cover it because the exam covers it. 52 52 00:01:49,670 --> 00:01:51,100 When I was growing up in the industry, 53 53 00:01:51,100 --> 00:01:53,040 we used hubs everywhere. 54 54 00:01:53,040 --> 00:01:55,500 Hubs were an easy way for us to connect network devices, 55 55 00:01:55,500 --> 00:01:58,000 such as clients and servers and put them together. 56 56 00:01:58,000 --> 00:01:59,380 They could be interconnected to provide 57 57 00:01:59,380 --> 00:02:01,140 even more ports if I needed to, 58 58 00:02:01,140 --> 00:02:02,920 by plugging one port of one hub 59 59 00:02:02,920 --> 00:02:04,500 into another port of another hub, 60 60 00:02:04,500 --> 00:02:06,950 and this would create a daisy chain effect. 61 61 00:02:06,950 --> 00:02:08,550 The problem is, that this could lead 62 62 00:02:08,550 --> 00:02:10,310 to increased network errors. 63 63 00:02:10,310 --> 00:02:12,050 Basically when you have a hub, 64 64 00:02:12,050 --> 00:02:14,090 information comes in one port of the hub 65 65 00:02:14,090 --> 00:02:16,760 and then gets spit out all of the other ports. 66 66 00:02:16,760 --> 00:02:19,760 So if you have a four port hub, one person is talking 67 67 00:02:19,760 --> 00:02:22,630 and it rebroadcasts it out to the other three people. 68 68 00:02:22,630 --> 00:02:24,770 This isn't a big deal when you have a four port hub, 69 69 00:02:24,770 --> 00:02:26,720 but if you have a 48 port hub, 70 70 00:02:26,720 --> 00:02:28,150 now when one person is talking, 71 71 00:02:28,150 --> 00:02:30,568 the other 47 people have to listen to it too. 72 72 00:02:30,568 --> 00:02:33,620 We're going to cover hubs a lot more in depth later on 73 73 00:02:33,620 --> 00:02:35,410 because they're the backbone of networking 74 74 00:02:35,410 --> 00:02:37,060 and switches that we're going to talk about 75 75 00:02:37,060 --> 00:02:38,490 and use in our networks today 76 76 00:02:38,490 --> 00:02:41,590 are actually a second generation version of hubs 77 77 00:02:41,590 --> 00:02:44,760 that combine hubs with another device called a bridge. 78 78 00:02:44,760 --> 00:02:46,440 Now, the next component we're going to talk about 79 79 00:02:46,440 --> 00:02:48,430 is a wireless access point. 80 80 00:02:48,430 --> 00:02:50,280 Wireless access points are devices 81 81 00:02:50,280 --> 00:02:51,760 that allow wireless devices 82 82 00:02:51,760 --> 00:02:53,980 to connect into your wired network. 83 83 00:02:53,980 --> 00:02:56,810 So if you're using your laptop or your smartphone right now, 84 84 00:02:56,810 --> 00:02:58,520 and you're connecting over wifi, 85 85 00:02:58,520 --> 00:03:01,360 you're actually into a wireless access point. 86 86 00:03:01,360 --> 00:03:03,030 These are commonly used in homes, 87 87 00:03:03,030 --> 00:03:04,800 small businesses, colleges, 88 88 00:03:04,800 --> 00:03:06,890 and even large enterprise networks. 89 89 00:03:06,890 --> 00:03:10,470 Effectively, a wireless access point is a wireless hub. 90 90 00:03:10,470 --> 00:03:12,200 Whatever is broadcast out one way, 91 91 00:03:12,200 --> 00:03:13,890 goes out the other way as well. 92 92 00:03:13,890 --> 00:03:16,190 We're going to talk a lot more about wireless access points 93 93 00:03:16,190 --> 00:03:18,110 when we get to the wireless devices section 94 94 00:03:18,110 --> 00:03:19,800 later on in this course. 95 95 00:03:19,800 --> 00:03:22,350 The next component we have is called a switch. 96 96 00:03:22,350 --> 00:03:24,740 Now, a switch is a smarter version of a hub. 97 97 00:03:24,740 --> 00:03:26,760 It connects network devices, such as clients 98 98 00:03:26,760 --> 00:03:29,140 and servers together, just like a hub did, 99 99 00:03:29,140 --> 00:03:30,630 but there's a big difference here. 100 100 00:03:30,630 --> 00:03:33,800 Switches can learn which devices are on which ports. 101 101 00:03:33,800 --> 00:03:35,580 So instead of taking it in one port 102 102 00:03:35,580 --> 00:03:38,170 and pushing out the other ports, two, three and four, 103 103 00:03:38,170 --> 00:03:39,950 as we did with a four port hub, 104 104 00:03:39,950 --> 00:03:42,200 a switch will take it in on port one 105 105 00:03:42,200 --> 00:03:45,780 and then send it out only to port two, three or four, 106 106 00:03:45,780 --> 00:03:47,780 whichever one it's trying to talk to. 107 107 00:03:47,780 --> 00:03:49,563 And so I like to think about this, 108 108 00:03:50,487 --> 00:03:52,243 instead of us being in a room and broadcasting 109 109 00:03:52,243 --> 00:03:53,510 our message to everyone in the class, 110 110 00:03:53,510 --> 00:03:55,730 I take the single person I want to talk to, 111 111 00:03:55,730 --> 00:03:58,280 put them into a closet with me and then we talk over there. 112 112 00:03:58,280 --> 00:04:00,680 That way we're not disturbing everybody else. 113 113 00:04:00,680 --> 00:04:02,460 Now this is the big benefit of a switch. 114 114 00:04:02,460 --> 00:04:04,930 And we're going to talk a lot more about switches later on 115 115 00:04:04,930 --> 00:04:07,360 when we get into the ethernet fundamental section. 116 116 00:04:07,360 --> 00:04:09,100 Switches are only going to forward traffic 117 117 00:04:09,100 --> 00:04:11,720 received from one port to the destination port. 118 118 00:04:11,720 --> 00:04:14,200 And so we call these smart hubs essentially, right? 119 119 00:04:14,200 --> 00:04:16,830 Because they act like hubs, but there are a lot smarter, 120 120 00:04:16,830 --> 00:04:19,060 but instead we're going to actually call them switches 121 121 00:04:19,060 --> 00:04:20,500 'cause that's the right term. 122 122 00:04:20,500 --> 00:04:22,730 These are they going to be providing you with more security 123 123 00:04:22,730 --> 00:04:25,090 and more efficient use of bandwidth than a hub did. 124 124 00:04:25,090 --> 00:04:27,230 And this is going to give us a lot better use 125 125 00:04:27,230 --> 00:04:29,080 inside of our networks. 126 126 00:04:29,080 --> 00:04:31,830 The next device we have to cover is called a router. 127 127 00:04:31,830 --> 00:04:32,840 Now a router is used 128 128 00:04:32,840 --> 00:04:34,880 to connect two different networks together. 129 129 00:04:34,880 --> 00:04:37,290 They're going to intelligently make forwarding decisions 130 130 00:04:37,290 --> 00:04:40,500 from one network to the next, based on its logical address, 131 131 00:04:40,500 --> 00:04:42,210 which we refer to as an IP address 132 132 00:04:42,210 --> 00:04:44,180 or internet protocol address. 133 133 00:04:44,180 --> 00:04:46,610 Most modern routers are going to rely on IP. 134 134 00:04:46,610 --> 00:04:47,630 Although there are other 135 135 00:04:47,630 --> 00:04:49,320 routing protocols out there as well. 136 136 00:04:49,320 --> 00:04:51,030 We're going to talk a lot more about routers. 137 137 00:04:51,030 --> 00:04:54,990 In fact, we have an entire section dedicated to routing. 138 138 00:04:54,990 --> 00:04:56,600 Next, we have media. 139 139 00:04:56,600 --> 00:04:59,040 Now media is what we use to connect two devices 140 140 00:04:59,040 --> 00:05:01,010 or a device to a switch port. 141 141 00:05:01,010 --> 00:05:02,830 These can be things like copper cable, 142 142 00:05:02,830 --> 00:05:06,590 fiber optic cable, or even radio waves if you're using wifi. 143 143 00:05:06,590 --> 00:05:08,810 It doesn't really matter what the media type is. 144 144 00:05:08,810 --> 00:05:10,350 But we have to understand that media 145 145 00:05:10,350 --> 00:05:12,470 is the things that connect everything. 146 146 00:05:12,470 --> 00:05:14,620 If there's a break in the cable or the media, 147 147 00:05:14,620 --> 00:05:16,780 your networks aren't going to work right. 148 148 00:05:16,780 --> 00:05:19,420 Each type of media has its own strengths and weaknesses. 149 149 00:05:19,420 --> 00:05:22,020 And we're going to talk all about those later in the course, 150 150 00:05:22,020 --> 00:05:24,350 for example, copper is very cheap to use, 151 151 00:05:24,350 --> 00:05:25,980 but it can't go very far. 152 152 00:05:25,980 --> 00:05:28,080 Fiber optic on the other hand can go really far, 153 153 00:05:28,080 --> 00:05:29,820 but it costs a lot of money. 154 154 00:05:29,820 --> 00:05:31,830 Each one has its own bandwidth limitations, 155 155 00:05:31,830 --> 00:05:34,740 capacity limitations and distance limitations. 156 156 00:05:34,740 --> 00:05:36,470 Now we're going to get into those specifics 157 157 00:05:36,470 --> 00:05:37,540 later on in the course, 158 158 00:05:37,540 --> 00:05:39,350 because you're going to have to memorize each of them, 159 159 00:05:39,350 --> 00:05:41,640 including down to how many feet they can cover. 160 160 00:05:41,640 --> 00:05:43,760 For example, if I'm talking about a copper cable, 161 161 00:05:43,760 --> 00:05:44,950 how long it can go, 162 162 00:05:44,950 --> 00:05:47,400 or a fiber optic cable, how long it can go. 163 163 00:05:47,400 --> 00:05:49,010 And we'll talk about that later on 164 164 00:05:49,010 --> 00:05:52,360 when we get into the ethernet section down the road. 165 165 00:05:52,360 --> 00:05:53,890 The last component we need to talk about 166 166 00:05:53,890 --> 00:05:56,950 is a wide area network link, or a WAN link. 167 167 00:05:56,950 --> 00:05:59,040 Now a WAN link is going to physically connect 168 168 00:05:59,040 --> 00:06:02,260 two networks together that are geographically dispersed. 169 169 00:06:02,260 --> 00:06:03,470 So when you look at the internet, 170 170 00:06:03,470 --> 00:06:05,930 it's really just a big series of WAN links. 171 171 00:06:05,930 --> 00:06:07,220 If I go to your house right now, 172 172 00:06:07,220 --> 00:06:09,160 and I connect my laptop to your network 173 173 00:06:09,160 --> 00:06:10,640 and you didn't have a WAN link, 174 174 00:06:10,640 --> 00:06:12,950 we would only be able to talk inside your house. 175 175 00:06:12,950 --> 00:06:14,960 We wouldn't be able to make it to the outside world 176 176 00:06:14,960 --> 00:06:18,300 and go to Facebook or Google, or even back to my house. 177 177 00:06:18,300 --> 00:06:20,390 That's what a WAN link allows you to do. 178 178 00:06:20,390 --> 00:06:23,000 Whether you're using it lease line, a DSL line, 179 179 00:06:23,000 --> 00:06:25,100 a cable line, a fiber optic line, 180 180 00:06:25,100 --> 00:06:28,960 a cellular, satellite, microwave, it really doesn't matter. 181 181 00:06:28,960 --> 00:06:30,420 All of those are WAN links. 182 182 00:06:30,420 --> 00:06:32,380 It's your connection to the outside world. 183 183 00:06:32,380 --> 00:06:34,220 And it has to be routed through a router, 184 184 00:06:34,220 --> 00:06:35,720 back into your network. 185 185 00:06:35,720 --> 00:06:37,470 This is going to connect your internal network 186 186 00:06:37,470 --> 00:06:39,690 to the external networks, and when we do this, 187 187 00:06:39,690 --> 00:06:41,030 like we take your small office, 188 188 00:06:41,030 --> 00:06:43,220 your home office and we connect it to the internet, 189 189 00:06:43,220 --> 00:06:45,030 that's exactly what we're doing. 190 190 00:06:45,030 --> 00:06:46,810 So we'll talk more about WAN links later, 191 191 00:06:46,810 --> 00:06:49,933 because we have another entire section dedicated to those.