WEBVTT - Internet Architecture 0:00:00.320 --> 0:00:02.880 Brought to you by the reinvented two thousand twelve camera. 0:00:03.240 --> 0:00:08.920 It's ready. Are you get in touch with technologies with 0:00:09.080 --> 0:00:17.880 tech Stuff from how stuff works dot com. Hello there, everybody, 0:00:17.880 --> 0:00:20.360 and welcome to tech stuff. My name is Chris Poette 0:00:20.360 --> 0:00:22.720 and I'm the tech editor here at how stuff works 0:00:22.760 --> 0:00:26.360 dot Com. Sitting across from me, as he often does 0:00:27.000 --> 0:00:33.120 at this very table, would be senior writer Jonathan. Hey there, so, 0:00:33.360 --> 0:00:36.239 uh so, what do you want to talk about today? Well, 0:00:36.600 --> 0:00:39.040 it's not what I want to talk about, it's what 0:00:39.120 --> 0:00:42.639 Alexander wants us to talk about. There's what Alexander had 0:00:42.680 --> 0:00:45.760 to say. Hey, guys, I find your podcasts very educating. 0:00:45.760 --> 0:00:48.199 I'm a computer science major, but I have a difficulty 0:00:48.240 --> 0:00:51.200 understanding the architecture of the Internet. So it'll be really 0:00:51.280 --> 0:00:54.280 nice for you to make a podcast addressing the Internet architecture. 0:00:54.600 --> 0:00:58.200 Continue the good work, Well, Alexander, we decided we would 0:00:58.240 --> 0:01:02.480 tackle Internet architecture, which is you know, it's it's conceptually 0:01:02.480 --> 0:01:05.559 it's a pretty simple thing, uh it it involves two 0:01:06.720 --> 0:01:10.640 different categories of of of concepts. I guess you could 0:01:10.680 --> 0:01:14.080 say you got your hardware and then you got your protocols, 0:01:14.959 --> 0:01:17.320 and that pretty much you know, the marriage of the 0:01:17.319 --> 0:01:20.639 two is where the Internet comes into play. Now, before 0:01:20.640 --> 0:01:23.280 we get to bog down with the whole thing, we're 0:01:23.280 --> 0:01:27.800 gonna start very simply. Let's take a trip back to 0:01:28.920 --> 0:01:33.399 the sixties, shall we. Right, I guess that means that 0:01:34.000 --> 0:01:38.720 we're gonna pop into the time machine. Liz is already 0:01:38.760 --> 0:01:41.319 giggling because she's here. She's actually gonna We're gonna drag 0:01:41.400 --> 0:01:44.319 Liz into the time machine with us. She probably won't 0:01:44.360 --> 0:01:47.200 say anything, but she'll be back there with her hand 0:01:47.280 --> 0:01:50.360 over her mouth giggling. All right, let's just set this 0:01:50.440 --> 0:01:52.680 back to the mid sixties and pop on back. And 0:01:53.000 --> 0:01:56.960 let's let's take a little visit to to uh, the California. 0:01:57.120 --> 0:02:09.000 Look at ARPA back in the day, dude. So here 0:02:09.000 --> 0:02:15.520 we are, California Route sixty six, right down the road, Chris, Chris, 0:02:17.160 --> 0:02:19.480 that's true. It is the only road in the sixties 0:02:19.480 --> 0:02:23.079 in California. Well, according to popular culture, I guess welcome 0:02:23.120 --> 0:02:27.240 to Misinformation Podcast Limited. So anyway, we are here to 0:02:27.280 --> 0:02:31.680 talk about arpanet. Okay, alright. So arpanet was a project 0:02:32.040 --> 0:02:35.680 that was government funded too. It was an attempt to 0:02:35.800 --> 0:02:42.079 create a network between various computer nodes to make sure 0:02:42.120 --> 0:02:46.640 that we could transmit information from one major computer to another. 0:02:46.680 --> 0:02:49.519 And you have to remember, of course, right now, back 0:02:49.520 --> 0:02:55.040 in the sixties, computers are these enormous machines that compared 0:02:55.080 --> 0:02:58.240 to the the desktop computer that you may have in 0:02:58.280 --> 0:03:00.799 front of you back over in uh the year two 0:03:00.840 --> 0:03:04.600 thousand nine, um are not that powerful, not that sophisticated. 0:03:05.360 --> 0:03:09.160 But the really important thing is they don't they aren't 0:03:09.160 --> 0:03:12.519 networked together. They aren't able to send information back and forth. 0:03:13.360 --> 0:03:15.799 Now there's a group of people who are working very 0:03:15.840 --> 0:03:21.360 diligently to create a system where two or more computers 0:03:21.360 --> 0:03:24.359 can transmit information between one another, even if they're working 0:03:24.440 --> 0:03:28.359 on completely different operating systems. Yeah, that that was actually 0:03:28.360 --> 0:03:31.960 one of the big problems because there had been uh 0:03:32.040 --> 0:03:34.880 computer networks before that, but they were all networks of 0:03:34.920 --> 0:03:38.680 computers running the same operating system. They were very local situations, 0:03:38.880 --> 0:03:41.600 right or actually some of them were sort of like 0:03:42.000 --> 0:03:45.080 bulletin board systems from what I understand, and that you 0:03:45.120 --> 0:03:47.560 could hook up to the network, but you know, it 0:03:47.640 --> 0:03:51.720 wasn't a permanent situation, and it was also it also 0:03:51.760 --> 0:03:53.880 required you to be running the same operating system, and 0:03:53.880 --> 0:03:55.400 it was very limited in what it could do, and 0:03:55.440 --> 0:03:57.840 you had another kind of sort of network in the 0:03:57.880 --> 0:04:00.320 sense that you had a centralized computer and now a 0:04:00.360 --> 0:04:03.880 bunch of dumb terminals where you are time sharing with 0:04:03.920 --> 0:04:08.080 that computer. It's not terms, it's not really networking because 0:04:08.080 --> 0:04:11.640 you're really tapping into the same processor and same storage 0:04:11.720 --> 0:04:14.440 unit as everybody else. You know, you don't have your 0:04:14.440 --> 0:04:17.480 own individual one. So it's not not the same as networking, 0:04:17.520 --> 0:04:21.360 but it's it's similar in concept. So now you have 0:04:21.400 --> 0:04:24.480 to find a way to connect these different machines together. 0:04:24.560 --> 0:04:27.440 And this group of people were working together to create 0:04:27.560 --> 0:04:32.160 our pannet, the first major computer network between computers running 0:04:32.160 --> 0:04:34.800 different operating systems, and they did it, yep. And that 0:04:35.000 --> 0:04:37.880 it's it's probably important at least who mentioned is a 0:04:37.880 --> 0:04:42.360 a sideline Why it's important to the government that we 0:04:42.360 --> 0:04:43.800 were able to do this. I mean a lot of 0:04:43.839 --> 0:04:48.280 these institutions that were involved in this were research universities, right, 0:04:48.440 --> 0:04:51.000 and you know they wanted to share information, but it 0:04:51.040 --> 0:04:54.680 was also important for national security reasons too. Yeah, I 0:04:54.680 --> 0:04:58.240 mean I had a dual purpose government and education, right. 0:04:58.320 --> 0:05:00.920 One of the one of the benefits that um, I'm sorry, 0:05:03.760 --> 0:05:06.760 but the one of the important benefits here to remember 0:05:06.880 --> 0:05:11.200 is that the um by by distributing information, uh and 0:05:11.279 --> 0:05:15.840 by creating a network between different computers, you could protect 0:05:15.920 --> 0:05:20.080 against a catastrophic attack. If someone were to take out 0:05:20.160 --> 0:05:23.279 part of your information system, you would still have other 0:05:23.279 --> 0:05:26.760 computers that would be able to pass information along within 0:05:26.839 --> 0:05:30.120 this this complex network. Now, that was not something necessarily 0:05:30.120 --> 0:05:31.640 that was in the minds of people when they were 0:05:31.640 --> 0:05:35.360 first building our Bonette, but it did become a benefit 0:05:35.520 --> 0:05:37.800 as people saw it later on down the road. So 0:05:37.880 --> 0:05:41.120 let's uh So, the thing about our Bonnette that we 0:05:41.120 --> 0:05:43.880 should remember is that this is the time and place 0:05:43.960 --> 0:05:48.039 where people began to design the protocols that would later 0:05:48.080 --> 0:05:51.120 come into play when we talk about the Internet. Now, 0:05:51.160 --> 0:05:55.560 these protocols are probably the most important aspect of Internet architecture. 0:05:55.560 --> 0:05:57.600 I mean, you've got your physical hardware, and that's important 0:05:57.600 --> 0:06:00.719 because without it, you don't have any connections. But without 0:06:00.720 --> 0:06:03.880 the protocols, you don't have a common language with which 0:06:03.920 --> 0:06:08.080 all computers can use to to communicate, right, I mean, yeah, 0:06:08.520 --> 0:06:10.719 that's the really cool thing about the Internet is that 0:06:10.760 --> 0:06:13.600 because of these protocols, no matter what kind of computer 0:06:13.680 --> 0:06:17.040 you're using, you are able to send and receive information 0:06:17.120 --> 0:06:20.640 from other computers. All right, So let's Uh, let's pop 0:06:20.680 --> 0:06:22.840 back in the machine and I I dig the sixth 0:06:22.839 --> 0:06:25.240 season all. Don't get me wrong, you know I love 0:06:25.279 --> 0:06:28.040 the music, but we have business to attend to. Back 0:06:28.040 --> 0:06:30.400 in two thousand nine. Alright, let's pop back in, Liz, 0:06:30.520 --> 0:06:40.640 do you mind clipping the switch for Uce? Awesome? Thanks? 0:06:40.720 --> 0:06:42.760 I wish you guys could see that at any rate. 0:06:43.080 --> 0:06:45.000 So now here we are, back in two thousand nine. 0:06:45.440 --> 0:06:49.200 So the protocols designed back uh in the sixties and seventies, 0:06:49.240 --> 0:06:52.400 really what those are what we depend upon today in 0:06:52.520 --> 0:06:56.000 order to communicate over the Internet. Ye. As a matter 0:06:56.040 --> 0:06:57.880 of fact, a lot of them are still in use, 0:06:57.960 --> 0:07:02.680 even though they're not necessarily uh something that you can see. Um. 0:07:02.720 --> 0:07:04.880 You know, some of them are are more common than others. 0:07:04.880 --> 0:07:08.280 I mean, one of the invisible ones probably the I 0:07:08.279 --> 0:07:10.280 would I would say the most important one would be 0:07:10.320 --> 0:07:14.040 t c P i P Y, which is the Transfer 0:07:14.080 --> 0:07:18.000 Control Protocol Internet Protocol. Yes, um, and that's that one 0:07:18.080 --> 0:07:21.360 is pretty much invisible because that's you know, you your 0:07:21.360 --> 0:07:25.360 computer hooking up to the Internet and transferring information back 0:07:25.440 --> 0:07:29.000 and forth. But you don't really see that happening, right, 0:07:29.120 --> 0:07:32.880 And let's just to think back on the whole arpen 0:07:33.080 --> 0:07:36.040 ed deal arpen ed it self was not the Internet. 0:07:37.000 --> 0:07:40.200 It wasn't. You can call it a kind of a 0:07:40.400 --> 0:07:43.200 grandfather to the Internet if you like, But it was 0:07:43.360 --> 0:07:47.920 just a network. The Internet is a network of networks. 0:07:48.000 --> 0:07:51.840 It is constantly changing, It is always evolving. As more 0:07:51.880 --> 0:07:56.200 networks come online or leave, the Internet itself changes. Well, 0:07:56.200 --> 0:07:58.880 that's what the protocols do, is they make They made 0:07:58.920 --> 0:08:02.880 it possible to network networks. Right, so as more UH 0:08:03.040 --> 0:08:06.120 computers were able to use T C P I P 0:08:06.320 --> 0:08:08.320 to talk to one another, and it was possible to 0:08:08.360 --> 0:08:10.679 hook other networks up to the arper net, and thus 0:08:11.400 --> 0:08:13.640 the evolution of the Internet. Right. So, you even had 0:08:13.680 --> 0:08:17.920 things like satellite networks that could interconnect with the land 0:08:17.960 --> 0:08:21.600 based networks. You have cables that go underneath the ocean 0:08:22.440 --> 0:08:26.240 that connect continents together, and you have satellites that connect 0:08:26.240 --> 0:08:31.080 continents together. All of these different systems together comprise the 0:08:31.120 --> 0:08:34.439 Internet that we know love, that Chris and I depend 0:08:34.480 --> 0:08:39.160 upon for our livelihood. Um, now, why are you does 0:08:39.160 --> 0:08:44.040 that scary? That's pretty blunt? Yeah, we do. I mean 0:08:44.080 --> 0:08:46.280 without the Internet, there's no house stuff works dot com, 0:08:46.280 --> 0:08:49.360 there's no tech stuff, there's no job for you and I, 0:08:49.440 --> 0:08:55.079 and we'd be working somewhere else. So yea for the Internet, 0:08:55.200 --> 0:08:58.160 all right. So the protocols, protocols are the common language. 0:08:58.160 --> 0:09:00.520 It's so if you think of each operating system having 0:09:00.559 --> 0:09:03.280 its own native language. And when we're talking operating system, 0:09:03.320 --> 0:09:07.600 remember we're not just talking Windows or Linux or or 0:09:07.720 --> 0:09:11.880 the mac os, where there are hundreds of operating systems 0:09:11.880 --> 0:09:14.640 out there, some of which are proprietary to a very 0:09:14.679 --> 0:09:19.000 specific set number of machines. Has nothing to you know, 0:09:19.040 --> 0:09:22.400 they and they would look as foreign to anyone used 0:09:22.440 --> 0:09:26.680 to Windows or Mac or Lenox as as a truly 0:09:26.720 --> 0:09:29.160 foreign language would to you, like you know, if you 0:09:29.200 --> 0:09:30.840 were to go to a country where you didn't speak 0:09:30.880 --> 0:09:33.400 the language, same sort of thing. Your computer would not 0:09:33.400 --> 0:09:36.840 be able to communicate with these computers normally, But because 0:09:37.200 --> 0:09:40.920 of protocols like t c P I P, these computers 0:09:40.960 --> 0:09:45.440 can exchange information and it will be understandable on either 0:09:45.640 --> 0:09:50.160 end of the line, which is pretty phenomenal. So, and 0:09:50.200 --> 0:09:53.040 when we're talking about a network of networks, that network 0:09:53.080 --> 0:09:56.600 can be made up of practically anything. We can talk 0:09:56.640 --> 0:09:58.880 about something as small as a home network, where that 0:09:58.920 --> 0:10:03.000 home network may just be one computer and whatever peripherals 0:10:03.040 --> 0:10:05.199 you happen to have attached to it. Or it may 0:10:05.240 --> 0:10:07.120 be that you have three or four computers that are 0:10:07.120 --> 0:10:10.400 all network together that are then have a connection to 0:10:10.480 --> 0:10:14.720 the outside world through an Internet service provider, um, but 0:10:15.640 --> 0:10:18.040 your home network that's a network. Or it could be 0:10:18.520 --> 0:10:21.600 a local area network where several machines are all network together, 0:10:21.800 --> 0:10:23.920 like an office network exactly. For example, if I want 0:10:23.920 --> 0:10:26.960 to send a message to Chris, my messages don't necessarily 0:10:27.000 --> 0:10:30.440 go all the way out to the Internet and then 0:10:30.520 --> 0:10:33.800 come back. They're on a local area network. So and 0:10:34.000 --> 0:10:35.760 a message I said to Chris is going to get 0:10:35.760 --> 0:10:39.080 there very very quickly, and it doesn't require going out 0:10:39.320 --> 0:10:43.679 to the outside world. It's all self contained. But our 0:10:43.760 --> 0:10:46.960 local area network also obviously has a connection to the 0:10:46.960 --> 0:10:49.920 Internet to the outside world, because otherwise I wouldn't be 0:10:49.960 --> 0:10:54.120 able to do any research. That's a that's a positive. Yes, yeah, 0:10:54.400 --> 0:10:56.000 it turns out I have to do that a lot. 0:10:56.679 --> 0:10:59.560 You know. Another protocol that that Jonathan uses when he 0:10:59.600 --> 0:11:02.920 does his research would be Hypertext Transfer Protocol, Yes ht 0:11:02.920 --> 0:11:05.720 t P, which is the HTTP you see at the 0:11:05.720 --> 0:11:07.920 beginning of a web address, right, And of course we 0:11:07.960 --> 0:11:10.360 should also point out the World Wide Web and the 0:11:10.360 --> 0:11:13.560 Internet are two different things. The Worldwide Web is an 0:11:13.559 --> 0:11:16.439 interface built on top of the Internet, is not the 0:11:16.440 --> 0:11:19.840 Internet itself. The Internet is far more complex than just 0:11:19.880 --> 0:11:23.400 the World Wide Web, although in a lot of ways 0:11:24.080 --> 0:11:28.040 it's not for most people, which is why for most people, 0:11:28.320 --> 0:11:31.440 for most people, their main their main interaction with the 0:11:31.480 --> 0:11:35.520 Internet is limited to two things, email and the World 0:11:35.520 --> 0:11:40.360 Wide Web. But the Internet itself. Again, we're talking about 0:11:40.840 --> 0:11:43.679 a network of networks, so it's more complex than that, 0:11:44.040 --> 0:11:47.240 even if your own interactions tend to be pretty simple. 0:11:48.000 --> 0:11:51.720 So now let's talk about some of the hardware that 0:11:51.840 --> 0:11:54.120 you find in the Internet. Really, the Internet can be 0:11:54.160 --> 0:11:59.120 divided up into two categories of machines, clients and servers. 0:11:59.480 --> 0:12:02.839 All right, So every machine on the Internet is either 0:12:02.880 --> 0:12:05.360 a client or a server, or it can switch. It 0:12:05.400 --> 0:12:07.400 can be a server or it can become a client 0:12:07.559 --> 0:12:12.200 depending on the situation. Clients are, in general, the devices 0:12:12.280 --> 0:12:16.000 that you that you are using to try and access information. 0:12:16.040 --> 0:12:20.360 You are requesting information from a server. Your client sends 0:12:20.440 --> 0:12:25.240 this request out to a local server, which, if the 0:12:25.280 --> 0:12:28.160 local server does not have access to this information, it 0:12:28.200 --> 0:12:31.280 will send it out to a regional server, which, if 0:12:31.360 --> 0:12:33.719 it does not have access to that information, will then 0:12:33.760 --> 0:12:35.960 send it to a national server, and so on. It 0:12:36.040 --> 0:12:38.959 keeps going further up the chain until it reaches the 0:12:39.000 --> 0:12:41.520 point where it can access the information you are requesting. 0:12:42.160 --> 0:12:46.320 It pulls that information from another server and then sends 0:12:46.320 --> 0:12:50.280 it back down the line to you. Awesome, that's it 0:12:50.360 --> 0:12:53.199 sounds pretty um you make it sound really simple. It is. Well, 0:12:53.240 --> 0:12:55.600 you know what, if you look at a big picture scale, 0:12:55.640 --> 0:12:58.920 it is pretty simple. Some pretty amazing things have to 0:12:59.000 --> 0:13:03.240 happen for this to work properly. For example, the computers 0:13:03.320 --> 0:13:06.000 have to know where all the other computers are, you know. 0:13:06.000 --> 0:13:08.640 It has to has to be able to figure out oh, 0:13:08.679 --> 0:13:12.080 based upon this I P address. Then I have to 0:13:12.120 --> 0:13:15.400 contact this other server over here, which can then at 0:13:15.480 --> 0:13:18.040 least point me in the right direction to get to 0:13:18.080 --> 0:13:20.800 the information, even if this server itself does not have 0:13:20.880 --> 0:13:23.480 the information I need. And not only that, but when 0:13:23.520 --> 0:13:25.760 it sends the information, it splits it up into lots 0:13:25.800 --> 0:13:29.080 of tiny little bits called packets. Yes, it makes me 0:13:29.160 --> 0:13:31.920 always think that, you know what I always think of 0:13:31.920 --> 0:13:34.439 when I think of information being split into packets and 0:13:34.480 --> 0:13:38.160 then sent to be reassembled back at the your computer. Right. No, 0:13:38.800 --> 0:13:40.720 you're not gonna say ketchup, are you? No? No, you 0:13:40.760 --> 0:13:47.160 can't honestly, Mike TV right, chocolate factory, Yes, because you 0:13:47.200 --> 0:13:50.719 think of exactly yeah, that's exactly the right image too. 0:13:51.360 --> 0:13:53.320 If you've seen the movie, you know that he gets 0:13:53.360 --> 0:13:55.280 broken down and had lots and lots of aty bitty 0:13:55.280 --> 0:13:59.720 pieces and then reassembled on the television screen. Your email 0:13:59.800 --> 0:14:03.400 is my smaller than it was when Yes, wow, you 0:14:03.400 --> 0:14:06.400 know that's why. That's why web pages when we make them, 0:14:06.600 --> 0:14:08.880 are much bigger over here at how stuff works. If 0:14:08.920 --> 0:14:10.560 you came in and looked at one of our web pages, 0:14:10.880 --> 0:14:13.760 they are like three stories tall. But of course they 0:14:13.800 --> 0:14:15.720 get very tiny on the internet, which is why they 0:14:15.760 --> 0:14:17.760 look so small in your screen. Someone is going to 0:14:17.800 --> 0:14:21.360 write in that is also more from Misinformation Love Podcast Limited. 0:14:22.120 --> 0:14:25.680 Uh okay, so alright, so alright. Granted the analogy is 0:14:25.720 --> 0:14:28.160 not perfect, but that's what I always think of. I'm sorry, 0:14:28.160 --> 0:14:30.880 I just wanted to It's amusing to me. But no, 0:14:31.040 --> 0:14:35.600 that that's that's pretty much it accepted. Doesn't travel over 0:14:35.640 --> 0:14:38.880 the air waves generally, it you know, proceeds down the 0:14:40.120 --> 0:14:45.880 series of tubes. Well well okay, no, it goes the 0:14:46.120 --> 0:14:48.360 packets are broken up, and actually they don't proceed in 0:14:48.360 --> 0:14:52.000 an orderly fashion. No, Um, they are. They're essentially labeled 0:14:52.080 --> 0:14:53.760 with a little bit of information at the beginning in 0:14:53.800 --> 0:14:56.760 the end of each packet and UH, as a matter 0:14:56.800 --> 0:14:58.960 of fact, there's some redundancy going on. The same packets 0:14:58.960 --> 0:15:01.760 are sent in diferent places because from time to time, 0:15:01.760 --> 0:15:06.960 computers connect and disconnect and um or whatever. Yeah, and 0:15:07.160 --> 0:15:10.120 for well, for whatever reasons, they connect and disconnect. The 0:15:10.120 --> 0:15:12.920 thing is, um Genet was saying, it is pretty amazing 0:15:12.920 --> 0:15:15.160 that they can find one another. Well, it's even more 0:15:15.160 --> 0:15:18.400 amazing when you consider that machines fail or get shut 0:15:18.440 --> 0:15:23.440 off or you know, UH suddenly become available, and then 0:15:23.560 --> 0:15:27.240 there's another connection in between. Well that that redundancy helps 0:15:27.560 --> 0:15:30.160 the packets go from one place to another, and then 0:15:30.160 --> 0:15:34.240 they're reassembled based on the instructions in the header and 0:15:34.560 --> 0:15:37.720 foot or of that that individual packet to be reassembled 0:15:37.720 --> 0:15:40.760 into a file. Say you know, UM, a movie that 0:15:40.840 --> 0:15:43.560 you purchase online. That's a that's a big file and 0:15:43.600 --> 0:15:45.400 it's broken down into lots and lots and lots of 0:15:45.400 --> 0:15:48.320 little packets and reassembled it on your computer. Right, And 0:15:48.360 --> 0:15:51.640 these packets can spread across various parts of the network, 0:15:52.040 --> 0:15:54.600 again depending on where you need to connect. For example, 0:15:54.680 --> 0:15:58.520 let's say that you, Uh, you are a customer of 0:15:58.520 --> 0:16:00.640 a specific I s P. I'm not the name any 0:16:00.720 --> 0:16:04.440 here because they're hundreds of them, big ones and small ones. 0:16:04.720 --> 0:16:06.880 But you're a customer of let's say you are a 0:16:06.880 --> 0:16:09.560 customer of I s P A. Okay, we're just saying 0:16:09.600 --> 0:16:14.040 A as in that's the designation. Yeah, they're very good. 0:16:14.160 --> 0:16:17.000 Their customer service is really really excellent. So I s 0:16:17.040 --> 0:16:20.800 P A and UH, you connect to your I s 0:16:20.880 --> 0:16:24.200 P or Internet service provider and you are typing in 0:16:24.240 --> 0:16:26.320 a web address. You want to get access to a 0:16:26.320 --> 0:16:30.520 specific web address, and that web address, uh is for 0:16:30.720 --> 0:16:33.800 a a page that exists on a server that is 0:16:33.880 --> 0:16:38.840 not within that Internet service providers network. So the Internet 0:16:38.840 --> 0:16:42.080 service provider has to then connect to what is called 0:16:42.160 --> 0:16:46.960 a network access point. Network access points are points on 0:16:47.000 --> 0:16:52.120 the Internet where multiple networks connect, right, So it's sort 0:16:52.160 --> 0:16:56.120 of like a like a stoplight, yeah, or an intersection. Yeah, 0:16:56.240 --> 0:16:59.240 it's exactly. So I s P A does not have 0:16:59.720 --> 0:17:02.200 does not directly connect to the server that contains the 0:17:02.240 --> 0:17:05.119 web page you want. But I s P B it 0:17:05.200 --> 0:17:07.199 does exist on I s P B, you can you 0:17:07.200 --> 0:17:09.720 can connect to it through there. So you have to 0:17:09.760 --> 0:17:12.399 go to a network access point where both A and 0:17:12.520 --> 0:17:17.480 B have a connection. And then because the the protocols 0:17:17.520 --> 0:17:21.560 allow different networks and computers to communicate with one another, 0:17:22.240 --> 0:17:25.120 the information from the request from s P A can 0:17:25.119 --> 0:17:29.520 be answered by I s P B. Now, uh, if 0:17:29.560 --> 0:17:32.080 it has to go even further up and eventually hits 0:17:32.119 --> 0:17:34.840 what we call the backbone of the Internet. Now, the 0:17:34.880 --> 0:17:39.800 backbone is owned by multiple UM owners. We're talking about 0:17:39.880 --> 0:17:44.600 government's major corporations, major I s p s. They own 0:17:44.720 --> 0:17:48.000 what is called the backbone, which which is the trunk 0:17:48.440 --> 0:17:53.520 of the Internet. Yeah, it isn't really UM, I wouldn't 0:17:53.560 --> 0:17:56.200 say incorrect to think of it almost like you would 0:17:56.240 --> 0:17:59.920 a tree, because um, what they call the last miles 0:18:00.240 --> 0:18:04.159 between you and the local switches handles much less bandwidth 0:18:04.240 --> 0:18:07.920 than what's actually available in the Internet backbone. I mean 0:18:07.960 --> 0:18:12.320 we're talking hundreds and hundreds of megabits per second transfer speeds. 0:18:12.320 --> 0:18:15.520 But you need that on the on the backbone because uh, 0:18:15.560 --> 0:18:20.000 these are the major thoroughfares are almost like you use 0:18:20.000 --> 0:18:23.359 another metaphor, like an interstate. There's a lot more traffic, 0:18:23.359 --> 0:18:25.880 it's moving on much faster speed. And then you get 0:18:25.920 --> 0:18:28.960 to your you know, your side roads, which is where 0:18:29.119 --> 0:18:31.200 your house might be right. Once you once you get 0:18:31.200 --> 0:18:33.119 to the backbone, that's where you're getting to the major 0:18:33.160 --> 0:18:38.640 communication between enormous networks. Part of my mixed metaphors, that's 0:18:38.640 --> 0:18:42.119 all right, So you get the major communication between networks 0:18:42.160 --> 0:18:44.800 along the backbone. Then once you get down to the 0:18:44.840 --> 0:18:47.879 network access point, you're talking about communication between a couple 0:18:47.920 --> 0:18:50.840 of networks, and then once you get beyond that, you're 0:18:50.840 --> 0:18:54.880 talking about communication within a single network. So each time, 0:18:54.920 --> 0:18:57.560 each step, you're getting slightly smaller until you get down 0:18:57.640 --> 0:19:01.080 to the original client that requested the information in the 0:19:01.119 --> 0:19:04.240 first place. So yeah, think of it like a tree 0:19:04.440 --> 0:19:08.200 and then a uh. The You could think of the 0:19:08.520 --> 0:19:12.040 network access point being a major branch that then forks 0:19:12.119 --> 0:19:14.840 into two smaller branches, which would be the two different 0:19:14.840 --> 0:19:20.680 Internet service provider networks. Um, it's you know, like I said, 0:19:20.880 --> 0:19:23.840 it might be a little weird to to imagine it 0:19:23.920 --> 0:19:27.399 in a physical sense, but really it's it's all just 0:19:27.480 --> 0:19:32.200 about connecting and uh and sending information through various connections. 0:19:32.200 --> 0:19:36.520 I mean, anytime you're actually requesting information, the information is 0:19:36.520 --> 0:19:39.840 passing through lots and lots and lots of different machines 0:19:39.920 --> 0:19:42.840 to get you both the request to go out from 0:19:42.920 --> 0:19:45.880 you to the destination and the information from the destination 0:19:45.920 --> 0:19:48.840 back to you. UM. And it doesn't all follow the 0:19:48.880 --> 0:19:53.320 same path. UM. Something you might try if you're interested 0:19:54.040 --> 0:19:57.680 in learning a little bit about your particular connection. UM, 0:19:57.720 --> 0:20:00.600 you could try something called a trace route, which will 0:20:00.600 --> 0:20:03.920 show you some of the different places where your connection 0:20:04.040 --> 0:20:09.399 is is linking up with other computers on the internet. UM. 0:20:09.440 --> 0:20:12.560 You know, I could get into greater detail. But UM, 0:20:12.600 --> 0:20:16.200 I forgot to look that up. UM. But UM, it 0:20:16.320 --> 0:20:18.320 just occurred to me actually, and so UM, but you 0:20:18.320 --> 0:20:19.760 can you can find that out. You can also do 0:20:19.800 --> 0:20:23.280 a ping, which will tell you how far how fast UM, 0:20:23.320 --> 0:20:26.960 the signal is transferred from your request is transferred from 0:20:27.080 --> 0:20:31.600 your computer to the receiver machine. UM. You can you 0:20:31.600 --> 0:20:34.280 can look at you know that you can look up 0:20:34.280 --> 0:20:36.720 how to do that online. But UM, you know, if 0:20:36.720 --> 0:20:40.360 you're just vaguely curious about UM other machines in your 0:20:40.400 --> 0:20:43.040 area and and that. But you will see something called 0:20:43.040 --> 0:20:44.960 an IP address for most of those machines if you 0:20:45.000 --> 0:20:48.159 do a trace route. UM. And that's important because I 0:20:48.240 --> 0:20:51.719 P addresses are how machines are hooked up to the network. 0:20:51.720 --> 0:20:55.600 Because each UM to use my streets metaphor, well, we'll 0:20:55.600 --> 0:20:59.000 stick with that one. UM. You know, you need a 0:20:59.040 --> 0:21:03.800 street address for people to send mail UM or for 0:21:03.840 --> 0:21:06.280 information to get to so you know if your your 0:21:06.280 --> 0:21:10.240 computer has its own address UM, usually assigned to you 0:21:10.320 --> 0:21:12.679 by your I s P, which may or may not 0:21:12.920 --> 0:21:20.040 change depending on depending on your Yeah. So so for 0:21:20.080 --> 0:21:23.000 every instance where you are connected to the Internet, the 0:21:23.040 --> 0:21:26.679 machine you are connecting through, whether that's a computer or 0:21:26.720 --> 0:21:30.080 a smartphone or any other kind of Internet capable device, 0:21:30.560 --> 0:21:33.000 is going to have its own IP address. Now that 0:21:33.080 --> 0:21:36.479 address may change depending on your Internet service provider and 0:21:36.640 --> 0:21:40.359 UH it won't change through the duration of your of 0:21:40.440 --> 0:21:43.840 your current stay, but it might change from one instance 0:21:43.880 --> 0:21:45.720 to another. So if you log off and turn everything 0:21:45.760 --> 0:21:47.879 off and then you log on again later, you may 0:21:47.920 --> 0:21:50.119 have a different IP address again depending on your I 0:21:50.240 --> 0:21:53.240 s P. UH. The I s p s for servers 0:21:53.320 --> 0:21:57.200 that serve up information very rarely change. They usually stay 0:21:57.240 --> 0:22:00.920 pretty static UM, which is helpful because when you're when 0:22:00.920 --> 0:22:03.359 you're trying to connect to a server UH to to 0:22:03.520 --> 0:22:07.520 access information, if it stays the same, then that makes 0:22:07.560 --> 0:22:10.040 it easier to do repeated connections to that server. You 0:22:10.080 --> 0:22:13.200 don't have to worry about looking it up every single time. 0:22:13.920 --> 0:22:16.760 It as a matter of fact um that uh. That 0:22:16.920 --> 0:22:20.600 also is important to the domain name servers or d 0:22:20.760 --> 0:22:24.920 n s UM because you know, these these IP addresses, 0:22:24.920 --> 0:22:30.640 Internet protocol addresses are a series of four octets um 0:22:30.680 --> 0:22:35.560 basically zero to two five separated by periods. So you 0:22:35.600 --> 0:22:39.320 could have for example, zero dot zero dot zero dot zero, 0:22:39.920 --> 0:22:45.640 you know, or any number zero for each of them. Um, 0:22:45.720 --> 0:22:48.480 And and that's what an IP address looks like. Now, um, 0:22:49.600 --> 0:22:52.000 you have to say, if you wanted to visit how 0:22:52.000 --> 0:22:55.200 stuff works dot com, you'd have to know our IP 0:22:55.320 --> 0:22:59.080 address and that could get really annoying because you know, 0:22:59.240 --> 0:23:01.399 on all those commercid holes you see, Yeah, check us 0:23:01.400 --> 0:23:08.320 out at zero dot four five dot five six three whatever. Anyway, 0:23:10.600 --> 0:23:13.000 read that number again. And I don't think the Internet 0:23:13.000 --> 0:23:14.920 would be nearly as popular if you had to do that. 0:23:15.160 --> 0:23:18.760 So they came up with the system of domain names, 0:23:19.080 --> 0:23:22.320 and in order to manage that, the domain name server 0:23:22.480 --> 0:23:25.920