Internet Architecture

Published Dec 2, 2009, 5:04 PM

In this episode, the TechStuff guys tackle Internet architecture, from the basic components to the complex details of servers, clients and IP addresses.

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

Brought to you by the reinvented two thousand twelve camera. It's ready. Are you get in touch with technologies with tech Stuff from how stuff works dot com. Hello there, everybody, and welcome to tech stuff. My name is Chris Poette and I'm the tech editor here at how stuff works dot Com. Sitting across from me, as he often does at this very table, would be senior writer Jonathan. Hey there, so, uh so, what do you want to talk about today? Well, it's not what I want to talk about, it's what Alexander wants us to talk about. There's what Alexander had to say. Hey, guys, I find your podcasts very educating. I'm a computer science major, but I have a difficulty understanding the architecture of the Internet. So it'll be really nice for you to make a podcast addressing the Internet architecture. Continue the good work, Well, Alexander, we decided we would tackle Internet architecture, which is you know, it's it's conceptually it's a pretty simple thing, uh it it involves two different categories of of of concepts. I guess you could say you got your hardware and then you got your protocols, and that pretty much you know, the marriage of the two is where the Internet comes into play. Now, before we get to bog down with the whole thing, we're gonna start very simply. Let's take a trip back to the sixties, shall we. Right, I guess that means that we're gonna pop into the time machine. Liz is already giggling because she's here. She's actually gonna We're gonna drag Liz into the time machine with us. She probably won't say anything, but she'll be back there with her hand over her mouth giggling. All right, let's just set this back to the mid sixties and pop on back. And let's let's take a little visit to to uh, the California. Look at ARPA back in the day, dude. So here we are, California Route sixty six, right down the road, Chris, Chris, that's true. It is the only road in the sixties in California. Well, according to popular culture, I guess welcome to Misinformation Podcast Limited. So anyway, we are here to talk about arpanet. Okay, alright. So arpanet was a project that was government funded too. It was an attempt to create a network between various computer nodes to make sure that we could transmit information from one major computer to another. And you have to remember, of course, right now, back in the sixties, computers are these enormous machines that compared to the the desktop computer that you may have in front of you back over in uh the year two thousand nine, um are not that powerful, not that sophisticated. But the really important thing is they don't they aren't networked together. They aren't able to send information back and forth. Now there's a group of people who are working very diligently to create a system where two or more computers can transmit information between one another, even if they're working on completely different operating systems. Yeah, that that was actually one of the big problems because there had been uh computer networks before that, but they were all networks of computers running the same operating system. They were very local situations, right or actually some of them were sort of like bulletin board systems from what I understand, and that you could hook up to the network, but you know, it wasn't a permanent situation, and it was also it also required you to be running the same operating system, and it was very limited in what it could do, and you had another kind of sort of network in the sense that you had a centralized computer and now a bunch of dumb terminals where you are time sharing with that computer. It's not terms, it's not really networking because you're really tapping into the same processor and same storage unit as everybody else. You know, you don't have your own individual one. So it's not not the same as networking, but it's it's similar in concept. So now you have to find a way to connect these different machines together. And this group of people were working together to create our pannet, the first major computer network between computers running different operating systems, and they did it, yep. And that it's it's probably important at least who mentioned is a a sideline Why it's important to the government that we were able to do this. I mean a lot of these institutions that were involved in this were research universities, right, and you know they wanted to share information, but it was also important for national security reasons too. Yeah, I mean I had a dual purpose government and education, right. One of the one of the benefits that um, I'm sorry, but the one of the important benefits here to remember is that the um by by distributing information, uh and by creating a network between different computers, you could protect against a catastrophic attack. If someone were to take out part of your information system, you would still have other computers that would be able to pass information along within this this complex network. Now, that was not something necessarily that was in the minds of people when they were first building our Bonette, but it did become a benefit as people saw it later on down the road. So let's uh So, the thing about our Bonnette that we should remember is that this is the time and place where people began to design the protocols that would later come into play when we talk about the Internet. Now, these protocols are probably the most important aspect of Internet architecture. I mean, you've got your physical hardware, and that's important because without it, you don't have any connections. But without the protocols, you don't have a common language with which all computers can use to to communicate, right, I mean, yeah, that's the really cool thing about the Internet is that because of these protocols, no matter what kind of computer you're using, you are able to send and receive information from other computers. All right, So let's Uh, let's pop back in the machine and I I dig the sixth season all. Don't get me wrong, you know I love the music, but we have business to attend to. Back in two thousand nine. Alright, let's pop back in, Liz, do you mind clipping the switch for Uce? Awesome? Thanks? I wish you guys could see that at any rate. So now here we are, back in two thousand nine. So the protocols designed back uh in the sixties and seventies, really what those are what we depend upon today in order to communicate over the Internet. Ye. As a matter of fact, a lot of them are still in use, even though they're not necessarily uh something that you can see. Um. You know, some of them are are more common than others. I mean, one of the invisible ones probably the I would I would say the most important one would be t c P i P Y, which is the Transfer Control Protocol Internet Protocol. Yes, um, and that's that one is pretty much invisible because that's you know, you your computer hooking up to the Internet and transferring information back and forth. But you don't really see that happening, right, And let's just to think back on the whole arpen ed deal arpen ed it self was not the Internet. It wasn't. You can call it a kind of a grandfather to the Internet if you like, But it was just a network. The Internet is a network of networks. It is constantly changing, It is always evolving. As more networks come online or leave, the Internet itself changes. Well, that's what the protocols do, is they make They made it possible to network networks. Right, so as more UH computers were able to use T C P I P to talk to one another, and it was possible to hook other networks up to the arper net, and thus the evolution of the Internet. Right. So, you even had things like satellite networks that could interconnect with the land based networks. You have cables that go underneath the ocean that connect continents together, and you have satellites that connect continents together. All of these different systems together comprise the Internet that we know love, that Chris and I depend upon for our livelihood. Um, now, why are you does that scary? That's pretty blunt? Yeah, we do. I mean without the Internet, there's no house stuff works dot com, there's no tech stuff, there's no job for you and I, and we'd be working somewhere else. So yea for the Internet, all right. So the protocols, protocols are the common language. It's so if you think of each operating system having its own native language. And when we're talking operating system, remember we're not just talking Windows or Linux or or the mac os, where there are hundreds of operating systems out there, some of which are proprietary to a very specific set number of machines. Has nothing to you know, they and they would look as foreign to anyone used to Windows or Mac or Lenox as as a truly foreign language would to you, like you know, if you were to go to a country where you didn't speak the language, same sort of thing. Your computer would not be able to communicate with these computers normally, But because of protocols like t c P I P, these computers can exchange information and it will be understandable on either end of the line, which is pretty phenomenal. So, and when we're talking about a network of networks, that network can be made up of practically anything. We can talk about something as small as a home network, where that home network may just be one computer and whatever peripherals you happen to have attached to it. Or it may be that you have three or four computers that are all network together that are then have a connection to the outside world through an Internet service provider, um, but your home network that's a network. Or it could be a local area network where several machines are all network together, like an office network exactly. For example, if I want to send a message to Chris, my messages don't necessarily go all the way out to the Internet and then come back. They're on a local area network. So and a message I said to Chris is going to get there very very quickly, and it doesn't require going out to the outside world. It's all self contained. But our local area network also obviously has a connection to the Internet to the outside world, because otherwise I wouldn't be able to do any research. That's a that's a positive. Yes, yeah, it turns out I have to do that a lot. You know. Another protocol that that Jonathan uses when he does his research would be Hypertext Transfer Protocol, Yes ht t P, which is the HTTP you see at the beginning of a web address, right, And of course we should also point out the World Wide Web and the Internet are two different things. The Worldwide Web is an interface built on top of the Internet, is not the Internet itself. The Internet is far more complex than just the World Wide Web, although in a lot of ways it's not for most people, which is why for most people, for most people, their main their main interaction with the Internet is limited to two things, email and the World Wide Web. But the Internet itself. Again, we're talking about a network of networks, so it's more complex than that, even if your own interactions tend to be pretty simple. So now let's talk about some of the hardware that you find in the Internet. Really, the Internet can be divided up into two categories of machines, clients and servers. All right, So every machine on the Internet is either a client or a server, or it can switch. It can be a server or it can become a client depending on the situation. Clients are, in general, the devices that you that you are using to try and access information. You are requesting information from a server. Your client sends this request out to a local server, which, if the local server does not have access to this information, it will send it out to a regional server, which, if it does not have access to that information, will then send it to a national server, and so on. It keeps going further up the chain until it reaches the point where it can access the information you are requesting. It pulls that information from another server and then sends it back down the line to you. Awesome, that's it sounds pretty um you make it sound really simple. It is. Well, you know what, if you look at a big picture scale, it is pretty simple. Some pretty amazing things have to happen for this to work properly. For example, the computers have to know where all the other computers are, you know. It has to has to be able to figure out oh, based upon this I P address. Then I have to contact this other server over here, which can then at least point me in the right direction to get to the information, even if this server itself does not have the information I need. And not only that, but when it sends the information, it splits it up into lots of tiny little bits called packets. Yes, it makes me always think that, you know what I always think of when I think of information being split into packets and then sent to be reassembled back at the your computer. Right. No, you're not gonna say ketchup, are you? No? No, you can't honestly, Mike TV right, chocolate factory, Yes, because you think of exactly yeah, that's exactly the right image too. If you've seen the movie, you know that he gets broken down and had lots and lots of aty bitty pieces and then reassembled on the television screen. Your email is my smaller than it was when Yes, wow, you know that's why. That's why web pages when we make them, are much bigger over here at how stuff works. If you came in and looked at one of our web pages, they are like three stories tall. But of course they get very tiny on the internet, which is why they look so small in your screen. Someone is going to write in that is also more from Misinformation Love Podcast Limited. Uh okay, so alright, so alright. Granted the analogy is not perfect, but that's what I always think of. I'm sorry, I just wanted to It's amusing to me. But no, that that's that's pretty much it accepted. Doesn't travel over the air waves generally, it you know, proceeds down the series of tubes. Well well okay, no, it goes the packets are broken up, and actually they don't proceed in an orderly fashion. No, Um, they are. They're essentially labeled with a little bit of information at the beginning in the end of each packet and UH, as a matter of fact, there's some redundancy going on. The same packets are sent in diferent places because from time to time, computers connect and disconnect and um or whatever. Yeah, and for well, for whatever reasons, they connect and disconnect. The thing is, um Genet was saying, it is pretty amazing that they can find one another. Well, it's even more amazing when you consider that machines fail or get shut off or you know, UH suddenly become available, and then there's another connection in between. Well that that redundancy helps the packets go from one place to another, and then they're reassembled based on the instructions in the header and foot or of that that individual packet to be reassembled into a file. Say you know, UM, a movie that you purchase online. That's a that's a big file and it's broken down into lots and lots and lots of little packets and reassembled it on your computer. Right, And these packets can spread across various parts of the network, again depending on where you need to connect. For example, let's say that you, Uh, you are a customer of a specific I s P. I'm not the name any here because they're hundreds of them, big ones and small ones. But you're a customer of let's say you are a customer of I s P A. Okay, we're just saying A as in that's the designation. Yeah, they're very good. Their customer service is really really excellent. So I s P A and UH, you connect to your I s P or Internet service provider and you are typing in a web address. You want to get access to a specific web address, and that web address, uh is for a a page that exists on a server that is not within that Internet service providers network. So the Internet service provider has to then connect to what is called a network access point. Network access points are points on the Internet where multiple networks connect, right, So it's sort of like a like a stoplight, yeah, or an intersection. Yeah, it's exactly. So I s P A does not have does not directly connect to the server that contains the web page you want. But I s P B it does exist on I s P B, you can you can connect to it through there. So you have to go to a network access point where both A and B have a connection. And then because the the protocols allow different networks and computers to communicate with one another, the information from the request from s P A can be answered by I s P B. Now, uh, if it has to go even further up and eventually hits what we call the backbone of the Internet. Now, the backbone is owned by multiple UM owners. We're talking about government's major corporations, major I s p s. They own what is called the backbone, which which is the trunk of the Internet. Yeah, it isn't really UM, I wouldn't say incorrect to think of it almost like you would a tree, because um, what they call the last miles between you and the local switches handles much less bandwidth than what's actually available in the Internet backbone. I mean we're talking hundreds and hundreds of megabits per second transfer speeds. But you need that on the on the backbone because uh, these are the major thoroughfares are almost like you use another metaphor, like an interstate. There's a lot more traffic, it's moving on much faster speed. And then you get to your you know, your side roads, which is where your house might be right. Once you once you get to the backbone, that's where you're getting to the major communication between enormous networks. Part of my mixed metaphors, that's all right, So you get the major communication between networks along the backbone. Then once you get down to the network access point, you're talking about communication between a couple of networks, and then once you get beyond that, you're talking about communication within a single network. So each time, each step, you're getting slightly smaller until you get down to the original client that requested the information in the first place. So yeah, think of it like a tree and then a uh. The You could think of the network access point being a major branch that then forks into two smaller branches, which would be the two different Internet service provider networks. Um, it's you know, like I said, it might be a little weird to to imagine it in a physical sense, but really it's it's all just about connecting and uh and sending information through various connections. I mean, anytime you're actually requesting information, the information is passing through lots and lots and lots of different machines to get you both the request to go out from you to the destination and the information from the destination back to you. UM. And it doesn't all follow the same path. UM. Something you might try if you're interested in learning a little bit about your particular connection. UM, you could try something called a trace route, which will show you some of the different places where your connection is is linking up with other computers on the internet. UM. You know, I could get into greater detail. But UM, I forgot to look that up. UM. But UM, it just occurred to me actually, and so UM, but you can you can find that out. You can also do a ping, which will tell you how far how fast UM, the signal is transferred from your request is transferred from your computer to the receiver machine. UM. You can you can look at you know that you can look up how to do that online. But UM, you know, if you're just vaguely curious about UM other machines in your area and and that. But you will see something called an IP address for most of those machines if you do a trace route. UM. And that's important because I P addresses are how machines are hooked up to the network. Because each UM to use my streets metaphor, well, we'll stick with that one. UM. You know, you need a street address for people to send mail UM or for information to get to so you know if your your computer has its own address UM, usually assigned to you by your I s P, which may or may not change depending on depending on your Yeah. So so for every instance where you are connected to the Internet, the machine you are connecting through, whether that's a computer or a smartphone or any other kind of Internet capable device, is going to have its own IP address. Now that address may change depending on your Internet service provider and UH it won't change through the duration of your of your current stay, but it might change from one instance to another. So if you log off and turn everything off and then you log on again later, you may have a different IP address again depending on your I s P. UH. The I s p s for servers that serve up information very rarely change. They usually stay pretty static UM, which is helpful because when you're when you're trying to connect to a server UH to to access information, if it stays the same, then that makes it easier to do repeated connections to that server. You don't have to worry about looking it up every single time. It as a matter of fact um that uh. That also is important to the domain name servers or d n s UM because you know, these these IP addresses, Internet protocol addresses are a series of four octets um basically zero to two five separated by periods. So you could have for example, zero dot zero dot zero dot zero, you know, or any number zero for each of them. Um, And and that's what an IP address looks like. Now, um, you have to say, if you wanted to visit how stuff works dot com, you'd have to know our IP address and that could get really annoying because you know, on all those commercid holes you see, Yeah, check us out at zero dot four five dot five six three whatever. Anyway, read that number again. And I don't think the Internet would be nearly as popular if you had to do that. So they came up with the system of domain names, and in order to manage that, the domain name server actually connects the name that you know, how stuff works dot com with the IP address for the website, so that it's you know, you have a static IP address, which is the dedicated address for that and it can be found at how stuff works dot com. So all you have to remember is the name that is, uh, you know, a name that you can that's easy to remember in your head, right exactly. So for example, you know, it's just like computer languages. Computer languages are designed so that humans can can program because we think more easily in terms of like words and and and strings of letters and things of that nature. But that's not machine read bowl. The machines need numbers, ones and zeros. So really, ultimately the even the the numbers in an IP address eventually become ones and zeros. But uh, yeah, so www, dot how stuffworks. Dot Com is not machine readable. That's the domain name servers job is to translate that into the correct IP address, which might mean looking up the domain name server for all dot Com addresses, and then that would eventually be able to point to the right uh server that would have the specific address for house supports dot Com. Um, this is getting a little more granular than I expected, but yeah, that's that is a good A good point is that without the IP addresses, the Internet doesn't work, or at least the being able to track down specific information on the Internet wouldn't work. You would you know, you wouldn't be able to direct anything to anyone because there'd be no way of knowing where to send any information. Yeah, well no, that's well, that's the important thing I think is that you've got your IP address, which identifies your machine. You have an IP address of the machine on the other end that you know, or that your computer knows is where it needs to go and the protocols. You know, it's got the information it needs and it already has a connection to those machines through the network of networks. So using that, you know, you've got the ability to, you know, do all kinds of things use using net. Do email transfer files on FTP, that's file transfer protocol, tell net if you want to, if you're so inclined, Hey, that's how I met my wife. Hey, well, you know, and there are other ones to gopher ways. You know, there are a lot of these older protocols, some of which are very um minimally used at this point, but are still you know, possible using the Internet. And it's the funny thing is a lot of this technology that the protocols and IP addresses are essentially the same that were invented in the sixties and seventies, and uh, you know, with minimal revisions. Of course, one of the reasons that Internet service providers have to assign I P addresses dynamically, which is, you know, a new one every time you log on, uh, you know, reboot your motum er or a dial in if you're still using a dial in connection. I'm very sorry. Um, it's because so many people are using the Internet now that they realized while we're going to run out of addresses eventually, especially when you figure that most people have more than one Internet capable device. People, most people who are already on the Internet, I should say not most people period. Um, so that in fact, I'm sorry, I was just gonna say, that's why they amended the IP address to be i p V six, which is basically just extends the number of octets in the IP address to make more combination possible. Combination, huge, huge expansion. Actually yes, because right now, if you guys listen to our our twenty eight problem podcast, we had this great time where we talked about how many seconds you could count up to until you hit the eight and starts over again because it's a thirty two bit number. Same thing here with the the octet system, it gave us a maximum of and this this is a kind of a fake maximum because not all addresses are available to start with. But if you were able to use every single address within that zero to octet range, you would have a maximum of four billion, two d ninety four million, nine hundred sixty seven thousand, two hundred addresses, which sounds like a lot. I mean four billion, that's a lot, But you think about it, there are a lot more people in countries that are just tuning in, if you will, to the Internet. Yeah, heck, China's exploding on the Internet right now. And again people might have multiple devices and not all of those addresses are usable. So that was why various groups we're working on on a new set of protocols in order to address this problem before it becomes you know, before you get to a point where you cannot add any more devices to the Internet because you've run out of IP addresses. That's where the i p v six comes in. So the octet version was a thirty two bit system. The i p v six is uh is a hundred twenty eight bit system, which pretty much solves that problem for the foreseeable future. Because again we're talking exponential growth here, We're not you know, it's not just oh, that's you know, four times as many. No no, no, no, no, it's way more than that. And it's in fact, it's such a large number that I can't rattle it off like I did the four billion number, because that, in comparison, is a tiny number. So um, yeah, again, that will solve the problem in the foreseeable future. And I don't know, uh, I don't know about the other you know, a lot of changes to other protocols, such as t c P, I P and UH and Hypertext Transfer Protocol. I think for the foreseeable future, those will probably stay similar anyway. I mean, they seem to hold up reasonably well. Every once in a while you hear people say that the Internet is going to uh explode or fail because there's so many people on it. But I think, um, it's one of those things to where people are gradually adding more capacity. I mean, as a stuff wears out there, you know, technology allows new and expanding connections. I remember when I first worked UH at a at a place that had a a T one line. I used to think that was really fast, and I thought, well, I'm gonna look that up. Well, it turns out it's about one point five megabits per second, which is you know, an average DSL speed. Um, you can find much faster now and um, you know it's it's the average connection to the home now is you know, well, the average broadband connection is I think around three megabits per second. I didn't look that up, so you know, feel free to uh it's the same me an email. But no, I mean it's it's becoming more normal to see speeds of three and six megabets to the home when broadband is available, so and some some places you know, even higher, and and fiber is becoming more popular as an option now, so you know, I think that they're going to be forced you know, the the owners of the backbone will probably be forced to expand as time goes on. But I mean, there's a big commercial interest in the Internet now. You know, now that it's no longer just a an educational and government U utility, so many people rely on it for a lot of different reasons that you know, it's um, you know, it's not worthwhile to let it collapse under the weight of the traffic traveling on it. There's the best at interest. I am done, But I mean it's again, it's it's kind of our cane and interesting at the same time, you know. I mean, you can get a lot more annual and a lot more technical about it too, But we should just be thankful for the fact that we had some some brilliant minds working on these protocols in the first place, because otherwise, what we would have is a bunch of separate networks that would be incapable of communicating with one another. So we would have regions a very rich content and connectivity and other regions that would be very poorly served. Uh, and there'd be no way to share the wealth, or even two regions that were both very rich but could not share that information among each other, so you'd have big gaps and info on one versus the other, depending on you know, the specialties. So uh, yeah, it's it's mainly the protocols. The hardware is important, but again, without the protocols in place, all the hardware in the world is not gonna matter to you because they're not gonna know the machines will not be able to communicate with each other. So actually, and you know, now that I think about it, it might have been nice that such a small group of people were working on this, because if we had relied on you know, the governments of the world to agree on protocols, yeah, we'd we'd be way behind behind. You know, it's hard to get a lot of people to agree on any one thing, so well, we we would probably have a bunch of Again, we would probably have a bunch of independent networks that didn't work very well together. And right now we have, you know, lots of networks that can all communicate using the same basic set of protocols. So good job, I'm are you. I don't have anything else. Good Let's let's wrap up. I don't philosophical as it was. I don't have any listener mail to end today, but I do have a little listener tweet And this Twitter message comes from Nico Stamatolos, who said to me, how come your podcasts seem always short no matter how much time you and Chris talk weird? You know what, That's an awesome compliment, because sometimes we sit here and we're like, seriously, we talked about that for forty four minutes. Conspiracy theories. Yeah, I'm glad that you enjoy it. And I know that some of our listeners sometimes think that we go on a little too long. I recommend you listen to us at one and a halftime speeds can here. Thanks a lot. If any of you want to write us, our email address is tech Stuff at how stuff works dot com. If you want to send me a Twitter message, my Twitter handle is at John Strickland and mine is at tech stuff Chris. So, yeah, we we do read listener tweets occasionally, not that often, but I'm trying to save those so that I can make sure I can acknowledge on air whenever possible. And remember, you could read all about Internet architecture, domain name servers, IP addresses. We have articles on all this information. If you want to see some really cool illustrations that that show what we've been talking about, I recommend you go to how stuff works dot com. We have all of that information there. Um, sometimes that stuff is easier seen. Yeah, yeah, and we've got some nice animations and everything to kind of kind of illustrate these points. So if you still are confused, visit our website and Chris and I will talk to you again really soon. For more on this and thousands of other topics, visit how stuff works dot com and be sure to check out the New Tech Stuff blog now on the House Stuff Works homepage, brought to you by the reinvented two thousand twelve camera. It's ready, are you

In 1 playlist(s)

  1. TechStuff

    2,425 clip(s)

TechStuff

TechStuff is getting a system update. Everything you love about Tech Stuff now twice the bandwidth w 
Social links
Follow podcast
Recent clips
Browse 2,422 clip(s)