How the Internet really works: Into the depths of Internet infrastructure

My name's Tom Paseka. I'll just give another minute for people coming in to sit down. But I've spent pretty much my entire career over multiple decades building Internet infrastructure. And so I wanted a really entry-level discussion on how the Internet really works. Make sure this works. There we go. The Internet starts in your hand. When you take out your phone, you tap the glass on the front of your phone. Where does it go? A lot of people think it's just Wi-Fi. It all just works through Wi-Fi. You'll often hear people, the younger generation say, I need a Wi-Fi cable. Which is a really interesting concept for me because how is it a cable if it's Wi-Fi? So where did it go? You tap your device, goes radio across the Wi-Fi of course, goes to the building network. So in this building, if you look up to the roof, you can see right there, there's an access point. So when you're connected to Wi-Fi, there's one there, there's another one there, and more at the back as well. That's what your phone is speaking to if you're on the Wi-Fi network. If you're on the cellular network, there are small cells in this room. I don't see any, but there's probably some just outside. And so it needs to connect to something, and from that, there are cables that it then connects into, out to your Internet provider and off to a larger network. It's a physical journey. So again, we're not just talking about Wi-Fi and radio signals. There's a physical foundation of it. A lot of civil engineering that happens hiding in plain sight. And this is where you can get into really fun stuff. So radios inside, like I mentioned, this picture right here is a small cell. I believe this one is in South Korea. You'll see these across buildings, especially in Asia. They do a lot of densification of their cellular networks. They put these, it's effectively like a Wi-Fi hotspot, but they sit them inside the building so you can get better cell signal. These are some other examples of the cellular networks. This one here is in San Francisco. It is in the Sunset District. That's a cell phone tower built on top of a power line. It looks pretty ugly, but it's there, it's visible, and you can instantly see all of the cables coming in and out of it. That's what's making it run and connecting to the rest of the Internet. The picture on the right is in Vietnam, where they look for very, very dense cellular networks. So they actually set these up all along the roadside. So you can see Viettel 5G. There's about a dozen of these in a few blocks. They're really making sure that you have a good radio signal, and these red parts is actually the radio antennas there. So all of this is visible. Sometimes it isn't. So this is a great example that especially happens here in the United States is people want to make the cell phone towers less visible. And so you'll drive around and you'll see something like this. It looks like a pine tree, but it's actually a cell tower. They spray paint those leaves onto it and kind of hide it. These are actually pretty common. I know of at least a dozen locations here in the Bay Area where they have beautified cell towers like this. But it's also under your feet. So when you walk around here, especially in the United States, you'll see this very often. These are from in my neighborhood. You see these spray paints on the road and you think, what's this? They're preparing for doing construction. These two ones here, when it's an orange marker like this, if you can read the letters on it, it says MCI. Does anyone know what MCI is? I got these three here, but anyone else? Charlie? So MCI is the old name for Verizon. That is their fiber there. And then you can see on top of it, there's L3, which is Level 3, which is now Lumen. And so this is marking when they're doing construction work. There's fiber going through this path here. That's where their conduit is. That's what your cell phone's connecting to eventually. It's connecting through things, going through those lines. So if you're using a Verizon cell, your data is traversing that buried line there at some point in its journey. But there are a lot of these. They're all different sizes and scales. You can see this is a much larger one. This is a Sprint one. Sprint is a network that no longer exists. The fiber network is now owned by Cogen Communications. But they're a longtime company built next to the railroads and with the railroads and have a very large fiber network. Here as well, you can see AT&T buried cable. So if someone was doing construction, they requested it to go out there and mark where the cable is. And so they made sure that it doesn't get impacted by construction works. You get a special picture there with my dog. There he is. His name is Toto. But here you can see, again, more construction here. But in this case, they're saying there's no MCI, there's no ZAO, no CRC, no EXT. So all of these different carriers are not in this space at the mark that they're preparing to do construction in. And on the right -hand side, this is where it can get really messy. This is an example in Indonesia where typically they don't actually bury the fiber like you have on the left side in a lot of other countries. It's just laying on top of the sidewalk. Sometimes it's not even protected. So you can see the conduit is broken, and it's not very clear, but the fiber is there hanging out of that conduit. This isn't very stable, but it is there under your feet. The infrastructure is physical, and it is there with you. And so conduit sometimes protects the tubes, sometimes it doesn't. That previous picture was a great example of that. But fiber carries light. I have a prop, and so I'll ask for two people from the audience if they can step up if anyone wants to. I'm going to pick on June and Noah. Sorry, guys. So grab it in the middle. So this is a typical fiber line. This is a single-mode fiber. This is what carries most traffic on the Internet, this type of fiber. And it's very easy to recognize when it's happening. When I'm sending a light through it, you can see it flashing on June's hand and reflecting out of there. It looks very simple. Light just goes through the tube. Sometimes you may get bends, and it may not be very clear, but you can see the light starting to escape when it's bent too much. These things can be very fragile as well. If you see the light flashing there with June, that has disconnected it. That's as simple as the fiber is. This is effectively the same things that run under the ocean, that run under the streets, that is carrying all of your Internet traffic from your phone to the Internet. Thank you both. I have a prize for participation too. Noah. Thank you. So light does the long-distance work, as we've just seen. This is just an example across two meters, a meter and a half of fiber distance. But that same principle works for thousands of miles. If you're going from here on the West Coast, there are cables that go all the way to Asia, to Australia. They shoot a light beam just like that, a little bit more powerful. But it's the same principle, and it goes all the way through in a single plane of glass. Light is what carries it. I have an example here that I'll show, and you can come up after the session. This is a submarine cable, a segment of one. The exact same technology that we see there, but there's a lot of interesting bits to this here. So continuing through. When you think of the cloud, it becomes a very nebulous term. It doesn't really have a definition. You think the cloud could be up there, it could be anywhere. But the cloud actually has a street address. Who here has deployed in US East 1? Everyone who's a developer has probably deployed in US East 1 and runs things in US East 1. That's it. If you open Google Maps, go to Ashburn, Virginia, and you'll see a whole bunch of buildings that look like this. It's even marked on Google Maps, Amazon US East 1. It's there, it's visible, it has an address. The same is true with all Internet services. There is a physicality to them. I just demonstrated the physicality of the fiber, but communications live here. The information, the applications, they all run in physical addresses. But how do you get there? So your provider, coming from your phone, connecting to the Wi-Fi, connecting through the fiber that I mentioned, goes to your Internet service provider. There is an Internet exchange or an interconnection agreement that will happen, which is not dissimilar than I had here. You have your provider on one side, another provider on the other, and they do that. It's really that simple. Plug into each other, the communications can continue through, and the request goes on. This is an example of another building where this type of interconnection and meeting of networks happens. This is, I believe this is the Equinix campus in Ashburn as well. So if you can find US East 1, it's about half a mile away from US East 1, and you can see Equinix DC IBX. This is a very big interconnection hub in the region. There are thousands of networks inside that building, thousands or tens of thousands of those cables plugging in between them, continuing the communication. There is no center of the Internet. Sorry, the black slide doesn't work very well there, but you can envision the continents out of that. There is no one center of the Internet. One of the big things that you'll often hear is that 70% of the world's Internet traffic traverses through Northern Virginia. The Ashburn City Council often says this. I believe it's on their webpage as well. And a lot of that is just because of that Equinix building that I just showed before, as well as US East 1 being there. And so there is a lot of concepts that, hey, Internet traffic is all based there, but that's a myth. It is not true. When you access the Internet, taking again from your phone, going to the Wi-Fi, almost all of your communications stay in the same city that you're in. If you're in a major city, it's going to be here. Let's say you're a little bit further out, say Sacramento, it's probably coming down to the Bay Area, but there's a lot still in Sacramento as well. So the Internet traffic doesn't go through there. The Internet itself is actually not designed to be able to bring enough traffic through there. It's an interesting thing is that there's a very limited amount of this in the ground. There simply isn't enough fiber to be able to carry all of the world's traffic to a single location. When you think of capacity-wise, there's a lot of capacity going short distances. The further the distance you go, the capacity shrinks and shrinks and shrinks. Across an ocean, so this is really fun. Who here thinks their Internet traffic goes through satellites? Unless you're using Starlink. Right, so today practically no Internet traffic uses satellites. Unless your last mile, your subscription service is something like Starlink. Intercontinental traffic is almost entirely delivered through submarine cables. There are a few island nations that don't have submarine cables, and so they will often get satellite backlinks or those submarine cables may get severed. But all of the traffic going long distance across the Internet is really on fibers like this. It's a common myth that the satellites are required for that, but really it's this fiber that's in the ground or laying on the ground or underneath the oceans. 99% of intercontinental data connectivity is via submarine cables. Since the submarine cables have become so relevant, it's just not viable to use satellites anymore for that volume of traffic. The satellites were really useful when voice calls were a thing, but who here makes phone calls anymore? The other thing is just capacity. One cable like this, when you think about what it can do, this can do a billion voice calls concurrently on this one cable. The satellite simply can't do that. The Internet is also not a fixed route. This is another thing. As we said, there are no hubs that everything has to run through, and so everything can actually go different routes all the time. We have Tom here from Cloudflare's network engineering team, who spends a lot of time optimizing those different routes. But there are many different corridors that the Internet uses. There is no one fixed place that it has to happen. Cloudflare's Internet infrastructure is spread across so many of these different locations, and we use lots of different routes for that traffic flow. Why does a network like Cloudflare exist, and how does this relate to what we've talked about, the Internet? I gave you the journey between your device and Cloudflare, but there's a lot of reasons for why we exist and what we do. Who here knows how TCP works at a high level? Okay, that's great. That's way better than I expected. You know what the three-way handshake is, right? Lots of heads nodding. If I'm doing a handshake, so if I'm the client, the communication server is over there, I've got to walk, make the communication, go back, do this, get back there, and then go back there again. That's the three-way handshake that happens. And that can take a long time. When you're talking across the world, so if we use an example coming from Australia to US East 1 in Virginia, that's a very long way to go to make that communication three times before you can even start communicating. So in a network like Cloudflare, we bring the handshake just to a very small distance. We're able to cache the data that's there and not need to extend it the whole distance through. From our nodes, we can optimize that long distance much better using that network that we've described with all of the physical infrastructure to make it quicker. And if all you're relying on is that short handshake, communications work much better. AI is obviously the hot topic now, but it also has an address. It happens in those same buildings that we described. It happens even on your device. Everything still has a physical mode to it, and the models all use that same infrastructure. This is where a network like ours is hugely optimized. User to application is that very short path. The applications model to data and tools can go back and forth across our network through those optimized paths. You've probably heard a lot about workers, workers AI, AI gateway over your past time here so far. All of this is running at all of those locations, so that short handshake that we have inside your city is able to go much quicker. You're able to get a better experience in general. You can see the journey, so this is a big thing. When you go outside, I want you to have a look at the Internet infrastructure that's all around you. From your device, through the street, through the networks that are visible, and you can see everything else that's going on there. So, Internet infrastructure isn't just somewhere else. It isn't just in the cloud. It's actually all around you. And like I said, I want you to step away and see what you can notice on your way home. Thank you very much.