How the company behind League of Legends rebuilt its own internet backbone so that it’s faster for gamers

Top League of Legends players compete for millions of dollars each year.
Top League of Legends players compete for millions of dollars each year.
Image: AP Photo/Ted S. Warren
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Flickering spells and rampaging dragons. Fighters assaulting and retreating through gray stone lanes. Monsters and fireballs and victories that hinge on clicking milliseconds faster than your opponent. This is Summoner’s Rift, the gaming terrain of League of Legends (LoL), a multi-player video game that 67 million people play every month. To imagine that number, think of the entire population of the UK seated in front of glowing computer screens.

Players who want to win big in the game’s dark landscape need some obvious things, such as weapons and excellent hand-eye coordination. But they also need fast connections. To ensure they have those, Riot Games, the company that makes League of Legends, has taken the unconventional step of building its own internet superhighway. The company would not disclose financial metrics to Quartz, but Riot Games is a leader in competitive gaming, or e-sports. In October the best LoL players will compete in the 2016 World Championships for a top prize of $1 million.

LoL championships can draw tens of thousands of spectators. Millions more watch online.
LoL championships can draw tens of thousands of spectators. Millions more watch online.
Image: Flickr/artubr

Building-out a proprietary network is a bold move for a company like Riot Games. Though fairly large by game company standards—they have over 2,000 employees—it is tiny compared to the few internet giants, such as Google or Amazon. Those companies have become known for building their own infrastructure. Google, for instance, started working with the Unity bandwidth consortium in 2008. It invested $300 million in the FASTER undersea cable network, which took two years to complete and went live this June (2016). Facebook and Microsoft have to partnered to build MAREA across the Atlantic with a 160 terabytes per second capacity, and Amazon made its first investment in a submarine cable project May 2106.

That’s a lot of effort spent trying to save players a few milliseconds. To what end? A Quartz reader like you may not care if this site loads in 1.2 seconds versus 0.8. But a small delay can leave a gamer in League of Legends dead in a pit. Yu-Chen Liu, a Taiwanese LoL player ranked in the top 2.5% of all players in Taiwan—one of the most popular countries for LoL—describes playing with a slow network as being like shooting at a moving target. Slow connections can lose data: Players may disappear and reappear in different places or bounce around the map. Building a private network for the roughly 27 million people who play League of Legends every day ensures that all the internet traffic from Netflix watchers and Spotify listeners doesn’t interrupt their game.

The internet was not built for gaming

To be fair and fun, online gaming must be fast—as close to real-time as possible. Gamers measure the communication speed with ping time, which is simply the time it takes for a message from the player to reach the game server and come back. A fast, or “low,” ping indicates a more responsive connection. Players on low ping connections have their spells hit the targets milliseconds faster, and they see what other players are doing sooner.

LoL players connect from all over the world through many different internet service providers, such as Time Warner and Verizon. Some of those providers may favor the cheapest routes over the fastest. For example, if a player is in San Jose, California connecting to the original server in Oregon, the shortest path might be this:

A map showing a direct connection between San Jose, CA and Hillsborough, OR.

But the cheapest route for data for internet service providers (ISPs) may require a detour that involves visiting multiple cities. For example, LoL traffic between California and Oregon was at one point being sent through Denver, Colorado. According to a Riot Games blog post, “That’s a brutal 500% increase [in ping time]. To the ISPs and their backbone providers, this is acceptable—but not to games like LoL.”

A map showing a realistic connection between California and Oregon, with a stop in Colorado.

The network routers themselves are also inefficient. Typical routers are optimized for packets, or chunks of data, that are around 1,500 bytes. Packets of gaming data, by contrast, tend to be much smaller. A LoL packet can be as small as 55 bytes. By controlling its own network, Riot Games can optimize its routers for these smaller packets, ensuring they zip across the network as quickly as possible. It’s normal for game companies to have servers all over the country, but these sort of fine-grained network optimizations are rare.

These changes have real in-game consequences for LoL players. Routers handling those larger packets may get overloaded and be forced to discard some—so-called dropped packets. Most internet applications simply resend dropped packets, but video games are moving so quickly they don’t have time to do so. When packets drop during League of Legends gamers may teleport, disappear, or suddenly die for no apparent reason. When playing competitively that could be more than annoying, it could be the difference between a cash prize or ignominious defeat.

How Riot Games built its own network

Building a gaming infrastructure is sort of like setting up a highway system. First, to move traffic, you need roads: Riot leased fiber optic cables that connect major US cities. Secondly, not everyone starts at the same place, so you need interchanges and on-ramps: Riot set-up its own routers and placed them strategically at exchange points where they can connect to multiple ISPs.

A map shows the locations of Riot Games public and private connections.

Once you have the infrastructure set up, you need road signs to tell travelers that you have the best route: Riot worked with ISPs to ensure traffic is routed over its new network, rather than the old, slow paths. So far, a year after their network launched in North America, Riot has seen ping times for 80% of their US players fall below 80ms. They’ve since expanded their network to Europe and are working to bring it to South America, Australia, and Asia.

To mark their success, Stephen Peyton Maynard-Koran, then technical director at Riot, wrote a three-part series on the company’s engineering blog about how the network was put together. According to Diego Dompe, a member of Technical Steering Committee for OpenSwitch Project, this type of transparency helps fuel the ecosystem of innovation. For Maynard-Koran it’s core to what the company does: “It’s easy to think that challenges like these should be handled exclusively by companies with a profile like that of Amazon, Facebook, and Google, but I don’t buy that… I see no reason that the lessons learned there can’t apply to firms that aren’t quite their size.”

Projects such as Riot’s can be seen as a part of what’s been called the “flattening” of the internet. Traditionally, construction of private, national, and international networks has been limited to service providers, the biggest e-commerce companies, and those in specialized, high-performance fields such as high-frequency stock trading. However, the explosion of data available online is leading more companies to specialize in speed. Today, Riot’s superhighway only serves League of Legends traffic, but Maynard-Koran says that other game companies have asked about using their network. Presumably non-game companies, such as those offering telemedicine services, can’t be far behind.

As the quality of the internet improves, some experts see a future where real-time interaction is exactly that. Ankit Singla, an assistant professor from Swiss Federal Institute of Technology in Zurich who does work on speed of light internet, thinks our internet interactions may hit a threshold that are devoid of any perceptible time. When? According to Singla, “This might happen faster than you expect; remember that not too far back, we were still using pigeons for communication.” And all gamers remember how bad the lag was then.

Everyone hates lag.
Image: Riot Games

The LoL championships photo used in this story was shared under a CC BY 2.0 license on Flickr. It has been cropped.