A Google data center

When it comes to internet speed, small, often obscure things can make a big difference.

Take the congestion control algorithm. A piece of code standardized in the 1980s, the algorithm slows data transfers when it detects that a network is getting overloaded.


The congestion control algorithm is a tiny part of the much more complicated methods by which our devices get data to and from the internet. But it can significantly affect speeds.

For example, after Google in March started using a congestion control algorithm of its own design with YouTube, it saw an speed increase of 4% worldwide - and a 14% gain in some countries, according to a blog entry.

That kind of a gain may seem small, but it represents the average boost and takes into account every single site visit. From that perspective, the boost translates into a meaningful difference.

The new congestion control algorithm, which Google calls BBR, for Bottleneck Bandwidth and Round-trip propagation time, is just another example of the search giant's push to improve network speeds, said Neal Cardwell, a senior staff software engineer at the company. Google is trying to light a fire under the tech industry and spur it to follow suit, he said.

"Google wants to help the internet get as fast as it can," Cardwell said.

As fast as you can

This isn't Google first effort to speed up the internet. The company pioneered technologies like the QUIC protocol, which was another attempt to reduce congestion and rev up transfer speeds. It's also developed several innovations in the Google Chrome browser to make websites and web apps load quicker and more smoothly.

The new BBR algorithm, which Google is now with and its cloud service, was the fruit of two years of research at Google, Cardwell said. Under the protocol it replaced, anything connected to the internet would automatically halve its speed if it detected that "packets," or units of data, were getting lost in transmission amid congestion. Google's BBR algorithm essentially gives the network a way to predict what those lost packets were and where they were going, allowing it to avoid slowing transfer rates.

google congestion

Google explains how its new congestion algorithm works, in chart form.

Yes, it's super technical. But it's a good example of how seemingly small changes can have big effects.

Companies outside Google are already seeing benefits from using BBR.WP Engine, a company that hosts Word Press blogging sites via Google's Cloud Platform, has seen the loading speeds for those blogs increase dramatically thanks to the new algorithm, company founder Jason Cohen said in the Google post. Other companies and organizations taking advantage of the Google Cloud Platform should see similar speed increases - without having to lift a finger.

The next step, said Cardwell, is to push BBR to be incorporated into the TCP transmission standard that underlies the entire internet. Talks are already underway, he said.

In the meantime, Google plans to publish the algorithm so any developer can use it. The search giant is hoping other companies will see Google's success with BBR and want to follow in its footsteps.

"Down the road, we would like to see others use it," Cardwell said.