Google recommends TCP tweaks for faster web

The web as it is today is a big network of devices all over the world connected together. A Google blog post by Yuchung Cheng, who’s part of the ‘Make The Web Faster’ team has listed a number of changes to TCP (Transmission Control Protocol) that can help speed up the Internet by a fair bit. Internet browsers access web pages in streams and several connections are made simultaneously to download elements of these pages. For example, there are hundreds of images and elements on pages, and bunches of them are downloaded simultaneously, while the rest of them are queued up. There are, of course, issues with latency in such scenarios, which need to be bypassed.

Determined for a faster web

Yuchung goes on to explain that one of the things that can help is to increase the TCP initial congestion window to 10, so latency can be reduced. Google has been tinkering around with these settings and have seen good results from this testing. Another parameter that can be tweaked is with the initial timeout value from 3 seconds to 1 second. Google feels that Internet connection speeds have improved, since its early days and therefore, there isn’t the need for such a large timeout period, these days. This should also help in reducing latency. Google also recommends enabling something called TFO (TCP Fast Open), which they claim can reduce load times by 10 percent on average and it can even be as high as 40 percent. The last of the points being talked about is PPR (Proportional Rate Reduction), which is more of an improved recovery system for networks that are unstable and where there’s plenty of congestion. 

All of this development and testing by Google is openly available. Google is working on the Linux kernel to try and spread this tweaked TCP and they hope that someday, the whole world would be using the tweaked version, which in turn would result in better efficiency on the web. Check out Google's ‘Let’s make the web faster' blog here.