Network acceleration with TCP Fast Open

Getting There Faster


With TCP Fast Open, Google introduces a protocol extension, implemented in the Linux kernel, that avoids unnecessary latency in network traffic and promises up to 41 percent acceleration, depending on the application.

In mid-2011, Google’s “Make the web faster” team, which is led by Sivasankar Radhakrishnan, Arvind Jain, Yuchung Cheng, and Jerry Chu, presented a draft for reducing preventable latency. The technique, which is called TCP Fast Open (TFO), depends on streamlining the process of opening a TCP session.

The idea itself is not new – way back in 1994, RFC1379 and RFC1644 specified the conceptually similar Transactional TCP (T/ TCP). Unfortunately, an analysis published in September 1996 revealed serious security issues with T/TCP [5], and the technique failed to establish itself on a broader front. Based on this previous experience, the Google team refined the approach when developing TFO, leading to an improved result. Linux kernel 3.6 implements the necessary client-side infrastructure, and 3.7 will include support for TFO on the server end, so it looks like the era of faster TCP connections might be just around the corner.