TCP Fast Open

Session information has not yet been published for this event.


One Line Summary

Data exchange during TCP handshake


According to Chrome browser stats, over 1/3 HTTP requests today need to first complete the TCP handshake. This extra one RTT is rather large since most requests complete in only a few RTTs.

TCP Fast Open (TFO) allows exchanging and consuming data during the initial connection handshake, thus provides a latency saving of one RTT compared to standard TCP requiring the handshake to complete before data can be exchanged/consumed. Naively doing does not work because it creates new reliability issues and DoS vulnerabilities. Several RFCs also allow sending data in SYN or SYN-ACK packets, but none is directly useful for current web applications. Therefore, we designed TFO to address these issues and the detail is available at

We will discuss the design, the Linux implementation, and the performance results in the talk.


performance, TCP, networking


  • Yuchung Cheng

    Google Inc


    Yuchung Cheng is software engineer at Google. As part of Google’s make-the-web-faster initiative, he works on improving TCP protocol performance for today’s web applications and implementing the new ideas in Linux kernel. He is also an active member in IETF and several networking research communities.