TCP Fast Open is a TCP extension that enables client and servers to place data inside the SYN and SYN+ACK packets during the three-way handshake. This extension has been pushed by google to speedup short transfers. It is defined in RFC7413 and its Linux implementation is described in a nice LWN.net article.

Despite being supported by Linux and Apple, it has not yet been widely deployed on servers. Recent measurements collected by netray.io show that a growing number of servers support TFO.

• source: https://twitter.com/netray_io/status/1160954722074943488?s=09

This blog post was written to inform the readers of Computer Networking: Principles, Protocols and Practice about the evolution of the field. You can subscribe to the Atom feed for this blog. These notes are also posted on the ebook’s Facebook page