TCP Fast Open

TCP Fast Open is an extension of the TCP protocol. TCP Fast Open to accelerate the exchange of data over TCP, by the first two of the three elements of the TCP handshakes are combined. For this purpose, after the first handshake on the client side, a cookie is stored that is used for subsequent requests for authentication. Thus the response speed of web services to be improved considerably.

TCP Fast Open is the IETF since 2012 in draft form. The Linux kernel supports TCP Fast Open on the client side since version 3.6 and server side since version 3.7. Since version 3:13, it is used by default.