TCP Fast Open

January 12, 2022 · 1 min · Gray King

tags: TCP,Network,5W1H

TCP Fast Open(TFO):

WHY TFO is proposed?

TCP Three-Way Handshake for every new TCP connection is too expensive.
WHAT is the TFO?

TCP Fast Open (TFO) is a mechanism that aims to reduce the latency penalty imposed on new TCP connections.
HOW the TFO reduce the latency on new TCP connections?

TFO allows data transfer within the SYN packet.
WHEN the TFO is avaiable.

TFO support is now avaiable in Linux 3.7+ kernels, and should be enabled by a viable option in both client and server side.
WHAT limitations does TFO have?
- Maximum size limited.

Links to this note

Networking 101: Building Blocks of TCP

tags: TCP,High Performance Browser Networking 原文链接：https://hpbn.co/building-blocks-of-tcp/。 Overview The 4th version of RFC 675, and final two seperate RFCs: RFC 791 - Internet Protocol(IPv4) RFC 793 - Transmission Control Protocol TCP provides: Effective abstraction. A reliable network running over unreliable channel. Hiding most the complexity of network communication: retransmission of lost data, in-order delivery, congestion control and avoidance, data integrity, and more. Three-Way Handhsake Sequence numbers are important for keep in-order delivery, and they are picked randomly from both sides for security reasons....