Four-way Teardown

Architecture Digest

Oct 13, 2020 · Fundamentals

Understanding TCP Protocol: Header Fields, Three‑Way Handshake, and Four‑Way Teardown

This article explains the TCP protocol’s header structure, the purpose of each field, how the three‑way handshake establishes a reliable connection, why three steps are needed, and the four‑step process used to gracefully close a TCP session, including verification with Wireshark.