Liangxu Linux

Apr 13, 2023 · Fundamentals

Why TCP Window Full Slows Your Transfer and How to Diagnose It with Wireshark

This article walks through a real‑world case of slow file copying between Beijing and Shanghai data centers, explains why Wireshark reports “TCP Window Full”, shows how to locate the relevant packets, calculate bytes‑in‑flight, and assess the impact on transfer speed using I/O graphs and window‑scaling analysis.