One Road — A Multiplexing Course

Understand multiplexing and demultiplexing from toy-track intuition to practical systems.

What you'll learn

• Why multiplexing exists and where it fits
• How labels, frames, and sequence numbers turn one connection into many conversations
• Fair scheduling and head-of-line blocking
• OS-level demultiplexing by ports and sockets
• I/O multiplexing and event loops
• HTTP/2 streams and media timestamp multiplexing
• Build your own multiplexed protocol over WebSocket

Quick start

npx serve .

or

open index.html

Prerequisites

• A browser (any modern browser)
• Node.js 22+ (for running tests and the WebSocket server)