An interactive explainer
Between your laptop and a server sits a chain of routers free to drop, delay or reorder anything they carry. Watch three packets turn that into a conversation — then watch a packet vanish and see which side notices, and how.
TCP · Three-way handshake · Packet loss and retries
Networking · Beginner · 9 min · How two strangers agree they can hear each other — an interactive explainer on ViLearn, with a simulation and a knowledge check. All explainers.
Related: How a service decides who gets in · How the internet finds google.com · How two strangers get a secret past everyone in the room