🚀

CDNs & Edge Caching

Medium

Free preview · 2 of 5 steps

Latency is distance divided by speed

Physics limits network speed. Light travels at ~200,000 km/s through fiber (2/3 of speed of light).

A round-trip from Lithuania to a server in San Francisco (9,000 km): minimum 90ms just for physics. In practice, with routing overhead: 180ms+.

CDNs (Content Delivery Networks) solve this by putting cached copies of content close to users — in data centers spread globally. Cloudflare has 300+ Points of Presence (PoPs) worldwide.

Packets in motion — click to inspect:

1 / 2

Space to play/pause · ← → to step