The Physical Internet

The internet is not wireless and it is not a cloud. At its core, it is a massive network of physical fiber optic cables, many running along the ocean floor. Over 400 submarine cables carry 99% of intercontinental internet traffic.

Each packet travels independently through a route selected by network routing tables and policies, and that route can change as networks update paths or route around failures. Most intercontinental packets cross undersea cables, while satellites handle a much smaller share of traffic. Packets may arrive out of order and get reassembled at the destination.