[klodolph]

The submarine cables are more or less like other physical mediums for networks, like WiFi or ethernet.

You could easily say that your home network “doesn’t run vanilla IP/TCP/UDP” since it’s actually running 1000BASE-T, or Ethernet.

What you do is take your IP packets and shove them into ethernet frames when you send them across your local network. Your modem will pull the IP packets out from the ethernet frame, and send them out to the internet inside something else like PPP or a different ethernet network. We call this vanilla IP/TCP/UDP, running on top of ethernet.

Submarine fiber optic cables are the same. It’s still vanilla IP/TCP/UDP.