Some parts of the world are not that well connected; Australia and South Africa to name a few. And if a cable is damaged , this can cause severe congestion.
- https://www.submarinecablemap.com/ as at 2017
- Alcatel used to have a HUGE map showing the various undersea fibre optic cable connections between Australia and the rest of the world. Here’s a saved 2006 version World_Map_LR
- http://www.iscpc.org/ The international cable protection committee has a database of cables under the sea