> how expensive and congested these networks were back in the day. And the reason for that is that basically you needed a wire connecting from one phone to ano

> how expensive and congested these networks were back in the day. And the reason for that is that basically you needed a wire connecting from one phone to another: https://en.wikipedia.org/wiki/Circuit_switching https://en.wikipedia.org/wiki/Circuit_switching On the way to modern day digital packet switching (where you just send the bits for millions of connections down massive capacity pipes) there was multiplexing, etc. but it was a long and hard road.