[jjav]

> Now that is insane.

Remember it used to be a switched physical circuit. In the early days the switching was done by people, later it was automated. But you still had a circuit from phone to phone.

When one side hung up, the circuit is still live. Eventually it timed out and the switch disconnected it, but it took a while (don't remember how long). So you could hang up a phone, walk to a different room and pick up another phone and the same call circuit was still live (as long as the other side didn't also hang up meanwhile).