> Do you remember landlines, and how responsive they were? They weren't always, except for local calls. My Background: I made a lot overseas phone calls in th

> Do you remember landlines, and how responsive they were? They weren't always, except for local calls. My Background: I made a lot overseas phone calls in the 1980's to talk to my father, from North America to Japan. I also took a telecom class going through uni. When calling Japan, not only was it crazy expensive, but the connection was typically terrible. We considered it amazing to be calling Japan at all, so that was ok. Issues: 1. Latency, just start talking when the ringing stops. If you wait to hear the person say "hello" they'd generally hang up before they heard you. Sometimes it would be around 5s latency, we always said this must be "satellite" connections vs using undersea cables. 2. Voice quality. You could hear and recognize the person on the far side, but that's about it. 3. Cost. I don't remember the cost exactly since I was young, but I remember it was between $2-$5/min in 1980's dollars. Calls were short. Latency was a major focus of telecom networks for a couple of reasons. One was human, obviously humans really prefer low latency in telecom networks. Good old school POTS lines also have to sidetone[1] the old fashioned way, and if the round trip time gets too high it's really disruptive to hear your own voice > 300ms later. But this causes a big echo problem, so have a shorter round trip time makes the echo cancellation filters shorter/easier. 1) Sidetone is hearing your own voice come out of the speaker. Analog POTS lines are super cool this way, on longer connections the signal is weaker so the sidetone is weaker, so the human speaks louder. This means their own voice is louder so the person at the far end can hear them over the weaker signal.