Doing some research into the theory of load testing and traffic loads, I read about the Poisson distribution, which led to Agner Krarup Erlang, which led to early phone switches.

It’s fascinating to realize that the work we do every day with web servers, which seems like a recent modern technology, was predated by guys like Erlang working with early phone switches over 100 years ago. Phone switches were the first servers: central machines connected to a large number of potential clients. In building these switches, the early engineers had to figure out from scratch how to anticipate the possible work load, so they could build switches large enough but not too large. The whole of queueing theory springs from the theories worked out by telephone switch engineers.

And they were clever guys, even adjusting the UI to lighten the load on the switches. When dialing a rotary phone, the particular digits determined how long the switch was engaged before the call could be routed. So when they allocated area codes,