A telco I used to work for did this like two decades ago but even better, they mapped incoming support calls (customers) to stations, and if more than N came in

A telco I used to work for did this like two decades ago but even better, they mapped incoming support calls (customers) to stations, and if more than N came in during a certain period for the same DSLAM it triggered some kind of alert. Same thing happens (should happen) when you visit your ISPs website and look for registered downtime — many requests from one zip code from multiple ips should trigger an alarm if the isp is competent.