my first guess as to “what is a loop cable system” would “a system of cables that are looping around”
I imagine they’re run between custom-made 50 year old modems that communicate in some rudimentary way any electrical engineering student could recreate from first principles, which is why it costs $212m to replace them. But there’s a good chance that the real answer will be something like “oh nothing so fancy, it’s just mechanical relays and 300 miles of asbestos-sheathed lamp wire” and that’s why it costs $212m to replace them.
