I launched RustNet in 1992 as "the first ISDN ISP in Michigan." We offered a blindingly fast …

Ahh, good ol’ pair gain, where the ILEC would basically share one circuit between 2 houses. Saves money from not having to run a second circuit, plus the sound quality isn’t too awful as long as you’re deaf. I also worked at an ISP. Customers would sometimes call to complain about how much we must suck because their shiny new 56k modem wouldn’t train up past 28.8, and it couldn’t possibly be on their end because they lived in a neighborhood of brand new McMansions. That’s when we had the diplomatic mission of explaining how Ma Bell saved a whole lot of money at the expense of the customer’s phone quality. As long as we’re swapping horror stories, I can summarize another one in 1 word: Winmodem. shudder

Prepping a pair for ISDN could involve removing load coils (very common in more rural areas) or “designing” the pair by removing bridged taps. Both of these actions improved the quality of the facility. Also, if the facility ran through a pair gain system (or subscriber loop carrier) a reprovisioning onto a different card could be massively beneficial. I have fond recollections of the areas in rural Maine where the SLC mode kept my customers well below the maximum theoretical capability of their 56K modems, causing the normal complaints. Dialup was fun!

I had ISDN in Southeast Michigan (bit north of Mt. Clemens) back in the late 90s and it was amazing. Being local, your stoy really caught my ear. I wonder about that timing, though, because 56K modems weren't available in '92. They didn't get to be a thing that people could buy until '97 or so, IIRC. (I worked retail computer support at the time, and USRobotics did a neat sales presentation at Henry Ford Manor where, if we went to an "educational" session about the technology, we got a free modem. I already had ISDN by that time so I didn't really need it, but it was still neat. And a couple-hundred-dollar modem, for free, for a retail employee seemed like quite a perk.)

Another trick was to ask the ILEC for an alarm circuit between two premises, giving you a dedicated circuit via dry copper pairs between them.

Oh first ISPs are fun. I worked for the first commercial ISP in Hungary in 1995. At the time phone lines were still a hot commodity -- it takes a bit of time to fix decades of neglect, after all (Hungary was a Soviet satellite until 1989 and the wait time for a landline was ~ten years in the 80s). So supply side for lines was low and prices were high. On the other hand, the potential income for the ISP was limited because, well, it's 1995, not many people or businesses even know what Internet is good for. So how on earth did they afford the necessary many lines? Well, see, they didn't. The guys running the place got wind of a CO in an older district in Budapest has excess capacity so they rented a flat next to the CO and drilled the wall . Presto! Plenty phone lines without installation costs.