ISDN was awesome. I had that going on for a bit, too. It was great to experience parts of what some folks (mostly the French, IIRC) had commonly used for such a long time.

Nearly-instant dialup. And not just for a single ISP, but other ISPs as well: The circuit and the Internet service were provided by different entities.

Switch to a different ISP? No problem -- no appointments or installers making new holes in the house required. Just plug in a different phone number, username, password, and done.

And since each B channel was independent, one could do voice calls while the other did data -- dynamically, as-needed. Performance was resolute: Calls were perfect in their consistency, and data rates were precisely 64 kilobytes per second, per channel, symmetric, and not one bit more nor less -- and with constant latency (what jitter?).

And to not leave it to implication for those who don't know: An ISP wasn't required at all. Two people with ISDN could move data between their computers without involving the Internet. The circuits were switched in an any-to-any to fashion.

Want to play a two-player computer game a buddy, with voice chat, over ISDN in 1999? No problem: Use one B channel for data, the other for voice, and get gaming. The circuits are dedicated to these tasks for the duration of the game, and latency is a fixed constant (no Internet used at all, and no lag spikes either).

We've really lost something with the death of this point-to-point, circuit-switched technology. We're probably better off with the best-effort packet switched IP business we wound up using instead, but we've lost something nonetheless. It offered some neat opportunities and was a fun system to explore.