Yep it's the main spot in nashville for voice stuff. Has local access switches (dms 100), tandem, and LD goes out of there. At&t I think also has their long haul optical transport and some core ip backbone stuff there.

I was the first person in my town to get residential ISDN back in ~1996. I was a fledgling admin on the network team and work paid for it. It took me almost three months to help the local telco get it up and running, but we could never get 64kbps on the data channels because of some weird issue with the switch. (Still beat the hell out of dial up)

I think your comment is the first time I’ve read or thought about the DMS 100 since then.

Bellsouth took a few days to get my ISDN up and running and it worked great for about a year [0] - then it went down and they couldn't get it working again. Bonded ISDN channels at 128kbps was amazing - fast, and no waiting 15+ seconds for an analog modem to handshake.

[0] Uzi Nissan was my ISP, famous for vigorously owning nissan.com. I was sorry to hear that he had passed away this year from COVID-19. https://jalopnik.com/uzi-nissan-internet-domain-owner-who-fo...

Tragically there was nothing simple about ISDN. A customer would have to know their switch type at the CO and there were a number of other things that could break it. At least with a T1/DS1 you only had to worry about SF/ESF, B8ZS/AMI and number of channels.

> Tragically there was nothing simple about ISDN

I’ve been working with some old telco equipment as part of a handful of projects and lord, has this hit me. Particularly some old PRI terminals I have are throwing me around left and right.

Interesting. In many European countries ISDN was widespread in the mid-to-late ‘90s. There were millions of customers in Germany alone, I think.

It was slow compared to the DSL connections that replaced it, but I don’t remember hearing too many negative things about ISDN reliability.

(I bet the only real legacy of this technology is the album by the Future Sound of London which is named ISDN.)

I could have this wrong but we had offices in Amsterdam and Berlin and ISDN in Europe wasn't nearly as polluted with old standards as it was in the US. I don't even think a 56kbps B channel was an option in Europe. I stood up dial plants in both continents and I distinctly recall it being plug and play over the pond.

We also used the ISDN to back up our circuits and Cisco had a pretty cool demand system that would just use what was needed to service the demand.

The most brutal thing I saw was when someone compromised a customer ISDN router (the small Ascend boxes with the curses UI) and changed the creds to login to their ISP and disconnected it and forced it to redial repeatedly. The local telco charged you for every ISDN call if it was a business line and since ISDN call initiaton/setup are instant - they had a several thousand dollar phone bill. I recall seeing the RADIUS server getting slammed with auth failure for days when that happened.

Yep!!! We had to tweak some settings because the router would constantly flap channels during DR tests and we were getting billed for the call setups (international ISDN calls were not cheap lol).

It was cheaper to have stable excess capacity.

ISDN was pretty much plug and play when I had it back in the day. The gateways were available off the shelf (IIRC mine came from CompUSA) and you could get them with either one or two B channels, as I recall.

That's BRI ISDN. PRI has a lot more channels. Also, there was dial setup and PPP vs IDSN bonding. So it can be complex.

Yes indeed. I had the pleasure to work for Ascend Communications for 4 years. The bulk of our business was the Ascend Max TNT that could terminate dozens of PRI lines into hundreds of digital modems. They were the bread and butter for early ISPs. For BRI lines, there was the Pipeline 50, remarkable little box with a BRI input and Ethernet output. Good times.

I was a big MaxTNT customer. The cooling on those were interesting. Also worked with the earlier Cascade BSTDX 9000 and CBX 500.

I've been wondering if it's one of the 5G weirdos who got tired of burning down antennas on the street and started thinking bigger.

If they're technically capable to make something this sophisticated, surely they'd know that all the 5G conspiracy theories are technically bunk?

Although there are 2 variants of 5G weirdoism: the "cancer waves!" one and the "it gives us Covid!" one. The latter is easier to debunk...

The only 5g conspiracy I’ve heard of was that Huawei and ZTE work closely with the CCP and installing infrastructure from those manufacturers may give China a grip over a huge swath of domestic communications.

Well there's a considerable portion of the population that believe 5g causes brain cancer and sterilization.

And COVID, and basically anything else they think is bad and want a thing to blame.

People that believe that 5G causes cancer or covid aren't the type of people who have reasonable, rational thought processes. There are doctors that believe the earth is flat...

Knowledge or expertise in one field does not always transfer to another one. C.f. Ben Carson, famed neurosurgeon, thought the Pyramid's were built to store grain.

to be fair that's what happens when you listen to your pastor on matters of egyptology...

I wonder if this points the feds in the direction of a disgruntled ex employee?

Old school bell core CO