51–60 of 164 posts
Earlier quoted context omitted.
Ma Bell used -48v DC in the US, which was backed by a giant lead acid battery at the local exchange. It was quite common to have ADSL circuits working during major power outages, so long as the modem and servers were on redundant power. It might still be worth coming up with a USB charger circuit, but I assume current draw is metered.
And 90V RMS AC to ring the bell on POTS lines.
I had ISDN back in 1996 and it was great. It felt dramatically faster than a 56k modem because ISDN has much lower latency. Web pages were so simple in those days they loaded almost instantly.
I remember the jump from 28k and 56k to a 128k ISDN when playing Myth TFL, Quake 2 and Half-Life in the late 90s. It was marvelous!
But for a brief time just before the turn of the century, it made sense to get ISDN at home (in the US).
I already had a free 24x7 dialup account from a local ISP that I'd done some work for (the free lifetime account was part of my pay for a job).
And the local phone company was circulating mailers for ISDN circuits -- installed for free, and with a very low monthly rate, and with unmetered local calls.
So I asked my ISP buddies if it'd be OK, and they said sure, but asked that I keep the channel count low unless I was really using it.
It worked great.
I was able to set up my (ZyXEL) all-in-one ISDN router to keep one B channel connected at all times, and to connect the second B channel only when average bandwidth utilization required it.
The ZyXEL box also had two POTS jacks for connecting telephones. One of them was used for the house landline, and the other was connected to an analog modem for BBS duties.
The circuit had two phone numbers assigned, and either POTS port could use either B channel.
It worked slick: Always-on, low-latency internet that got faster on demand (connecting the second channel and logging it in took only a fraction of a second), with a static IP and customized reverse DNS.
And the dedicated POTS jacks worked great: These provided the highest quality telephone calls I had ever heard.
Management was automatic: Inbound calls would drop a B channel automatically if that was needed, and so would placing an outbound call.
It all happened transparently, thanks to a combination of software at all ends (my end, the phone company end, and the ISP end) with MLPPP running the show in IP land.
A beautiful symphony of weird telephony tricks, all working in time to be useful and reliable.
And I do not know if it was common, but my particular circuit was provisioned so as to allow me to specify any number I wanted for caller ID purposes.
So on outbound calls, I could change my Caller ID to any number I wished.
I never used this function for personal gain, but I could, for instance, call up a friend's place and have their mom's phone number (and name, due to how CID works) show up on Caller ID.
"Hey, yo. I'm totally at your mom's house right now. What? No, it is like that. No, she's sleeping right now -- you know how it is."
"Except: Just kidding. I'm at home by myself as usual, and just fucking around with my ISDN line because I have no life. But that was a neat trick, wasn't it?"
On the ISP side, ISDN was a crucial part of scaling out dial-up ISPs. CLECs (Bay Baby Bells) would route calls from geographically large calling areas --- all of Chicago, say --- to a single colo cage on an ISDN PRI. Access concentrators (then called "terminal servers" --- Portmasters, Ascend routers, Cisco AS5x00s) would take 56k modem calls on individual PRI channels.
incidentally, there were many terminal servers that didn't require authentication, or would accept default credentials. this was a common way to get free internet access back in the day!
The love for ISDN was absurd. In Germany they even rolled out slower DSL services for a while to keep ISDN alive (ASDL-over-ISDN).
What was great about ISDN is that it started the trend of flat rates in some places. As you kept the modem connected 24/7 you could still do phone calls. I’m not sure we would have seen flat rates as quickly without it. Latency also was amazing compared to 56k. For online gaming it felt amazing.
//edit: one interesting memory I had was that upgrading from ISDN to DSL would wreck latency. Most ISPs thus gave you to option to disable interleaving to improve latency for online play.
ISDN did have multiple channels, in Germany you would get two data channels (B1 and B2-channel, 64 kB/s), and the line has a D-channel (something like 4kB/s) for network purposes. First you could bundle the B-channels to get twice the speed, at twice the price and the land line was busy if one did that. That feature got me into trouble with my parents quite regularly. Second someone figured out that the D-channel can…
For normal internet browsing the single ISDN connection (64 kbps) was enough. Then later in 1999, Napster[2] launched and I was hooked! This made me use bundling ISDN channels quite a lot. Because of the cheaper tariffs, weekends where great because I enabled the bundling around midnight until early in the morning, so my parents wouldn't notice. :-)
I was on ISDN until 2002, when ADSL was available here and we could be online 24/7 for a fixed price. I do remember my ISP (XS4ALL) still had a fair-use-policy for downloading, which they removed a few years later.
[1] https://www.acm.nl/en/publications/publication/9213/OPTA-agr...
ISDN was a true gamechanger for me. Before that, we had a 56k modem and I couldn't go online without blocking my parents' phone connection. Also, with ISDN came our first internet flatrate.