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Yup. I worked on the "Rapport" series of switches at Bell Canada. It was DS1 (Digital Signal 1) out one end and a rack full of Zyxel modems on the other side.
by OhMeadhbh 2y ago
Yup. I worked on the "Rapport" series of switches at Bell Canada. It was DS1 (Digital Signal 1) out one end and a rack full of Zyxel modems on the other side. The idea was RBOCs (Regional Bell Operating Companies) would put these in their CO (Central Office) and terminate 56k modem signals over the analog "last mile" loop to the customer premises and then do Frame Relay over the phone company's data lines to your ISP.
I know Southwest Bell bought a number of them and stuffed them in a closet north of downtown Dallas. During the install I remember having to explain what Ethernet was to their techs. They were EXCELLENT at phone standards, but had decided the data world was threatening and were determined to never learn anything about it.
I know that between around '93 and '97 if you dialed AOL from D/FW there was a good chance your call would be terminated somewhere within a mile or two of your house and the bits flowing between your Compaq Presario and AOL would be sent digitally from the local CO to AOL's data center in Sterling, VA.
This line of business was (of course) destroyed by consumer DSL and cable modems, but for about 5 years it was fairly popular with the phone companies. ISDN at the time was a bit pricey for most households and a modem is a one-off purchase. Most people I knew using things like AOL or CompuServe were using a hand-me-down 36k modem on a crappy 33MHz 486sx running DOS / Win3.1 / Win95 and were fairly cost-sensitive.
- plorg 2y agoRevealing my ignorance here, but was (is?) there a telephone equivalent of anycast such that, say, the 1-800-... Or 1-900... numbers would be routed differently based on location? My basic knowledge of phone systems suggests it would at least be possible.
- iptel 2y agoAbsolutely, when call hits local switch it can be terminated differently based on its location. Particularly pertinent for modem based services in the 90s. A single national dialup number would terminate on 100s of local pops and routing decisions would be done to keep traffic as local as possible.
- timthorn 2y agoInternet Thruway from Nortel allowed multiple ISPs to use the same local termination hardware; If I remember the details correctly, different national numbers could be terminated on the same box, with the subsequent IP traffic routed to the correct ISP.
- function_seven 2y agoWikipedia has good info on how RespOrgs handle this: https://en.wikipedia.org/wiki/Toll-free_telephone_numbers_in_the_North_American_Numbering_Plan#Routing_in_the_U.S https://en.wikipedia.org/wiki/Toll-free_telephone_numbers_in....
- timthorn 2y agoYes, the Intelligent Network was the big thing in the 1990s. It allowed for routing as you describe as well as calling cards and many other features: https://en.m.wikipedia.org/wiki/Intelligent_Network https://en.m.wikipedia.org/wiki/Intelligent_Network
- pantulis 2y agoOh the joys of watching terminal logs with SS7 data frames!
- xattt 2y agoWas there any way for the customer to somehow interact with SS7 frames? We’ve had techs come to our home in Canada in the 1990s, and I remember being fascinated with their mystical toolbox phone that seemed to uncover hidden phone line functionality. Almost like the whip in Indiana Jones.
- pantulis 2y agoI don't think so, but who knows. In my case I was working at a telco so everything was very obvious at the dev environments.
- cantrecallmypwd 2y ago911 and 0 (operator).
- shrubble 2y agoYes, but it would usually be based on the first 3 or 6 numbers of your phone number. The first 3 are of course “area code” and the 6 are called “NPA-NXX”. This has blurred some due to line number portability and cell phones.
- mschuster91 2y agoYes, at the very least 911 (US) / 112 (EU) run on that system. For SIP numbers routing depends on the address you set up in the phone provider's portal, so if you're using bring-your-own-SIP to provide landline phone service in your house, you absolutely have to keep the address current or you risk dialing 911 and ending up on the dispatch of your old addres...
- kdmtctl 2y agoNot in the US, but we had a country-wide number that each local station simply routed to a local extension. Sometimes, even multi-line wasn’t available at some stations, so it was just a sequential list of extensions to try. Looks like a hack, but it worked flawlessly.
- rasz 2y ago> DS1 (Digital Signal 1) out one end and a rack full of Zyxel modems on the other side Why use real physical modems when you already have subscribers signals converted to convenient digital form in DS1 bundle? Wouldnt it make more sense to put a box with one fat DSP doing 24 modems all in bulk inside a box with DS1 and Ethernet sockets at the ISP location instead?
- icedchai 2y agoThis did happen eventually. In the late 90's, various companies (Cisco, Ascend) provided boxes that could handle 24 modems on a single T1 port (PRI or channelized T1.) This massively improved ISP port density. Before that, it was racks and racks of modems...
- actionfromafar 2y agoIIRC it was the only way to support 56k.
- icedchai 2y agoYes! The ISP side needed to be digital to get a 56K connection.
- deleted 2y ago[deleted]
- timthorn 2y agoI was working for one of the telco equipment firms around that time. We made a box that would terminate TDM trunks and had it in the lab. I was installing Windows 2000 on a PC in the lab (manual disk swapping required) when, hidden behind another rack, several shelves full of physical modems all started calling the box at once, speakers on.
- wffurr 2y agoI am trying to imagine the racket that must have made. Amazing how vivid that modem sound is in memory.
- ubercore 2y agoCompaq Presario catching strays.
- immibis 2y agoIsn't DSL basically the same thing? If you live in a jurisdiction with unbundled local loops (which I suspect you do not), your phone company terminates your DSL at their nearest "office" (often a roadside equipment cabinet nowadays) and then does Metro Ethernet over the phone company's data lines to your ISP. If you don't live in that jurisdiction, it's the same but your ISP and your phone company are the same company. Also you don't dial your ISP with a number.
- Suppafly 2y ago>I know that between around '93 and '97 if you dialed AOL from D/FW there was a good chance your call would be terminated somewhere within a mile or two of your house and the bits flowing between your Compaq Presario and AOL would be sent digitally from the local CO to AOL's data center in Sterling, VA. Around the end of the dialup era, I noticed a bunch of similar low cost dialup services all used the same phone numbers, is this part of the reason, or were they all just reselling the same internet access or something?
- zinekeller 2y agoNot GP, but this reminds me of how modern GPON (including XGS-, 50G-) works in some areas, like NBN (Australia), NTT FLETS (Japan) and Openreach (UK) where the fiber runs, on what is essentially, a PPPoE or IPoE pipe that tunnels the connection from the customer to the real ISP the user subscribed. Switzerland (basing at least on Init7 docs) has somehow decided on fiber-optic being a real dumb pipe, which is really nice but I imagine that it is costly.