5 ms·

Does anyone know of an article like this about the dial in modem systems and infrastructure for some of the early dialup services?

alex_hitchins 10y ago
I worked for a large UK organisation that had cut back on their dialup access but still had 50 or so modems in racks for field workers to dial in to to get their email etc. Also some site to site links remained a dialup connection. Sorry, no fancy pictures or anything interesting, just reminded me of the time.
- nixgeek 10y ago
  At least a couple of the Dyn datacenters had dialup for out-of-band access back in 2013, think its all Ethernet now.
  - p_l 10y ago
    Dial up lines are still available in some datacenters, had some both for services and for OOB access as recent as 2015 (San Jose)
    - setq 10y ago
      Lots of companies still have inbound dialin access for EDI stuff still running on POS systems from the 1990s. It's scary really.
      - deleted 10y ago
        [deleted]
    - nixgeek 10y ago
      Yup. Lotta places will now give you 1Mbps 95% on FastE inclusive with a service contract, if you ask nicely, and are taking a cage with 20+ racks. Datacenters which ask you to pay it's usually <$50 MRC. Would guess the transition is slow because if it ain't broke why fix it, and its often a lot more than just provisioning a new circuit, you have to update process documentation, etc.
    - alex_hitchins 10y ago
      A few Datacentres I know have POTS/ISDN capability as they host a fair view VOIP companies. I assume at some point that VoIP call needs to get into the existing telephone network somehow. Also, companies would locate their telephony stack in a DC and route over ethernet just so the kit was more secure and in disaster scenarios they pick up anywhere.
    - api 10y ago
      It's also used for OOB access in high security environments in case you are getting strategically DDOSed. Makes me wonder what you'd find wardialing in 2016.
    - ccakes 10y ago
      I've used dial up via a cheap modem to a Cisco 2500 as recently as a few years ago for OOB console access. It's not gold plated but still works fine More recently though it's all been on ethernet handoff either via the DC or a local provider
  - bluedino 10y ago
    AT&T installs a USR modem for the pots line to manage the routers for their bVoIP
acveilleux 10y ago
A few decent things I could find online that jive with what I remember: https://www.patton.com/technotes/build_yourself_an_isp.pdf https://www.patton.com/technotes/build_yourself_an_isp.pdf http://www.gwi.net/behind-the-scenes-of-a-90s-internet-start-up-2/ http://www.gwi.net/behind-the-scenes-of-a-90s-internet-start... https://news.ycombinator.com/item?id=8352432 https://news.ycombinator.com/item?id=8352432 The absolute minimum, and representative of the very first dial-up ISPs: http://www.linuxjournal.com/article/2025 http://www.linuxjournal.com/article/2025 http://www.datamation.com/erp/article.php/615281/My-own-private-ISP.htm http://www.datamation.com/erp/article.php/615281/My-own-priv... There used to be a lot of nice material on this subject but a lot of it has been obsolete and rotted away from the web over the last 15-20 years. The larger dial-up ISPs used Cisco AS series boxes (or equivalent) with PRI (i.e.: phone over T1) connections (24 lines/each) to a centralized RADIUS server for authentication. They are/were the last hold outs providing dial up. Smaller ISPs were more of a '94 to '99 thing. Usually they used cyclades or equivalent serial port cards with up to 16 serial ports per card and an external modem per port. Eventually this morphed into boxes with multiple modems in them and access servers that did the ppp termination and the authentication (to a RADIUS server) as scale increased. US Robotics was probably the best reputed player in the modem space.
- halbritt 10y ago
  Lots of people used the US Robotics Total Control boxes in the early 90s. http://www.kmj.com/tcont.html http://www.kmj.com/tcont.html
  - acveilleux 10y ago
    That's what I had in mind when I said "boxes with multiple modems in them".
  - vidarh 10y ago
    They were also way too expensive for a lot of smaller ISPs.
- jsjohnst 10y ago
  In my smaller regional ISP we started off using USR courier and sportster modems with Cyclades cards before moving over to Livingston Port masters. I ended up selling the company before moving to all digital incoming lines (needed to support 56k modems).
_wmd 10y ago
I can't speak for early early dial up infrastructure, but by the turn of the century the equipment involved was not all that impressive to look at. A typical configuration would terminate the analogue lines over ISDN, which supported somewhere up to 30 B channels ('voice calls') over a single cable, running alongside one or two Ethernet cables to a single router with one or more modem option cards installed. We had Cisco boxes in the last place I worked that handled dialup, looking pretty much like this: http://www.ciscomax.com/datasheets/3600/Cisco_3640.jpg http://www.ciscomax.com/datasheets/3600/Cisco_3640.jpg
- aidenn0 10y ago
  Are you sure you're not thinking of T-1 (24 B channels) rather than ISDN which was most typically 1 or 2 B channels? [edit] ISDN is a catch-all term tat included BRI (2 B channels) and T-1 (24 B channels) and E-1 (30 B channels) so the parent comment is correct.
  - jsjohnst 10y ago
    Your edit mostly got it right with the exception that it wasn't commonly called a T-1 or E-1 and the numbers are slightly off. * ISDN BRI = two 64k B channels and one 16k D channel * ISDN PRI over T1 = twenty three 64K B channels and one 64k D channel * ISDN PRI over E1 = thirty 64k B channels and one 64k D channel (time slot 0 on the E1 was used as a sync channel and wasn't considered a B or D) T1/E1 was considered an analog circuit with 24 or 32 respective 64kbps voice channels using in band signaling effectively limiting each channel to 56k. ISDN PRI used the same cabling and channel separation, but instead ran a digital circuit with out of band signaling enabling the full 64k to be available for voice and data. ISDN PRI (and BRI) also allowed the option to be packet based (similar to X.25) rather than circuit switched for data transmission.
    - aidenn0 10y ago
      In the 90s in my little corner of the mid Atlantic US at least, it was very commonly called a T1 or DS1 and the terms were used interchangeably even though they refer to slightly different things (at least by sysadmins; use the terms wrong around a telecom equipment engineer and you'd likely get corrected).
jsjohnst 10y ago
I'll dig up photos of the ISP I founded back in 1993. I've got the evolution of it from 1993 till I sold it in 97, but they were all film photos for obvious reasons. Surprised I never took the time to post before.
- hacktothefuture 10y ago
  I would love to see those!
- Overtonwindow 10y ago
  Yes please !!
icedchai 10y ago
I worked at a couple of small ISPs in the mid 90's, and built the dialup infrastructure of one from scratch. I remember using Xylogics Annex terminal servers connected to either 16 or 32 individual USR modems. There were stacks of modems, each with its own power brick, serial, and RJ-11 connection. This was a few years before everything went digital with PRI lines (T1s that let you do digital modems, basically.)

alex_hitchins 10y ago

I worked for a large UK organisation that had cut back on their dialup access but still had 50 or so modems in racks for field workers to dial in to to get their email etc. Also some site to site links remained a dialup connection. Sorry, no fancy pictures or anything interesting, just reminded me of the time.

nixgeek 10y ago
At least a couple of the Dyn datacenters had dialup for out-of-band access back in 2013, think its all Ethernet now.
- p_l 10y ago
  Dial up lines are still available in some datacenters, had some both for services and for OOB access as recent as 2015 (San Jose)
  - setq 10y ago
    Lots of companies still have inbound dialin access for EDI stuff still running on POS systems from the 1990s. It's scary really.
    - deleted 10y ago
      [deleted]
  - nixgeek 10y ago
    Yup. Lotta places will now give you 1Mbps 95% on FastE inclusive with a service contract, if you ask nicely, and are taking a cage with 20+ racks. Datacenters which ask you to pay it's usually <$50 MRC. Would guess the transition is slow because if it ain't broke why fix it, and its often a lot more than just provisioning a new circuit, you have to update process documentation, etc.
  - alex_hitchins 10y ago
    A few Datacentres I know have POTS/ISDN capability as they host a fair view VOIP companies. I assume at some point that VoIP call needs to get into the existing telephone network somehow. Also, companies would locate their telephony stack in a DC and route over ethernet just so the kit was more secure and in disaster scenarios they pick up anywhere.
  - api 10y ago
    It's also used for OOB access in high security environments in case you are getting strategically DDOSed. Makes me wonder what you'd find wardialing in 2016.
  - ccakes 10y ago
    I've used dial up via a cheap modem to a Cisco 2500 as recently as a few years ago for OOB console access. It's not gold plated but still works fine More recently though it's all been on ethernet handoff either via the DC or a local provider
- bluedino 10y ago
  AT&T installs a USR modem for the pots line to manage the routers for their bVoIP

acveilleux 10y ago

A few decent things I could find online that jive with what I remember: https://www.patton.com/technotes/build_yourself_an_isp.pdf https://www.patton.com/technotes/build_yourself_an_isp.pdf http://www.gwi.net/behind-the-scenes-of-a-90s-internet-start-up-2/ http://www.gwi.net/behind-the-scenes-of-a-90s-internet-start... https://news.ycombinator.com/item?id=8352432 https://news.ycombinator.com/item?id=8352432 The absolute minimum, and representative of the very first dial-up ISPs: http://www.linuxjournal.com/article/2025 http://www.linuxjournal.com/article/2025 http://www.datamation.com/erp/article.php/615281/My-own-private-ISP.htm http://www.datamation.com/erp/article.php/615281/My-own-priv... There used to be a lot of nice material on this subject but a lot of it has been obsolete and rotted away from the web over the last 15-20 years. The larger dial-up ISPs used Cisco AS series boxes (or equivalent) with PRI (i.e.: phone over T1) connections (24 lines/each) to a centralized RADIUS server for authentication. They are/were the last hold outs providing dial up. Smaller ISPs were more of a '94 to '99 thing. Usually they used cyclades or equivalent serial port cards with up to 16 serial ports per card and an external modem per port. Eventually this morphed into boxes with multiple modems in them and access servers that did the ppp termination and the authentication (to a RADIUS server) as scale increased. US Robotics was probably the best reputed player in the modem space.

halbritt 10y ago
Lots of people used the US Robotics Total Control boxes in the early 90s. http://www.kmj.com/tcont.html http://www.kmj.com/tcont.html
- acveilleux 10y ago
  That's what I had in mind when I said "boxes with multiple modems in them".
- vidarh 10y ago
  They were also way too expensive for a lot of smaller ISPs.
jsjohnst 10y ago
In my smaller regional ISP we started off using USR courier and sportster modems with Cyclades cards before moving over to Livingston Port masters. I ended up selling the company before moving to all digital incoming lines (needed to support 56k modems).

_wmd 10y ago

I can't speak for early early dial up infrastructure, but by the turn of the century the equipment involved was not all that impressive to look at. A typical configuration would terminate the analogue lines over ISDN, which supported somewhere up to 30 B channels ('voice calls') over a single cable, running alongside one or two Ethernet cables to a single router with one or more modem option cards installed. We had Cisco boxes in the last place I worked that handled dialup, looking pretty much like this: http://www.ciscomax.com/datasheets/3600/Cisco_3640.jpg http://www.ciscomax.com/datasheets/3600/Cisco_3640.jpg

aidenn0 10y ago
Are you sure you're not thinking of T-1 (24 B channels) rather than ISDN which was most typically 1 or 2 B channels? [edit] ISDN is a catch-all term tat included BRI (2 B channels) and T-1 (24 B channels) and E-1 (30 B channels) so the parent comment is correct.
- jsjohnst 10y ago
  Your edit mostly got it right with the exception that it wasn't commonly called a T-1 or E-1 and the numbers are slightly off. * ISDN BRI = two 64k B channels and one 16k D channel * ISDN PRI over T1 = twenty three 64K B channels and one 64k D channel * ISDN PRI over E1 = thirty 64k B channels and one 64k D channel (time slot 0 on the E1 was used as a sync channel and wasn't considered a B or D) T1/E1 was considered an analog circuit with 24 or 32 respective 64kbps voice channels using in band signaling effectively limiting each channel to 56k. ISDN PRI used the same cabling and channel separation, but instead ran a digital circuit with out of band signaling enabling the full 64k to be available for voice and data. ISDN PRI (and BRI) also allowed the option to be packet based (similar to X.25) rather than circuit switched for data transmission.
  - aidenn0 10y ago
    In the 90s in my little corner of the mid Atlantic US at least, it was very commonly called a T1 or DS1 and the terms were used interchangeably even though they refer to slightly different things (at least by sysadmins; use the terms wrong around a telecom equipment engineer and you'd likely get corrected).

jsjohnst 10y ago

I'll dig up photos of the ISP I founded back in 1993. I've got the evolution of it from 1993 till I sold it in 97, but they were all film photos for obvious reasons. Surprised I never took the time to post before.

hacktothefuture 10y ago
I would love to see those!
Overtonwindow 10y ago
Yes please !!

icedchai 10y ago

I worked at a couple of small ISPs in the mid 90's, and built the dialup infrastructure of one from scratch. I remember using Xylogics Annex terminal servers connected to either 16 or 32 individual USR modems. There were stacks of modems, each with its own power brick, serial, and RJ-11 connection. This was a few years before everything went digital with PRI lines (T1s that let you do digital modems, basically.)