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I wonder what the bps limits would be. Can it do 33.6k? Didn't V.90 (56k) require a special setup with ISPs where you had fewer that one analog-to-digital hop?

I wonder what the bps limits would be. Can it do 33.6k? Didn't V.90 (56k) require a special setup with ISPs where you had fewer that one analog-to-digital hop? And IIRC, you could go from a 56k modem to another 56k modem. ISPs had different hardware.

jsjohnst 7y ago
> And IIRC, you could go from a 56k modem to another 56k modem. Nope, the theoretical max between two 56k modems via a normal CO connection is 38k, in reality it usually meant 33.6k at best. As you sorta alluded to, a 56k modem increases that due to the removal of the ADC on the ISP side, with the ISP having a digital connection to the CO.
- djsumdog 7y ago
  ah sorry, I meant to say "couldn't go from 56k to 56k." BBS sysops were maxed out at 33.6k.
  - dspillett 7y ago
    If you were looking to upload anything you limited your modem to 36k6 anyway as the higher options were asymmetric with upload rates half that of download. When I connected to my ISP at the time with no limits set I'd get between 38K and 41K which gave 19K-to-20.5K up, but I could reliably get a 36k6 symmetric link both ways if I told the modem not to bother trying for faster. Of course for most uses this is fine as it is with asymmetric connections today: most users download a lot more than they upload. There was also extra latency with the faster connections IIRC, so gamers would stick to 36k6 too.
    - djsumdog 7y ago
      That takes me back to the HS\Link protocol I used on BBSes back in the day, which let you upload and download at the same time: https://en.wikipedia.org/wiki/HS/Link https://en.wikipedia.org/wiki/HS/Link http://qodem.sourceforge.net/hslink/shsmith.htm http://qodem.sourceforge.net/hslink/shsmith.htm
    - jsjohnst 7y ago
      I think you mean 33.6k (or 33k6). V.34 tops out at 33.6k so unless you were using a non-standard protocol on an extraordinarily clean copper connection, you wouldn’t have gotten that. As to the asymmetrical part of your comment, definitely true in my experience there. I could go into detail on the technical reasons why that was the case, but don’t see the point unless someone wants me too.
      - dspillett 7y ago
        Yep, I meant 33k6. Same typo twice.

jsjohnst 7y ago

> And IIRC, you could go from a 56k modem to another 56k modem. Nope, the theoretical max between two 56k modems via a normal CO connection is 38k, in reality it usually meant 33.6k at best. As you sorta alluded to, a 56k modem increases that due to the removal of the ADC on the ISP side, with the ISP having a digital connection to the CO.

djsumdog 7y ago
ah sorry, I meant to say "couldn't go from 56k to 56k." BBS sysops were maxed out at 33.6k.
- dspillett 7y ago
  If you were looking to upload anything you limited your modem to 36k6 anyway as the higher options were asymmetric with upload rates half that of download. When I connected to my ISP at the time with no limits set I'd get between 38K and 41K which gave 19K-to-20.5K up, but I could reliably get a 36k6 symmetric link both ways if I told the modem not to bother trying for faster. Of course for most uses this is fine as it is with asymmetric connections today: most users download a lot more than they upload. There was also extra latency with the faster connections IIRC, so gamers would stick to 36k6 too.
  - djsumdog 7y ago
    That takes me back to the HS\Link protocol I used on BBSes back in the day, which let you upload and download at the same time: https://en.wikipedia.org/wiki/HS/Link https://en.wikipedia.org/wiki/HS/Link http://qodem.sourceforge.net/hslink/shsmith.htm http://qodem.sourceforge.net/hslink/shsmith.htm
  - jsjohnst 7y ago
    I think you mean 33.6k (or 33k6). V.34 tops out at 33.6k so unless you were using a non-standard protocol on an extraordinarily clean copper connection, you wouldn’t have gotten that. As to the asymmetrical part of your comment, definitely true in my experience there. I could go into detail on the technical reasons why that was the case, but don’t see the point unless someone wants me too.
    - dspillett 7y ago
      Yep, I meant 33k6. Same typo twice.