On Tue, Aug 9, 2016 at 10:31 PM, tony duell <a...@p850ug1.demon.co.uk> wrote: > The problem is that one of the 300 baud Bell tones is effectively the > same as (I think) the long-distance clearing signal. Something like that > anyway. If you connect your 300 baud US modem over here it will > effectively cause the exchange to hang up.
Wow, I knew the tones were different, but I thought that was just the typical NIH syndrome, doing it different to be different. CCITT (later ITU-T) V.21 (300 bps full duplex), V.23 (1200 bps half-duplex) and V.22 (1200 bps full-duplex) modem protocols were never popular in the US; Bell 103, 202, and 212, respectively, were used instead. So what did people do if they needed to make a data call to the US? Was that just not done until the US started using CCITT modem protocols such as V.22bis (2400 bps)?
