Re: Free market?
"(*)That [V90] required BT to install modems in telephone exchanges so that one of the D/A conversions could be skipped."
Utter tripe. V90 only requires that the analogue local loop at the subscriber end is converted to and from 8kHz 8-bit digital at the local exchange as it always is with digital exchanges. If the other end, e.g. at an ISP, is digital it can then control the DAC/ADC in the subscriber's exchange directly allowing it to provide anything up to just under 64kbps using a bit of fancy digital signal processing. BT didn't have to do anything to help other than putting the digital exchanges in and supporting ISDN. (The reason why V.90's top rate is only 56kbps is because in some digital systems in other countries, the telco nicks one out of eight bytes to handle signalling instead of doing it out of band.)