Standards and transmission speeds over the telecommunications network have increased, and nowadays, 56,000 bit/s are most common.
It is not only the modem itself which determines the speed, but also the PTT line.
The quality of the line is largely affected by the distance, the number of stations and relays.
Most high-speed modems can automatically reduce their speed in order to maintain a high transmission quality.
Within telephone communications, it is very important to comply with the accepted standards, since the transmitter and receiver have no way of knowing what devices are being used on either side.
