5 ms·

And even for 56kbps, you need to have the ISP end talk digitally to the telco, so that you don't get the noise (including from the DAC) of the local loop on the

And even for 56kbps, you need to have the ISP end talk digitally to the telco, so that you don't get the noise (including from the DAC) of the local loop on the ISP end. That's really what pushes the SNR far enough down to make it work (and why the uplink is only 33.6kbps; I guess they didn't want to try to make a separate modulation for that direction).

marcus0x62 3y ago
V.92 supported up to 48kbps uplinks, but that standard caught on about as well as you might imagine an analog modem standard from the year 2000/2001 to. https://en.m.wikipedia.org/wiki/ITU-T_V.92 https://en.m.wikipedia.org/wiki/ITU-T_V.92