V.90 is a 56Kbps data transmission standard formulated by the ITU (International Telecommunication Union). Through the use of compression schemes such as V.42bis, the modem can operate at a rate of 56Kbps on the standard public switched telephone network (PSTN). Receive data. (Download 56KB/s and upload 33.6kb/s)
V.90Modem will detect the line during dial-up access to determine whether there is analog/digital conversion in the downstream channel. If V.90Modem detects the presence of analog/digital conversion, it will connect in V.34 mode. When the remote modem does not support the V.90 protocol, the V.90 analog modem will also try to establish a V.34 connection. After connection, V.90Modem will identify 256 possible voltage values and restore them to 8000PCM code/sec. In theory, the download speed will be close to 64Kbps(8,000×8bits/code)
