v.21 300 bps modem standard

v.22 1200 bps modem standard

v.22bis 2400 bps modem standard

v.23 1200/75 bps modem standard

v.24 rs232 serial interface definition

v.25bis command standard for synchronous operation

v.27ter 2400 - 4800 bps fax standard

v.29 9600 bps fax standard

v.32 2400 - 9600 bps modem standard

v.32bis 4800 - 14400 bps modem standard

v.34 2400 - 28800 bps modem standard

v.fc 2400 - 28800 bps, proprietary standard by rockwell. (extinct)

v.terbo 16800 - 19200 bps, proprietary standard by at&t. (extinct)