| V8 | Procedures for starting sessions of data transmission over the public switched telephone network |
|---|---|
| v21 | 300 bits per second duplex modem standardized for use in the general switched telephone network |
| V22 | 1200 bits per second duplex modem standardized for use in the general switched telephone network and on point-to-point 2-wire leased telephone-type circuits |
| V22bis | 2400 bits per second duplex modem using the frequency division technique standardized for use on the general switched telephone network and on point-to-point 2-wire leased telephone-type circuits |
| V25 | Automatic answering equipment and general procedures for automatic calling equipment on the general switched telephone network including procedures for disabling of echo control devices for both maually and automatically established calls |
| V32 | A family of 2-wire, duplex modems operating at data signalling rates of up to 9600 bit/s for use on the general switched telephone network and on leased telephone-type circuits |
| V32bis | A duplex modem operating at data signalling rates of up to 14 400 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuit |
| V34 | A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits |
| V42 (MNP,LAPM) |
Error-correcting procedures for DCEs using asynchronous-to-synchronous conversion |
| V42bis | Data compression procedures for data circuit terminating equipment (DCE) using error correction procedures |