V21

1 definition found

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  V.21
       
           An {ITU-T} {modem} {protocol} for 300 bits per
          second two-wire {full-duplex} communications using {Frequency
          Shift Keying} {modulation}.
       


          All modern modems support both V.21 and the close variant,
          Bell 103.
       
          (1996-07-22)