Source : Free On-Line Dictionary of Computing

V.32
     
        The {ITU-T} standard {protocol} for {modem}s transmitting at
        4800 or 9600 bits per second.  {V.32bis} extended this to
        14400 bps.
     
        V32 and V.32bis acheive bidirectional data transmission not by
        having different sets of tones at each end but by subtracting
        what is sent from what is received.
     
        (1994-12-15)