Toshiba V.92 - Manual (Page 67)

67 AT Commands
AT command formats
5.375 x 8.375 ver 2.4.0
&Gn V.22bis guard tone control
This command determines which guard tone, if any, to
transmit while transmitting in the high band (answer mode).
This command is only used in V.22 and V.22bis mode. This
option is not used from North America and is for
international use only.
Result Codes:
&Kn Local flow control selection
Result Codes:
&G0 Guard tone disabled (default).
&G1 Sets guard tone to 550 Hz.
&G2 Sets guard tone to 1800 Hz.
OK n=0,1,2
ERROR Otherwise
&K0 Disables flow control.
&K3 Enables RTS/CTS flow control (default).
&K4 Enables XON/XOFF flow control.
OK n=0,3,4
ERROR Otherwise