Toshiba V.92 - Manual (Page 61)

61 AT Commands
AT command formats
5.375 x 8.375 ver 2.4.0
Nn Modulation handshake
This command controls whether or not the local modem
performs a negotiated handshake at connection time with the
remote modem when the communication speed of the two
modems is different.
Result Codes:
On Return online to data mode
Result Codes:
N0 When originating or answering, this is for
handshake only at the communication standard
specified by S37 and the ATB command.
N1 When originating or answering, begin the
handshake at the communication standard
specified by S37 and the ATB command
(default).
During handshake, a lower transmission speed
may be selected.
OK n=0,1
ERROR Otherwise
O0 Instructs the modem to exit online command
mode and return to data mode (see AT escape
sequence, +++).
O1 This command issues a retrain before returning
to online data mode.
O3 This command issues a rate renegotiation before
returning to online data mode.
OK n=0,1,3
ERROR Otherwise