CCITT V.25bis Dialing
D-33920-A2-GN31-30 November 1996
ET
is similar to the Call Failure Messages Busy Signal and T
runk Busy and the result code
BUSY.
NS
is similar to the Common Operational Message Invalid Number and the result code ERROR.
CB
is similar to the Call Failure Messages Dial Line in Use and No Dial-T
est and the result code
ERROR.
RT
is similar to the Call Failure Message No Answer Tone and the result code NO CARRIER.
AB
is similar to the Call Failure Messages No Dial T
one and No Dial-DTR and the result code
NO DIALT
ONE and ERROR.
NT
is similar to the Call Failure Message No Quiet Answer and the result code NO ANSWER.

Call Connecting (CNX)

The CNX response informs the DTE that the modem has connected to the remote modem. CNX
is similar to the A
T result code CONNECT.
The CNX response format is CNX.

Delayed Call Indicator

The DLC response is issued to the DTE if the modem is not currently allowed to call the
number. DLC is similar to the AT result code DELAYED.
The DLC response format is:
DLCn
Where: n is the delay (in minutes) before the number can be called.
Call Answer Commands
Call
Answer commands disable or enable the modem’
s AutoAnswer function. These commands
are issued from the DTE. Call Answer commands include Incoming Call (INC), Disregard
Incoming Call (DIC) and Connect Incoming Call (CIC).

Incoming Call (INC)

The INC response informs the DTE that the modem has detected a ring tone. At this point, the
DTE can issue the DIC command to disable the modem from answering the call. INC is similar
to the AT result code RING.

Disregard Incoming Call (DIC)

The DIC command prevents the modem from answering an incoming call. This command is
only valid once the DTE receives an incoming call (INC) response from the modem. A DIC
must be issued within 5 seconds after receiving an INC.
The DIC command format is DIC.
If DIC is issued within 5 seconds, the modem sends the V
AL response to the DTE. If DIC is
issued after 5 seconds, INV is returned.