D-13910-A2-GN32-40 September 1998
ITU-T V.25bis Dialing Commands
and Responses
Overview
This appendix describes V.25bis dialing commands and responses. ITU-T V.25bis is an
international dialing protocol that permits direct and stored number dialing using DTEs in either
Asynchronous, Bisynchronous, or HDLC operating mode. The 391x Series modems support
V.25bis request and answer commands. As commands are entered from the DTE, the 391x Series
modems issue a response to the DTE which indicates if the call failed or connected, or if the
command is valid or invalid.
The following sections discuss those V.25bis commands supported by the 391x Series modems and
the response to those commands. Tables D-1 and D-2 list the V.25bis commands and response
messages.
NOTE
The 391x Series modem must be configured for V.25bis dialing.
Refer to DTE Dialer Type configuration option in Table 5-3 of
Chapter 5, DCP Configuration.
Call Request Commands
Call Request commands are issued from the DTE to the modem and are responsible for initiating
dial calls. Call Request commands include Call Request with Number Provided (CRN) and Call
Request with Stored Memory Address Provided (CRS).
Call Request with Number Provided (CRN)
The CRN command dials the telephone number entered from the DTE. CRN is similar to the ATD
command.
The CRN command format is:
CRNn
Where: n is the telephone number to be dialed.
D