Cisco MICA Modem Dial Modifiers for
Cisco AS5300 and AS5800 Universal Access
Servers
June 22, 2001
This feature module describes dial modifier support for Cisco MICA modems through enhanced
Cisco MICA attention (AT) commands on Cisco AS5300 and Cisco AS5800 universal access servers.
This document includes the following sections:
•
Feature Overview, page 1
•
Supported Platforms, page 3
•
Supported Standards, MIBs, and RFCs, page 3
•
Prerequisites, page 3
•
Configuration Tasks, page 3
•
Configuration Examples, page 6
•
Command Reference, page 7
•
Glossary, page 9
Feature Overview
Dial modifiers permit multi stage dialing for outbound modem calling through public (PSTN) and
private switched telephone networks.
The Cisco MICA Modem Dal Modifiers feature is enabled by arguments to the ATD AT command. The
AT prefix informs the modem that commands are being sent to it, and the D (dial string or dial) suffix
dials a telephone number, establishing a connection. With Cisco MICA Modem Dal Modifiers running
Cisco IOS Release 12.1(5)T or higher, you can enter the following dial modifiers after the D in your dial
string: X, W, and the comma (,) character. These modifiers had been previously accepted without error
but ignored in Cisco MICA modems.
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Feature Overview
Table 1
Dial Modifiers for Cisco MICA Modems
Dial
Modifier
Definition
X
Switches to in-band dual tone multifrequency (DTMF) mode for any subsequent digits
remaining in the ATD string. The X dial modifier has been added to serve as a
delimiter for the host when processing the dial string. Allows Cisco MICA portware
to be used in many environments that do not support DTMF dialing (for example,
PRI).
W
Waits for dial tone then switches to in-band DTMF mode for any subsequent digits
remaining in the ATD string. The W dial modifier also acts as a delimiter between the
primary and secondary sections of the dial string, so that no additional X modifier is
needed. Once either an X or a W has been parsed in the dial string, any additional X
modifiers are ignored. Additional W modifiers cause Cisco MICA to wait for a dial
tone.
,
Delay: Number of seconds in S8. Default is 2 seconds.
The (,) dial modifier is treated as a silent DTMF tone for the duration of seconds
specified in S8. The (,) is acted on only after the call switching module (CSM) has
been transitioned into DTMF mode, which requires either that it follow an X or a W
in the dial string or that the T1/E1 is configured for DTMF signaling.
In the following example dial string, the portion of the string before the X is dialed for the given line
type used in your configuration. All digits after the X generate the appropriate DTMF tones.
atdT5551234x,,567
Benefits
Universal Service
The Cisco MICA Modem Dal Modifiers feature meets industry demands for multi role, multi application
access server capabilities.
Standard Feature
The Cisco MICA Modem Dal Modifiers feature is available as part of the listed standard features offered
by the Cisco MICA modem platform and the AT command set contained within Cisco MICA modems.
Related Documents
2
•
AT Command Set and Register Summary for MICA Six-Port Modules
•
Cisco AS5x00 MICA 6-Port and 12-Port Modem Module Portware/Cisco IOS Software
Compatibility Matrixes
•
Cisco IOS Configuration Guide Master Index, Cisco IOS Release 12.1
•
Cisco IOS Command Reference Master Index, Cisco IOS Release 12.1
•
Release Notes for Cisco MICA Portware Version 2.7.2.0 on Cisco AS5x00 Universal Access Servers
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Supported Platforms
Supported Platforms
•
Cisco AS5300
•
Cisco AS5800
Supported Standards, MIBs, and RFCs
Standards
No new or modified standards are supported by this feature.
MIBs
No new or modified MIBS are supported by this feature.
To obtain lists of supported MIBs by platform and Cisco IOS release, and to download MIB modules,
go to the Cisco MIB web site on Cisco Connection Online (CCO) at
http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
No new or modified RFCs are supported by this feature.
Prerequisites
You must be running Cisco IOS Software Release 12.1(5)T or higher.
Configuration Tasks
See the following section for configuration tasks for the Cisco MICA Modem Dal Modifiers feature.
Each task in the list is identified as either optional or required.
•
Using X, W, and (,) Dial Modifiers (required)
•
Verifying Modem Connection (optional)
Using W, X, and (,) Dial Modifiers
To send AT commands to the modem, you must first put the modem in AT command mode. Entering AT
command mode involves a reverse Telnet procedure. Enter AT command mode from Cisco IOS
privileged EXEC mode using reverse Telnet.
Note
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Cisco MICA does not support the modem at-mode commands used in Cisco IOS line configuration
mode. Therefore, you cannot issue AT commands to Cisco MICA modems from the Cisco IOS
command line.
3
Configuration Tasks
Command
Purpose
Step 1
Router> enable
Enters privileged EXEC command mode.
Step 2
Router# show modem
Displays a high-level performance report for all
the modems or a single modem inside the
Cisco AS5300. Modems are listed by slot/modem
(for example, 1/0, 1/1, and so on). Locate the
terminal (TTY) line number you want to configure
with the AT commands in the Modem column.
TTY lines can be 0 through 47 and beyond,
depending on the number of modems you have.
Step 3
Router# configure terminal
Enters global configuration mode. Executes
configuration commands from the terminal.
Step 4
Router(config)# line 1
Enters config-line global configuration mode.
Identifies a specific TTY line for configuration
and begins the command in-line configuration
mode collection mode. You must enter the relative
number of the terminal line (or the first line in a
contiguous group) that you want to configure
when the line type is specified. Numbering begins
with zero.
Step 5
Router(config-line)# modem inout
Allows line to support dial-in and dial-out
connections.
Step 6
Router(config-line)# transport output telnet
Allows outbound Telnet connection.
Step 7
Router(config-line)# exit
Exits to global configuration mode.
Step 8
Router(config)# ip host modem1 2001 209.165.200.225
Configures a reverse Telnet connection to the
modem. In this example, ip-host maps the
hostname to the IP address (modem1 is the name
used in this example to represent the modem), and
2001 is the two-digit line number of the modem,
prefixed by 20. If you do not know which line
number to use, enter the show line command and
check the resulting display for TTY numbers that
have inout listed in the Modem column. The
show line command displays the TTYs by number
(for example, TTY1, TTY2, and so on).
Step 9
Router(config)# telnet modem1
Requests Telnet session with modem1. The Telnet
connection is open when you see the word Open.
Trying modem1 (172.21.102.35, 2001)... Open
User Access Verification
Username:
Password:
Step 10
4
at
OK
Enter your username and password.
Enters AT command mode. There is no command
prompt in AT command mode. The modem returns
OK when you are in AT command mode.
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Configuration Tasks
Command
Purpose
[0-9|A-D|*|#|x|w|,]
Step 11
atd
Step 12
ctrl-shift-6 x
Exits AT command mode and returns to privileged
EXEC mode when you have finished entering AT
commands (or hold down the Control and Shift
keys and press 6, release, then press X).
Router# disconnect
Ends the Telnet connection.
Enters the ATD dial string command followed by
X, W, or (,). The 0-9, A-D, *, and # symbols are
valid characters that can be entered before the X,
W, or (,) dial modifiers. Enter these characters
without spaces after entering the ATD prefix.
Use these guidelines when you send AT commands to a modem:
•
Commands are executed when you press Return or Enter.
•
Command lines are limited to 128 characters, not including the AT prefix and return characters. Dial
strings are limited to 49 characters.
•
You can enter several commands on the same command line, as long as you do not exceed the
128-character limit. Enter commands with no spaces or separators between them. The commands
are executed in the order in which they appear on the command line. If an individual command fails
(system returns ERROR), any subsequent commands on that line are not executed.
•
Certain commands work only if they are the last command on the line. Such commands include
A (answer), D (dial), H (hang up), Z (reset), and any command that takes time to execute or that
does not return a result immediately.
•
Spaces within AT commands are permitted anywhere except between the A and the T. For example,
enter ATS0?, AT S0?, ATS 0?, but not A TS0?.
•
Commands can be entered as uppercase, lowercase, or mixed case.
•
Enter Ctrl-C (^C) to abort a partially entered command. The modem echoes ^C.
•
Use the Backspace key (or another key specified in register S5) to erase characters on the command
line, except for the leading characters AT. To clear the characters AT, press Return for a fresh
command line.
•
A missing numeric argument is assumed to be zero. For example, the Quiet command Q is
equivalent to Q0.
•
The modem operates in the following modes:
– Command state: The modem is idle and waiting for commands.
– Setup state: Establishing a connection.
– Online state: Connected to another modem. To return to the online state from any other state,
enter ATO and press Return. You will see a fresh connect message.
– Escape state: Allows you to enter commands while the modem is online. To go to escape state,
enter the +++ default escape code. When you enter the +++ command, pause for at least a
second before and after typing it, but do not pause between characters. Do not press Return.
Wait for the OK prompt before entering commands.
For more information about AT commands, refer to the Cisco document, AT Command Set and Register
Summary for MICA Six-Port Modules.
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5
Configuration Examples
Verifying Modem Connection
If you are unable to connect to the modem, check the following:
•
Enter the show users EXEC command to verify that the modem state is idle. You should see that the
line is not in use. Shows TTY reverse Telnet status information.
•
Enter the show line EXEC command to verify that the line is configured for modem inout. Shows
TTY reverse Telnet status information.
•
Enter the show modem EXEC command and its variations to provide modem connection
information. If you do not have any connected calls, the modem is idle and the display shows no (*)
characters next to the modem.
•
Check to see if the virtual terminal connections to lines in the access server require passwords.
•
Check to see if the speed between the modem and the access server are the same. They are likely to
be different. If they are different, switch off the modem, then switch it back on. This should match
the speed of the modem with the speed of the access server.
Configuration Examples
Use example dial strings in this section as a guide.
•
The following examples show a call placed to 555-1234 with a dial extension of 1234 after a wait
of four seconds.
PRI example:
atd5551234x,,1234
CAS example:
atd5551234,,1234
•
The following examples show a call placed to 555-1234, with a wait of four seconds, then a dial to
extension 71, which enables the dial tone for placing an outbound call. After detecting the outbound
dial tone, a call to 555-0987 is placed.
PRI example:
atd5551234x,,71w5550987
CAS example:
atd5551234,,71w5550987
•
The following examples show a call placed to 555-1212 (which, for this example, provides a second
dial tone for placing calls known as a call bridge) and then a wait for the dial tone indicated by the
W. When the dial tone is detected, 555-1234 is dialed. There is no X in this PRI example, because
the W will act as the delimiter to indicate to the CSM that there has been a transition to DTMF
dialing.
PRI example:
atd5551212w5551234
CAS example:
atd5551212w5551234
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Command Reference
Command Reference
This section documents the modified command that enables the Cisco MICA Modem Dal Modifiers
feature. All other commands used with this feature are documented in the Cisco IOS Release 12.2
command reference publications.
•
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ATD
7
Command Reference
ATD
To enable dial modifiers X, W, or the comma (,) character on Cisco MICA modems, use the ATD
command in the command state AT command mode.
ATD [X | W |,]
Syntax Description
AT
Attention. Informs the modem that commands are being sent to it.
D
Dial string or dial command character. Dials a telephone number,
establishing a connection. Always make the dial command the last (or the
only) command on the command line. The dial string can contain a a
maximum of 49 characters; valid characters are the digits 0 to 9 and, for
tone dialing, the letters A, B, C, and D, and the characters # and *.
X
Switches to in-band dual tone multifrequency (DTMF) mode for any
subsequent digits remaining in the ATD string. The X dial modifier has
been added to serve as a delimiter for the host when processing the dial
string. Allows Cisco MICA portware to be used in many environments that
do not support DTMF dialing (for example, PRI).
W
Waits for dial tone then switches to in-band DTMF mode for any subsequent
digits remaining in the ATD string. The W dial modifier also acts as a
delimiter between the primary and secondary sections of the dial string, so
no additional X modifier is needed. Once either an X or a W has been parsed
in the dial string, any additional X modifiers are ignored. Additional W
modifiers cause Cisco MICA to wait for a dial tone.
,
Delay: Number of seconds in S8. Default is two seconds.
The (,) dial modifier is treated as a silent DTMF tone for the duration of
seconds specified in S8. The (,) is only acted on after the CSM has been
transitioned into DTMF mode, which requires that it either follow an X or
a W in the dial string, or that the T1/E1 is configured for DTMF signaling.
Defaults
No default behavior or values.
Command Modes
Command state AT command mode.
Command History
Release
Modification
12.1(5)T
Dial modifiers X, W, and (,) accepted by Cisco MICA modems.
Usage Guidelines
The W and (,) modifiers work similarly to those used in a standalone analog modem.
The W dial modifier monitors the audio content within the DS-0 channel. When the conditions of dial
tone are detected, any numeric characters in the ATD string following a W are asserted as in-band. If the
W is found in the remainder in the string, it is acted upon in accordance with its functional definitions.
8
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Glossary
The Cisco MICA dial tone detector is required to detect a normal, continuous dial tone. You can
optionally set the dial tone detector to recognize a credit card dial tone, which is characterized by a short,
one-time 500ms tone with a volume decay not lasting more than 500 ms. If no dial modifier is present
in an ATD string, then all digits are passed to the Cisco IOS software for delivery to the Public Switched
Telephone Network (PSTN), according to the specific type of trunk being used by the access server
(channelized T-1, E-1, or primary rate ISDN).
If the ATD state is already in the in-band DTMF mode, any further digits appearing in the ATD string
are sent as in-band DTMF tones. Once the state machine is in the in-band DTMF mode, it does not go
back to the mode where digits are passed to the Cisco IOS software for trunk signaling.
Examples
The following shows a sample PRI call:
atd5551234x,,71w5550987
Note
atd5551234
Number is dialed.
x
Switches to DTMF mode.
,,
Four-second pause.
71
Dials the digits 71.
w
Waits for a dial tone.
5550987
A second number is dialed.
Depending on switch and equipment interactions, extra comma characters (,) might be required in
the dial modifiers string.
Glossary
AT command set—The modem command-line interpreter contained within Cisco MICA modems.
CAS—channel-associated signaling.
CSM—call switching module.
DTMF—dual tone multifrequency.
MICA—Modem ISDN channel aggregation. Used as a generic term to describe the Telebit high-density
modem technology.
PRI—Primary Rate Interface. ISDN interface to primary rate access. Primary rate access consists of a
single 64-Kbps D channel plus 23 (T1) or 30 (E1) B channels for voice or data.
PSTN—Public Switched Telephone Network.
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9
Glossary
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