Rotating Through Dial Strings
This feature was introduced.
This document describes the Asynchronous Line Monitoring feature feature in Cisco IOS Release 12.2(8)T and includes the following sections:
•Supported Standards, MIBs, and RFCs
The Cisco IOS software allows multiple dial strings (telephone numbers) to be configured for outgoing calls. In previous releases of the Cisco IOS software, the dial string used for a particular outgoing call was always the first telephone number in the dial string list. It was not possible to customize the selection or otherwise participate in deciding which dial string should be used first. But in Cisco IOS Release 12.2(8)T, the Asynchronous Line Monitoring feature feature allows the order in which dial strings should be dialed to be specified.
The Asynchronous Line Monitoring feature feature allows you to specify the dialing order when multiple dial strings are configured. Options for dialing order are as follows:
•Sequential—Dial using the first dial string configured in a list of multiple strings.
•Round-robin—Dial using the dial string following the most recently successful dial string.
•Last successful call—Dial using the most recently successful dial string.
This feature takes advantage of information available from a previous call attempt, such as the call was unsuccessful or the line was busy, and thereby increases the rate of successful calls.
Additional information about configuring networks that can take advantage of the Asynchronous Line Monitoring feature feature can be found in the Cisco IOS Dial Technologies Configuration Guide, refer to the chapter "Configuring Peer-to-Peer DDR with Dialer Profiles" in the part "Dial-on-Demand Routing Configuration." In the same manual, also refer to the chapter "Configuring ISDN Caller ID Callback," in the part "Callback and Bandwidth Allocation Configuration."
•Cisco 1400 series
•Cisco 1600 series
•Cisco 2400 series
•Cisco 2600 series
•Cisco 800 series
•Universal Route Module (URM)
Determining Platform Support Through Feature Navigator
Cisco IOS software is packaged in feature sets that support specific platforms. To get updated information regarding platform support for this feature, access Feature Navigator. Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature.
Feature Navigator is a web-based tool that enables you to quickly determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image.
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Feature Navigator is updated regularly when major Cisco IOS software releases and technology releases occur. For the most current information, go to the Feature Navigator home page at the following URL:
Supported Standards, MIBs, and RFCs
To obtain lists of supported MIBs by platform and Cisco IOS release, and to download MIB modules, go to the Cisco MIB website on Cisco.com at the following URL:
The Asynchronous Line Monitoring feature feature is used in configurations that apply to both legacy dialers and dialer profiles. The dialing order you configure applies to dial strings configured on an interface by the dialer string and dialer map configuration commands. See the documents listed in the "Related Documents" section for more information about using these commands to configure dial strings.
See the following sections for the configuration tasks for this feature. Each task in the list is identified as either required or optional.
•Configuring the Order of Dial Strings (required)
•Verifying Dial String Order (optional)
Configuring the Order of Dial Strings
To specify the order in which dial strings should be dialed, use the following command in interface configuration mode:
Router(config-if)# dialer order [sequential | round-robin | last-successful]
Specifies the dialing order when multiple dial strings are configured. Use one of the following optional keywords:
•sequential—Starts dialing the first dial string configured in a list of multiple strings.
•round-robin—Starts dialing using the dial string that occurs after the most recently successful dial string.
•last-successful—Starts dialing using the most recently successful dial string.
The dialer order command keywords can be configured on a per-interface basis. You can use this command in interface configurations that apply to both legacy dialers and dialer profiles. See the "Configuration Examples" section to see how this command is used with both these dialer types.
Verifying Dial String Order
To verify that the dial string order is configured correctly, perform the following step:
Step 1 To check the dial string order configuration, enter the show running-config interface command with the appropriate interface type at the privileged EXEC prompt:
Router# show running-config interface dialer 1
Current configuration : 96 bytes
Check that a dialer order command is listed in the configuration displayed. If no dialer order command is listed, that indicates the default sequential dial string order is configured.
Step 2 To see a report of the call types, telephone numbers, and call duration, enter the show isdn history command at the privileged EXEC prompt:
Router# show isdn history
To troubleshoot the Asynchronous Line Monitoring feature feature, use the debug dialer command in privileged EXEC mode.
Monitoring and Maintaining the Asynchronous Line Monitoring feature Feature
To monitor and maintain the Asynchronous Line Monitoring feature feature, use the EXEC commands included in the steps in the "Verifying Dial String Order" section.
This section provides the following configuration examples:
•Legacy Dialer with Multiple Dial Strings Example
•Dialer Profile Configuration with Multiple Dial Strings Example
Legacy Dialer with Multiple Dial Strings Example
The following example configures the dialing software to try the telephone number (dial string) of the last successful call when starting a new call, rather than the first telephone number in the list:
ip address 10.2.1.130 255.255.255.0
dialer map ip 10.2.1.131 name jones1 modem-script test 5554004
dialer map ip 10.2.1.131 name jones1 modem-script test 5554005
dialer map ip 10.2.1.131 name jones1 modem-script test 5554006
dialer order last-successful
Dialer Profile Configuration with Multiple Dial Strings Example
The following example configures the dialing software to try the telephone number following the most recently used telephone number (dial string) when starting a new call, rather than the first telephone number in the list:
ip address 10.1.1.130 255.255.255.0
The following commands are introduced or modified in the feature or features documented in this module. For information about these commands, see the Cisco IOS Dial Technologies Command Reference at http://www.cisco.com/en/US/docs/ios/dial/command/reference/dia_book.html. For information about all Cisco IOS commands, go to the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or to the Cisco IOS Master Commands List
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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.
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