Table Of Contents
Multi-Chassis Hunting for
Voice over Frame Relay
Tandem Nodes
Multi-Chassis Hunting for
Voice over Frame Relay
Tandem Nodes
Feature Overview
This feature enables routers acting as tandem nodes in a Voice over Frame Relay environment to continue dial-peer hunting if the tandem node receives a "user-busy" disconnect code from a destination router.
This feature is used for a configuration in which a tandem router is configured with multiple dial peer entries that route a call to the same destination number, but on different destination routers. In this configuration, after all routes to the first router entry in the dial-peer list are active, a new call will not "roll over" to the next router in the dial-peer list.
This failure to route to the second destination router happens when the bandwidth on the Voice over Frame Relay interface is greater than the maximum capacity of the first destination router. This condition allows the tandem router to attempt to place a new call to the first router because it has indications from the first router that there is more capacity based on the bandwidth setting. When the first destination router receives the call, if all of the ports are in use, the destination router returns a "user-busy" disconnect reason code to the tandem router. The tandem router interprets the disconnect reason code as meaning there is no available destination for the call, causing it to return a busy tone to the initiating caller
The tandem router fails to try other routers in the dial-peer list after receiving "user disconnect" reason code, and so it terminates the call attempt.
This feature is a workaround for this situation.
Benefits
This feature provides a workaround for enabling a tandem router to continue dial-peer hunting if it receives a "user-busy" disconnect code from a destination router.
Supported Platforms
This feature is supported on the following platforms:
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Cisco 2600 Series routers
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Prerequisites
The following are the prerequisites for this feature:
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Supported MIBs and RFCs
None.
Configuration Task
To configure multi-chassis hunting on a Voice over Frame Relay tandem router, complete the following step in global configuration mode:
Configuration Example
The following example configures a tandem router to continue dial-peer hunting if it receives a "user-busy" disconnect code.
configure terminal voice hunt user-busyCommand Reference
This section documents a new command.
voice hunt user-busy
To configure a tandem router so it does not stop dial-peer hunting if it receives a "user-busy" disconnect code from a destination router, use the voice hunt user-busy global configuration command. To configure the tandem router so it does stop dial-peer hunting if it receives a "user-busy" disconnect code (the default option), use the no form of this command.
voice hunt user-busy
no voice hunt user-busySyntax Description
This command has no arguments or keywords.
Default
The tandem router stops dial-peer hunting when it receives a "user-busy" disconnect code.
Command Modes
Global configuration
Command History
Usage Guidelines
This command applies only to routers acting as tandem nodes in a Voice over Frame Relay environment.
This command is used for a configuration in which a tandem router is configured with multiple dial peer entries that route a call to the same destination number, but on different destination routers. In this configuration, after all routes to the first router entry in the dial-peer list are active, a new call will not "roll over" to the next router in the dial-peer list.
This failure to route to the second destination router happens when the bandwidth on the Voice over Frame Relay interface is greater than the maximum capacity of the first destination router. This condition allows the tandem router to attempt to place a new call to the first router because it has indications from the first router that there is more capacity based on the bandwidth setting. When the first destination router receives the call, if all of the ports are in use, the destination router returns a "user-busy" disconnect reason code to the tandem router. The tandem router interprets the disconnect reason code as meaning there is no available destination for the call, causing it to return a busy tone to the initiating caller
The tandem router fails to try other routers in the dial-peer list after receiving a "user disconnect" reason code, and so it terminates the call attempt. Using this command, you can perform dial-peer hunting on multiple destination routers even if the tandem router receives a "user-busy" disconnect reason code from one of the destination routers.
Example
The following example configures the tandem router to continue dial-peer hunting if it receives a "user-busy" disconnect code from a destination router:
voice hunt user-busy