Cisco IOS Software Releases 12.0 T

Table Of Contents

Local Voice Busyout on the Cisco MC3810

Feature Summary

Benefits

List of Terms

Restrictions

Platforms

Prerequisites

Supported MIBs and RFCs

Configuration Tasks

Configuring the Busyout Trigger Event for Serial Network Interfaces

Configuring the Busyout Trigger Event for Voice Ports

Configuring the Voice Port to Busyout Under Specified Conditions

Forcing the Voice Port into Busyout State

Configuration Examples

Example 1

Example 2

Example 3

Command Reference

busyout forced

Syntax Description

Default

Command Mode

Usage Guidelines

Example

Related Commands

busyout-monitor

Syntax Description

Default

Command Mode

Usage Guidelines

Example

Related Commands

busyout-seize

Syntax Description

Default

Command Mode

Usage Guidelines

Example

Related Commands

show voice busyout

Syntax Description

Command Mode

Usage Guidelines

Example

Related Commands

voice-port busyout

Syntax Description

Default

Command Mode

Usage Guidelines

Example

Related Commands

Local Voice Busyout on the Cisco MC3810

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Feature Summary

The local voice busyout feature for the Cisco MC3810 is designed to busy out the trunks assigned to a PVC whose pipe is broken so that the PBX will not attempt to seize the circuit. This allows the PBX to route or reroute a given call based on the actual availability of trunks.

This feature is not supported on the BRI Voice Module (BVM), which will be available in a future release.

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Note   This feature is different from busy-back. Busy-back refers to the signal sent from within the network to the calling party that indicates a busy (or congested) state anywhere along the route, up to and including the condition of the called party. When the number of available Digital Signal Processors (DSPs) is less than the number of incoming trunks from a PBX, a call from the PBX will connect to dead air. The capability to provide a busy-back signal because no DSPs are available is not supported on the Cisco MC3810 as part of this feature.

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Benefits

Local voice busyout provides the following benefits:

•A group of voice ports can be marked busy if the link is broken

•Specific voice ports in a PVC application can be marked busy under specified conditions

By marking ports busy, the call is forced back to the originating equipment (typically a PBX), which then reroutes the call over an alternate facility. This ensures that if a link is broken, a caller will not experience a "dead air" state that accompanies a connection that never terminates.

List of Terms

E&M—Stands for recEive and transMit (or Ear and Mouth). E&M is a trunking arrangement generally used for two-way switch-to-switch or switch-to-network connections. Cisco's analog E&M interface is an RJ-48 connector that allows connections to PBX trunk lines (tie lines). E&M is also available on E1 and T1 digital interfaces.

FXO—Foreign Exchange Office. An FXO interface connects to the Public Switched Telephone Network's (PSTN) central office and is the interface offered on a standard telephone. Cisco's FXO interface is an RJ-11 connector that allows an analog connection to be directed at the PSTN's central office or to a station interface on a PBX.

FXS—Foreign Exchange Station. An FXS interface connects directly to a standard telephone and supplies ring, voltage, and dial tone. Cisco's FXS interface is an RJ-11 connector that allows connections to basic telephone service equipment, keysets, and PBXes.

Restrictions

The following restrictions and limitations apply to the Cisco MC3810 local voice busyout implementation:

•For switched calls, a call can still pass through an alternate interface, if specified. A voiceport needs to be busied out only if all interfaces are down. To configure this case, the voice-port busyout command must be specified for each interface. The voice port is then placed in busyout state if all the specified interfaces are down.

•This feature does not monitor end-to-end connectivity, meaning only the immediate interface connection is monitored. As a result, the interface might be up, but the call still might not go through if the PVC is down. Busyout for specific PVCs or subinterfaces is not available.

•The busyout feature will not be activated under the following conditions:

•No DSP resources are available

•No bandwidth is available

These two conditions can be addressed by configuring alternate routing.

Platforms

This feature is supported on the Cisco MC3810 only.

Prerequisites

The following configuration tasks should be completed before configuring this feature:

•Configure Voice over Frame Relay, Voice over ATM, or Voice over HDLC, including configuring local and voice-network dial peers.

•Configure the Cisco MC3810 voice ports.

Supported MIBs and RFCs

None.

Configuration Tasks

When the network trunk goes down, you need to busy out all the voice ports of the access side to prevent the Cisco MC3810 from accepting new calls from the access side to the network trunk. After the voice ports are placed into the busy out state, the PBX connected to the Cisco MC3810 access side can reroute calls through other trunks.

The Cisco MC3810 will consider a network trunk down when the data link layer control goes down, even if the physical layer is still up.

You can configure a busyout trigger event at both the serial interface level and the voice-port level. If there is a conflict between the interface-level trigger event and the voice-port level trigger event, meaning the trigger events for each are different, the voice-port-level trigger event will overwrite the interface level trigger event.

If more than one interface is configured for a busyout trigger event, voice ports will not be busied out until all of the interfaces are down.

Configuring the Busyout Trigger Event for Serial Network Interfaces

To configure the voice-port busyout trigger event for a serial network interface, complete the following steps in configuration mode:

Step	Command	Purpose
1	router(config)# interface serial 0:x	Enter serial interface configuration mode.
2	router(config-if)# voice-port busyout	Busy out all voice-ports associated with this serial interface. Note   This command busies out all voice ports associated with the interface, except any voice ports configured to busy out under specific conditions, as described in the "Configuring the Voice Port to Busyout Under Specified Conditions" section
3	router# show voice busyout	Verify the busyout status.

When you configure voice-port busyout from a serial network interface, all voice ports are placed into a busyout state when the serial interface goes down.

To configure the voice-port busyout trigger event for the ATM interface, complete the following steps in configuration mode:

Step	Command	Purpose
1	router(config)# interface atm 0	Enter interface configuration mode for the ATM interface.
2	router(config-if)# voice-port busyout	Busy out the voice-port associated with the ATM interface. Note   This command busies out all voice ports associated with the interface, except any voice ports configured to busy out under specific conditions, as described in the "Configuring the Voice Port to Busyout Under Specified Conditions" section
3	router# show voice busyout	Verify the busyout status.

Configuring the Busyout Trigger Event for Voice Ports

On voice ports, you can either configure the voice port to busyout under specified conditions, or you can manually force the voice port into a busyout state using the following procedures:

•Configuring the Voice Port to Busyout Under Specified Conditions

•Forcing the Voice Port into Busyout State

Configuring the Voice Port to Busyout Under Specified Conditions

You can specify that for a given voice port, certain conditions will trigger a voice port to enter busyout state. To configure this setting, complete the following steps:

Step	Command	Purpose
1	router(config)# voice-port slot/port	Enter voice-port configuration mode.
2	router(config-voiceport)# busyout monitor serial {0 | 1} | 0:0	Place the voice port into monitor state. You can monitor either serial 0, serial 1, or serial 0:0, but only one of these interfaces at once. When in monitor mode, if the interface goes down, it triggers a busyout on the voice port.

You can configure how the voice port will handle the seize conditions (for FXO and FXS voice ports only). To configure the seize conditions, complete the following steps:

Step	Command	Purpose
1	router(config)# voice-port slot/port	Enter voice-port configuration mode.
2	router(config-voiceport)# busyout seize {ignore | repeat}	Configure the busyout seize state for the voice port. After you enter this command, you will receive no response or output; however, when you enter the show voice port summary command, the busyout state for the voice port will be shown.

The busyout seize action depends on the voice port signaling type. For information on the different busyout actions that take place, see . For E&M voice ports, the busyout action is always seize.

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Note   The Cisco MC3810 returns the voice ports to an idle state when the event that triggered the busyout disappears.

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Table 1 Busyout Procedure Actions 

Voice-Port Signaling Type	Procedure Setting (busyout-option command)	Busy Out Actions
FXS Loop Start	Default	Remove the power from the loop. For analog voice ports, this is equivalent to removing the ground from the tip lead. For digital voice ports, the port will generate the bit pattern equivalent to removing the ground from the tip lead, or will busy out if the bit pattern exists.
FXS Loop Start	Ignore	Ignore the ground on the ring lead.
FXS Ground Start	Default	Ground the tip lead and stay at this state.
FXS Ground Start	Ignore	1 Leave the tip lead open. 2 Ignore the ground on the ring lead.
FXS Ground Start	Repeat	1 Ground the tip lead. 2 Wait for the far end to close the loop. 3 The far end closes the loop. 4 If the far end then opens the loop, FXS removes the ground from the tip lead. 5 FXS waits for several seconds before returning to Step 1.
FXO Loop Start	Default	Close the loop and stay at this state.
FXO Loop Start	Ignore	1 Leave the loop open. 2 Ignore the ringing current on the ring level.
FXO Loop Start	Repeat	1 Close the loop. 2 After the detected far end starts the power denial procedure, FXO opens the loop. 3 After the detected far end has completed the power denial procedure, FXO waits for several seconds before returning to Step 1.
FXO Ground Start	Default	Ground the tip lead.
FXO Ground Start	Ignore	1 Leave the loop open. 2 Ignore the running current on the ring lead, or ground on the tip lead.
FXO Ground Start	Repeat	1 Ground the ring lead. 2 Remove the ground from the ring lead, and close the loop after the detected far end grounds the tip lead. 3 When the detected far end removes the ground from tip lead, FXO opens the loop. 4 FXO waits for several seconds before returning to Step 1.
E&M Immediate Start	Default (only option available)	Seize the far end by setting lead busy.
E&M Delay Start	Default (only option available)	Seize the far end by setting lead busy.
E&M Wink Start	Default (only option available)	Seize the far end by setting lead busy.

Forcing the Voice Port into Busyout State

To force the voice port into a busyout state, complete the following steps in configuration mode:

Step	Command	Purpose
1	router(config)# voice-port slot/port	Enter voice-port configuration mode.
2	router(config-voiceport)# busyout forced	Place the voice port into busyout state.
3	router# show voice busyout	Verify the busyout status.

When you perform the previous procedure, the specified voice port is forced into a busyout state when the interface is down. When the busyout forced command is entered, the voice port is forced unconditionally into a busyout state.

When you enter the busyout forced command to a voice port under an interface (such as serial 0:0), when the interface goes down it becomes a condition for the voice port to go down. If more than one interface has the voice-port busyout interface command configured, all interfaces must be down for the busyout to take effect.

When you force the voice port into the busyout state, you must manually force the voice port out of the busyout state by entering the no busyout forced voice-port command.

Configuration Examples

The following configuration examples configure interface serial local voice busyout The examples also show other commands necessary for the configuration.

Example 1

The following example configures voice port 1/1 into forced busyout state:

Router(config)# voice-port 1/1 
  Type of VoicePort is FXS 
Router(config-voiceport)# busyout forced 
Router(config-voiceport)#  
00:09:46: port 0 is forced into busyout state 
Router(config-voiceport)# end 
Router# show voice busyout 
If following network interfaces are down, voice port will be put into busyout state 
The following voice ports are in busyout state 
 
1/1     	is forced into busyout state

Example 2

The following example configures voice port 1/2 to busyout monitor mode, monitoring serial 0:

Router(config)# voice-port 1/2 
  Type of VoicePort is FXS 
Router(config-voiceport)# busyout-monitor serial 0 
1/2 is in busyout state 
Router(config-voiceport)# end 
Router# show voice busyout 
If following network interfaces are down, voice port will be put into busyout state 
The following voice ports are in busyout state

1/1     	is forced into busyout state 
1/2     	is in busyout state caused by Serial0

Example 3

The following example configures voice port 1/3 to the busyout seize repeat state:

Router(config)# voice-port 1/3 
  Type of VoicePort is FXO 
Router(config-voiceport)# busyout-seize repeat 
Router(config-voiceport)#  
Router(config-voiceport)# end 
Router# show voice busyout 
If following network interfaces are down, voice port will be put into busyout state 
The following voice ports are in busyout state

1/1     	is forced into busyout state 
1/2     	is in busyout state caused by Serial0

Command Reference

The following new or revised commands are used to configure the local voice busyout feature:

•busyout forced

•busyout-monitor

•busyout-seize

•show voice busyout

•voice-port busyout

busyout forced

To force the voice port into busyout state, use the busyout forced voice-port configuration command. To remove the voice port from busyout state, use the no form of this command.

busyout forced
no busyout forced

Syntax Description

This command has no arguments or keywords.

Default

The voice-port is not in busyout state.

Command Mode

Voice-port configuration mode.

Usage Guidelines

This command first appeared in Cisco IOS Release 12.0(3)T.

When you force a voice port into busyout state, you must enter the no busyout forced command to remove the busyout state from the voice port.

Example

The following example configures the voice port on the Cisco MC3810 into forced busyout state:

voice-port 1/1 
 busyout forced

Related Commands

busyout-monitor
busyout-seize
show voice busyout
voice-port busyout

busyout-monitor

To place a voice port into busyout monitor state, use the busyout-monitor voice-port configuration command. To remove the busyout monitor state on the voice-port, use the no form of this command.

busyout-monitor interface
no busyout-monitor interface

Syntax Description

interface

•The interface associated with the voice port that will be monitored for events that would trigger a voice-port busyout. Choices are the following: •Serial 0 •Serial 1 •Serial 0:0

Default

The voice port is not in busyout monitor state.

Command Mode

Voice-port configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 12.0(3)T.

This command is only supported on the Cisco MC3810.

When you place the voice port in busyout monitor state, the voice port monitors the serial interface for events that would trigger the voice port to enter busyout state

Example

The following example configures the voice port to monitor serial port 0:0 for events that would trigger a busyout state on the voice port:

voice-port 1/1 
 busyout-monitor serial 0:0

Related Commands

busyout forced
busyout-seize
show voice busyout
voice-port busyout

busyout-seize

To change the busyout seize procedure for a voice port, use the busyout-seize voice-port configuration command. To restore the default busyout seize state on the voice-port, use the no form of this command.

busyout-seize {ignore | repeat}
no busyout-seize {ignore | repeat}

Syntax Description

ignore	On busyout, leaves the loop open and ignores the incoming signal.
repeat	On busyout, seizes the far end and ignores all incoming signals until the far end release. Remove the seize signal, wait for one second before starting to seize the far end again.

Default

On busyout, the loop is closed and remains in the busyout state.

Command Mode

Voice-port configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 12.0(3)T.

This command is only supported on the Cisco MC3810.

Example

The following example configures the busyout seize to the ignore state:

voice-port 1/1 
 busyout-seize ignore

Related Commands

busyout forced
busyout-monitor
show voice busyout
voice-port busyout

show voice busyout

To display information about the voice busyout state, use the show voice busyout privileged EXEC command.

show voice busyout

Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 12.0(3)T.

This command is only supported on the Cisco MC3810.

Example

The following example displays the busyout information:

show voice busyout

If following network interfaces are down, voice port will be put into busyout state 
ATM0 
Serial0 
The following voice ports are in busyout state 
 
1/1     	is forced into busyout state 
1/2     	is in busyout state caused by network interfaces 
1/3     	is in busyout state caused by ATM0 
1/4     	is in busyout state caused by network interfaces 
1/5     	is in busyout state caused by Serial0

Related Commands

busyout forced
busyout-monitor
busyout-seize
voice-port busyout

voice-port busyout

To place all voice ports associated with a serial or ATM interface into a busyout state, use the voice-port busyout interface configuration command. To remove the busyout state on the voice ports associated with this interface, use the no form of this command.

voice-port busyout
no voice-port busyout

Syntax Description

This command has no arguments or keywords.

Default

The voice port(s) on the interface are not in busyout state.

Command Mode

Interface configuration mode

Usage Guidelines

This command first appeared in Cisco IOS Release 12.0(3)T.

This command is only supported on the Cisco MC3810.

This command busies out all voice port associated with the interface, except any voice ports configured to busy out under specific conditions using the busyout monitor and busyout-seized commands.

Example

The following example turns the voice-port(s) associated with serial interface 1 into busyout state:

interface serial 1 
 voice-port busyout

The following example turns the voice-port(s) associated with ATM interface 0 into busyout state:

interface atm 0

 voice-port busyout

Related Commands

busyout forced
busyout-monitor
busyout-seize
show voice busyout