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The emergency number preemption (also called 911-preemption) feature enables you to configure a list of emergency numbers. When the maximum number of incoming or outgoing connections on a dial-peer is reached, the other non-emergency calls are preempted from the session initiation protocol (SIP) dial-peer, allowing the emergency call to go through.
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
The Emergency Number Preemption feature works only for maximum-connections-based call admission control (CAC) and not bandwidth-based CAC.
The emergency number is 911 in the U.S.A., but it may not be the same in other parts of the world; so this emergency number can configured by the user. This feature is triggered by the following two conditions:
When the emergency preemption feature is triggered, the non-emergency call is preempted and the current emergency call is allowed to go through. If it cannot find another non-emergency call to preempt, the current emergency call will fail.
Note | Using this feature, the existing multi-level precedence preemption (MLPP) feature is leveraged, as MLPP can preempt calls. |
1.
enable
2.
configure terminal
3.
voice service voip
4.
emergency
number
5.
end
1.
enable
2.
configure terminal
3.
voice mlpp
4.
preemption
voip-trunk sip
5.
exit
6.
dial-peer voice tag voip
7.
max-conn number
8.
end
Perform this task to verify the configuration for the emergency number preemption. The show commands can be entered in any order.
1.
enable
2.
show dial-peer voice tag
3.
show voice mlpp voip-trunk sip
Use the debug voip mlpp command to troubleshoot the Emergency Number Preemption feature.
Device> enable Device# configure terminal Device(config)# voice service voip Device(conf-voi-serv)# emergency 912 913 Device(conf-voi-serv)# end
Device> enable Device# configure terminal Device(config)# voice mlpp Device(config-voice-mlpp)# preemption voip-trunk sip Device(config-voice-mlpp)# exit Device(config)# dial-peer voice 30 voip Device(config-dial-peer)# max-conn 2 Device(config-dial-peer)# end
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.Feature Name |
Releases |
Feature Information |
---|---|---|
Nano CUBE (Emergency Number Preemption) |
15.3(3)M |
The emergency number preemption (also called 911-preemption) feature enables you to configure a list of emergency numbers. When the maximum number of incoming or outgoing connections on a dial-peer is reached, the other non-emergency calls are preempted from the session initiation protocol (SIP) dial-peer, allowing the emergency call to go through. |