CCIE Voice Study

CME gives users the ability, if they are members of a hunt-group, to interactively login and logout of hunt groups. This is achieved in normal operation through the HLog key, or using Feature Access Codes (FAC). When operating in CME fallback (/SRST) mode, however, the options are somewhat reduced. This is because the HLog key doesn't seem to behave as it should - however don't despair, as there are other options!

The answer is dynamic hunt-groups and FAC. In order to provide users the ability to login and logout of hunt-groups, the following configuration elements should be observed:

• The system must first be configured for CME fallback
• The ephone-dn's must be defined, since the permission to dynamically join groups is defined under the ephone-dn
• The ...

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When a phone re-registers in SRST to the local gateway, it can take more than 2 minutes by default when connectivity is restored to CallManager before the IP phone unregisters from SRST and reregisters to Cisco Unified Communications Manager.

This interval is controlled by the Connection Monitor Duration. This value is set globally (Enterprise Parameters) and overridden at the Device Pool.

Take a simple SRST configuration.

call-manager-fallback
 ip source-address 172.16.1.1 port 2000
 max-ephones 52
 max-dn 192
 system message primary CUCM is down... Run away!

All that is required on the CallManager side is to configure an SRST reference, and assign that reference under the device pool. Once the link ...

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