You can gracefully "busy-out" (graceful out-of-service) 6608 module B-channels for troubleshooting purposes. This can be configured in the Cisco CallManager Administrator web pages. To do this, perform these steps:
Go to the Cisco CallManager Administrator web pages.
Select Service > Service Parameters.
Select any server from the drop down box, and select the Cisco CallManager service from the drop down box.
Click the Advanced button to display all of the advanced service parameters.
Under the Cluster Wide Parameters (Device - PRI and MGCP Gateway) heading, refer to the parameter called Change B-Channel Maintenance Status 1 (with four other parameters with similar titles for status 2-5). This paramater allows the Cisco CallManager to change the individual B-channel maintenance status for PRI interface in real-time for troubleshooting.
A detailed description of how to configure these advanced service parameters can be found by clicking the service parameter name to bring up the context-sensitive help.
Changes to service parameters usually require that the service which was modified is restarted before changes take effect.
For more details and configuration options, refer to the context-sensitive help for the service parameter.