This is the way it works. When IP phone A hangs up CallManager tears down the call. This is why busy is not heard on the IP phone B because the call is torn down. This is the same way you cell phone will react. Calls from IP phone to PSTN should work the same way.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.