I have a request regarding the above cisco number, Please would it be possible to have an engaged tone when user is on the phone to someone.
You can set the "Busy trigger per Button" value on a phone to 1. With this setting, if the user is on a call, the caller for a second call will hear busy tone.
There is no way in CUCM to provide a special tone or ringback if a user is already on a call, and you're either calling other line, or below the busy trigger for a line with a call.
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