In Microsoft Teams, when a user is on a call and receives another call, the default behaviour is to alert the user to the 2nd incoming call with a audio notification and a pop-up. This behaviour is a common complaint from end users.
To help address this Microsoft introduced the BusyOnBusy functionality. The user would not receive an alert and the caller would hear a busy tone. Definitely an improvement but still not perfect.
Now with the ability to follow a user’s call answering rules, we finally have voicemail on busy.
How to setup voicemail on busy
Policy: Teams Calling
Values: Enabled | Unanswered | Disabled
When set to Unanswered, the user’s “If unanswered” settings will take effect, such as routing to voicemail, forwarding to another user or forward to another number.
This can either be applied to everyone using the Global (org-wide) policy, per users or by group using a group assignment policy.
Setting the parameter to “unanswered” is currently only available via PowerShell using the Set-CSTeamsCallingPolicy cmdlet:
Set-CsTeamsCallingPolicy -Identity "Voicemail on busy" -BusyOnBusyEnabledType Unanswered
The important part with this setting, is that it is following a user’s “Call answering rules” -> “If unanswered” setting. So for this to work, a user need to have the “If unanswered” set to “Voicemail”.