SnomONE 4.5, handsets are 300s and 320s.
Each extension account has call forwarding configured to overflow an incoming call to a hunt group on busy or NA.
When the users are away from their desks, they hit the DND button expecting the extension to show as busy and the call to overflow. I'm almost certain that this was the behaviour when the system was first installed!
What is actually happening is that the caller is getting an 'unavailable' message instead.
How can we configure the system to overflow calls when DND is set rather than rejecting them?