When you enable the Server Do Not Disturb (DND) feature, the phone ignores all incoming calls and propagates the DND status to the Avaya Cloud Office server. The phone does not present incoming calls and does not receive alerting ringtone or incoming call pop-ups. You can change the DND settings on the phone, or your system administrator can change them on the ACO server. The latest settings override the previous, regardless of where you change them.