For Snom phone models 710/715, there is a slight display difference when using the DND mode on phones using the 220.127.116.11 firmware. With previous versions of firmware, when DND was active, a banner would be displayed across the screen; with 18.104.22.168 and newer versions, this is not the case. Instead, it just displays a small message.
In order to fix this problem:
1. Copy all of the following URL:
2. Replace “phoneIPaddress” with that of the phone you are using.
3. Enter into your web browser and it should fix the problem. The DND message should now look like the one below.