After upgrading the phone from 188.8.131.52 to 8.7.5.x, the phone no longer displays the "DND Active!" notification message in the upper left corner of the LCD on the Snom 710 phone.
Starting in 8.7.5.x the setting "status_msgs_that_are_blocked" includes the status message "CurrentIdentityIsDnd"
PhoneHasVoiceMessages PhoneHasTextMessages CurrentIdentityIsDnd PhoneProvisioningFailed
If you would like to revert the phone to the old behavior found in 184.108.40.206 you can modify this setting using Provisioning or change it on a per phone basis with a single HTTP GET to the phone's IP address
http://phoneIPaddress/dummy.htm?settings=save&status_msgs_that_are_blocked=PhoneHasVoiceMessages PhoneHasTextMessages PhoneProvisioningFailed
Note: This can also be used on the D715/715 as well