Your UniTel voice device includes a feature/setting labeled DND - Do Not Disturb.
Enabling this mode will prevent the device from Ringing when you receive an inbound call to your Extension.
NOTE: This feature only prevents ringing on the Device that is DND-enabled. Each Device has it's own DND setting. If you are using multiple Devices for your Employee Extension such as a Desk Phone, Softphone and Mobile App, your other provisioned devices will continue to Ring when an inbound call is received.
DND on the UniTel Voice Mobile App:
To enable DND from the Mobile App: From the Keypad screen tap your Extension number in the top left of your device, then toggle Do Not Disturb On/Off
DND on a Desk Phone:
On Desk Phones this feature is typically assigned to a softkey below the LCD display. It will be visible while the phone is not in use. To Enable DND mode, press the DND button. To disable DND mode, press the button a second time.