6.9.2 Configuring the Fallback Emergency Caller ID for a user
Optional the Fallback Emergency Caller ID can also be configured in the user extension settings. This setting is used when an emergency number is called from a device associated which this user extension and no caller ID is available. This can be a desk phone in which the user is logged in, a softphone client (like the Desktop or Mobile app), or a managed mobile phone linked to the user.
The number that you can configure here could be for instance the emergency response number of the department or building were the user is working.