Lync Server users can have a private line for incoming calls. This enables calls from important business contacts and family members to be easily identified and receive priority handing. Calls to a user’s private number are uniquely identified on the incoming toast and with a distinct ring. Calls to private lines override DND and other redirection settings to ensure that they always route to the user.
This feature benefits users who provide their private line to an important caller such as a priority customer or family member because they know the incoming call will always ring through to their endpoint.