Another alternative to basic call forwarding is called Filtered Forwarding. It allows a user to select only specific numbers or area codes that will trigger the forwarding function to his mobile number or other destinations.
The feature, also known as Caller ID forwarding, is ideal for a worker going on a vacation or one that needs to have time to focus on urgent projects instead of dealing with their normal call load.
An administrator uses the feature to enter a list of numbers whom the worker would like to receive calls from (important clients, co-workers, suppliers, service providers etc.) and the forwarding number(s). The system will only forward calls to the destination number with a caller ID matching a number on the list. All other calls will be automatically transferred to voicemail.
Combining this feature with scheduled forwarding really gives a user specific control on the way he receives calls, allowing him to receive calls only from specific numbers at specific times of the day.
Learn how to set up Filtered Forwarding.