Busy Lamps are a feature that indicate presence and availability of fellow users. Busy Lamp Field (BLF) is a light on the IP phone which tells you whether another extension connected to the same system is busy or not. They allow you to see if a colleague is busy on another call, whether to put a caller on hold or to transfer the call. If the user has enabled a “Do Not Disturb”, you can see from phone. This is a particularly useful tool if you have colleagues in different offices.
Busy Lamps are enabled by the administrator within the Call Set Up –> Incoming –> Advanced Set Up
Another use for Busy Lamp Fields is for call centers and customer support groups. Employees can know when their colleagues are available to take a support call or if the supervisor is busy and cannot be with another customer at present.