Busy Lamp Field (BLF)

The Busy Lamp Field or BLF is an indicator on the desk phone. It can be programmed to signify specific conditions or features. The BLF is controlled by a hosted PBX.

A BLF can be used to indicate whether the extension is ‘idle’ or ‘in use.’ It can be used to program speed dial numbers as well. It is also programmed to indicate the calls on waiting or in the call park. A BLF can also be used to indicate if the Call Flow Control has been activated on a particular extension or not.

For example, when the front desk gets a call for a particular extension they check the BLF light. If they notice that it is ‘ON,’ they will immediately ask the caller to either leave a message or call back later. If the caller chooses to leave a message, his call is transferred to the voicemail.