What is the difference between BLA and BLF?
BLA stands for Bridged Line Appearance. It allows a user to receive and make calls on the line appearance of another user that appears on their phone. It also shows whether that user is on the phone or not. BLF stands for Busy Lamp Field. It will show you if the user is on the phone or not, and allows you to use that button as a speed dial to call that user. You can not make a call on that user’s line from your phone.