A BLF key stands for Busy Lamp Field, it allows you to monitor the status of another extension in your Hosted PBX service. It allows you to see if the other extensions phones is ringing or on hold by changing the colour of the LED.
Please note, the steps here assume you have a sidecar addon to your Cisco phone. If you don’t please see alternative instructions here.
For a Cisco SPA series phone you can use the following steps:
Browse to the IP Address of the phone (to find the IP address see the tip at the bottom of this article)
Click the admin link followed by advanced
Next click Att Console
Make sure Unit 1 is enabled (enable Unit 2 if you have two sidecars)
Set Attendant Console Call Pickup Code to **
Set the Unit 1 Key with – fnc=blf;sub=EXTENSION_NUMBER@$PROXY Replace EXTENSION_NUMBER with the remote extension e.g. 1001
You can repeat the previous step for all the remote extension you want to monitor