To Activate Call Waiting on your airtel fixed line – Dial 118.
How To Use-
Press FLASH followed by 2, and take the second incoming call keeping the first one on hold. FLASH + 2 will bring you back to the first call. Flash + 2 functions like a toggle key. FLASH +1 will connect to the waiting caller and disconnect the active call. FLASH + 0 will keep you connected to the active call and disconnect the waiting call.
To Deactivate Call Waiting on you airtel Fixed Line – Dial 119
Please note – This service is free of charge, Available in all circles