Calling Features (*) FAQ
How do I configure my Call Waiting service? (*70)
If someone calls while you are already on a call, a distinctive sound will inform you that a second call is waiting. You can put the first call on hold and answer the second.
If you do not want to be disturbed during an important call, you can deactivate Call Waiting by using *70. Call Waiting will automatically be reactivated when you hang up.