Call pick-up allows you to answer another telephone in your call pick-up group (Within your department). If there are multiple ringing lines, the first ringing phone in the group is the one you will pick up. The subscriber can pick up an incoming call while the telephone is ringing, but cannot pick up a call that is already in progress.
When a call is ringing on another extension within your pick up group and you wished to answer it, pick up your phone and dial *11. This will answer the incoming call.