You can use call waiting to receive an audible warning when you are in a call and another call comes in. You can then choose to put the first caller on hold to answer the second call and swap between the two calls.
To check whether your telephone is set up to use call waiting, dial *#43#.
To set up call waiting, dial *43#.
When someone calls you while you are already in a call, you hear the call waiting tone. At the same time, the new caller hears an announcement that you are currently in a call but have been informed that a new caller is waiting.
To talk the new caller, press the Recall button on your telephone. The first caller is put on hold and you are connected to the new caller.
To swap to the caller currently on hold, press the Recall button. The caller you were talking to is put on hold and you are connected to other caller.
To connect to the other caller if one of the callers hangs up, press the Recall button.
If you hang up while a caller is still on hold, your telephone rings immediately. When you answer, you are connected to the caller that you left on hold.
You can cancel call waiting for an individual call but leave it in operation for subsequent calls. For example, you may want to do this before making a fax call or before making an call in where you do not want to be disturbed.
To cancel call waiting before making a call, dial #43#.