call waiting

Hi,

Unfortunately there is no way to receive a message when somebody is already in a call. With various carriers there is a voice message informing you that they are already calling, but that's not with every carrier.

Some carriers in the U.S. used to play a beep at the end of the ring but I haven't noticed that in years.

But, regardless of whether or not they are on a call, the end result is the same: they are not answering you. Leave a message.