There are several possible call path options if there is not an available agent to assist a caller.  Admins can set the call flow to automatically end the call with a message like, “There are no available representatives to take your call. Please hang up and try your call again later, goodbye.”  But simply ending the call is, of course, not preferable if other options are available.  Admins may opt to have unanswered calls automatically forwarded to voice mailboxes, forwarded to another agent, or even forwarded back to the main IVR menu for additional options.