Call Forwarding - No Answer (CFNA) permits a called subscriber to have the system send incoming calls addressed to the called subscriber's Directory Number to another Directory Number (forward-to number) or to the called subscriber's designated voice mailbox, when the subscriber fails to answer, or is otherwise inaccessible (including no paging response, the subscriber's location is not known the subscriber is reported as inactive, Call Delivery not active for a roaming subscriber, Do Not Disturb active, etc.). CFNA does not apply when the subscriber is considered to be busy.