Signal used by the operator at the receiving end of an established connection to recall an operator at originating end. Synonym: Audible Ringing Tone.

Permits the answering point to ring the hung up telephone on a held circuit; this feature is useful when a calling party has failed to provide all necessary information to the answering point before hanging up.

The tone heard by a calling party when, at the called-party's end, the telephone is ringing or the system is otherwise being alerted of the incoming call.

A personalization service for mobile phones. When a caller dials a ringback user, a song replaces the typical ringing noise before the user picks up.