A rapid busy signal, often known as a reorder tone, indicates that the number dialled cannot be reached. Reorder tones are typically played after a recorded message outlining the problem discovered during a failed contact attempt.
There are numerous difficulties that can disrupt service or prevent callers from reaching the number they dialled. According to the Telecommunications Industry Association, a reorder tone is employed when there is no viable transmission path, indicating that the dialled number is unavailable. A reorder tone resembles the busy signal used to indicate that a line is in use, although it is substantially faster.