Audible signal to the caller indicating that the call cannot be processed through the network
Example of a North American reorder tone
Listen to a reorder tone from North America.
Example of a European reorder tone
Listen to a reorder tone from Europe.
Example of a British reorder tone
Listen to a reorder tone from the United Kingdom.
Problems playing these files? See media help.
The reorder tone, also known as the fast busy tone, or the congestion tone, or all trunks busy (ATB) tone is an audible call progress tone in the public switched telephone network (PSTN) that is
returned to a calling party to indicate that the call cannot be processed through the network.[1]
The tone characteristics vary by country or telephone administrations. In North America it is a dual-frequency tone of 620 Hz and 480 Hz interrupted 120 times per minute at a cadence of 0.25 seconds on, 0.25 off, i.e., two beeps per second.
In EU countries and those following ETSI (European Telecommunication Standards Institute) recommendations, the cadence is the same as North America, i.e. 0.25 seconds on / 0.25 seconds off, but with a 425 Hz tone.
The UK reorder tone uses a 400 Hz tone with a cadence of 0.4 seconds on, 0.35 seconds off, 0.225 seconds on, 0.525 seconds off. In some instances the Number Unobtainable Tone may be used instead. This is a continuous, uninterrupted 400 Hz tone.
The signal is used to indicate that the destination is unreachable, either because all circuits (trunks) are busy, the called number is out of service, the call is unroutable, or sometimes that an invalid code has been dialed.[1] A PBX also often indicates an invalid extension, while dialing an invalid telephone number on the PSTN usually results in playing the triple special information tone and a recorded announcement.
Some European networks may return the reorder tone as a generic error signal for invalid or incorrect numbers or where a particular call type is not supported or has been barred.
Some switches, notably in Europe where open dial plans are used, analyse a number as it's dialled, and may even return a reorder tone before the complete number is dialled if the initial sequence of digits are invalid.
The reorder tone is sometimes confused with the busy signal because they use the same frequencies and differ only in that the busy signal's beeping sounds have a slower cadence than those of the reorder tone.
^ ab"NENA Master Glossary Of 9-1-1 Terminology" (PDF). National Emergency Number Association (NENA). Archived from the original (PDF) on June 22, 2012. Retrieved 2012-10-05.
North American reordertone Listen to a reordertone from North America. Example of a European reordertone Listen to a reordertone from Europe. Example...
automatically resolved, the calling user receives the congestion tone, also called reordertone. If the called station is already busy and cannot accept a second...
one half second ON and one half second OFF. Reordertone, also often called fast busy tone, is the same tone, but with a cadence of 0.25 of a second ON...
institution owned by the Alberta government All trunks busy, the reordertone, or fast busy tone, on public switched telephone networks ATB (Advanced trace...
progress tones are dial tone, ringing tone, busy tone, and the reordertone. A loud stutter tone is used to alert subscribers of a handset left off-hook, effectively...
military vehicle used for crossing difficult swampy terrain Fast busy, or reordertone, a type of telephone signal Feedback, in signaling systems Femtobarn...
ToneScript is a description syntax for the characteristics of call-progress tones. A call progress tone is a pattern of audible tones played to the caller...
not want to be disturbed) a fast busy signal (also called reordertone or overflow busy tone) signifying that there is congestion in the telephone network...
number which did not complete. For example, if a customer encountered a reordertone (a fast busy signal), it could indicate "all circuits busy," or a problem...
few cycles of the reorder, busy, or the off-hook tone (e.g. in US), or between five and fifteen seconds of the Number Unobtainable tone (e.g. in UK). On...
because no circuits are available, the caller typically receives the reordertone ("fast-busy" signal) and is unable to reach the called party. In military...
telephony, a special information tone (SIT) is an in-band international standard call progress tone consisting of three rising tones indicating a call has failed...
receive a reordertone from their local or tandem exchange. If the calls were overflowed to the tandem route, the caller would receive a busy tone from the...
"fast busy" reorder signal to tell the user to try again later. The basic protocol for finding a free line worked by playing a 2600 Hz tone into the line...
(Convergent Books, 2019) ISBN 9780281078622 The Wisdom Pattern: Order, Disorder, Reorder (Franciscan Media, 2020) ISBN 978-1632533463 Why Be Catholic?: Understanding...
the twelve-tone technique, derivation is the construction of a row through segments. A derived row is a tone row whose entirety of twelve tones is constructed...
realise that they overpaid for the item, return the item to the seller, then reorder the identical item directly from the manufacturer. The cost of processing...
and equipment simply returned a number unobtainable, reorder or SIT (special information) tone to indicate an error. In some networks recordings for...
off-hook tone (howler tone) or a 480/500 Hz high tone (which would subsequently bleed into adjacent lines via crosstalk). Off-hook tone is a tone of increasing...
with a simple rule: First fill each slot with a successive integer. Then reorder them such that the average distance between two successive numbers in the...
A fan edit is a version of a film modified by a viewer, that removes, reorders, or adds material in order to create a new interpretation of the source...
WIDTH NO-BREAK SPACE, has the important property of unambiguity on byte reorder, regardless of the Unicode encoding used; U+FFFE (the result of byte-swapping...
areas: input requirements; e.g. working capital, material, replacement or reorder time, and set-up requirements. throughput requirements, often viewed as...
Global Information