Call-progress tone
Encyclopedia
In telephony
, call progress tones are audible
tone
s sent from the public switched telephone network (PSTN) central office or a private branch exchange (PBX) to calling parties
to indicate the status
of phone calls.
Equipment such as fax machines and modem
s are designed to recognise dial tones and busy tones.
The ITU-T
E.180 and E.182 recommendations define the technical characteristics and intended usage of some of these tones. ToneScript
is a tone description format that may be used to specify the tone.
Telephony
In telecommunications, telephony encompasses the general use of equipment to provide communication over distances, specifically by connecting telephones to each other....
, call progress tones are audible
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...
tone
Status tones
Status Tones are short tones that are generated and placed on the Telephone Line while a call is being initiated, while it is being conducted, and while it is being monitored by a third party to inform all on the line of an actve or defined event....
s sent from the public switched telephone network (PSTN) central office or a private branch exchange (PBX) to calling parties
Calling party
The calling party is a person who initiates a telephone call over the public switched telephone network, usually by dialing a telephone number....
to indicate the status
Status tones
Status Tones are short tones that are generated and placed on the Telephone Line while a call is being initiated, while it is being conducted, and while it is being monitored by a third party to inform all on the line of an actve or defined event....
of phone calls.
Equipment such as fax machines and modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
s are designed to recognise dial tones and busy tones.
The ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
E.180 and E.182 recommendations define the technical characteristics and intended usage of some of these tones. ToneScript
ToneScript
ToneScript is a mini script used to describe the characteristics of Call progress tones-Description:A call progress tone is a pattern of tones made audible to the caller, conveying some status about the call. Despite its name, a call-progress tone could be a sequence of tones, that may be repeated...
is a tone description format that may be used to specify the tone.
Types
Major ones encountered by the public on a regular basis are listed in bold:- busy tone or busy signalBusy signalA busy signal in telephony is an audible or visual signal to the calling party that indicates failure to complete the requested connection of that particular telephone call....
- call waitingCall waitingCall waiting , in telephony, is a feature on some telephone networks. If a calling party places a call to a called party which is otherwise engaged, and the called party has the call waiting feature enabled, the called party is able to suspend the current telephone call and switch to the new...
tone - comfort tone
- conference callConference callA conference call is a telephone call in which the calling party wishes to have more than one called party listen in to the audio portion of the call. The conference calls may be designed to allow the called party to participate during the call, or the call may be set up so that the called party...
tone - confirmation tone
- congestion tone
- dial toneDial toneA dial tone is a telephony signal used to indicate that the telephone exchange is working, has recognized an off-hook, and is ready to accept a call. The tone stops when the first numeral is dialed...
- end of three-party service tone (three-way calling)
- executive override tone
- holdHold (telephone)In telephony, a call may be placed on hold, in which case the connection is not terminated but no verbal communication is possible until the call is removed from hold by the same or another extension on the key telephone system. Music on hold or On Hold Messaging may be played for the caller while...
ing tone - howler tone
- intercept tone
- intrusion tone
- line lock-out tone
- negative indication tone
- notify tone
- number unobtainable tone
- pay tone
- payphonePayphoneA payphone or pay phone is a public telephone, often located in a phone booth or a privacy hood, with pre-payment by inserting money , a credit or debit card, or a telephone card....
recognition tone - permanent signalPermanent signalPermanent Signal in US telephony jargon, or Permanent Loop in British usage, is a condition in which a POTS line is off-hook without connection for an extended period of time. This is indicated in modern switches by the silent termination after the off hook tone times out and the telephone...
tone - preemption tone
- queueQueue areaQueue areas are places in which people queue for goods or services. Examples include checking out groceries or other goods that have been collected in a self service shop, in a shop without self service, at an ATM, at a ticket desk, a city bus, or in a taxi stand.Queueing is a phenomenon in a...
tone - recall dial tone
- record tone
- recorder warning toneRecorder warning toneIn telecommunication, a recorder warning tone is a tone transmitted over a telephone line to indicate to the called party that the calling party is recording the conversation....
- ringback toneRingback toneA ringback tone is an audible indication that is heard on the telephone line by the caller while the phone they are calling is being rung. It is normally a repeated tone, designed to assure the calling party that the called party's line is ringing, although the ring-back tone may be out of sync...
or ringing tone - ringtone or ringing signal
- second dial tone
- special dial tone
- special information toneSpecial information toneIn telephony, a special information tone is an international standard three beep signal indicating a call did not go through and usually precedes a recorded announcement explaining the problem...
(SIT) - waiting tone