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Reorder Tone
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. 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, uninterrup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Switched Telephone Network
The public switched telephone network (PSTN) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for public telephony. The PSTN consists of telephone lines, fiber-optic cables, microwave transmission links, cellular networks, communications satellites, and undersea telephone cables interconnected by switching centers, such as central offices, network tandems, and international gateways, which allow telephone users to communicate with each other. Originally a network of fixed-line analog telephone systems, the PSTN is now predominantly digital in its core network and includes terrestrial cellular, satellite, and landline systems. These interconnected networks enable global communication, allowing calls to be made to and from nearly any telephone worldwide. Many of these networks are progressively transitioning to Internet Protocol to carry their telephony traffi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena such as oscillations, waves, or for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ETSI
The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization operating in the field of Information and communications technology, information and communications. ETSI supports the development and testing of global technical standards for ICT-enabled systems, applications and services. Overview and history ETSI was set up in 1988 by the European Conference of Postal and Telecommunications Administrations (European Conference of Postal and Telecommunications Administrations, CEPT) following a proposal from the European Commission (EC). ETSI is the officially recognized body with a responsibility for the standardization of information and communication technologies (ICT). It is one of the three bodies officially recognized by the European Union as a European Standards Organisation (ESO), the others being European Committee for Standardization, CEN and CENELEC. The role of the ESOs is to support EU regulation and policies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Private Branch Exchange
A business telephone system is a telephone system typically used in business environments, encompassing the range of technology from the key telephone system (KTS) to the private branch exchange (PBX). A business telephone system differs from an installation of several telephones with multiple central office (CO) lines in that the CO lines used are directly controllable in key telephone systems from multiple telephone stations, and that such a system often provides additional features for call handling. Business telephone systems are often broadly classified into key telephone systems and private branch exchanges, but many combinations (hybrid telephone systems) exist. A key telephone system was originally distinguished from a private branch exchange in that it did not require an operator or attendant at a switchboard to establish connections between the central office trunks and stations, or between stations. Technologically, private branch exchanges share lineage with central ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extension (telephone)
In residential telephony, an extension telephone is an additional telephone wired to the same telephone line as another. In middle 20th century telephone jargon, the first telephone on a line was a "Main Station" and subsequent ones "Extensions" or even called as intercom. Such extension phones allow making or receiving calls in different rooms, for example in a home, but any incoming call would ring all extensions and any one extension being in use would cause the line to be busy for all users. Some telephones intended for use as extensions have built-in intercom features; a key telephone system for a small business may offer two to five lines, lamps indicating lines already in use, the ability to place calls on 'hold (telephone), hold' and an intercom on each of the multiple extensions. In business telephony, a telephone extension may refer to a phone on an internal telephone line attached to a private branch exchange (PBX) or Centrex system. The PBX operates much as a communi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Number
A telephone number is the address of a Telecommunications, telecommunication endpoint, such as a telephone, in a telephone network, such as the public switched telephone network (PSTN). A telephone number typically consists of a Number, sequence of digits, but historically letters were also used in connection with telephone exchange names. Telephone numbers facilitate the switching and routing of telephone call, calls using a system of destination code routing. Telephone numbers are entered or dialed by a calling party on the originating telephone set, which transmits the sequence of digits in the process of signaling to a telephone exchange. The exchange completes the call either to another locally connected subscriber or via the PSTN to the called party. Telephone numbers are assigned within the framework of a national or regional telephone numbering plan to subscribers by telephone service operators, which may be commercial entities, state-controlled administrations, or ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Special Information Tone
In 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. It usually precedes a recorded announcement describing the problem.BOC Notes on the LEC Networks - 1994 Signalling - SR-TSV-002275 Issue 2, April, 1994 Because the SIT is well known in many countries, callers can understand that their call has failed, even though they do not understand the language of the recorded announcement (e.g., when calling internationally) instead of assuming the recording is voicemail or some other intended function. Like a dial tone or busy signal, the SIT is an in-band signal intended both to be heard by the caller, and to be detected by automated dialing equipment to determine a call has failed. In North America, the AT&T/Bellcore SIT standard allows the frequency and duration of the tones to vary slightly - making eight distinct messages specifically for automated equipment; indicating no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intercept Message
An intercept message is a telephone recording informing the caller that the call cannot be completed, for any of a number of reasons ranging from local congestion, to disconnection of the destination phone, number dial errors or network trouble along the route. Background Before automation, calls to a disconnected or non-working number would be diverted to an intercept operator. The operator would ask what number the subscriber was attempting to call, determine the reason for the intercept and relay the information to the calling party. The first automatic intercept systems used rotating magnetic drums containing multiple recorded phrases, with a computer or mechanical control system playing phrases in the proper sequence. Initially, the caller was given the option to remain on the line for a live operator after the announcement was completed; this has since been removed. These messages are generally performed by female voices, although male voices are used as well. Jane Barbe, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Busy Signal
A busy signal (or busy tone or engaged tone) in telephony is an audible call-progress tone or audible signal to the calling party that indicates failure to complete the requested connection of that particular telephone call. The busy signal has become less common in the past few decades due to the prevalence of call waiting and voicemail. Reasons for a busy signal An otherwise unspecified busy signal indicates that the called number is occupied: * The called number is talking with another caller on the phone * The number is calling out * Someone else has called the number or is calling the number at the same time * The other line was left off-hook * It is otherwise unavailable The standard busy signal sometimes occurs (sometimes with an intercept message played over the busy) at the end of a call to indicate the other party has hung up (see Disconnect tone), but mostly the off-hook tone is used. In some phone companies in the United Kingdom, the busy signal is played af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
