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DASS2
Digital Access Signalling System 2 (DASS2) is an obsolescent protocol defined by British Telecom (BT) for digital links to PSTN based on ISDN. Although still available on request, it has been superseded by ETS 300 102 ("EuroISDN"). DASS2 is an improved version over DASS1, based on experiences with DPNSS. In the UK, the ISDN concept was first introduced to customers by BT with their DASS2 connections. DASS2 (Digital Access Signalling System) is a BT-designed signalling standard, and was introduced before the Q.931 standard was finalised by the international community. British Telecom used the term ISDN when describing their DASS2 lines. DASS2 lines are provided to customers on a 2 Mbit/s link and can handle 30 simultaneous calls (64 kbit/s each). DASS2 is still offered by BT and other UK carriers. Q.931 is the name of the CCITT document that describes the agreed signalling format for International ISDN. CCITT had previously been known as ''International Telegraph and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DPNSS
The Digital Private Network Signalling System (DPNSS) is a network protocol used on digital trunk lines for connecting to PABX. It supports a defined set of inter-networking facilities. DPNSS was originally defined by British Telecom. The specification for the protocol is defined in BTNR188. The specification currently comes under the Network Interoperability Consultative Committee. History DPNSS was developed in the early 1980s by British Telecom (BT), or its forerunner, Post Office Telecommunications in recognition that the emerging Digital Private Circuit Primary Rate product 'Megastream' had to address the market for both data and voice, the latter being significantly greater because of the market for PBXs. At the time, BT dictated what signalling could be used on its leased lines and, whilst it only had a minority interest in the sales of PBXs, was requested by the PBX manufacturers to produce a standard to prevent the creation of a plethora of conflicting PBX protocols bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DASS1
Digital Access Signalling System 1 (DASS1) is a proprietary protocol defined by British Telecom to provide ISDN services in the United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan .... It is now obsolete, having been replaced by DASS2. This too will become obsolete over the coming years as Q.931, a European standard, becomes widely adopted in the EU. References BT Group History of telecommunications in the United Kingdom Integrated Services Digital Network {{telecomm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocol (computing)
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics, and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses predetermined for that particular situation. The specified behavior is typically independent of how it is to be implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: ''protocols are to communica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Telecom
BT Group plc (formerly British Telecom) is a British Multinational corporation, multinational telecommunications holding company headquartered in London, England. It has operations in around 180 countries and is the largest provider of fixed-line, Internet access, broadband and Mobile telephony, mobile services in the UK, and also provides subscription television and Information technology, IT services. BT's origins date back to the founding in 1846 of the Electric Telegraph Company, the world's first public telegraph company, which developed a nationwide communications network. BT Group as it came to be started in 1912, when the General Post Office, a government department, took over the system of the National Telephone Company becoming the monopoly telecoms supplier in the United Kingdom. The Post Office Act of 1969 led to the GPO becoming a public corporation, Post Office Telecommunications. The ''British Telecom'' brand was introduced in 1980, and became independent of the R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSTN
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 tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Services Digital Network
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work on the standard began in 1980 at Bell Labs and was formally standardized in 1988 in the CCITT "Red Book". By the time the standard was released, newer networking systems with much greater speeds were available, and ISDN saw relatively little uptake in the wider market. One estimate suggests ISDN use peaked at a worldwide total of 25 million subscribers at a time when 1.3 billion analog lines were in use. ISDN has largely been replaced with digital subscriber line (DSL) systems of much higher performance. Prior to ISDN, the telephone system consisted of digital links like T1/ E1 on the long-distance lines between telephone company offices and analog signals on copper telephone wires to the customers, the " last mile". At the time, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ETS 300 102
Digital Subscriber Signalling System No. 1 (DSS1) is a digital signalling protocol (D channel protocol) used for the ISDN. It is defined by ITU-T I.411 (ETS 300 102). It supports Bearer Capability, Low Level Compatibility and High Level Compatibility, ANI, DNIS and redirected number signaling in both directions. A standard developed by ETSI for Europe is known as Euro-ISDN or E-DSS1 or simply EDSS1 (European DSS1). DSS1/EDSS1 protocol, in contrast, for example, to the protocol QSIG, was designed for use as access to public ISDN and asymmetric in the sense that it suggests a link with the network side at one end (digital public telephone exchange) and the user (private branch exchange (PBX)) - at the other. Since the market for ISDN equipment was open, ETSI provided guidance to suppliers of ISDN equipment by means of the minimum requirements for inter-connectivity to ISDN networks. These documents, called NET3 for BRI and NET5 for PRI lines, described a set of protocol tests ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCITT
The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) is one of the three Sectors (branches) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Communication Technology, such as X.509 for cybersecurity, Y.3172 and Y.3173 for machine learning, and H.264/MPEG-4 AVC for video compression, between its Member States, Private Sector Members, and Academia Members. The World Telecommunication Standardization Assembly (WTSA), the sector's governing conference, convenes every four years. ITU-T has a permanent secretariat called the Telecommunication Standardization Bureau (TSB), which is based at the ITU headquarters in Geneva, Switzerland. The current director of the TSB is Seizo Onoe (of Japan), whose 4-year term commenced on 1 January 2023. Seizo Onoe succeeded Chaesub Lee of South Korea, who was director from 1 January 2015 until 31 December 2022. Prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DSS1
Digital Subscriber Signalling System No. 1 (DSS1) is a digital signalling protocol (D channel protocol) used for the ISDN. It is defined by ITU-T I.411 (ETS 300 102). It supports Bearer Capability, Low Level Compatibility and High Level Compatibility, ANI, DNIS and redirected number signaling in both directions. A standard developed by ETSI for Europe is known as Euro-ISDN or E-DSS1 or simply EDSS1 (European DSS1). DSS1/EDSS1 protocol, in contrast, for example, to the protocol QSIG, was designed for use as access to public ISDN and asymmetric in the sense that it suggests a link with the network side at one end (digital public telephone exchange) and the user (private branch exchange (PBX)) - at the other. Since the market for ISDN equipment was open, ETSI provided guidance to suppliers of ISDN equipment by means of the minimum requirements for inter-connectivity to ISDN networks. These documents, called NET3 for BRI and NET5 for PRI lines, described a set of protocol tests ... [...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] |
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east. Europe shares the landmass of Eurasia with Asia, and of Afro-Eurasia with both Africa and Asia. Europe is commonly considered to be Boundaries between the continents#Asia and Europe, separated from Asia by the Drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea, and the waterway of the Bosporus, Bosporus Strait. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and Europe ... is formed by the Ural Mountains, Ural River, Caspian Sea, Caucasus Mountains, and the Black Sea with its outlets, the Bosporus and Dardanelles." Europe covers approx. , or 2% of Earth#Surface, Earth's surface (6.8% of Earth's land area), making it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DSS2
Digital Subscriber Signalling System No. 2 (DSS2), as the successor to DSS1, is also a digital Digital usually refers to something using discrete digits, often binary digits. Businesses *Digital bank, a form of financial institution *Digital Equipment Corporation (DEC) or Digital, a computer company *Digital Research (DR or DRI), a software ... signalling protocol (D channel protocol) used for the B-ISDN. References Integrated Services Digital Network {{Telecomm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
