The 5ESS Switching System is a Class 5 telephone electronic switching system developed by Western Electric for the American Telephone and Telegraph Company (AT&T) and the Bell System in the United States. It came into service in 1982 and the last unit was produced in 2003.
Direct distance dialing (DDD) is a telecommunication service feature in North America by which a caller may, without operator assistance, call any other user outside the local calling area. Direct dialing by subscribers typically requires extra digits to be dialed as prefixes to the directory telephone number of the destination. International Direct Distance Dialing (IDDD) extends the system beyond the geographic boundaries of the North American Numbering Plan (NANP).
Network topology is the arrangement of the elements of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial fieldbusses and computer networks.
Anchor Exchange was an underground, hardened telephone exchange built in Birmingham, England. Construction commenced in 1953 under the guise of building an underground railway. It opened in September 1957 at a cost of £4 million. It was located nominally on Newhall Street. However its network of tunnels extended from at least the Jewellery Quarter to Southside.
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reachable by a system of destination code routing. Telephone numbering plans are defined in each of the administrative regions of the public switched telephone network (PSTN) and in private telephone networks.
A sender is a type of circuit and system module in 20th-century electromechanical telephone exchanges. It registered the telephone numbers dialed by the subscriber, and transmitted that information to another part of the exchange or another exchange for the purpose of completing a telephone call. Some American exchange designs, for example, of the No. 1 Crossbar switch used originating senders and terminating senders. The corresponding device in the British director telephone system was called a "director" and, in other contexts, "register".
System X is the digital switching system installed in almost all telephone exchanges throughout the United Kingdom, from 1980 onwards.
Direct inward dialing (DID), also called direct dial-in (DDI) in Europe and Oceania, is a telecommunication service offered by telephone companies to subscribers who operate private branch exchange (PBX) systems. The feature provides service for multiple telephone numbers over one or more analog or digital physical circuits to the PBX, and transmits the dialed telephone number to the PBX so that a PBX extension is directly accessible for an outside caller, possibly by-passing an auto-attendant.
Fiber to the x or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber optic cables are able to carry much more data than copper cables, especially over long distances, copper telephone networks built in the 20th century are being replaced by fiber.
The Number One Crossbar Switching System (1XB), was the primary technology for urban telephone exchanges served by the Bell System in the mid-20th century. Its switch fabric used the electromechanical crossbar switch to implement the topology of the panel switching system of the 1920s. The first No. 1 Crossbar was installed in the PResident-2 central office at Troy Avenue in Brooklyn, New York which became operational in February 1938.
The Number One Electronic Switching System (1ESS) was the first large-scale stored program control (SPC) telephone exchange or electronic switching system in the Bell System. It was manufactured by Western Electric and first placed into service in Succasunna, New Jersey, in May 1965. The switching fabric was composed of a reed relay matrix controlled by wire spring relays which in turn were controlled by a central processing unit (CPU).
TXE, was a family of telephone exchanges developed by the British General Post Office (GPO), designed to replace the ageing Strowger switches.
Historically, a foreign exchange service (FX) was an access service in a telecommunications network in which a telephone in a given exchange area is connected, via a private line, as opposed to a switched line, to a telephone exchange or central office in another exchange area, called the foreign exchange, rather than the local exchange area where the subscriber station equipment is located. To call originators, it appears that the called party having the FX service is located in the foreign exchange area. It is assigned a telephone number of the foreign exchange. The telecommunication circuit between central offices that implements foreign exchange service has complementary interface types at each end. At the foreign central office that provides the service, the interface is called the foreign exchange office (FXO) end, and at the end where the subscriber station is connected, it provides the foreign exchange station (FXS) interface.
Ringing is a telecommunication signal that causes a bell or other device to alert a telephone subscriber to an incoming telephone call. Historically, this entailed sending a high-voltage alternating current over the telephone line to a customer station which contained an electromagnetic bell. It is therefore also commonly referred to as power ringing, to distinguish it from another signal, audible ringing, or ringing tone, which is sent to the originating caller to indicate that the destination telephone is in fact ringing.
The original North American area codes were established by the American Telephone and Telegraph Company (AT&T) in 1947, after the demonstration of regional Operator Toll Dialing during the World War II period. The program had the goal of speeding the connecting times for long-distance calling by eliminating intermediary telephone operators. Expanding this technology for national use required a comprehensive and universal, continent-wide telephone numbering plan.
PSTN network topology is the switching network topology of a telephone network connected to the public switched telephone network (PSTN).
A telephone exchange, also known as a telephone switch or central office, is a crucial component in the public switched telephone network (PSTN) or large enterprise telecommunications systems. It facilitates the interconnection of telephone subscriber lines or digital system virtual circuits, enabling telephone calls between subscribers.
Telex is a telecommunication service that provides text-based message exchange over the circuits of the public switched telephone network or by private lines. The technology operates on switched station-to-station basis with teleprinter devices at the receiving and sending locations. Telex was a major method of sending written messages electronically between businesses in the post–World War II period. Its usage went into decline as the fax machine grew in popularity in the 1980s.
A group switching centre (GSC) was a United Kingdom telephone exchange used to provide local and trunk routing to local exchanges within its own and if required, adjacent group areas.
The Panel Machine Switching System is a type of automatic telephone exchange for urban service that was used in the Bell System in the United States for seven decades. The first semi-mechanical types of this design were installed in 1915 in Newark, New Jersey, and the last were retired in the same city in 1983.
