Throughout the 20th century, telephone switchboards were devices used to connect circuits of telephones to establish telephone calls between users or other switchboards. The switchboard was an essential component of a manual telephone exchange, and was operated by switchboard operators who used electrical cords or switches to establish the connections.
An intermediate distribution frame (IDF) is a distribution frame in a central office or customer premises, which cross connects the user cable media to individual user line circuits and may serve as a distribution point for multipair cables from the main distribution frame (MDF) or combined distribution frame (CDF) to individual cables connected to equipment in areas remote from these frames.
In telephony, a main distribution frame is a signal distribution frame for connecting equipment to cables and subscriber carrier equipment.
Phreaking is a slang term coined to describe the activity of a culture of people who study, experiment with, or explore telecommunication systems, such as equipment and systems connected to public telephone networks. The term phreak is a sensational spelling of the word freak with the ph- from phone, and may also refer to the use of various audio frequencies to manipulate a phone system. Phreak, phreaker, or phone phreak are names used for and by individuals who participate in phreaking.
A registered jack (RJ) is a standardized telecommunication network interface for connecting voice and data equipment to a service provided by a local exchange carrier or long distance carrier. Registration interfaces were first defined in the Universal Service Ordering Code (USOC) system of the Bell System in the United States for complying with the registration program for customer-supplied telephone equipment mandated by the Federal Communications Commission (FCC) in the 1970s. They were subsequently codified in title 47 of the Code of Federal Regulations Part 68. Registered Jack connections began to see use after their invention in 1973 by Bell Labs. The specification includes physical construction, wiring, and signal semantics. Accordingly, registered jacks are primarily named by the letters RJ, followed by two digits that express the type. Additional letter suffixes indicate minor variations. For example, RJ11, RJ14, and RJ25 are the most commonly used interfaces for telephone connections for one-, two-, and three-line service, respectively. Although these standards are legal definitions in the United States, some interfaces are used worldwide.
BellSouth, LLC was an American telecommunications holding company based in Atlanta, Georgia. BellSouth was one of the seven original Regional Bell Operating Companies after the U.S. Department of Justice forced the American Telephone & Telegraph Company to divest itself of its regional telephone companies on January 1, 1984.
In telecommunications, a distribution frame is a passive device which terminates cables, allowing arbitrary interconnections to be made.
The Pacific Bell Telephone Company is a telephone company that provides telephone service in California. The company is owned by AT&T Inc. through AT&T Teleholdings, and, though separate, is now marketed as “AT&T”. The company has been known by a number of names during which its service area has changed. The formal name of the company from the 1910s through the 1984 Bell System divestiture was The Pacific Telephone and Telegraph Company. As of 2002, the name “Pacific Bell” is no longer used in marketing, Pacific Bell is still the holder of record for the infrastructure of cables and fiber through much of California.
In telecommunications, trunking is a technology for providing network access to multiple clients simultaneously by sharing a set of circuits, carriers, channels, or frequencies, instead of providing individual circuits or channels for each client. This is reminiscent to the structure of a tree with one trunk and many branches. Trunking in telecommunication originated in telegraphy, and later in telephone systems where a trunk line is a communications channel between telephone exchanges.
Rochester Telephone Corporation was a company that provided local telephone service to Rochester, New York. The company was founded in 1920 as a merger of Rochester Telephonic Exchange and Rochester Telephone Company. In 1995 the company became Frontier Corporation, trading on the NYSE under the FRO symbol. Ownership passed to Global Crossing in 1999, and then, in 2001, to Citizens Utilities Corporation, which later changed its name to Frontier Communications.
The New York Telephone Company (NYTel) was organized in 1896, taking over the New York City operations of the American Bell Telephone Company.
RCMAC stands for recent change memory administration center, sometimes mistakenly called recent change message accounting center, in late 20th century Bell System parlance, or recent change memory administration group (RCMAG). It is an organization of people in a phone company which is responsible for programming the service and features purchased by residential and business customers into the central office. Generally the term is used only in large US phone companies called Regional Bell Operating Companies (RBOCs).
The serving area interface or service area interface (SAI) is an outdoor enclosure or metal box that allows access to telecommunications wiring.
A marker is a type of special purpose control system that was used in electromechanical telephone central office switches. Switches employing markers belong to a class of switches known as "common control", as the purpose of a marker is to control the closure of contacts in the switching fabric that connect a circuit between the calling party and the called party. This is in contrast to "direct control" switches, where the switching elements were controlled directly by the customer's dial, such as the Step by Step switch. The term marker came from its use to mark a path of links through the switching fabric. A marker's comprehensive view of the switching fabric allowed it to find and assemble a path from one terminal to another, if the links were available, unlike the earlier graded progressive systems in which a path might not be found.
Tip and ring are the names of the two conductors or sides of a telephone line. The terms refer to the telephone plugs used for connecting telephone calls in manual switchboards. One side of the line is connected to the metal tip of the plug, and the second is connected to a metal ring behind the tip, separated and insulated from the tip by a non-conducting material. When inserted into a jack, the plug's tip conductor connects first, followed by the ring conductor. In many European countries, tip and ring are referred to as the A and B wires.
A telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers.
The telex network was a customer-to-customer switched network of teleprinters similar to a telephone network, using telegraph-grade connecting circuits for two-way text-based messages. 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.
Operations Support Systems (OSS), Operational Support Systems in British usage, or Operation System (OpS) in NTT, are computer systems used by telecommunications service providers to manage their networks. They support management functions such as network inventory, service provisioning, network configuration and fault management.
Digital Data Systems, or DDS, was a consultancy firm specializing in operations support systems (OSS) and business support systems (BSS) in the public switched telephone network (PSTN) and carrier marketplace within the telecommunications industry. DDS was an independent provider of OSS and BSS during a time when such systems were provided by the large telecommunications switch vendors. It completed in OSS / BSS head-to-head against AT&T, Northern Telecom, and others in providing services that sold and deployed amongst the Regional Bell Operating Companies, including: Bell Atlantic, Southwestern Bell, and Pacific Telesis. It had a hardware joint venture with MIPS Computer Systems who provided the hardware platform upon which it ran. The business was acquired by Computer Sciences Corporation (CSC) in 1992.
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.
