The Switching Control Center System was an

operations support system Operations support systems (OSS), operational support systems in British usage, or Operation System (OpS) in Nippon Telegraph and Telephone, NTT are computer systems used by telecommunications service providers to manage their networks (e.g., tele ...

developed by Bell Laboratories and deployed during the early 1970s. This

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

system was first based on the

PDP-11 The PDP–11 is a series of 16-bit minicomputers originally sold by Digital Equipment Corporation (DEC) from 1970 into the late 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of a ...

product line from

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until ...

and used the CB Unix

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

and custom

application software Application software is any computer program that is intended for end-user use not operating, administering or programming the computer. An application (app, application program, software application) is any program that can be categorized as ...

and

device drivers In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabli ...

that were developed and maintained by

Bell Labs Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the compa ...

Columbus, Ohio Columbus (, ) is the List of capitals in the United States, capital and List of cities in Ohio, most populous city of the U.S. state of Ohio. With a 2020 United States census, 2020 census population of 905,748, it is the List of United States ...

USA. SCCS was ported to the AT&T 3B20 and 3B5 computers running

UNIX System V Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

Release 2 in the early 1980s. Prior to the SCCS, many

telephone company A telecommunications company is a kind of electronic communications service provider, more precisely a telecommunications service provider (TSP), that provides telecommunications services such as telephony and data communications access. Many t ...

switching centers were staffed 24 hours a day 365 days a year. With SCCS, telephone companies could significantly reduce the number of technicians and dispatch them as required to resolve problems or perform

routine maintenance The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure and supporting utilities in industrial, business, and residential installat ...

operations. During the early 1970s, telephone companies began to phase out the older electromechanical switching systems such as the Number 1 Crossbar, Number 5 Crossbar, and step-by-step circuit switching systems and replace them with newer electronic switching systems that were controlled by proprietary computers but still used analog switch fabrics such as Bell-proprietary ferreed switch devices. The SCCS system was phased out during the late 1990s and replaced by an OSS known as Network Monitoring and Analysis or NMA that was developed by Bell Communications Research now Telcordia Technologies. AT&T developed additional products based on SCCS software, such as Compulert. The primary purpose of the SCCS system was to provide operations,

administration Administration may refer to: Management of organizations * Management, the act of directing people towards accomplishing a goal: the process of dealing with or controlling things or people. ** Administrative assistant, traditionally known as a se ...

maintenance The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure and supporting utilities in industrial, business, and residential installa ...

, and

provisioning Provisioning may refer to: * Provisioning (technology), the equipping of a telecommunications network or IT resources * Provisioning (cruise ship), supplying a vessel for an extended voyage ** Provisioning of USS ''Constitution'' * Provisionin ...

( OAMP) functions for

network operations staff. The SCCS accepted as input the slow 110

baud In telecommunications and electronics, baud (; symbol: Bd) is a common unit of measurement of symbol rate, which is one of the components that determine the speed of communication over a data channel. It is the unit for symbol rate or modulat ...

Teletype A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Init ...

messages from circuit

switching systems In telecommunications, an electronic switching system (ESS) is a telephone switch that uses solid-state electronics, such as digital electronics and computerized common control, to interconnect telephone circuits for the purpose of establishing tele ...

such as the Number 1 ESS, Number 2 ESS, Number 3 ESS, Number 5 ESS, and Traffic Service Position System (

TSPS The Traffic Service Position System (TSPS) was developed by Bell Labs in Columbus, Ohio to replace traditional cord switchboards. The first TSPS was deployed in Morristown, New Jersey in 1969 and used the Stored Program Control-1A CPU, "Piggybac ...

) network switches and provide analysis, reports, troubleshooting support, and other functions using newer faster DataSpeed-40 terminals. This system was documented in the Bell System Technical Journal and

AT&T AT&T Inc., an abbreviation for its predecessor's former name, the American Telephone and Telegraph Company, is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the w ...

internal Bell System Practices during the 1970s.

References

{{reflist Telephony