Switching Control Center System
Encyclopedia
The Switching Control Center System was an Operations Support System
developed by Bell Laboratories and deployed during the early 1970s. This computer
system was first based on the PDP-11
product line from Digital Equipment Corporation
and used the CB Unix
operating system
and custom application software
and device drivers that was developed and maintained by Bell Labs
in Columbus, Ohio
USA. SCCS was ported to the AT&T 3B20 and 3B5
computers running UNIX System V
Release 2 in the early 1980s.
Prior to the SCCS, many telephone company
switching centers were staffed 24 hours a day 365 days a year. Deployment of the SCCS allowed telephone companies to significantly reduce the number of technicians by implementing a local switching control center office and dispatch technicians as required to resolve problems or perform routine maintenance 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 system
s that were controlled by proprietary computers but still used analog switch fabrics such as Bell-proprietary fereed switch devices.
The SCCS system was phased out during the late 1980s 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
, maintenance
, and provisioning
(OAMP
) functions for telephone company
network operations staff. The SCCS accepted as input the slow 110 baud
Teletype
messages from circuit
switching systems such as the Number 1 ESS
, Number 2 ESS, Number 3 ESS, Number 5 ESS
, and Traffic Service Position System
(TSPS) 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
internal Bell System Practices
during the 1970s.
Operations support system
Operations support systems are computer systems used by telecommunications service providers. The term OSS most frequently describes "network systems" dealing with the telecom network itself, supporting processes such as maintaining network inventory, provisioning services, configuring network...
developed by Bell Laboratories and deployed during the early 1970s. This computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
system was first based on the PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
product line from Digital Equipment Corporation
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
and used the CB Unix
CB Unix
Columbus UNIX was, according to Marc Rochkind, a variant of the UNIX operating system internal to Bell Labs. It was developed at the Columbus, Ohio branch and was little-known outside the company...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
and custom application software
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
and device drivers that was developed and maintained by Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
in Columbus, Ohio
Columbus, Ohio
Columbus is the capital of and the largest city in the U.S. state of Ohio. The broader metropolitan area encompasses several counties and is the third largest in Ohio behind those of Cleveland and Cincinnati. Columbus is the third largest city in the American Midwest, and the fifteenth largest city...
USA. SCCS was ported to the AT&T 3B20 and 3B5
AT&T Computer Systems
AT&T Computer Systems is the generic name for American Telephone & Telegraph's unsuccessful attempt to compete in the computer business. In return for divesting the local Bell Operating Companies , AT&T was allowed to have an unregulated division to sell computer hardware and software.Prior to the...
computers running UNIX System V
UNIX System V
Unix System V, commonly abbreviated SysV , is one of the first commercial versions of the Unix operating system. It was originally developed by American Telephone & Telegraph and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4...
Release 2 in the early 1980s.
Prior to the SCCS, many telephone company
Telephone company
A telephone company is a service provider of telecommunications services such as telephony and data communications access. Many were at one time nationalized or state-regulated monopolies...
switching centers were staffed 24 hours a day 365 days a year. Deployment of the SCCS allowed telephone companies to significantly reduce the number of technicians by implementing a local switching control center office and dispatch technicians as required to resolve problems or perform routine maintenance 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
Strowger switch
The Strowger switch, also known as Step-by-Step or SXS, is an early electromechanical telephone switching system invented by Almon Brown Strowger...
circuit switching systems and replace them with newer electronic switching system
Electronic switching system
In telecommunications, an electronic switching system is:* A telephone exchange based on the principles of time-division multiplexing of digitized analog signals. An electronic switching system digitizes analog signals from subscriber loops, and interconnects them by assigning the digitized...
s that were controlled by proprietary computers but still used analog switch fabrics such as Bell-proprietary fereed switch devices.
The SCCS system was phased out during the late 1980s 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
Business operations
Business operations are those ongoing recurring activities involved in the running of a business for the purpose of producing value for the stakeholders...
, administration
System administrator
A system administrator, IT systems administrator, systems administrator, or sysadmin is a person employed to maintain and operate a computer system and/or network...
, maintenance
Maintenance, Repair and Operations
Maintenance, repair, and operations or maintenance, repair, and overhaul involves fixing any sort of mechanical or electrical device should it become out of order or broken...
, and provisioning
Provisioning
In telecommunication, provisioning is the process of preparing and equipping a network to allow it to provide services to its users. In NS/EP telecommunications services, "provisioning" equates to "initiation" and includes altering the state of an existing priority service or capability.In a...
(OAMP
OAMP
OAMP, traditionally OAM&P, stands for operations, administration, maintenance, and provisioning. The addition of 'T' in recent years stands for troubleshooting, and reflects its use in network operations environments...
) functions for telephone company
Telephone company
A telephone company is a service provider of telecommunications services such as telephony and data communications access. Many were at one time nationalized or state-regulated monopolies...
network operations staff. The SCCS accepted as input the slow 110 baud
Baud
In telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...
Teletype
Teleprinter
A teleprinter is a electromechanical typewriter that can be used to communicate typed messages from point to point and point to multipoint over a variety of communication channels that range from a simple electrical connection, such as a pair of wires, to the use of radio and microwave as the...
messages from circuit
Telecommunication circuit
A telecommunication circuit is any line, conductor, or other conduit by which information is transmitted.A dedicated circuit, private circuit, or leased line is a line that is dedicated to only one use...
switching systems such as the Number 1 ESS
1ESS switch
The Number One Electronic Switching System, the first large-scale Stored Program Control telephone exchange or Electronic Switching System in the Bell System, was introduced in Succasunna, New Jersey, in May 1965. The switching fabric was composed of reed matrixes controlled by wire spring relays...
, Number 2 ESS, Number 3 ESS, Number 5 ESS
5ESS Switch
The 5ESS Switch is a Class 5 telephone electronic switching system sold by Alcatel-Lucent. This digital central office telephone circuit switching system is used by many telecommunications service providers.-History:...
, and Traffic Service Position System
Traffic Service Position System
Traffic Service Position System was developed by Bell Labs in Columbus, Ohio to replace traditional cord switchboards. The first TSPS was deployed in 1969 and used the Stored Program Control-1A CPU, "Piggyback" twistor memory and IGFET Insulated Gate Field Effect Transistor solid state memory...
(TSPS) 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
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
internal Bell System Practices
Bell System Practices
The Bell System Practices is a multi-volume encyclopedia of technology information developed and formerly maintained by the Bell System's Bell Labs for use by its employees. Everything from accounting and human resources procedures to complete technical breakdowns of every product serviced by the...
during the 1970s.