Switching Control Center System

The "Switching Control Center System" was an Operations Support System developed by Bell Laboratories and deployed during the early 1970's. This computer system was based on the PDP-11 product line from Digital Equipment Corporation and used the Unix operating system and custom application software that was developed and maintained by Bell Labs in Naperville, Illinois USA.

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 1970's, telephone companies also phased 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 fereed switch devices.

The SCCS system was phased out during the late 1980's and replaced by an OSS known as Network Monitoring and Analysis or NMA that was developed by Bell Communications Research now Telcordia Technologies.

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 1970's.