Abstract :
The SP-1, a new family of computer-controlled telephone switching systems, represents a unique technological initiative for Canada. Besides the creation of a new item of telecommunications equipment, the project marks the emergence of a powerful design force in Bell-Northern Research, and of an aggressive manufacturing organization in Northern Electric Company. The article traces the development of the main types of switching equipment which have been used in the industry, up to the present day. It then shows how evolving Canadian competence in telecommunications R&D has removed the previous reliance on design information and manufacturing knowhow from the Bell System in the U.S.A. After outlining the SP-1 project and the various machines in the family, the article goes on to discuss the philosophy applied to both software and hardware, and concludes by surveying briefly the performance of the machines in service.