No. 1 ESS apparatus and equipment

No. 1 ESS provides a greater variety of services than any prior complex switching system, in central offices of greater capacity, but with more highly standardized equipment of much smaller volume. Much of the credit for this achievement is due to the use of fast electronic circuits under control of a generic program. Apparatus and equipment development was aimed at accenting the benefits in this system, disciplining options to concentrate demands on a few standard frame building blocks, minimizing the varieties and codes of apparatus to take advantage of economies inherent in large volume production, and combining these with flexibility and versatility in a dependable, maintainable, compatible system that will provide all services wanted now and in the future.