No.4 ESS: Data/Trunk Administration and Maintenance
J. A. Giunta, S. F. Heath, J. T. Raleigh, Matt Smith · Bell System Technical Journal · 1977
A large data base supports both switching and maintenance functions in No. 4 ess, a system which has the capability to switch a half million calls per hour on over 100,000 trunks. The data base is described here along with the subsystems that are used to support the installation and maintenance of both the data base and the trunks. The design and organization of these subsystems have been significantly impacted by the real-time needs of the call-processing system and the need to provide accurate, cost-effective ways to install and maintain the large number of trunks and their associated data bases.