No. 4 ESS: Data/Trunk Administration and Maintenance

Two key elements in a No. 4 ESS are the trunks over which customer calls are placed and the data base which supports the call-handling function. Both the trunks and the data base require initial installation followed by ongoing maintenance and change processes. The data bases provided in No. 4 ESS and the subsystems that were developed to support the initial installation and maintenance of both the data bases and the trunks will be described. The No. 4 ESS data/trunk administration and maintenance subsystems are depicted in Fig. 1. They are structured about the work centers, data bases, and operating features of the 1A Processor and two minicomputer systems, the Circuit Maintenance System 1A (CMS 1A) and the Centralized Automatic Reporting on Trunks (CAROT) system. The 1A Processor contains the data base to perform the No. 4 ESS call-processing function and to access and control the trunks to perform maintenance functions. The CMS data base contains equipment-related, trunk-layout, and administrative information needed to perform the 1203