Indian Hill Bell Laboratories 5ESS(R) Switch ISDN Centrex

AT&T Bell Laboratories in Naperville, Illinois has contracted with Illinois Bell Telephone for 11,000 lines of Integrated Services Digital Network (ISDN) Centrex service to be operational by year end 1989. The ISDN service takes advantage of enhanced telephony features, ISDN key system capabilities, integrated call coverage systems, and integrated voice and data on the same connection. The service is provided by an AT&T 5ESS(R) Switch with the 5E5 generic and several adjunct systems provide enhanced services such as Calling Name Display, Station Message Detail Recording, and extensive network management capabilities. This paper provides an overview of the pre- and post-ISDN environment, the ISDN implementation, and describes some of the ISDN applications being used.