ISDN: Theory Becomes Reality at McDonald's Corporation (NOT KNOWN IF PUBLISHED BECAUSE AUTHOR HAS LEFT AT&T)

With the cutover of the 5ESS (TM) Switch, Generic 4.2, on December 18, 1987, ISDN became a reality for AT&T, Illinois Bell Telephone Company (IBT) and McDonald's. The ISDN services provide the end-to-end digital network access on existing loop between the Central Office (CO) and the end-user and supports simultaneous voice and data services.