USHERING IN THE ERA OF ISDN.

AT&T is developing many products and services to support the new era of Integrated Services Digital Network (ISDN). ISDN will furnish end-to-end connections that can handle voice, data, and video traffic in digital form as easily as today's networks handle voice traffic. ISDN will also provide a framework of compatibility for products made by AT&T and other manufacturers. AT&T equipment and systems that will play key roles in implementing ISDN include the 4ESS switch, 5ESS switch, the Digital Access and Cross Connect System (DACS), No. 2 Signal Transfer Point, the No. 1 Packet Switching System, D5 Digital Terminal System, System 75 and System 85 PBXs, Information Systems Network (ISN).