ISDN and the 5ESS(TM) Switch
04 May 1987
AT&T's 5ESS(TM) Switch offers advanced ISDN services and capabilities beginning with the 5E4 Generic release in 1986/1987. Internationally standard Q.931 functional signaling messages are used to control basic call connections on these interfaces. Extensions to the CCITT standards are used to provide advanced Supplementary Voice Services. This session describes AT&T's approach to define these extensions. Initial 5ESS(TM) ISDN trial results for the Basic Rate Interface protocol are discussed.