Considerations for ISDN planning and implementation

THE INFORMATION AGE has created such a diversity between the Communications needs of the business user and the residential Community that one common-denominator public telephone network can no longer serve everyone. The time when evolutionary network enhancements can be justified and implemented will come too late to be acceptable to a large body of business users, because of this diversity of needs. The emerging proliferation of technological bypass of local telephone facilities in the United States is symptomatic of the need for one or more shared wideband/ broadband overlay networks to serve the business community. This environment requires accelerated introduction of digital technologies in the telephone network for provision of high-speed end-to-end digital services including data, facsimile, and video. This necessitates the use of Overlay facilities and networks to meet present business customer demands until the loop plant in the common-denominator network can evolve to optimally meet the varied demands of the whole community. This paper describes past progress and current plans for the introduction of digital technologies for switching, interexchange trunking, and the local loop for an end-to-end digital network. The paper also discusses the implementation of common-channel signaling, based on CCITT´s SSN07 in the circuit-switched network, as well as the use of an overlay packet-switched network for provision of data commumcations and videotex services.