CCITT Recommendations--Network Aspects of the ISDN

This paper presents an outline of the key network standards issues addressed in CCITT as a necessary part of the development and implementation of ISDN. The results achieved in the 1981-1984 Study Period focused on ISDN network functional requirements, ISDN numbering plan, connection types to link ISDN interfaces across the network, and the relationship of the ISDN protocol model with the seven-layer ISO model. The additional network issues which must be resolved in the current (1985-1988) Study Period are identified and briefly discussed. Of particular interest are internetworking between ISDN and existing networks, numbering plan interworking, routing, and maintenance standards. The market success of ISDN depends upon early resolution of these network standards to meet the field trials scheduled for 1986-1988 and the first implementations expected in 1988-1990.