The communication bridge for message handling and protocol conversion services between ISDN and PSDN

This paper proposes the design of the Integrated Service Digital Network (ISDN) Access Subsystem (INAS) in order to provide ISDN subscribers with various information services through the Advanced Communications Processing Systems (ACPS). We designed the functional modules of the INAS which were accommodated by the existing open-structure ACPS. In addition to defining the MAS protocol reference model and the call control procedures for the interface between the MAS and the Packet Network Access Subsystem (PNAS), we designed the transfer service primitives used to deliver the information between the network access subsystems and the switching fabric within the ACPS. Thus, ISDN subscribers have easy access to the information services and business using ISDN in Korea will be more activated