The IBM Enterprise Systems Connection (ESCON) Architecture

The IBM Enterprise Systems Connection (ESCON™) Architecture™ is the architecture for the new fiber optic serial-I/O channels for the processors in the IBM System/390
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family. The architecture is based on message exchanges, which replace the byte-oriented protocols of the predecessor parallel interface architecture. Its interconnection topology employs a dynamic crosspoint switch. This paper describes the major functional components of the architecture and discusses some of the technical problems that were solved during its development.