The tree-structured distributed network front-end processor architecture

Contemporary front-end processors, such as the IBM 3705, 1 Memorex 1380, 2 Burroughs Data Communications Processor 3 and the MERIT Communications Controller, 4 share the same general architecture depicted in Figure 1 . Communication lines are associated on a one-on-one basis with line adapters. These are connected in small groups (clusters) to the local processor, and perhaps to the local memory, through line interface bases. In a similar manner, the host system input/output channels are associated on a one-on- one basis with channel adapters which are connected to the local processor and memory. The architecture can be thought of as a minicomputer system in which the channel adapters and line interface base/line adapter subsystems are input/output devices. In fact, many front-end processors are configured in precisely this fashion.