Design and performance considerations in LAN-to-host interconnect gateway

The author describes the characteristics of local area networks (LANs) and the host channel, and examines the issues that are important to the design and performance of a gateway between them. The particular design and implementation of the IBM 3172 LAN-to-host interconnect controller are used to demonstrate how these issues are considered. The hardware and software structures of IBM 3172 interconnect controller are described. The major design considerations are host channel interface, traffic crossing the gateway, buffer space, main processor speed, software path lengths, frame size, and block size. Simulation performance results are presented and discussed. Simulation results show that the main factors affecting the throughput of the controller are frame processing overhead, LAN frame size, and host channel block size.<>