With the advancement of VLSI/WSI and optical technologies, high-performance communication networks (ranging from wide/local area networks to multiprocessor systems) have become a reality. Such communication networks are capable of supporting high bandwidth transfers, a large number of attached stations and the integration of distributed heterogeneous computing resources. This thesis concerns with the following two areas which fall under the category of high performance communications: High-Speed Networks for local or metropolitan area and Multi-stage Interconnection Networks (MINs) for shared-memory multiprocessor systems.