Myrinet is a new type of local-area network (LAN) based on the technology used for packet communication and switching within "massively-parallel processors" (MPPs). Think of Myrinet as an MPP message-passing network that can span campus dimensions, rather than as a wide-area telecommunications network that is operating in close quarters. The technical steps toward making Myrinet a reality included the development of (1) robust, 25m communication channels with flow control, packet framing, and error control; (2) self-initializing, low-latency, cut-through switches; (3) host interfaces that can map the network, select routes, and translate from network addresses to routes, as well as handle packet traffic; and (4) streamlined host software that allows direct communication between user processes and the network.