Tnet: a reliable system area network for 1/0 and ipc

TNet is a new system area network designed to support current and future needs for reliable, efficient communi cations among processors and peripherals. It is an exten sible hardwarelsoftware layer that allows very large configurations by logically and physically isolating the processor busses from the 1/0 busses. TNet is a worm hole-routed, packet-switched, point-to-point, system area network. The first i?nplementation has JWII-duplex, byte serial links with electrical interfaces supporting either backplane connections or inter-cabinet cables. Variable length packets contain up to 64-bytes of data per packet. Met transactions consist of pairs of request-response packets allowing data to either be pushed or p4ed across the network. The network is designed to support many simultaneous, low-latency, DMA transfers for both inter-processor communications and 1/0.