ATOMIC: A Low-Cost, Very-High-Speed LAN

ATOMIC is an inexpensive O(gigabit) speed LAN built by USC/ISI. It is based upon Mosaic technology developed for fine-grain, message-passing, massively parallel computation. Each Mosaic processor is capable of routing variable length packets, while providing added value through simultaneous computing and buffering. ATOMIC adds a general routing capability to the native Mosaic wormhole routing through store-and-forward. ATOMIC scales linearly, with a small interface cost. Each ATOMIC channel has a data carrying capacity of 500Mb/s. A prototype ATOMIC LAN has been constructed along with host interfaces and software that provides full TCP/IP compatibility. Using ATOMIC, 1,500 byte packets have been exchanged between hosts at an aggregate transfer rate of more than 1Gb/s. Other tests have demonstrated throughput of 5.25 million packets per second over a single channel. This paper describes the architecture and performance of ATOMIC.