ATOMIC: A Low-Cost, Very-High-Speed, Local Communication Architecture

ATOMIC1 is an inexpensive O(gigabit) speed LAN built by USC/ISI. It is based upon Mosaic technol ogy 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 500Mbls. A prototype ATOMIC LAN has been con structed along with host interfaces and software that pro vides full TCP/IP compatibility. Using ATOMIC, 1J00 byte packets have been exchanged between hosts at an aggregate transfer rate of more than lGbls. Other tests have demonstrated throughput of 5.25 million packets per second over a single Mosaic channel. This paper describes the architecture and performance of ATOMIC.