Accession Number : ADA202002

Title :   Design of a Network for Concurrent Message Passing Systems,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE MICROSYSTEMS RESEARCH CENTER

Personal Author(s) : Song, Paul Y.

Report Date : AUG 1988

Pagination or Media Count : 131

Abstract : We describe the design of the network design frame (NDF), a self-timed routing chip for a message-passing concurrent computer. The NDF uses a partitioned data path, low-voltage output drivers, and a distributed token-passing arbiter to provide a bandwidth of 450 Mbits/sec into the network. Wormhole routing and bidirectional virtual channels are used to provide low latency communications, less than 2us latency to deliver a 216 bit message across the diameter of a 1K node mess-connected machine. To support concurrent software systems, the NDF provides two logical networks, one for user messages and one for system messages. The two networks share the same set of physical wires. To facilitate the development of network nodes, the NDF is a design frame. The NDF circuitry is integrated into the pad frame of a chip leaving the center of the chip uncommitted. We define an analytic framework in which to study the effects of network size, network buffering capacity, bidirectional channels, and traffic on this class of networks. The response of the network to various combinations of these parameters are obtained through extensive simulation of the network model. Through simulation, we are able to observe the macro behavior of the network as opposed to the micro behavior of the NDF routing controller. (RH)

Descriptors :   *CHANNELS, *CHIPS(ELECTRONICS), *COMPUTER PROGRAMS, *DATA TRANSMISSION SYSTEMS, *MESSAGE PROCESSING, *MODELS, *SIMULATION, BEHAVIOR, FRAMES, NETWORKS, NODES, PATHS, PHYSICAL PROPERTIES, RESPONSE, SIZES(DIMENSIONS), WIRE.

Subject Categories : Command, Control and Communications Systems
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE