A Fast and Reliable Transport Protocol for Real-Time Distributed Systems

Abstract

In distributed manufacturing-oriented computer systems, major issues of real time applications such as reliability, distributed control algorithms, and deadline scheduling depend heavily on fast communication. Moreover, real time applications require that in some cases this communication must be reliable; in others, even receiving a message is not important becaus'e in a couple of time units (micro-, mili-, seconds) information will be transmitted again. These services depend mainly on transport and data link layer protocols. This paper pmsents the design and some implementation aspects of the transaction-like transport. protocol developed for supporting communication in a realtime environment. This protocol, called the RHODOS Reliable Datagram Protocol (RRDP), can provide reliable connectionless delivery of messages, supports different qualities of recovery service (at-most-once, at-least-once, and exactly-once), optimises communication by using multicast and broadcast facilities, and possesses inter-network capabilities. * This work was partly supported by the Australian Research Council under Grant A48831034