Analysis of Dual-Link Networks for Real-Time Applications

Next-generation networks are expected to support a wide variety of services. Some services such as video, voice, and plant control tra c have explicit timing requirements on a per-message basis rather than on the average. In this paper we develop a general model of dual-link networks to support real-time communication. We examine the desirable properties of this network and the di culties in achieving these properties. We then introduce the concept of coherence and develop a theory of coherent dual-link networks. We show that a coherent dual-link network can be analyzed as though it is a centralized system. We then discuss practical considerations in implementing a dual-link network, and implications of this work to address problems observed in the IEEE 802.6 metropolitan area network standard. The Software Engineering Institute is sponsored by the U.S. Department of Defense (DoD). This work is funded in part by the O ce of Naval Research. y This work is part of the author's doctoral dissertation at CarnegieMellon University, which was supported by Digital Equipment Corporation.