A study on the inaccessibility characteristics of ISO 8802/4 Token-Bus LAN

José Rufino and Paulo Veríssimo

From the Proceedings of the IEEE INFOCOM'92 Conference on Computer Communications, IEEE, May 1992, Florence, Italy

Abstract

Local area networks have long been established as the basis for distributed systems. Continuity of service and bounded and known message delivery latency are requirements of a number of applications, which are imperfectly fulfilled by standard LANs. Most previous studies have addressed this issue by computing worst-case access/transmission delays only for normal LAN operation.

However, LANs are subject to failures, namely partitions. Since most applications can live with temporary glitches in LAN operation, an alternative approach is to quantify all these glitches or temporary partitions, that we named inaccessibility, and derive a worst-case figure, to be added to the worst-case transmission delay in absence of faults. In these conditions, reliable real-time operation is possible on non-replicated LANs. This paper does an exhaustive study of the inaccessibility characteristics of the ISO 8802/4 token-bus LAN.

Also available as INESC AR/16-92 (gzip postscript).