Probabilistic Bounds on Message Delivery for the Totem Single-Ring Protocol

For fault-tolerant real-time distributed systems, the probability that a message is not delivered within its real-time deadline must be small enough that it does not adversely aaect system reliability. We investigate the delivery of messages for the Totem Protocol, a reliable ordered broadcast protocol that we have developed for fault-tolerant distributed systems with physical broadcasts over a local-area network. The total order on broadcast messages, constructed by the Totem Protocol, supports the maintenance of consistency of replicated information as, for example, in a replicated database. We present a methodology for determining the probability of satisfying bounds on the latency from message origination to ordered delivery in the presence of communication faults.