Specification and verification of reliability in dispatching multicast messages

Abstract

Multicasting some pieces of information such as messages or packets (called dispatches) from source node(s) to a group of target nodes are governed by a specific sequence in the networked systems. The sequence is called a consensus that indicates an ordering on dispatches to be viewed by the target nodes. Achievement of consensus is a concern in some networked based systems such as distributed ones because the lack of consensus leads to conflict among target nodes reaction. A consensus protocol has some properties to be checked when a source node multicasts a sequence of dispatches to target nodes. The CBCAST protocol is a consensus protocol having properties for ordering and synchronization of dispatches in network communications. This paper thinks of the properties and formulates axioms to check them. The axioms can be practiced for network applications such as group communication and web services. Our approach has two phases consisting of modeling and formulation. The first phase addresses specification of sender and recipient processes by tabular automata. The second phase addresses formulation of axioms using the automaton.