The IEEE 1394 high performance serial multimedia bus protocol allows several components to communicate with each other at high speed. In this paper we present a formal model and verification of a leader election algorithm that forms the core of the tree identify phase of the physical layer of the 1394 protocol. We describe the algorithm formally in the I/O automata model of Lynch and Tuttle, and verify that for an arbitrary tree topology exactly one leader is elected. A large part of our verification has been checked mechanically with PVS, a verification system for higher-order logic.

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A general basis for the definition of a finite but unbounded number of parallel processes is the equation S(n; dt) = P (0; get(0; dt))/ eq(n; 0) .(P (n; get(n; dt)) k S(n \Gamma 1; dt)). In this formula eq(n; 0) is an equality test, and get(n; dt) denotes the n-th data element in table dt . We derive a linear process equation with the same behaviour as S(n; dt ), and show that this equation is well-defined, provided one adopts the principle CL-RSP from [4]. In order to demonstrate the strength of our result, we use it for the analysis of a standard example. We show that n + 1 concatenated buffers form a queue of capacity n + 1. 1 Introduction Distributed algorithms are often configured as an arbitrarily large but finite set of processors that run a similar program. Using the formalism CRL (micro Common Representation Language [9]) this can be described, using recursion and operators for parallelism. Several benchmark verifications in CRL and process algebra are therefore based on the...

We report about the reachability analysis of fully parametrized models of the IEEE 1394 root contention protocol. This protocol uses timing constraints in order to elect a leader. The interesting point is that the timing constraints involve some parameters (transmission delay, bounds of waiting intervals), and the behavior of the protocol strongly depends on the relation between these parameters. In order to synthesize the relation ensuring the correct behavior of the protocol, we apply the symbolic reachability techniques implemented in the TReX tool. We take the unparameterized model of Root Contention protocol proposed in [24] and study different parametrized versions of this model. We are able to synthesize automatically all the relations already found by proof or experiments on the unparameterized versions. We compare our results with those reported or obtained using other tools for parametrized systems.

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Abstract. We define a cones and foci proof method, which rephrases the question whether two system specifications are branching bisimilar in terms of proof obligations on relations between data objects. Compared to the original cones and foci method from Groote and Springintveld [22], our method is more generally applicable, and does not require a preprocessing step to eliminate τ-loops. We prove soundness of our approach and give an application. 1

Abstract: We present a survey of formal speci cation techniques applied to the Tree Identify Protocol of the IEEE 1394 High Performance Serial Bus 1. Speci cations written in a variety of formalisms are compared with regard to a number of criteria including expressiveness, readability, standardisation, and level of analysis.

We present two probabilistic leader election algorithms for anonymous unidirectional rings with FIFO channels, based on an algorithm from Itai and Rodeh [20]. In contrast to the Itai-Rodeh algorithm, our algorithms are finite-state. So they can be analyzed using explicit state space exploration

Abstract: We present two probabilistic leader election algorithms for anonymous unidirectional rings with FIFO channels, based on an algorithm from Itai and Rodeh [Itai and Rodeh 1981]. In contrast to the Itai-Rodeh algorithm, our algorithms are finite-state. So they can be analyzed using explicit state space exploration; we used the probabilistic model checker PRISM to verify, for rings up to size four, that eventually a unique leader is elected with probability one. Furthermore, we give a manual correctness proof for each algorithm.

. The proposed ISO standard formal description technique E-LOTOS is used to describe a leader election protocol (that of the IEEE 1394 serial multimedia bus), allowing illustration of the new aspects of the language, particularly time and parallelism. Keywords: E-LOTOS (Enhancements to LOTOS), IEEE 1394, Protocols, Leader Election Algorithm, Formal Methods. 1 Introduction The proposed ISO standard formal description technique E-LOTOS is used to give a timed description of the leader election protocol of the IEEE 1394 serial multimedia bus, demonstrating the capabilities of the new language for describing communications protocols. The 1394 (FireWire) serial multimedia bus is an IEEE standard for multimedia communications. It connects together a collection of systems and devices in order to carry all forms of digitized video and audio quickly, reliably, and inexpensively. Its architecture is scalable, and it is "hot-pluggable", so a designer or user can add or subtract systems an...