Sungwon Kang

Formal Techniques for Networked and Distributed Systems: FORTE 2001

This book presents the latest worldwide results in theory and practice of formal techniques for networked and distributed systems. The theme of the book is addressed by specialized papers in the following areas: Formal Methods in Software Development, Process Algebra, Timed Automata, Theories and Applications of Verification, Distributed Systems Testing, Test Sequence Derivation. In addition, the last part of the book contains special contributions by leading researchers in the above areas to add breadth and give more perspectives to the results. This volume contains the selected proceedings of the International Conference on Formal Techniques for Networked and Distributed Systems (Forte 2001), which was sponsored by the International Federation for Information Processing (Ifip) and held in Cheju Island, Korea in August 2001. Forte 2001 combines two prestigious conferences, Forte (Formal Description Techniques for Distributed Systems and Communication Protocols) and Pstv (Protocol Specification Testing and Verification), and has more than 20 years of history. Formal Techniques for Networked and Distributed Systems will be essential reading for researchers and engineers working in the fields of communications, test equipment R&D, and telecommunications, as well as to software engineering tool developers.KEYNOTE SPEECHES.- Ranking Abstraction as Companion to Predicate Abstraction.- Developing High Quality Software with Formal Methods: What Else Is Needed?.- A Testing Architecture for Designing High-Reliable MANET Protocols.- REGULAR PAPERS.- A Composition Operator for Systems with Active and Passive Actions.- A Formal Semantics of UML StateCharts by Means of Timed Petri Nets.- A Hierarchy of Implementable MSC Languages.- Combining Static Analysis and Model Checking for Systems Employing Commutative Functions.- Fast Generic Model-Checking for Data-Based Systems.- Logic and Model Checking for Hidden Markov Models.- Proving ??-Calculus Properties with SAT-Based Model Checking.- Ad Hoc Routing Protocol Verification Through Broadcast Abstraction.- Discovering Chatter and Incompleteness in the Datagram Congestion Control Protocol.- Thread Allocation Protocols for Distributed Real-Time and Embedded Systems.- A Petri Net View of Mobility.- Modular Verification of Petri Nets Properties: A Structure-Based Approach.- An Improved Conformance Testing Method.- Resolving Observability Problems in Distributed Test Architectures.- Automatic Generation of Conflict-Free IPsec Policies.- A Framework Based Approach for Formal Modeling and Analysis of Multi-level Attacks in Computer Networks.- Model Checking for Timed Statecharts.- Abstraction-Guided Model Checking Using Symbolic IDA* and Heuristic Synthesis.- Modeling and Verification of Safety-Critical Systems Using Safecharts.- Structure Preserving Data Abstractions for Statecharts.- Amortised Bisimulations.- Proof Methodologies for Behavioural Equivalence in Dpi.- Deriving Non-determinism from Conjunction and Disjunction.- Abstract Operational Semantics for Use Case Maps.- ArchiTRIO: A UML-Compatible Language for Architectural Description and Its Formal Semantics.- Submodule Construction for Extended State Machine Models.- Towards Synchronizing Linear Collaborative Objects with Operational Transformation.- Designing Efficient Fail-Safe Multitolerant Systems.- Hierarchical Decision Diagrams to Exploit Model Structure.- Computing Subgraph Probability of Random Geometric Graphs: Quantitative Analyses of Wireless Ad Hoc Networks.- Formalising Web Services.- From Automata Networks to HMSCs: A Reverse Model Engineering Perspective.- Properties as Processes: Their Specification and Verification.- SHORT PAPERS.- Epoch Distance of the Random Waypoint Model in Mobile Ad Hoc Networks.- Automatic Partitioner for Behavior Level Distributed Logic Simulation.- Expressive Completeness of an Event-Pattern Reactive Programming Language.- Formalizing Interoperability Testing: Quiescence Management and Test Generation.- Formal Description of Mobile IPv6 Protocol.- Incremental Modeling Under Large-Scale Distributed Interaction.- The Inductive Approach to Strand Space.- Compositional Modelling and Verification of IPv6 Mobility.

Interoperability test suite derivation for communication protocols

Abstract This paper addresses the problem of interoperability testing for communication protocols. We develop a coherent framework of interoperability testing in which the notions of interoperability, interoperability testing, interoperability test case and interoperability test architecture are interrelated and a systematic interoperability test suite derivation method based on the framework. The approach to interoperability testing is illustrated with the example of the ATM Signaling Protocol. To demonstrate practicality of the approach, we implemented executable test suites derived by the method on a commercial ATM test platform, applied them for interoperability testing of various ATM equipment and analyzed the testing results.

Interoperability Test Suite Derivation for Symmetric Communication Protocols

Communication protocols are commonly designed in such a way that implementations of the same protocol can be used as peers for communication. Such a protocol is said to be symmetric. When two or more entities are employed to perform a certain task as in the case of communication protocols, the capability to do so is called interoperability and considered as the essential aspect of correctness of communicating systems. This paper deals with the problem of deriving interoperability test suite for control part of symmetric protocols. A new approach to efficient interoperability testing is described with justifications and the method of interoperability test suite derivation is shown with the example of the ATM Signaling protocol.

Relating interoperability testing with conformance testing

Conventionally the term conformance testing has been used to indiscriminately denote different types of conformance testing in a broad sense and the term interoperability testing has been used without regard to possibly different interoperability test architectures. This study classifies conformance testing into interface conformance testing and entity conformance testing and investigates how they can be related to interoperability testing as interoperability test architecture varies. It also discusses how the result of the investigation can be put into practical use for development of test suites and real test systems.

Test sequence generation for adaptive interoperability testing

When testing communicating systems, nondeterminism makes it a more difficult and evasive process. Adaptive testing is an efficient approach to testing nondeterministic systems. In this paper, we develop an interoperability test generation method for adaptive testing. Also we define a measure of testing cost and compare our method with the conventional approach.

An approach for testing asynchronous communicating systems

This paper studies the problem of testing concurrent systems as blackboxes described in asynchronous Communicating Finite State Machines. We present an approach to derive test cases in a succinct and formal way for the concurrent systems. The approach avoids the state space explosion problem by introducing a causality relation model to express true concurrency. A new test architecture for executing the test suite is also described.

An enhanced model for testing asynchronous communicating systems

This paper studies the problem of testing concurrent systems considered as blackboxes and specified using asynchronous Communicating Finite State Machines. In our previous work [Kim 96], an approach to derive test cases for concurrent systems was developed. The approach addressed the state space explosion problem by introducing a causality relation model and the concept of logical time to express true concurrency. This paper builds on and extends the previous work. The model is enhanced to improve the quality (i.e., verdict capability) of test cases by relaxing the unit-time assumption to any natural number and by presenting a computationally efficient algorithm for deriving the test cases. Finally the approach is generalized to describe timing constraints with any real numbers.

Interoperability Test Suite Derivation for the ATM/B-ISDN Signaling Protocol

In this paper, we propose a test derivation method suitable for testing interoperability for the class of communication protocols like the ATM/B-ISDN signaling protocol. For this, we begin by defining the notion of interoperability test case. Next we select an effective interoperability test architecture by carefully comparing advantages and disadvantages of three candidate test architectures. Then we present an interoperability test suite derivation method based on the definition of interoperability test case. For that, we give an algorithm for deriving from a given pair of FSMs a composite FSM and an interoperability test suite in parallel. In addition, occurrence orderings of output messages for all interoperability test cases are analyzed and their regularity is exploited to reduce the length of interoperability test cases.

Interoperability Test Suite Generation for the TCP Data Part Using Experimental Design Techniques

Test derivation methods suitable for interoperability testing of communication protocols were proposed in [1,2, 3] and applied to the TCP and the ATM protocols, The test cases that were generated by them deal with only the control part of the protocols. However, in real protocol testing, the test cases must manage the data part as well. For complete testing, in principle we must test all possible values of data part although it is impractical to do so. In this paper, we present a method generating the interoperability test suite for both the data part and the control part of protocols with the example of Tep connection establishment. In this process, we make use of experimental design techniques from industrial engineering to minimize the size of test suite while keeping testing capability. Experimental design techniques have been used for protocol confom1ance testing but not for intcruperability testing so far. We generate the test suite for data part by this method and show a possibility that we can test interoperability of protocols with the minimum number of test cases while maintaining the testing power.

Development and Application of ATM Protocol Conformance Test System

This paper presents development and application of ATM Conformance Test Sys-tem (ACTS), an automated test system for ATM protocols. ACTS is a test system that checks conformance of ATM terminal and network equipment implementing either ITU-T or ATM Forum user-network interface. This paper, after presenting the methodology and process used for developing ACTS, conducts case studies of its applications to real ATM equipment. By applying ACTS, we were able to detect numerous problems in protocol implementations of ATM equipment and analyze causes of the problems, thereby demonstrating the efficacy of ACTS as an efficient automated testing tool. Furthermore, by predicting the potential effects of the problems on interoperability, we show how ACTS can be used as a useful tool for ensuring interoperable ATM equipment.