Gyula Csopaki

Applying mutation analysis to SDL specifications

Mutation analysis is a fault based testing method used initially for code based software testing, and lately for specification based testing and validation as well. In this paper, the method is applied to SDL (Specification and Description Language) specifications. It is used to automate the process of conformance test generation and selection for telecommunications protocols. We present two algorithms for automatic test generation and selection. These provide the basis of the Test Selector tool developed at the Budapest University of Technology and Economics. We present the results of an empirical study using the tool.

High-level restructuring of TTCN-3 test data

TTCN-3 (Testing and Test Control Notation 3) [1,2,3] test suites developed for testing complicated systems contain a large number of test data definitions. These definitions are often redundant and lengthy, which leads to compilation and run-time inefficiencies. Our intention is to provide remedy for this problem, by proposing a method that restructures the test data definitions of an already existing TTCN-3 module. In this paper we introduce a model for TTCN-3 test data and a method for its optimization. The results of an empirical study using our approach is presented as well.

Performance analysis of concurrent PCOs in TTCN-3

This paper deals with a study and a mathematical model of concurrent Points of Control and Observation (PCOs) realized in Testing and Test Control Notation version 3 (TTCN-3). We study test scenarios that are gaining importance as TTCN-3 is emerging as a notation suitable for conducting load tests too. We investigate communication between parallel test components (PTCs) and analyze race conditions between the queues underlying the implemented PCOs. This way, we build an analytic model to investigate behavior of PCOs under stress conditions and to assess possible latencies messages in a TTCN-3 based load test system might suffer. We present a discrete-time Quasi Birth-Death process to predict performance indices of test components and we propose to use the results to avoid indefinite postponement in the communication of PTCs. Also, we aim to use the model for calculating traffic intensity limits under which it is feasible to use TTCN-3 for load testing. Furthermore, we present the output of the model together with an example load test scenario that is vulnerable to that types of latencies.

On FSM-Based fault diagnosis

We study the problem of fault diagnosis, i.e., localization of difference(s) between an implementation and a specification in systems modelled by finite state machines. We show that even considering only a single fault in a finite state machine there are some situations when the exact diagnosis of the fault cannot be assured. We give an algorithm for fault diagnosis. If it is possible the procedure exactly locates a single fault, and in case exact localization is unfeasible it provides the set of all potential differences between the implementation and the specification.

Testing of Communicating Systems

This paper presents an overview of the work we have developed at INT on different approaches to protocol and service testing. It is related to performing tests of communication protocols and telecommunication services based on techniques, such as, active test generation, passive testing, embedded testing and test execution.

Erratum to: Testing of Communicating Systems

Erratum to: G. Csopaki et al. (Eds.) Testing of Communicating Systems DOI: 10.1007/978-0-387-35567-2

Communication Protocol Implementation in Java

In this paper we examine the possibility of applying Java in the field of telecommunications. We present a method based on formal descriptions we worked out for implementation of communication protocols in Java. We demonstrate how SDL descriptions can be mapped to Java code. We bring out the code of some SDL/PR constructions common for every implementation and parts of SDL descriptions that are implementation specific and apply predefined code patterns. We touch on the problem of mapping abstract data types. This conception is presented by the example of sample telecom protocol INRES and possible connections to the environment are introduced. Then we raise and discuss the matter of automatic compilation and present an SDL/PR to Java compiler. We appraise efficiency of this compilation method and the performance of the realized system. Finally we talk over the advantages and drawbacks of applying Java and give some possible fields of applications.

PROCONSUL ON THE WAY TO AUTOMATED PROTOCOL ENGINEERING

The analysis, development and testing of communication protocols are complex problems. These tasks can be made easier with protocol development tools, which support the whole protocol development process from specification to testing. They are either stand-alone tools related to a specific protocol engineering function (e.g. validation) or integrated protocol workstations solving several functions. The protocol development tools are usually based on formal description techniques. This paper describes the notion of CAPE (Computer-Aided Protocol Engineering) derived from CASE (Computer-Aided Software Engineering) and presents the PROCONSUL protocol workstation. The intelligent editors of PROCONSUL are described in detail.