A Technique to Generate Feasible Tests for Communications Systems with Multiple Timers

We present a new model for testing real-time protocols with multiple timers, which captures complex timing dependencies by using simple linear expressions involving timerrelated variables. This new modeling technique, combined with the algorithms to eliminate inconsistencies, allows generation of feasible test sequences without compromising their fault coverage. The model is specifically designed for testing to avoid performing full reachability analysis, and to control the growth of the number of test scenarios. Based on extended finite state machines, it is applicable to languages such as SDL, VHDL, and Estelle. The technique models a realistic testing framework in which each I/O exchange takes a certain time to realize and timers can be arbitrarily started or stopped. A software tool implementing this technique is used to generate test cases for the US Army wireless standard MIL-STD 188-220

Formal Specification and Conformance Testing of Army Communications Protocols

During the past six years, ATIRP-sponsored faculty and students from the University of Delaware and the City College of New York, collaborating with scientists from CECOM and ARL, have helped advance the state-of-the-art in the design, development, and testing of Army communications protocols. Working closely together, these groups specified a complex real-life protocol (MIL-STD 188-220) in Estelle, and then used that formal specification to generate conformance test sequences. The test generation effort involved identifying and publishing results on three theoretical problems: (1) the timing constraint problem, (2) the controllability problem, and (3) the conflicting timers problem. Based on ATIRP's research results, two software packages were written to generate conformance test sequences for 188-220. These packages helped generate tests for 188-220's Data Link Types 1 and 4 services that were realizable without timer interruptions while providing a 200% increase in test coverage. The test cases have been delivered and are being used by a CECOM conformance testing facility

Experience in developing and testing network protocol software using FDTs

This paper presents the research effort to formally specify, develop and test a complex real-life protocol for mobile network radios (MIL-STD 188-220). As a result, the team of researchers from the University of Delaware and the City College of the City University of New York, collaborating with scientists from CECOM (an R&D facility of the US Army) and the US Army Research Laboratory, have helped advance the state-of-the-art in the design, development, and testing of wireless communications protocols. Estelle is used both as the formal specification language for MIL-STD 188-220 and the source to automatically generate conformance test sequences. The formal test generation effort identified several theoretical problems for wireless communication protocols (possibly applicable to network protocols in general): (1) the timing constraint problem, (2) the controllability problem, (3) inconsistency detection and elimination problem and (4) the conflicting timers problem. Based on the collaborative research results, two software packages were written to generate conformance test sequences for MIL-STD 188-220. These packages helped generate tests for MIL-STD 188-220’s Data Link Types 1 and 4 services that were realizable without timer interruptions while providing a 200 % increase in test coverage. The test cases have been delivered and are being used by a CECOM conformance testing facility