Quantifying the evolution of TTCN-3 as a language

Ten years of maintenance, nine published revisions of the standards for the Testing and Test Control Notation version 3 (TTCN-3), more than 500 change requests since 2006, and 10 years of activity on the official TTCN-3 mailing list add up to a rich history, not unlike that of many successful Open Source Software (OSS) projects. In this article, we contemplate TTCN-3 in the context of software evolution and examine its history quantitatively. We mined the changes in the textual content of the standards, the data in change requests from the past 5 years, and the mailing list archives from the past 10 years. In addition, to characterize the use of the TTCN-3 we investigated the meta-data of the contributions at the TTCN-3 User Conference, and the use of language constructs in a large-scale TTCN-3 test suite. Based on these data sets, we first analyze the amount, density, and location of changes within the different parts of the standard. Then, we analyze the activity and focus of the user community and the maintenance team in both the change request management system and the official TTCN-3 mailing list. Finally, we analyze the distribution of contributions at the TTCN-3 User Conference across different topics over the past 8 years and construct use anomalies during the development of a large-scale test suite. Our findings indicate that the TTCN-3 is becoming increasingly stable as the overall change density and intensity, as well as the number of change requests are decreasing, despite the monotonous increase in the size of the standards.     

Testing hybrid systems with TTCN-3 embedded

A testing language typically provides a set of test automation statements that allows for a systematic definition and automatic application of stimulation data (i.e. messages or signals) to a system under test. Moreover, it eases the assessment of the system’s reaction by providing customizable evaluation statements and functions. TTCN-3, the Testing and Test Control Notation, already provides universal and powerful concepts to describe tests for discrete, message-based systems. However, software-based control systems that are used to control physical processes often show continuous quantities that can be only poorly stimulated and assessed by means of the currently available language constructs in TTCN-3. In this article, we show how this problem can be solved by extending the TTCN-3 language. We introduce an extension of TTCN-3, namely TTCN-3 embedded, that provides concepts and constructs that directly address the specification of tests for continuous and hybrid real time systems. The extension includes the notion of streams that can be used to represent continuous quantities over time. In addition, TTCN-3 has been extended with the concepts of stream-based ports, sampling, equation systems, and with additional control flow structures. The concepts are integrated with standard TTCN-3 and allow for defining test cases that handle continuous quantities, as well as discrete state changes and the exchange of messages within the same concept space. The feasibility of the approach is shown by providing a small example from the automotive industry.     

Standardized TTCN-3 specifications for SIP-ISUP/ISDN interworking testing

ETSI technical committee TISPAN currently funds the development of TTCN-3 network integration test suites using TTCN-3. Specialist task forces (STF) have already been initiated to implement and validate abstract test suites focusing on, e.g., SIP/ISUP and SIP/ISDN interworking units. In this paper, we report on our implementation approach and experiences made in the STF on testing interworking between SIP and ISDN/ISUP. Special attention has been given to the reuse of know-how and of existing TTCN-3 code available due to the existing SIP conformance test suite and the TTCN-3 test framework developed by ETSI for IPv6. Validation has been done using the test laboratory of a telecom network provider.     

TTCN-3研究综述

随着网络技术的发展，TTCN-3在协议测试领域的运用越来越广泛。文章介绍了TTCN-3的发展过程和应用状况，阐述了其核心语言、表格及图形表示格式，重点分析了TTCN-3标准对比TTCN前版本改进的主要特性，并以此为基础提出TTCN-3的应用前景。     

Introducing 3D Cinematography [Guest editors' introduction]

Recent developments in computer vision and computer graphics, especially in such areas as multiple-view geometry and image-based rendering, are making it possible to generate 3D models of dynamic scenes from multiple cameras at video frame rates. The authors call this process 3D cinematography since it extends traditional cinematography from 2D (images) to 3D (solid objects that we can render with photorealistic textures from arbitrary viewpoints) at the same frame rate. The authors provide an overview of the field as well as introduce the articles in their Special Section on 3D Cinema.     

A conformance test suite for TTCN-3 tools

With more than 10 years of maturing through industrial use and standardization, the Testing and Test Control Notation (TTCN-3) has become a widely used technology that many businesses depend upon for ensuring their product quality. With the rising number of supporters and tools, the demand for a means to assess the standards compliance of TTCN-3 tools has increased. In this article, we describe the motivation, approach, methodology, and results of the still ongoing project to develop a standardized conformance test suite for TTCN-3 tools. We discuss the challenges involved in creating such a test suite, the way to deal with imposed resource limitations of the project, and where we think the effort is heading.     

Testing hybrid control systems with TTCN-3: an overview on continuous TTCN-3

TTCN-3 has gained increasing significance in recent years. It was originally developed to fit the needs of testing software-based applications and systems in the telecommunication industry and has shown its applicability to a wide range of other industrial domains in the mean time. TTCN-3 provides platform-independent, universal and powerful concepts to describe tests, especially for discrete, interactive systems. However, TTCN-3 addresses systems with discrete input and output characteristics only. The lack of powerful means that reasonably allow specifying and evaluating continuous data flow makes TTCN-3 sufficient neither for the automotive industry nor for other industries that deal with highly complex software-based control systems. This paper introduces the notion of streams, stream ports and stream templates to TTCN-3. It revises the initial design of continuous TTCN-3, a TTCN-3 extension for testing continuous or hybrid systems [20,21] and demonstrates the applicability for a case study that is typical for testing embedded control systems in the automotive industry.     

TTCN-3编译器符号表的设计和实现

TTCN-3是一种用于协议与软件测试的标准化测试语言。本文在对TTCN-3核心语言标准的研究基础上分析了TTCN-3核心语言的前向引用和Import机制等方面的规范与特点,设计并实现了一种TTCN-3符号表组织结构。在此基础上完成了TTCN-3到中间语言的编译转换。     

An approach to quality engineering of TTCN-3 test specifications

Experience with the development and maintenance of large test suites specified using the Testing and Test Control Notation (TTCN-3) has shown that it is difficult to construct tests that are concise with respect to quality aspects such as maintainability or usability. The ISO/IEC standard 9126 defines a general software quality model that substantiates the term “quality” with characteristics and subcharacteristics. The domain of test specifications, however, requires an adaption of this general model. To apply it to specific languages such as TTCN-3, it needs to be instantiated. In this paper, we present an instantiation of this model as well as an approach to assess and improve test specifications. The assessment is based on metrics and the identification of code smells. The quality improvement is based on refactoring. Example measurements using our TTCN-3 tool TRex demonstrate how this procedure is applied in practise. B. Zeiss is supported by a Ph.D. scholarship from Siemens AG, Corporate Technology.     

TTCN-3 语言非侵入式调试技术

TTCN-3(Testing and Test Control Notation version 3)是一种形式化的测试描述语言,被广泛应用于协议测试等领域。由于测试套的复杂度越来越高,测试人员迫切需要能够调试TTCN-3语言的技术。本文提出了一种非侵入式的TTCN-3语言调试方法,通过驱动第三方调试器对TTCN-3语言编译后生成的目标代码进行调试,同时结合语句映射和符号解析等算法,实现了基本的调试功能。实验结果表明,该调试技术对测试系统的执行性能影响非常小,能更好的满足对大型测试套的调试需求。     

Innovation and evolution in integrated web application testing with TTCN-3

Over the last 10 years there has been continuous innovation and evolution in the technology of web applications. While originally designed as a telecom testing platform, TTCN-3 has proven to be a flexible and powerful platform for web application testing throughout this period. Major challenges to testing have been integration with unit test frameworks, service-oriented architecture, rich client interfaces, and security vulnerabilities. Through careful analysis and practical experience in industrial projects we have developed mechanisms to address each of these aspects of web application testing in TCN-3. These mechanisms are summarized here with examples drawn from our industrial experience to show how TTCN-3 provides significant advantages for testing web applications in comparison to other tools typically used in industry. We also present a significant extension to the model architecture for TTCN-3 which greatly facilitates web application testing that has been implemented by a major vendor and is now under consideration by the ETSI standards committee.     

Special section: Smart water systems

The purpose of this Special Section is to provide an account of the state-of-the-art and perspectives for future research in the design and analysis of monitoring and control methods for smart water systems. This paper provides an overview of the six articles in the special section. Specifically, the special section consists of four review articles, as well as one vision and one tutorial article. These articles provide a review of leakage detection and isolation, a review of contamination event diagnosis, a review of state- space modelling of multiple reacting species in drinking water systems, a review of the application of model predictive control in Water Systems, a vision of optimizing pressure management and self-cleaning, as well as a tutorial for leakage detection and mitigation of potential contamination risk.     

TTCN-3数据系统到Java的翻译方案

TTCN-3数据系统的实现在遵照TTCN-3标准的基础上,还需要支持数据兼容等特性。针对该问题,给出一种TTCN-3数据系统到Java的翻译方案。利用Java语言具有的继承、多态等面向对象的特色,借鉴抽象工厂设计模式,通过检视分析翻译生成代码。证明该方案符合TTCN-3标准规定,并清晰地体现数据系统中的数据类型和数据值的功能区分。该方案支持不同数据类型的兼容和数据值之间的比较,并易于扩展。     

基于Web Service的TTCN-3远程测试系统

通过分析TTCN-3测试系统的通用结构,提出基于TTCN-3的远程测试概念,进而提出一种基于Web Service的ITCN-3远程测试系统体系架构,实现TTCN-3脚本的远程编辑、编译和执行,满足测试人员通过远程客户端自动地测试被测系统的需求.通过将该系统应用于某银行业务系统的测试,验证系统应用于远程自动化测试的有效性,提高测试效率.     

基于MSC的TTCN-3测试例生成研究

提出了从消息序列图(MSC)生成TTCN-3测试例的方法.测试者可以先针对被测系统(SUT)中感兴趣的部分利用MSC描述出具体的测试场景,再从MSC映射成TTCN-3测试例.将MSC映射成TTCN.3的方法主要包括对MSC文档、基本MSC和高级MSC这3部分的映射.     

TTCN-3语言类型系统到C++语言的翻译方案

在程序语言翻译技术中,如何有效地减少翻译后的代码数量是一个值得研究的性能问题。综合考虑TTCN-3语言中值和模板的定义和使用,提出一种新的TTCN-3语言到C++语言翻译方案。与现有的翻译方案相比,翻译后的C++代码与原TTCN-3代码比例由1∶20降低到1∶5左右。与此同时,新方案减少了类型信息副本的保存,提高内存的利用效率,更确切地说,提高了TTCN-3语言编译器和执行器的性能。此外,因为翻译后的C++代码与原TTCN-3代码基本一致,这使得代码的可读性得到改善,进而提高代码的可维护性。     

TTCN-3测试系统中模板匹配机制的一种实现方法

TTCN-3拥有一个功能强大且易于掌握的模板匹配机制。本文提出一种TTCN-3测试系统开发过程中模板匹配机制通用的、开放的实现方案。通过对模板匹配功能在TTCN-3测试系统中的作用进行深入分析,采用面向对象的程序设计语言C++实现TTCN-3测试系统中带有匹配机制的模板表示和模板匹配操作,并给出一个对于DNS协议实现功能测试的抽象测试套的翻译方案验证本文设计的合理性。     

基于TTCN-3的Web应用功能测试方法

针对日益增长的Web应用功能测试需求与测试重用需求,提出了一种基于TTCN-3的Web应用功能测试方法。该方法结合分层测试的思想以及TTCN-3的特点,提出将Web应用功能测试划分为页面内容测试、会话管理测试、使用场景测试等3个层次,并分别从这3个层次给出了采用TTCN-3进行测试的过程。该方法应用TTCN-3参数化设计测试用例的思想,有效分离了测试设计与测试实现,使测试用例具有高可重用性。结合实例,表明了该方法的有效性。     

面向对象的TTCN-3测试系统的实现

TTCN-3是一种被ETSI和ITU-T标准化的新一代协议和软件测试捕述表示法,有着广泛的应用前景。该文在对TTCN-3标准研究的基础上,以面向对象的思维描述了TTCN-3测试系统的总体结构的同时,探讨了编译系统和执行环境的具体史现和相戈算法,并给出了该标准的评价及应用标准。