TTCN-3

Testing and Test Control Notation (TTCN) is a standardized language used to write detailed test specifications. The latest version, TTCN-3, is developed and maintained by ETSI technical committee Methods for Testing and Specification (MTS) as the ES 201 873 series and by the ITU-T as ITU Recommendation Z.140 series.

At ETSI, TTCN-3 has been used for the development of conformance test implementation in a range of applications including:

• Session Initiation Protocol (SIP) for Voice over IP (VoIP)
• IPv6
• Digital Mobile Radio (DMR)
• HiperMAN / WiMax
• 3GPP^TM IP Multimedia Subsystem (IMS).

Although primarily used in telecommunications, TTCN is well accepted by industry and its use has spread into new domains including automotive, railway and financial applications.

TTCN-3

TTCN-3 has retained and improved much of the well-proven testing-specific capabilities of earlier versions. With its new syntax, TTCN-3 has the look and feel of a modern programming language. This general purpose, flexible and user friendly test language is easy to learn, use and implement with.

The TTCN-3 standard includes several presentation formats:

• a text-based Core Language (ES 201 873-1) for use in a conventional programming environment which serves as the basis for all formats
• a tabular format (ES 201 873-2) for users familiar with older versions of TTCN
• a graphical format (ES 201 873-3) expressing tests in an intuitive and easily readable form.

There are also hooks in the language that facilitate the development of proprietary, non-standardized presentation formats if required.

The TTCN-3 website gives further information on TTCN-3, including background, tutorials, pointers to tools, the mailing list and upcoming TTCN-3 related events.

Advantages of TTCN-3

• TTCN-3 is easy to learn as it has the look and feel of a regular programming language and tutorials, courses, and other publications are available.
• TTCN-3 is different from conventional programming or scripting languages as it has been specifically designed for testing, it is internationally standardized and off-the-shelf tools and test systems are readily available.
• It is a flexible testing technology as the language is completely independent of the implementation technology or operating system of the System Under Test.
• There are virtually no limits to adapt tests or a test system to the needs: it is scalable, test components can be used both to test or emulate interfaces, it is extensible and has multiple presentation formats.
• It can be used in many types of testing including valid, invalid, inopportune testing; software module, unit, layer, protocol, integration, laboratory testing; functional, load, distributed testing and regression, certification, approval testing.
• TTCN-3 has passed the test of time: the first standards were published in 2000, their concepts were based on TTCN-2, which had been applied in commercial testing for over a decade, it has since been used successfully in the certification of new technologies.

TTCN-3 application areas

Typical areas of application for TTCN-3 are protocols, services, APIs (Application Programming Interfaces), and software modules. However it is not restricted to conformance testing and can be used in areas such as:

• Interoperability testing
• Robustness testing
• Performance testing
• Regression testing
• System testing
• Integration testing.