Editing TTCN

[[File:MSC_representation_of_a_TTCN-3_test_case.png | thumb | right | alt=A chart of an interaction between a test-case and the suit using it. The test case gives a correct request to the suit which will then give a response on whether the test succeeded or not. | [[Message Sequence Chart]] representation of a basic TTCN-3 scenario.]]'''TTCN''' is a [[programming language]] used for testing of [[communication protocol]]s and [[web service]]s. A TTCN test suite consists of many [[test case]]s written in the TTCN programming language.
Until version 2 the language was written in tables and called '''''Tree and Tabular Combined Notation'''''. Reading and editing this language required special TTCN editors. Beginning with version 3 TTCN was renamed to '''''Testing and Test Control Notation'''''. It is now closer to current programming languages and can be edited with traditional editors. [[TTCN-3]] is more flexible than TTCN-2 in that it can be used for protocol testing as well as testing traditional software. 

All versions of TTCN need dedicated compilers or interpreters for execution.

TTCN is widely used, for example; [[ETSI]], [[International Telecommunication Union|ITU]] for the testing of telecommunication protocols. [[Conformance testing|Conformance test]] cases of  [[ETSI]] standards like [[ISDN]], [[DECT]], [[GSM]], [[Enhanced Data Rates for GSM Evolution|EDGE]], [[3G]], [[DSRC]] have also been written in TTCN. Recently it has also been used for testing various protocol standards e.g. [[Bluetooth]], [[Internet Protocol|IP]]. 

Execution of those [[test case]]s against products (e.g. phones, mobile phones, service enablers or network elements) is used to verify that the protocol implementation in those products meet the requirements defined by telecommunication standards.

TTCN is often combined with [[ASN.1]].

==Versions==

*TTCN-1: Standardized in 1992 by [[ISO]] and [[CCITT]] as ISO/IEC 9646-3 and [[CCITT]] X.292 for Open Systems Interconnection (OSI) conformance testing methodology and framework.
*TTCN-2: Standardized in 1998 by [[ISO]] and [[ITU]], adding concurrency and multiple modules support to TTCN-1.
*[[TTCN-3]]: Written by [[ETSI]] and standardized in 2000 by [[ITU]] under reference Z.140. It aimed at being a more generic testing language than TTCN-2. In 2007 the recommendation moved from Z.140 to Z.160.

==Background information==

[[Conformance testing]] means a test execution against a well-defined [[test case]], e.g. a test written in TTCN. [[Plug-test]]s, also called [[interoperability testing]], are test cases executed with a client - server model; e.g. Mail-Client against Mail-server, phone against network, Bluetooth headset against Bluetooth phone. Plug-tests are e.g. often executed at so-called unplug-tests.

[[Conformance testing|Conformance-test]]s and plug-tests complement each other. If properly done, interoperability errors found with plug-tests should lead to definition of new conformance test cases that cover the failed test.

== External links ==
*[http://itu.int/ITU-T/studygroups/com07/TTCN.html ITU TTCN Studygroup]
*[http://www.TTCN-3.org ETSI TTCN-3 web site]
*[http://www.blukaktus.com/TTCN3QRC_viewme.pdf TTCN-3 Quick Reference Card]

[[Category:ITU-T recommendations]]