The Testing and Test Control Notation (TTCN), is a language used to write detailed test specifications. TTCN has been used to specify tests for many kinds of applications, including mobile communications (GSM, 3G, TETRA), wireless LANs (Hiperlan/2), cordless phones (DECT), Broadband technologies (B-ISDN, ATM), CORBA-based platforms and Internet protocols such as IPv6, SIGTRAN, SIP and OSP.
The latest version of the language, TTCN version 3 (TTCN-3), is standardized by ETSI (ES 201 873 series) and the ITU-T (Z.140 series).