TTCN-3 (Testing and Test Control Notation version 3) is a strongly typed test scripting language used in conformance testing of communicating systems and a specification of test infrastructure interfaces that glue abstract test scripts with concrete communication environments. TTCN-3 has been developed by ETSI and its predecessor is TTCN-2. Despite sharing same fundamental concepts, TTCN-2 and TTCN-3 are essentially two different languages, the latter having simpler syntax and standardized adapter interfaces. TTCN-3 scripts can be combined with ASN.1 type definitions. ASN.1 is natively supported by major TTCN-3 tool vendors.