This Recommendation specifies the control interfaces for TTCN-3 test system implementations. The TTCN-3 control interfaces provide a standardized adaptation for management@ test component handling and encoding/decoding of a test system to a particular test platform. The present document defines the interfaces as a set of operations independent of a target language. The interfaces are defined to be compatible with the TTCN-3 standard (see clause 22). The interface definition uses the CORBA interface definition language (IDL) to specify the TCI completely. Clauses 8@ 9@ and 9.7 present language mappings for this abstract specification to the target languages Java@ ANSI C@ and C++. A summary of the IDL-based interface specification is provided in Annex A.