Scope This part of ISO/IEC 9314 contains the abstract test suite for the Fibre Distributed Data Interface (FDDI) token ring Media Access Control (MAC) layer protocol. This test suite was developed based on the principles defined in OSI Conformance Testing Methodology and Framework (ISO/IEC 9646) and written in Tree and Tabular Combined Notation (TTCN), and intended for testing conformance to the MAC standard (ISO/IEC 9314-2:1989) of any FDDI stations. The test methodology is the \"remote single layer test\" as described in ISO/IEC 9646. The abstract test scripts specify the MAC layer Protocol Data Units (PDU) to be exchanged between the two MAC entities, the MAC on the tester and the MAC on the Implementation Under Test (IUT). The tester is called the Lower Tester (LT). The test suite does not require use of any higher layer protocols, nor does it assume existence of Logical Link Control (LLC) layer implementation on the IUT. It expects, however, that the Station Management (SMT) function is available on the IUT. Since MAC itself does not originate any data frames, the tester uses SMT to test the processing capability of MAC by sending frames to SMT and observing the SMT originated response frames. The testing is expected to be conducted in a controlled environment with a minimum configuration (figure 1): a token ring with two stations, one being the LT and the other the IUT.