This Recommendation specifies requirements on both the test laboratory and client, for the conduct of the conformance assessment process. The requirements are those necessary to achieve comparability of results of tests on similar implementations performed by different test laboratories. This Recommendation also provides some guidance on the conformance assessment process. The text was developed jointly with ISO/IEC JTC1 and the main intent of this revision is to reflect the changes as a result of the work on Protocol Profile Testing Methodology (PPTM) and on Multi-Party Testing Methodology (MPyTM).