This Recommendation describes service observation in the international service in order to assess the quality of service obtained by the calling subscriber. It is essential to have factual or objective recording of observations (i.e. successful and unsuccessful calls), and to present them in the form of tables. The purpose of the revisions to this Recommendation are to include common channel Signalling System No. 7 features, to augment the QOS observations for Signalling Systems No. 5, No. 6 and R2 already present.