This Recommendation defines the interworking between the Signalling System No. 7 ISDN User Part 92 (ISUP) and the Signalling Systems No. 5, R2, TUP. ISDN UP 92 has been designed to allow peer-to-peer operation to a Q.767 exchange without requiring any knowledge of that situation. This means that different ISUP versions (like Q.767 and ISUP'92) cannot be considered as different signalling systems in an exchange. This specification is applicable to international transit exchanges, but may be used as a basis for the interworking in international gateway exchanges, because ISUP at the national side may also be based on ISUP'92.