The scope of this European Telecommunication Standard (ETS) is: i) to provide a detailed specification for the interworking between information elements contained in layer 3 messages sent on the MS-MSC interface (Call Control and Mobility Management parts of TS GSM 04.08) and parameters contained in MAP services sent over the MSC-VLR interface (TS GSM 09.02) where the MSC acts as a transparent relay of information; ii) to provide a detailed specification for the interworking between information elements contained in BSSMAP messages sent on the BSC-MSC interface (TS GSM 08.08) and parameters contained in MAP services sent over the MSC-VLR interface (TS GSM 09.02) where the MSC acts as a transparent relay of information; iii) to provide a detailed specification for the interworking as in i) and ii) above when the MSC also processes the information. Interworking for supplementary services is given in TS GSM 09.11. Interworking for the short message service is given in TSs GSM 03.40 and GSM 04.11. Interworking between the call control signalling of TS GSM 04.08 and the PSTN/ISDN is given in TSs GSM 09.03, GSM 09.07 and GSM 09.08. Interworking between the A and E interfaces for inter-MSC handover signalling is given in TSs GSM 09.07 and 09.08.