CONTENTS

 1     Closed User Group (CUG)
        1.1     Scope
        1.2     References
        1.3     Definitions and abbreviations
                  1.3.1     Definitions
                  1.3.2     Abbreviations
        1.4     Description
        1.5     Specification model
        1.6     CUG application process functions
                  1.6.1     Primitive interface AP/SACF
                  1.6.2     Procedures
        1.7     SACF
                  1.7.1     Primitive interface SACF/MTP
                  1.7.2     Procedures
        1.8     CUG ASE
                  1.8.1     Primitive interface SACF/CUG ASE
                  1.8.2     Procedures
        1.9     Interactions
                  1.9.1     Interactions with CS 1
                  1.9.2     Interactions with other supplementary services
       1.10     Interworking
                 1.10.1     Interworking with ISUP
                 1.10.2     Interworking with DSS 2
Appendix I – Instruction indicator setting