1 Scope
2 References
3 Definitions
3.1 Terms defined elsewhere
3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Introduction
7 Overview of the interconnection between two different IM CN subsystems
8 Technical specifications structure
9 Technical specifications
9.1 122-series, Service aspects
9.2 123-Series, Technical realization
9.3 124-series, Signalling protocols - user equipment to network
9.4 126-series, CODECs
9.5 129-series, Signalling protocols - intra-fixed-network
Bibliography