1 Scope
2
References
3
Definitions
4
Abbreviations
5
Protocol stack and system models
5.1 Protocol stack model
5.2 System model/overview
6
Interaction channel for PSTN
6.1 PSTN requirement
6.2 PSTN interfaces requirement
7
Interaction channel for ISDN
7.1 ISDN requirement
7.2 ISDN interfaces requirement