Rec. ITU-T T.123 (11/1994) – PROTOCOL STACKS FOR AUDIOGRAPHIC AND AUDIOVISUAL TELECONFERENCE APPLICATIONS
FOREWORD
CONTENTS
SUMMARY
1 Scope
    1.1 Networks identified
    1.2 Audio and video signals
    1.3 Two profile modes
    1.4 ISDN call set-up
2 Normative references
3 Definitions
4 Abbreviations
5 Multipoint configuration
6 Profile overview
7 Basic mode profiles
    7.1 ISDN basic mode profile
    7.2 CSDN basic mode profile
    7.3 PSDN basic mode profile
    7.4 PSTN basic mode profile
8 Extended mode profiles
    8.1 ISDN extended mode profile
    8.2 CSDN extended mode profile
    8.3 PSDN extended mode profile
    8.4 PSTN extended mode profile
9 Synchronization and convergence function
    9.1 SCF overview
    9.2 SCF procedures
    9.3 SCF messages
    9.4 Quality of Service parameters
10 Q.922 protocol parameters and options
11 Data link frame structure transparency for start-stop transmission
12 Physical sublayer formed by H.221 MLP channels
Annex A – Integration of multimedia signals framed according to Recommendation H.221
Appendix I – Audiographic conference call set-up in the ISDN
I.1 Introduction
I.2 Basic requirements
I.3 Connection phase
I.4 Phase A (ISDN D-channel protocol)
I.5 Phase B (H.242 protocol)
I.6 Phase C (T.120-Series protocol)
Appendix II – Possible profiles for local area networks
Appendix III – A possible profile for broadband ISDN