CONTENTS

 1     Scope
        1.1     Functional Reference Model
 2     References
 3     Definitions
        3.1     Functional Model Definitions
        3.2     Definition of Signalling Flow Objects
 4     Abbreviations
 5     Backbone Network Signalling Flows
        5.1     Object Reference Model
        5.2     Definitions
                  5.2.1     Object and call model definitions
                  5.2.2     Call model
                  5.2.3     Command and responses
                  5.2.4     Definition of signalling flow objects
        5.3     Backbone network establishment
                  5.3.1     Backward backbone network establishment composite flow
                  5.3.2     Forward Composite
                  5.3.3     Backward Composite With CMN
                  5.3.4     Forward Composite With CMN
        5.4     Call Modification Flows
                  5.4.1     Mid-Call Codec Modification
                  5.4.2     Mid-Call Codec Negotiation
                  5.4.3     Redirection Flows
        5.5     Call Release
                  5.5.1     Call Release Composite Without CMN
                  5.5.2     Call Release Composite With CMN
        5.6     Bearer Release
Annex A – Composite Structured AAL1 Signalling Flows
Annex B – ISUP "NNI" access establishment and release flows
Annex C – Overview of bearer redirection
Annex D – Overview of "Tunneling"
        D.1     Introduction
        D.2     Operation of the mechanism
                  D.2.1     Delayed Forwards Setup
                  D.2.2     Backwards Setup
                  D.2.3     Fast setup