CONTENTS

 2     Three-Party Service
        2.1     Introduction
                  2.1.1     Scope
                  2.1.2     References
                  2.1.3     Terms and definitions
                  2.1.4     Abbreviations
        2.2     Description
                  2.2.1     General description
                  2.2.2     Specific terminology
                  2.2.3     Qualification on the applicability to telecommunication services
                  2.2.4     State definitions
        2.3     Operational requirements
                  2.3.1     Provision/withdrawal
                  2.3.2     Requirements on the originating network side
                  2.3.3     Requirements in the network
                  2.3.4     Requirements at the destination network side
        2.4     Coding requirements
        2.5     Signalling requirements
                  2.5.1     Activation/deactivation/registration
                  2.5.2     Invocation and operation
        2.6     Interactions with other supplementary services
                  2.6.1     Call Waiting (CW)
                  2.6.2     Explicit Call Transfer (ECT)
                  2.6.3     Connected line identification presentation (COLP)
                  2.6.4     Connected line identification restriction (COLR)
                  2.6.5     Calling Line Identification Presentation (CLIP)
                  2.6.6     Calling Line Identification Restriction (CLIR)
                  2.6.7     Closed User Group (CUG)
                  2.6.8     Conference calling (CONF)
                  2.6.9     Direct-Dialling-In (DDI)
                 2.6.10     Diversion services
                 2.6.11     Line Hunting (LH)
                 2.6.12     Three-Party Service (3PTY)
                 2.6.13     User-to-User Signalling (UUS)
                 2.6.14     Multiple Subscriber Number (MSN)
                 2.6.15     Call hold (HOLD)
                 2.6.16     Advice of Charge (AOC)
                 2.6.17     Sub-addressing (SUB)
                 2.6.18     Terminal Portability (TP)
                 2.6.19     Completion of Calls to Busy Subscriber (CCBS)
                 2.6.20     Malicious Call Identification (MCID)
                 2.6.21     Reverse charging (REV)
                 2.6.22     Multi-Level Precedence and Preemption (MLPP)
                 2.6.23     Support of Private Numbering Plan (SPNP)
                 2.6.24     International telecommunication charge card
        2.7     Interactions with other networks
        2.8     Signalling flows
        2.9     Parameter values (timers)
       2.10     Dynamic description