Foreword1 Scope2 References3 Definitions, symbols and abbreviations4 General5 Network characteristics6 Interworking Reference Model for control plane interworking and user plane interworking7 Control plane interworking8 User Plane Interworking9 IMS-ALG and TrGW functionality for NAPT and IP Version Interworking10 IBCF – TrGW Interactions10.1 Overview10.2 Main Functions supported at the Ix Interface10.2.0 Introduction10.2.1 NAPT and IP version interworking10.2.2 Gate Management10.2.3 RTCP Handling10.2.4 IP Realm Indication10.2.5 Media Control10.2.6 Media Inactivity Detection10.2.7 QoS Packet Marking (differentiated services)10.2.8 Hanging Termination Detection10.2.9 Bandwidth Policing10.2.10 IMS end-to-end media plane security10.2.11 Through-Connection10.2.12 Emergency Call10.2.13 Explicit Congestion Notification support10.2.14 Optimal Media Routeing10.2.15 IP Realm Availability10.2.16 Access Transfer procedures with media anchored in ATGW10.2.17 Multimedia Priority Service (MPS) Support10.2.18 Coordination of Video Orientation10.2.19 Generic image attributes10.2.20 Interactive Connectivity Establishment (ICE)10.2.21 MSRP handling10.2.22 Alternative connection (ALTC) addresses management10.2.23 Video Region-of-Interest (ROI)10.2.24 SDP Capability Negotiation (SDPCapNeg)10.2.25 WebRTC Media Plane Optimization10.2.26 RTP-level pause and resume10.2.27 RTCP Codec Control Commands and Indications10.2.28 Delay Budget Information (DBI)10.3 Void10.4 Procedures 10.3 Void 29.1623GPPInterworking between the IM CN subsystem and IP networksRelease 17TS Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM