Content for TR 23.748 Word version: 17.0.0
6 Solutions p. 22
6.0 Mapping of Solutions to Key Issues p. 22
6.1 Solution #1: Provisioning URSP configuration to the UE to establish PDU Sessions for edge applications p. 24
6.1.1 Description p. 24
6.1.2 Procedures p. 24
6.1.3 Impacts on services, entities and interfaces p. 26
6.2 Solution #2: Local DNS based edge server address discovery p. 26
6.2.1 Introduction p. 26
6.2.2 Functional Description p. 27
6.2.3 Procedures p. 28
6.2.3.1 Procedure for Edge Server discovery when service start-up p. 28
6.2.3.2 Procedure for provisioning local DNS Server Address in the case of ULCL/BP p. 29
6.2.2.3 Procedure for provisioning local DNS Server Address in the case of SSC mode 2/3 p. 30
6.2.4 Impacts on existing entities and interfaces p. 31
6.3 Solution #3: DNS AF p. 31
6.3.1 Description p. 31
6.3.2 Procedures p. 32
6.3.2.1 High-level procedure using ECS option p. 32
6.3.2.2 Detailed procedure using ECS option p. 34
6.3.2.3 High-level procedure using DNS forwarding p. 38
6.3.3 Impacts on services, entities and interfaces p. 38
6.4 Solution #4: Providing the DNS authoritative server with IP addressing information about where the UE is located p. 39
6.4.1 Description p. 39
6.4.2 Procedures p. 40
6.4.3 Impacts on services, entities and interfaces p. 43
6.5 Solution #5: Server Discovery using DNS and IP Routing p. 44
6.5.1 Description p. 44
6.5.2 Procedures p. 45
6.5.2.1 Establishing PDU Session (assuming existing 5GS capabilities are used) p. 45
6.5.2.2 DNS behaviour at UE p. 45
6.5.2.3 UE IP Address in DNS Client Subnet Option p. 46
6.5.2.4 Provisioning Metrics in AF p. 47
6.5.2.5 AF Influenced Routes for Session Breakout p. 47
6.5.2.6 Flow Sequence Classic DNS and DoT p. 50
6.5.2.7 Flow Sequence for DoH p. 51
6.5.3 Impacts on services, entities and interfaces p. 52
6.6 Solution #6: Discovery of EAS based on DNS p. 52
6.6.1 Description p. 52
6.6.2 Procedures p. 54
6.6.3 Impacts on services, entities and interfaces p. 56
6.7 Solution #7: SMF/I-SMF selection based on DNAI p. 56
6.7.1 Solution description p. 56
6.7.1.1 General p. 56
6.7.2 Procedures p. 57
6.7.3 Impacts on services, entities and interfaces p. 60
6.8 Solution #8: Edge Application Server discovery using anycast DNS p. 60
6.8.1 Solution description p. 60
6.8.1.1 General p. 60
6.8.2 Procedures p. 60
6.8.3 Impacts on services, entities and interfaces p. 61
6.9 Solution #9: Assist DNS resolution without connectivity between local and central data network p. 62
6.9.1 Description p. 62
6.9.2 Procedures p. 63
6.9.3 Impacts on services, entities and interfaces p. 64
6.10 Solution #10: DNS for Distributed Anchor p. 65
6.10.1 Solution description p. 65
6.10.2 Procedures p. 66
6.10.2.1 High Level Procedure using DNS Distribution p. 66
6.10.2.2 High Level procedure using ECS Option p. 66
6.10.3 Impacts on services, entities and interfaces p. 67
6.11 Solution #11: DNS over HTTP p. 68
6.11.1 Solution description p. 68
6.11.1.1 General p. 68
6.11.1.2 Configuration of the UE p. 68
6.11.1.3 Example deployment architecture p. 68
6.11.2 Procedures p. 69
6.11.3 Impacts on services, entities and interfaces p. 69
6.12 Solution #12: PDU session re-anchoring p. 70
6.12.1 Solution description p. 70
6.12.2 Procedures p. 71
6.12.2.1 EAS Discovery triggered re-anchoring, KI#1 p. 71
6.12.2.2 Re-anchoring with AMF re-selecting different SMF, KI#5 p. 73
6.12.3 Impacts on services, entities and interfaces p. 75
6.13 Solution #13: 5GC support for UE selection of the DNS to use p. 76
6.13.1 Description p. 76
6.13.2 Procedures p. 80
6.13.2.1 Configuring DN priorities for appDomain information on PCF p. 80
6.13.2.2 Usage of DN priorities for appDomains information to configure URSP p. 80
6.13.2.3 SMF influence on UE preferences between multiple Recursive DNS Servers p. 81
6.13.3 Impacts on services, entities and interfaces p. 83
6.14 Solution #14: IP address discovery for the Service Switch mechanism - DNS handling in both UPF and EC p. 83
6.14.1 Description p. 83
6.14.1.1 Introduction p. 83
6.14.1.2 Solution description p. 84
6.14.2 Procedures p. 86
6.14.3 Impacts on services, entities and interfaces p. 87
6.15 Solution #15: IP address discovery for the Service Switch mechanism- DNS handling in UPF p. 87
6.15.1 Description p. 87
6.15.2 Procedures p. 88
6.15.2.1 Option 1: Supporting DNS handling function in UPF anchor p. 88
6.15.2.2 Option 2: Supporting DNS handling function in I-UPF(ULCL or BP) p. 89
6.15.3 Impacts on services, entities and interfaces p. 90
6.16 Solution #16: Edge Configuration Server Based Discovery p. 91
6.16.1 Introduction p. 91
6.16.2 Functional Description p. 92
6.16.3 Procedures p. 92
6.16.4 Impacts on services, entities and interfaces p. 93
6.17 Solution #17: Provisioning EC Parameters to the roaming UE related to PDU Sessions for edge applications p. 94
6.17.1 Description p. 94
6.17.2 Procedures p. 95
6.17.2.1 Provisioning EC Parameters the roaming UE related to PDU Sessions for edge applications p. 95
6.17.3 Impacts on services, entities and interfaces p. 95
6.18 Solution #18: Mapping the AS IP address to Edge Server IP address p. 95
6.18.1 Description p. 95
6.18.2 Procedures p. 96
6.18.3 Impacts on services, entities and interfaces p. 98
6.19 Solution #19: Edge Application Server discovery using an Address Resolution Function p. 98
6.19.1 Description p. 98
6.19.2 Procedures p. 99
6.19.2.1 General Procedure for ARF-based Solution p. 99
6.19.2.2 Procedure for UPF-based Solution p. 102
6.19.3 Impacts on services, entities and interfaces p. 105
6.20 Solution #20: DNS Inspector based EAS Discovery with UL CL p. 105
6.20.1 Description p. 105
6.20.2 Procedures p. 106
6.20.3 Impacts on services, entities and interfaces p. 107
6.21 Solution #21: Provisioning URSP configuration to the UE to establish PDU Sessions for edge applications based on Provisioning Domains p. 108
6.21.1 Description p. 108
6.21.2 Procedures p. 109
6.21.3 Impacts on services, entities and interfaces p. 110
6.22 Solution #22: DNS based EAS discovery supporting session breakout p. 110
6.22.1 Description p. 110
6.22.1.1 Deployment assumption of the solution p. 111
6.22.1.2 PDU session establishment p. 112
6.22.1.3 DNS resolution with Pre-established UL CL/BP/L-PSA p. 112
6.22.1.4 DNS resolution before and after Dynamic UL CL/BP/L-PSA insertion p. 112
6.22.2 Procedures p. 115
6.22.3 Impacts on services, entities and interfaces p. 118
6.23 Solution #23: DNS for AS Discovery at Edge Relocation p. 119
6.23.1 Solution description p. 119
6.23.2 Procedures p. 119
6.23.3 Impacts on services, entities and interfaces p. 123
6.24 Solution #24: Support of edge relocation, triggering of new DNS query by the UE p. 123
6.24.1 Solution description p. 123
6.24.2 Procedures p. 124
6.24.2.1 Distributed anchor and multiple sessions, SSC mode 3 p. 124
6.24.2.2 IPv6 multi homing with a BP p. 125
6.24.2.3 Session breakout using ULCL, UE is not aware of change of PSA for a flow p. 126
6.24.3 Impacts on services, entities and interfaces p. 126
6.25 Solution #25: Seamless Change of Edge for Stateful Applications p. 127
6.25.1 Description p. 127
6.25.2 Procedures p. 127
6.25.3 Impacts on services, entities and interfaces p. 131
6.26 Solution #26: Persistent address allocation for mobile UEs that need MEC access p. 131
6.26.1 Description p. 131
6.26.2 Procedures p. 131
6.27 Solution #27: Reducing packet loss during EAS relocation p. 132
6.27.1 Solution description p. 132
6.27.1.1 General p. 132
6.27.2 Procedures p. 133
6.27.3 Impacts on services, entities and interfaces p. 136
6.28 Solution #28: Supporting application server change based on AF notification p. 137
6.28.1 Description p. 137
6.28.2 Procedures p. 137
6.28.3 Impacts on services, entities and interfaces p. 139
6.29 Solution #29: CN-based edge relocation p. 140
6.29.1 General p. 140
6.29.2 Procedures p. 141
6.29.2.1 Procedure for edge relocation triggered by CN p. 141
6.29.2.2 Procedure for edge relocation triggered by application p. 142
6.29.2.3 Procedure for edge relocation triggered by application with application relocation exposure p. 143
6.29.2.4 Target AS IP address replacement procedures p. 144
6.29.3 Impacts on services, entities and interfaces p. 145
6.30 Solution #30: UE Agnostic EAS IP address replacement for traffic subject to edge computing p. 145
6.30.1 Description p. 145
6.30.2 Procedures p. 146
6.30.2.1 Example EAS IP address replacement procedures for different scenarios p. 146
6.30.2.1.1 EAS IP address replacement in the middle of EC Session p. 146
6.30.2.1.2 UE moves among EC Environments with DNAI and EAS IP address Change p. 147
6.30.2.1.3 EAS IP address Change under same DNAI due to EAS migration p. 148
6.30.2.1.4 From EC to Non-EC Environment due to UE Mobility p. 148
6.30.2.2 Impacts to existing 5GS procedures p. 149
6.30.2.2.1 AF Influence procedure p. 149
6.30.2.2.2 EAS IP address discovery p. 149
6.30.2.2.3 Initial EAS IP address replacement in Local PSA UPF p. 149
6.30.2.2.4 Triggering the EAS IP Address Replacement in Local PSA UPF after DNAI Change p. 150
6.30.2.2.5 AF triggered EAS migration in 5GC p. 150
6.30.3 Impacts on services, entities and interfaces p. 152
6.31 Solution #31 Application Relocation with UE assistance p. 152
6.31.1 General p. 152
6.31.2 Procedure for EAS relocation p. 153
6.31.3 Impacts on services, entities and interfaces p. 154
6.32 Solution #32: UE DNS cache flush p. 155
6.32.1 Description p. 155
6.32.2 Procedures p. 156
6.32.3 Impacts on services, entities and interfaces p. 156
6.33 Solution #33: IP preserving PSA relocation p. 157
6.33.1 Description p. 157
6.33.2 Procedures p. 158
6.33.2.1 PSA relocation triggered by UP event notification p. 158
6.33.2.2 PSA relocation (without UP event notification) p. 159
6.33.3 Impacts on services, entities and interfaces p. 160
6.34 Solution #34: Local DN notification to the UE during ULCL operations p. 161
6.34.1 Description p. 161
6.34.2 Procedures p. 163
6.34.2.1 Overview of local DN notification p. 163
6.34.2.2 Procedure for local DN notification control by PCF during local PSA insertion/relocation/removal p. 165
6.34.2.3 Procedure for AF requested local DN notification control during local PSA relocation p. 167
6.34.3 Impacts on services, entities and interfaces p. 169
6.35 Solution #35: Edge relocation considering with user plane latency requirement (SMF decision) p. 169
6.35.1 Description p. 169
6.35.2 Procedures p. 169
6.35.3 Impacts on services, entities and interfaces p. 170
6.36 Solution #36: Edge relocation considering user plane latency requirement (AF decision) p. 171
6.36.1 Description p. 171
6.36.2 Procedures p. 171
6.36.3 Impacts on services, entities and interfaces p. 172
6.37 Solution #37: AF-based EAS End-Point-Address update via External Parameter Provisioning p. 173
6.37.1 Description p. 173
6.37.2 Procedures p. 173
6.37.2.1 EAS-End Point update via Service Specific information Provisioning Procedures p. 173
6.37.2.2 EAS-End Point update via SMF-associated parameters Provisioning Procedures p. 175
6.37.3 Impacts on services, entities and interfaces p. 176
6.38 Solution #38: EAS change with reducing packet loss in uplink p. 176
6.38.1 Description p. 176
6.38.2 Procedures p. 177
6.38.2.1 Procedures for preventing packet loss in uplink with change of additional PSA p. 177
6.38.2.2 Procedures for preventing packet loss in uplink with simultaneous change of UL CL and additional PSA p. 179
6.38.3 Impacts on services, entities and interfaces p. 181
6.39 Solution #39: EAS relocation coordinated with PSA change p. 182
6.39.1 Description p. 182
6.39.2 Procedures p. 184
6.39.3 Impacts on services, entities and interfaces p. 185
6.40 Solution #40: Seamless change of Edge Application Sever for stateful applications by caching application status information in NEF p. 186
6.40.1 Description p. 186
6.40.2 Procedures p. 187
6.40.3 Impacts on services, entities and interfaces p. 188
6.41 Solution #41: Network Information Provisioning using the IP path p. 189
6.41.1 Solution description p. 189
6.41.2 Procedures p. 190
6.41.3 Impacts on services, entities and interfaces p. 190
6.42 Solution #42: Providing selected radio information to an App requiring it p. 191
6.42.1 Description p. 191
6.42.1.1 Overview p. 191
6.42.1.2 Variant relying on usage of MDT tracing p. 192
6.42.1.3 Variant relying on local NEF interrogating the MnS producer for NG RAN p. 193
6.42.2 Procedures p. 194
6.42.3 Impacts on services, entities and interfaces p. 196
6.43 Solution #43: Low Latency exposure API by using the distributed CAPIF framework feature p. 196
6.43.1 Introduction p. 196
6.43.2 Functional Description p. 197
6.43.3 Procedures p. 198
6.43.4 Impacts on existing entities and interfaces p. 199
6.44 Solution #44: Network Information Exposure to Local AF with Low Latency p. 199
6.44.1 Description p. 199
6.44.2 Procedures p. 200
6.44.3 Impacts on services, entities and interfaces p. 201
6.45 Solution #45: Using NAS message notify UE's application layer p. 201
6.45.1 Description p. 201
6.45.2 Procedures p. 203
6.45.3 Impacts on services, entities and interfaces p. 203
6.46 Solution #46: Local NEF Deployment for network information exposure to Local AF with Low Latency p. 203
6.46.1 Description p. 203
6.46.2 Procedures p. 204
6.46.3 Impacts on services, entities and interfaces p. 206
6.47 Solution #47: User Plane based Network Information Provisioning p. 206
6.47.1 Description p. 206
6.47.2 Procedures p. 207
6.47.3 Impacts on services, entities and interfaces p. 209
6.48 Solution #48: QoS monitoring information exposure based on unstructured data transmission mechanism p. 209
6.48.1 Description p. 209
6.48.2 Procedures p. 210
6.48.3 Impacts on services, entities and interfaces p. 210
6.49 Solution #49: Network Information Provisioning to EAS with low latency based on User Plane p. 211
6.49.1 Description p. 211
6.49.2 Procedures p. 212
6.49.3 Impacts on services, entities and interfaces p. 213
6.50 Solution #50: Activating the traffic routing towards Local Data Network per AF request p. 214
6.50.1 Description p. 214
6.50.2 Procedure p. 215
6.50.3 Impacts on services, entities and interfaces p. 216
6.51 Solution #51: Edge Relocation for all connectivity models p. 216
6.51.1 Solution description p. 216
6.51.2 Procedures p. 217
6.51.3 Impacts on services, entities and interfaces p. 219
6.52 Solution #52: Service Continuity at EAS relocation with PSA coexistence in session break-out scenarios p. 219
6.52.1 General p. 219
6.52.2 Procedures p. 220
6.52.2.1 Procedure for edge relocation triggered by the 5GC p. 220
6.52.2.2 Procedure for edge relocation triggered by the application p. 222
6.52.3 Impacts on services, entities and interfaces p. 224
6.53 Solution #53: Service Continuity at Edge Relocation with DNS triggered insertion of BP/ULCL and Edge PSA p. 224
6.53.1 General p. 224
6.53.2 Procedures p. 225
6.53.2.1 Edge Relocation Procedure p. 225
6.53.2.2 Edge Relocation procedure optimized with coordination via AF p. 226
6.53.3 Impacts on Existing Nodes and Functionality p. 228
6.54 Solution #54: EAS relocation for SSC mode 3 PDU Session p. 228
6.54.1 Description p. 229
6.54.2 Procedures p. 229
6.54.3 Impacts on services, entities and interfaces p. 230
6.55 Solution #55: Multiple AFs p. 230
6.55.1 Description p. 230
6.55.2 Procedures p. 231
6.55.3 Impacts on services, entities and interfaces p. 232
6.56 Solution #56: Edge NEF based Network Information Provisioning p. 232
