Content for TR 23.794 Word version: 17.0.0
5 Key Issues p. 10
5.1 Key Issue 1: Routing of IMS traffic via a localized UPF p. 10
5.2 Key Issue 2: Placement of IMS application server in localized environments p. 10
5.3 Key Issue 3: Network Slicing and IMS p. 11
5.4 Key Issue 4: Discovery of Network Functions p. 13
5.5 Key Issue 5: Enabling SBA-based Cx p. 14
5.6 Key Issue 6: Enabling SBA-based Sh p. 14
5.7 Key Issue 7: How can IMS utilize services provided by Npcf p. 14
5.8 Key Issue #8: How can IMS utilize services provided by 5GC NFs other than PCF p. 15
6 Solutions p. 15
6.1 Solution 1: Entire IMS in localized network p. 15
6.1.1 Description p. 15
6.1.1.1 General p. 15
6.1.1.2 Architecture p. 15
6.1.1.3 Determination of Localized Routing p. 16
6.1.1.4 Mobility Aspects p. 16
6.1.2 Impacts on existing nodes and functions p. 17
6.1.3 Solution Evaluation p. 17
6.2 Solution 2: IMS AS Influences routing of IMS media traffic as a 5G AF p. 17
6.2.1 Description p. 17
6.2.1.1 General p. 17
6.2.1.2 Architecture p. 17
6.2.1.3 Establishment Procedure p. 18
6.2.1.4 Mobility Aspects p. 19
6.2.2 Impacts on existing nodes and functions p. 20
6.2.3 Solution Evaluation p. 20
6.3 Solution 3: P-CSCF Influences routing of IMS media traffic as a 5G AF p. 20
6.3.1 Description p. 20
6.3.1.1 General p. 20
6.3.1.2 Architecture p. 20
6.3.1.3 Establishment Procedure p. 21
6.3.1.4 Mobility Aspects p. 22
6.3.2 Impacts on existing nodes and functions p. 23
6.3.3 Solution Evaluation p. 23
6.4 Solution 4: Multi-homing based PSA addition to the PDU Session for IMS for localized routing p. 23
6.4.1 Description p. 23
6.4.2 Impacts on existing nodes and functions p. 25
6.4.3 Solution Evaluation p. 26
6.5 Solution 5: Routing of IMS traffic via a localised UPF with two IP addresses p. 26
6.5.1 Description p. 26
6.5.2 Impacts on existing nodes and functions p. 27
6.5.3 Solution Evaluation p. 27
6.6 Solution 6: Routing of IMS traffic via a localised UPF with three IP addresses p. 27
6.6.1 Description p. 27
6.6.2 Impacts on existing nodes and functions p. 29
6.6.3 Solution Evaluation p. 29
6.7 Solution 7: IMS traffic local routing by applying AF influence mechanism p. 29
6.7.1 Description p. 29
6.7.2 Impacts on existing nodes and functions p. 31
6.7.3 Solution Evaluation p. 31
6.8 Solution 8: Application Function influence on network slice selection p. 31
6.8.1 Description p. 31
6.8.2 Impacts on existing nodes and functions p. 34
6.8.3 Solution Evaluation p. 34
6.9 Solution 9: Enhancements to Npcf services to support IMS functionality p. 35
6.9.1 Description p. 35
6.9.2 Impacts on existing nodes and functions p. 36
6.9.3 Solution Evaluation p. 37
6.10 Solution 10: Reuse of UDM services and operations for SBA-based Sh interface p. 37
6.10.1 Description p. 37
6.10.2 Impacts on existing nodes and functions p. 38
6.10.3 Solution Evaluation p. 38
6.11 Solution 11: Procedure for UE to route IMS traffic via multiple 5GC network slices to the same IMS network p. 38
6.11.1 Description p. 38
6.11.1.1 General p. 38
6.11.1.2 Procedure to route IMS traffic via different 5GC network slice p. 41
6.11.2 Impacts on existing nodes and functions p. 43
6.11.3 Solution Evaluation p. 43
6.12 Solution 12: New SBA services dedicated for Cx Operations p. 43
6.12.1 Solution overview p. 43
6.12.1.2 IMS Ncx Services p. 44
6.12.1.3 IMS procedure examples using SBA (Ncx Service Operations) p. 45
6.12.1.3.1 IMS Initial Registration p. 46
6.12.1.3.2 Subsequent IMS Registration p. 47
6.12.1.3.3 Network Initiated De-Registration p. 47
6.12.1.3.4 P-CSCF Restoration (HSS Option)/S-CSCF initiated Deregistration p. 48
6.12.1.4 IMS Ncx service Operations dedicated to Cx p. 49
6.12.2 Impacts on existing nodes and functions p. 49
6.12.3 Solution Evaluation p. 49
6.13 Solution 13: Reuse services and operations of UDM and NRF for SBA-based Cx interface p. 49
6.13.1 Description p. 49
6.13.2 Impacts on existing nodes and functions p. 52
6.13.3 Solution Evaluation p. 52
6.14 Solution 14: IMS utilize services provided by Npcf p. 52
6.14.1 Description p. 52
6.14.2 Impacts on existing nodes and functions p. 53
6.14.3 Solution Evaluation p. 53
6.15 Solution 15: IMS utilize services provided by AMF p. 53
6.15.1 Description p. 53
6.15.2 Impacts on existing nodes and functions p. 54
6.15.3 Solution Evaluation p. 54
6.16 Solution 16: Enabling SBI-based Sh Using New Service p. 55
6.16.1 Description p. 55
6.16.1a Sh Data Parameters p. 55
6.16.1a.1 IMS subscription related data p. 56
6.16.1a.2 IMS subscriber context data p. 57
6.16.1a.3 IMS operational data p. 57
6.16.1a.4 IMS-AS Repository and vendor specific data p. 57
6.16.2 Mapping of Sh Procedure to SBA Services p. 58
6.16.3 Additional Requirements p. 60
6.16.4 Impacts on existing nodes and functions p. 60
6.16.5 Solution Evaluation p. 60
6.17 Solution 17: Slicing information carried in the IMS registration and for T-ADS p. 60
6.17.1 Description p. 60
6.17.2 Registration Procedure p. 61
6.17.3 MT Procedure p. 62
6.17.4 Impacts on existing nodes and functions p. 62
6.17.5 Solution Evaluation p. 62
6.18 Solution 18: NRF based P-CSCF discovery p. 63
6.18.1 Description p. 63
6.18.1A P-CSCF selection p. 63
6.18.2 Impacts on existing nodes and functions p. 63
6.18.3 Solution Evaluation p. 64
6.19 Solution 19: IMS signalling and media of an application through one 5GC slice p. 64
6.19.1 Description p. 64
6.19.2 Impacts on existing nodes and functions p. 66
6.19.3 Solution Evaluation p. 66
6.20 Solution 20: Selection of Rx or N5 based on P-GW trunk id. p. 66
6.20.1 Description p. 66
6.20.2 Impacts to Existing Nodes and Functions p. 67
6.20.3 Evaluation p. 67
6.21 Solution 21: Selection of Nx or N5 based on UE Contact IP address p. 67
6.21.1 Description p. 67
6.21.2 Impacts to Existing Nodes and Functions p. 67
6.21.3 Evaluation p. 68
6.22 Solution 22: IMS services for SBA-based Cx interface p. 68
6.22.1 Description p. 68
6.22.2 Impacts on existing nodes and functions p. 70
6.22.3 Solution Evaluation p. 71
6.23 Solution 23: IMS services for SBA-based Sh interface p. 71
6.23.1 Description p. 71
6.23.2 Impacts on existing nodes and functions p. 73
6.23.3 Solution Evaluation p. 74
6.24 Solution 24: PCF discovery and selection for IMS p. 74
6.24.1 Description p. 74
6.24.2 Impacts on existing nodes and functions p. 74
6.24.3 Solution Evaluation p. 74
6.25 Solution 25: Selection of Nx or N5 based on two different P-CSCF FQDN/IP@ p. 74
6.25.1 Description p. 74
6.25.2 Impacts to Existing Nodes and Functions p. 75
6.25.3 Evaluation p. 75
6.26 Solution 26: Use of NRF for User identity to HSS resolution p. 76
7 Overall Evaluation p. 80
7.1 Evaluation of solutions addressing key issue #5 p. 80
7.2 Evaluation of solutions addressing key issue #6 p. 81
8 Conclusions p. 82
8.1 Conclusions Related to Key Issue #4 p. 82
8.2 Conclusions for Key Issue #5 and Key Issue #6 p. 82
8.3 Conclusions Related to Key Issue #7 p. 82
8.4 Conclusions Related to Key Issues #1, #2, #3 and #8 p. 83
$ Change History p. 84
