ETSI TS 133 128 V19.6.0 (2026-04)

Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; 5G; Security; Protocol and procedures for Lawful Interception (LI); Stage 3 (3GPP TS 33.128 version 19.6.0 Release 19)

RTS/TSGS-0333128vj60

General Information

• Status: Not Published
• Technical Committee: 3GPP SA 3 - Security
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Completion Date: 02-Apr-2026

Standards Content (Sample)

TECHNICAL SPECIFICATION
Digital cellular telecommunications system (Phase 2+) (GSM);
Universal Mobile Telecommunications System (UMTS);
LTE;
5G;
Security;
Protocol and procedures for Lawful Interception (LI);
Stage 3
(3GPP TS 33.128 version 19.6.0 Release 19)


3GPP TS 33.128 version 19.6.0 Release 19 1 ETSI TS 133 128 V19.6.0 (2026-04)

Reference
RTS/TSGS-0333128vj60
Keywords
5G,GSM,LTE,UMTS
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ETSI
3GPP TS 33.128 version 19.6.0 Release 19 2 ETSI TS 133 128 V19.6.0 (2026-04)
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ETSI
3GPP TS 33.128 version 19.6.0 Release 19 3 ETSI TS 133 128 V19.6.0 (2026-04)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 22
Introduction . 22
1 Scope . 23
2 References . 23
3 Definitions, symbols and abbreviations . 29
3.1 Definitions . 29
3.2 Symbols . 29
3.3 Abbreviations . 29
4 General . 30
4.1 Introduction . 30
4.2 Basic principles for internal interfaces . 32
4.3 Basic principles for external handover interfaces . 33
4.4 Service scoping . 34
4.4.1 General . 34
4.4.2 CSP service type . 34
4.4.3 Delivery type . 34
4.4.4 Location Reporting . 35
4.4.5 LALS Triggering . 35
4.4.6 Roaming Interception . 35
4.5 LI product filtering . 35
4.5.1 General . 35
4.5.2 Traffic policies . 35
5 Transport and Communications Protocol . 36
5.1 General . 36
5.2 Protocols for LI_X1 and LI_T interfaces . 36
5.2.1 General usage of ETSI TS 103 221-1 . 36
5.2.2 Usage for realising LI_X1 . 36
5.2.2.1 General . 36
5.2.2.2 Provisioning of the MDF2 and MDF3 . 37
5.2.2.2.1 General . 37
5.2.2.2.2 ActivateTask message for the MDF2 and MDF3 . 37
5.2.2.2.3 MediationDetails for the MDF2 and MDF3 . 38
5.2.2.3 Provisioning of the POIs and TFs . 38
5.2.2.3.1 General . 38
5.2.2.3.2 ActivateTask message for the POIs and TFs . 38
5.2.3 Usage for realising LI_X1 (management) . 38
5.2.4 Service scoping . 38
5.2.5 Usage for realising LI_T2 and LI_T3 . 39
5.2.6 Void . 40
5.2.7 Usage for realising LI_XEM1 . 40
5.2.8 Traffic policies . 41
5.3 Protocols for LI_X2 and LI_X3 . 41
5.3.1 General usage of ETSI TS 103 221-2 . 41
5.3.2 Usage for realising LI_X2 . 42
5.3.3 Usage for realising LI_X3 . 43
5.3.4 Service scoping . 43
5.3.5 Usage for realising LI_X2_LA . 43
5.4 Protocols for LI_HI1 . 44
5.4.1 General . 44
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5.4.2 Service scoping . 44
5.4.3 Location acquisition . 45
5.4.4 Traffic policies . 45
5.5 Protocols for LI_HI2 and LI_HI3 . 45
5.5.1 General . 45
5.5.2 Usage for realising LI_HI2 . 46
5.5.3 Usage for realising LI_HI3 . 47
5.5.4 Service scoping . 48
5.5.5 IRI Target Identifiers . 48
5.6 Protocols for LI_HI4 . 48
5.6.1 General . 48
5.6.2 Usage for realising LI_HI4 . 48
5.7 Protocols for LI_HIQR . 48
5.7.1 General . 48
5.7.2 Usage for realising LI_HIQR. 49
5.7.2.1 Request structure . 49
5.7.2.2 Request parameters . 49
5.7.2.3 Response structure . 51
5.8 Protocols for LI_XQR . 52
5.8.1 General . 52
5.8.2 Identity association requests . 52
5.8.3 Ongoing identity association requests. 52
5.8.4 Latest association requests . 53
5.9 Protocols for LI_XER . 53
5.10 Protocols for LI_ST interface . 54
5.10.1 Overview . 54
5.10.2 Storage . 54
5.10.3 Retrieval . 54
5.10.4 Removal . 54
5.11 Protocols for LI_HILA . 54
5.11.1 General . 54
5.11.2 Usage for realising LI_HILA . 55
5.11.2.1 Request structure . 55
5.11.2.2 Request parameters . 55
5.11.2.3 Response structure . 56
5.12 Protocols for LI_XLA . 58
5.12.1 General . 58
5.12.2 Usage for realising LI_XLA . 58
6 Network Layer Based Interception . 59
6.1 Introduction . 59
6.2 5G . 60
6.2.1 General . 60
6.2.2 LI at AMF . 60
6.2.2.1 Provisioning over LI_X1 . 60
6.2.2.1.1 General . 60
6.2.2.2 Generation of xIRI over LI_X2 . 61
6.2.2.2.1 General . 61
6.2.2.2.1A Simple data types for AMF . 61
6.2.2.2.2 Registration . 61
6.2.2.2.3 Deregistration . 64
6.2.2.2.4 Location update . 65
6.2.2.2.5 Start of interception with registered UE . 67
6.2.2.2.6 AMF unsuccessful procedure . 68
6.2.2.2.7 AMF identifier association/deassociation . 69
6.2.2.2.8 Positioning info transfer . 71
6.2.2.2.9 Handovers . 72
6.2.2.2.10 UE Configuration Update . 74
6.2.2.2.11 Trace . 75
6.2.2.2.11.1 General . 75
6.2.2.2.11.2 AMF RAN trace report . 76
6.2.2.2.12 UE policy transfer. 77
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3GPP TS 33.128 version 19.6.0 Release 19 5 ETSI TS 133 128 V19.6.0 (2026-04)
6.2.2.2.13 Service Accept . 77
6.2.2.2.14 UE context update . 78
6.2.2.2A Definitions for AMF message Types . 79
6.2.2.2A.1 Type: InitialRANUEContextSetup . 79
6.2.2.2A.2 Type: PDUSessionSetupRequestItem . 80
6.2.2.2A.3 Type: UERadioCapability . 81
6.2.2.2A.4 Type: UERadioCapabilityForPaging . 81
6.2.2.2A.5 Type: NRV2XServicesAuthorization . 81
6.2.2.2A.6 Type: LTEV2XServicesAuthorization . 82
6.2.2.2A.7 Type: TargetNSSAIInfo . 82
6.2.2.2A.8 Type: FiveGProSeAuthorizationIndication . 82
6.2.2.2A.9 Enumeration: IABAuthorizedIndicator . 83
6.2.2.2A.10 Enumeration: V2XUEAuthorizationIndicator . 83
6.2.2.2A.11 Enumeration: FiveGProSeAuthorizationIndicator . 83
6.2.2.2A.12 Type: UEDifferentiationInfo . 83
6.2.2.2A.13 Enumeration: MobileIABAuthorizedIndicator . 84
6.2.2.2A.14 Type: NASTransportInitialInformation . 84
6.2.2.2A.15 Type: RANUEContextModification . 85
6.2.2.2A.16 Type: RANDownlinkNASTransport . 86
6.2.2.3 Generation of IRI over LI_HI2 . 87
6.2.2.4 Identity privacy . 88
6.2.2A Identifier Reporting for AMF . 88
6.2.2A.1 Activation of reporting over LI_XEM1 . 88
6.2.2A.2 Generation of records over LI_XER . 88
6.2.2A.2.2 Association Events . 89
6.2.2A.2.3 Transmission to the ICF . 90
6.2.2A.2.4 Additional location reporting . 90
6.2.2A.2.4.1 Type: AdditionalCGIs . 90
6.2.2A.2.4.2 Type: AdditionalNCGI . 90
6.2.3 LI for SMF/UPF . 91
6.2.3.1 Provisioning over LI_X1 . 91
6.2.3.1.1 General . 91
6.2.3.1.2 Provisioning of the IRI-POI, IRI-TF and CC-TF in the SMF . 91
6.2.3.1.3 Provisioning of the MDF2 . 92
6.2.3.1.4 Provisioning of the MDF3 . 92
6.2.3.2 Generation of xIRI at IRI-POI in SMF over LI_X2 . 93
6.2.3.2.1 General . 93
6.2.3.2.2 PDU session establishment . 93
6.2.3.2.3 PDU session modification . 99
6.2.3.2.4 PDU session release . 102
6.2.3.2.5 Start of interception with an established PDU session . 104
6.2.3.2.6 SMF unsuccessful procedure . 106
6.2.3.2.7 MA PDU sessions. 110
6.2.3.2.8 PDU to MA PDU session modification . 123
6.2.3.2.9 ProSe remote UE report . 124
6.2.3.2.10 Start of interception with connected ProSe remote UE . 125
6.2.3.3 Triggering of the IRI-POI/CC-POI in the UPF from IRI-TF/CC-TF in the SMF . 126
6.2.3.3.1 LI_T2/LI_T3 interface specifics . 126
6.2.3.3.2 CC interception with multi-homed PDU session . 127
6.2.3.3.3 CC Interception only at PDU Session Anchor UPFs . 127
6.2.3.4 Additional details for triggering the IRI-POI in the UPF . 127
6.2.3.5 Generation of xIRI at UPF over LI_X2. 128
6.2.3.5.1 Packet data header reporting . 128
6.2.3.5.2 Fragmentation . 128
6.2.3.5.3 Packet Data Header Report (PDHR) . 128
6.2.3.5.4 Packet Data Summary Report (PDSR) . 128
6.2.3.6 Generation of xCC at CC-POI in the UPF over LI_X3 . 128
6.2.3.7 Generation of IRI over LI_HI2 . 129
6.2.3.8 Generation of CC over LI_HI3 . 130
6.2.3.9 Packet header information reporting . 130
6.2.3.9.1 General . 130
6.2.3.9.2 Provisioning details . 131
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6.2.3.9.3 PDHeaderReport record (deprecated) . 131
6.2.3.9.4 PDSummaryReport record (deprecated) . 132
6.2.3.9.5 Usage of the Internet Protocol Packet Reporting record . 134
6.2.3.10 Sharing LI state information over LI_ST . 134
6.2.3.10.1 Overview . 134
6.2.3.10.2 Storing LI state . 134
6.2.3.10.3 Retrieving LI state . 135
6.2.3.10.4 Removing LI state . 136
6.2.4 LI at UDM for 5G . 136
6.2.4.1 General description . 136
6.2.5 LI at SMSF . 136
6.2.5.1 Provisioning over LI_X1 . 136
6.2.5.2 Generation of xIRI over LI_X2 . 137
6.2.5.3 SMS Message . 137
6.2.5.4 Generation of IRI over LI_HI2 . 140
6.2.6 LI support at NRF . 141
6.3 4G . 141
6.3.1 General . 141
6.3.2 LI at MME . 141
6.3.2.1 Provisioning over LI_X1 . 141
6.3.2.2 Generation of xIRI over LI_X2 . 142
6.3.2.2.1 General . 142
6.3.2.2.2 MME identifier association/deassociation . 143
6.3.2.2.3 Attach . 144
6.3.2.2.4 Detach . 145
6.3.2.2.5 Tracking Area/EPS Location update . 147
6.3.2.2.6 Start of interception with EPS attached UE . 148
6.3.2.2.7 MME unsuccessful procedure . 149
6.3.2.2.8 Positioning info transfer . 150
6.3.2.2.9 Handovers . 151
6.3.2.2.10 Trace . 153
6.3.2.2.10.1 General . 153
6.3.2.2.10.2 MME RAN trace report . 153
6.3.2.2.11 Service Accept . 154
6.3.2.2A Definitions for MME message Types . 154
6.3.2.2A.1 Simple data types . 154
6.3.2.2A.2 Type: EPSHandoverType . 155
6.3.2.2A.3 Type: ERABContextList . 155
6.3.2.2A.4 Type: ERABContext . 155
6.3.2.2A.5 Type: ERABReleaseList. 155
6.3.2.2A.6 Type: ERABError . 156
6.3.2.2A.7 Type: EPSRANCause . 156
6.3.2.2A.8 Type: EPSHandoverRestrictionList . 156
6.3.2.2A.9 Type: EPSCSGInfo . 156
6.3.2.2A.10 Type: EPSProSeAuthorization . 157
6.3.2.2A.11 Type: EPSSubscriptionBasedUEDifferentiationIndication . 157
6.3.2.2A.12 Type: S1Information . 157
6.3.2.2A.13 Type: MMEServedGUMMEIList . 158
6.3.2.2A.14 Type: MMEServedGUMMEI . 158
6.3.2.2A.15 Type: EPSNASTransportInitialInformation . 158
6.3.2.2A.16 Type: BBFTunnelInformation . 159
6.3.2.2A.17 Type: LTENTNTAIInformation . 159
6.3.2.2A.18 Type: EPSRANUEContext. 160
6.3.2.2A.19 Enumeration: EPSCSFallbackIndicator . 161
6.3.2.3 Generation of IRI over LI_HI2 . 161
6.3.2.3.1 General . 161
6.3.2.3.2 Option A . 161
6.3.2.3.3 Option B and Option C . 162
6.3.3 LI at SGW/PGW and ePDG . 162
6.3.3.0 General . 162
6.3.3.1 Provisioning over LI_X1 . 162
6.3.3.1.1 General . 162
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3GPP TS 33.128 version 19.6.0 Release 19 7 ETSI TS 133 128 V19.6.0 (2026-04)
6.3.3.1.2 Non-CUPS Architecture . 164
6.3.3.1.3 CUPS Architecture . 164
6.3.3.1.4 Provisioning of the MDF2 . 164
6.3.3.1.5 Provisioning of the MDF3 . 164
6.3.3.2 Generation of xIRI over LI_X2 . 165
6.3.3.2.1 General . 165
6.3.3.2.2 PDN Connection Establishment or PDU Session Establishment in interworked EPS/5GS . 165
6.3.3.2.3 PDN Con
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