G.6.1 Scope of interception
33.1283GPPProtocol and procedures for Lawful Interception (LI)Release 18SecurityStage 3TS
The illustrations shown in the annex for the service type Messaging includes:
– MMS.
– SMS.
The interception for the MMS is done by the IRI-POI and CC-POI present in the MMS Proxy Relay. The interception for the SMS is done by the IRI-POI present in the SMSF and the MME (when MME provides the SMS service) and the IMS domain for SMS over IMS.
A target can be a subscriber of the CSP, an inbound roamer or a non-local ID. In the case where a target is a non-local ID, the party communicating with the target can be non-roaming, inbound roamer or outbound roamer. When a target is non-local ID, provisioning of HSS and LTF are not applicable.
For N9HR/S8HR, the LI functions for the inbound roamers are provided in the LMISF-IRI. To support the interception in LMISF-IRI, the initial configuration for N9HR/S8HR will have to be done as illustrated in clause G.5.2.
The interception of service type of Messaging includes:
– Delivery of IRI or CC based on the delivery type indicated in the warrant (the delivery of CC is applicable to MMS only).
– Whether a target is non-local ID.
– When required, the delivery of LALS reports based on the LALS triggering (applicable to SMS only).
In view of SMS over IMS, the CSP may have either an LBO based roaming architecture or a home-routed based roaming architecture. The CSP may have differing implementation options for LALS triggering.
Table G.6-1 shows the target identities that are applicable to different type of SMS use.
Table G.6-1: Target IDs as applicable to the interception of service type Messaging
|
SMS method |
GPSI |
SUPI |
PEI |
MSISDN |
IMSI |
IMEI |
IMPU |
IMPI |
|
MMS |
YES |
n/a |
n/a |
YES |
n/a |
n/a |
n/a |
n/a |
|
MMS (target non-local ID) |
YES |
n/a |
n/a |
YES |
n/a |
n/a |
n/a |
n/a |
|
SMS over IMS (local) |
YES (NOTE) |
As IMPI |
As IMEI |
YES (NOTE) |
As IMPI |
YES |
YES |
YES |
|
SMS over IMS (non-local ID) |
YES |
n/a |
n/a |
YES |
n/a |
n/a |
YES |
n/a |
|
SMS over 5GS |
YES |
YES |
YES |
As GPSI |
As SUPI |
As PEI |
n/a |
n/a |
|
SMS over 5GS (target non-local ID) |
YES |
n/a |
n/a |
As GPSI |
n/a |
n/a |
n/a |
n/a |
|
SMS over EPS |
n/a |
n/a |
n/a |
YES |
YES |
YES |
n/a |
n/a |
|
SMS over EPS (target non-local ID) |
n/a |
n/a |
n/a |
YES |
n/a |
n/a |
n/a |
n/a |
The target identity PEI collectively represents PEIIMEI and PEIIMEISV. Likewise, SUPI represents SUPIIMSI and SUPINAI whereas GPSI represents GPSIMISDN and GPSINAI. The target identity in the IMPI format may contain a value derived from a SUPI or an IMSI. The target identity in the IMPU format containing a SIP URI or TEL URI may contain a value derived from a GPSI, MSISDN, an E.164 number, or IMSI.
NOTE: The GPSI and MSISDN may also be the target IDs as an IMPU.
A part of LIPF logic is based on the target identity applicability shown in table G.6-1.