The SCEF in the home network and the IWK-SCEF in the visited network shall provide both IRI-POI and CC-POI functions.
Figure 7.11-1 gives a reference point representation of the LI architecture with SCEF as a CP NF and UP NF providing the IRI-POI and CC-POI functions for NIDD using SCEF. SCEF is the anchor point for PDN connection establishment and NIDD traffic.
The LIPF present in the ADMF provisions the intercept information associated with the following target identities to the IRI-POI present in the SCEF:
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IMSI.
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MSISDN.
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External Identifier.
The interception performed on the above three identities are mutually independent, even though, an xIRI may contain the information about the other identities when available.
The IRI-POI in the SCEF/IWK-SCEF shall generate xIRI when it detects the following specific events or information in both roaming and non-roaming situations:
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PDN connection establishment.
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PDN connection update.
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PDN connection release.
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Start of interception with established PDN connection.
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Unsuccessful procedure.
The PDN connection establishment xIRI is generated when the IRI-POI present in the SCEF/IWK-SCEF detects that a PDN connection for NIDD using SCEF has been established for the target UE. The SCEF plays the role of anchor point for that PDN connection.
The PDN connection update xIRI is generated when the IRI-POI present in the SCEF/IWK-SCEF detects that a PDN connection for NIDD using SCEF is modified for the target UE.
The PDN connection release xIRI is generated when the IRI-POI present in the SCEF/IWK-SCEF detects that a PDN connection for NIDD using SCEF is released for the target UE.
The start of interception with an established PDN connection xIRI is generated when the IRI-POI present in a SCEF/IWK-SCEF detects that interception is activated on the target UE that has an already established PDN connection for NIDD using SCEF in the EPS. When a target UE has multiple PDN connections, this xIRI shall be sent for each PDN connection with a different value of correlation information.
When additional warrants are activated on a target UE, MDF2 shall be able to generate and deliver the start of interception with an established PDN connection related IRI messages to the LEMF associated with the warrants without receiving the corresponding start of interception with an established PDN connection xIRI.
The unsuccessful procedure xIRI is generated when the IRI-POI present in the SCEF/IWK-SCEF detects an unsuccessful procedure for PDN connection establishment, update, release or data delivery, data reception.
SCEF/IWK-SCEF generates xCC for NIDD using SCEF if CC is requested.