TS29.244-g30 5.7 Support of Lawful Interception

5.7 Support of Lawful Interception

5.7.1 General

This clause specifies lawful interception with PFCP in EPC.

5.7.2 Lawful Interception in EPC

Requirements for support of Lawful Interception with a split SGW or PGW are specified in clauses 12.9 and 20.4 of 3GPP TS 33.107 [20].

User plane packets shall be forwarded from the UP function to the SX3LIF (or LMISF for S8HR) by encapsulating the user plane packets using GTP-U encapsulation (see 3GPP TS 29.281 [3]).

The CP function shall instruct the UP function to duplicate the packets to be intercepted and to forward them to the SX3LIF (or to the LMISF for S8HR) as specified in clause 5.2.3.

For forwarding data from the UP function to the SX3LIF (or LMISF for S8HR), the CP function shall set the DUPL flag in the Apply Action and set the Duplicating Parameters in the FAR, associated to the PDRs of the traffic to be intercepted, with the Destination Interface "LI Function" and set to perform GTP-U encapsulation and to forward the packets to a GTP-u F-TEID uniquely assigned in the SX3LIF (or LMISF for S8HR) for the traffic to be intercepted. The SX3LIF (or LMISF for S8HR) shall then identify the intercepted traffic by the F-TEID in the header of the encapsulating GTP-U packet.

5.7.3 Lawful Interception in 5GC

Requirements for support of Lawful Interception with SMF and UPF are specified in clauses 6.2.3 of 3GPP TS 33.127 [47]. The PFCP protocol is not used for Lawful Interception in 5GC.