3GPP 23.501 v20.2.0 — the document's own text

5.34.5 Usage of IPv6 multi-homing for a PDU Session controlled by I-SMF

Taught in 26. Relays, satellites, femtos and shared networks (The 5G system architecture, in depth).

This clause applies only in the case of non-roaming or LBO roaming as control of UL CL/BP in VPLMN is not supported in HR case.

When I-SMF is involved for a PDU Session, it is possible that the BP controlled by I-SMF is inserted into the data path of the PDU Session. The usage of a BP controlled by I-SMF in the data path of a PDU Session is depicted in Figure 5.34.5-1.

Figure 5.34.5-1: Multi-homed PDU Session: Branching Point controlled by I-SMF

The I-SMF determines whether BP will be inserted based on information received from SMF and the I-SMF selects the UPFs acting as BP and/or PDU Session Anchor providing local access to the Data Network.