3GPP 23.501 v20.2.0 — the document's own text
5.34.2.2 Non-roaming architecture
Taught in 26. Relays, satellites, femtos and shared networks (The 5G system architecture, in depth).
Figure 5.34.2.2-1 depicts the non-roaming architecture with an I-SMF insertion to the PDU Session without UL-CL/BP, using reference point representation.

NOTE 1: N16a is the interface between SMF and I-SMF.
NOTE 2: N38 is the interface between I-SMFs.
Figure 5.34.2.2-2 depicts the non-roaming architecture for an I-SMF insertion to the PDU Session with UL-CL/BP, using reference point representation.

For Local Offloading Management scenario in TS 23.548 [130], the architecture in Figure 5.34.2.2-2 applies with an additional reference point N88a for interface between I-SMF and EASDF, which is not shown for simplicity.