3GPP 23.501 v20.2.0 — the document's own text
5.8.2.5.2 Data forwarding between the SMF and UPF
Taught in 13. Where the packets actually go (The 5G system architecture, in depth), 5. The connection, and what is promised on it (The 5G system architecture, overview).
Scenarios for data forwarding between the SMF and UPF are defined as below:
Table 5.8.2.5.2-1: Scenarios for data forwarding between the SMF and UPF
| Scenario description | Data forwarding direction | |
|---|---|---|
| 1 | Forwarding of user-plane packets between the UE and the SMF e.g. DHCP signalling. | UPF to SMFSMF to UPF |
| 2 | Forwarding of packets between the SMF and the external DN e.g. with DN-AAA server | UPF to SMFSMF to UPF |
| 3 | Forwarding of packets subject to buffering in the SMF. | UPF to SMFSMF to UPF |
| 4 | Forwarding of End Marker Packets constructed by the SMF to a downstream node. | SMF to UPF |
| 5 | Forwarding of user data using Control Plane CIoT 5GS Optimisation | UPF to SMFSMF to UPF |