3GPP 23.501 v20.2.0 — the document's own text
5.28a.3 Topology Information for TSN TN
Taught in 22. Clocks, TSN and deterministic delivery (The 5G system architecture, in depth).
NG-RAN and UPF may support u-plane LLDP functionality to provide topology information to the TN. When LLDP is supported, AN-TL and CN-TL shall perform the LLDP functionality at the u-plane without the need to interact with the c-plane. Further there is no need for 5GS interaction with TN CNC directly. This is achieved with following measures:
- AN-TL and CN-TL implement the Transmit Only operation mode as defined in clause 9.1 of IEEE Std 802.1AB [97].
- The TSN End Station is pre-configured with parameter set for Transmit Only operating mode as defined in clause 9.2 of IEEE Std 802.1AB [97].
- The System Capabilities TLV may also be set to Station Only as defined in clause 8.5.8 of IEEE Std 802.1AB [97].