5G • RAN
NG-U Interface
N3 User Plane Interface
User plane reference point between gNodeB and User Plane Function (UPF) running GTP-U over UDP/IP.
Technical Explanation
The NG-U interface (N3 reference point) transports multi-gigabit user plane payload traffic between the radio access network and the 5G Core UPF. User packets are encapsulated in GTP-U headers carrying Tunnel Endpoint Identifiers (TEID) and QoS Flow Identifiers (QFI) for per-flow scheduling.
Key Functions
- Carries high-throughput user plane data traffic between gNodeB and UPF
- Encapsulates IP and Ethernet packets within GTP-U tunnels using TEIDs
- Conveys 6-bit QFI in GTP-U extension headers for end-to-end QoS enforcement
Specifications
3GPP TS 38.410, TS 29.281
Interfaces
N3NG-U
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