5G • Core Network
GTP-U
GPRS Tunneling Protocol User Plane
UDP/IP encapsulation protocol transporting user plane packets across N3, N9, F1-U, and Xn-U interfaces.
Technical Explanation
GTP-U (specified in 3GPP TS 29.281) runs over UDP port 2152. It encapsulates user IP or Ethernet packets within a standardized header containing a 32-bit Tunnel Endpoint Identifier (TEID) and optional extension headers carrying the QoS Flow Identifier (QFI) and Downlink Data Delivery Status (DDDS).
Key Functions
- Encapsulates user data across radio access and core transport networks
- Operates over UDP port 2152 using 32-bit Tunnel Endpoint Identifiers (TEID)
- Carries 5G extension headers conveying QFI and flow control feedback
Specifications
3GPP TS 29.281
Interfaces
N3N9F1-UXn-U
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