Section: 5.1.2.1 UE - P-GW user plane with E-UTRAN
Content: Legend: - GPRS Tunnelling Protocol for the user plane (GTP-U): This protocol tunnels user data between eNodeB and the S-GW as well as between the S-GW and the P-GW in the backbone network. GTP shall encapsulate all end user packets. End user Ethernet packets are only used with a combined PDN GW+SMF (as specified in TS 23.501[ System architecture for the 5G System (5GS) ]  [83]). - MME controls the user plane tunnel establishment and establishes User Plane Bearers between eNodeB and S-GW. - UDP/IP: These are the backbone network protocols used for routing user data and control signalling. - LTE-Uu: The radio protocols of E-UTRAN between the UE and the eNodeB are specified in TS 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [5]. Figure 5.1.2.1-1: User Plane