S5

GPRS Tunnelling Protocol User Plane (GTP-U)

in GTP-U, S4, S5, S8, Specification, LTE, S1, X2

GTP-U protocol is used over S1-U, X2, S4, S5 and S8 interfaces of the Evolved Packet System (EPS).

GTP-U Transport

in S4, S5, S8, Specification, UDP, IP, LTE, S1, X2

The transport layer for data streams over S1, X2, S4, S5 and S8  is an IP based Transport.