29.281: General Packet Radio System (GPRS) Tunnelling Protocol User Plane (GTPv1-U)

Info Page @ 3GPP
Rel-13
v13.2.0
Rel-12
v12.1.0
Rel-11
v11.6.0
Rel-10
v10.3.0
Rel-9
v9.3.0
Rel-8
v8.5.0