Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); General Packet Radio Service (GPRS); GPRS Tunnelling Protocol (GTP) across the Gn and Gp interface (V9.4.0; 3GPP TS 29.060 version 9.4.0 Release 9)
The present document defines the second version of GTP used on: ?the Gn and Gp interfaces of the General Packet Radio Service (GPRS); ? the Iu@ Gn and Gp interfaces of the UMTS system. NOTE: The version number used in the message headers is 0 for the first version of GTP described in GSM 09.60@ and 1 for the second version in 3GPP TS 29.060. From release 8 onwards@ the normative specification of the user plane of GTP version 1 is 3GPP TS 29.281 [41]. All provisions about GTPv1 user plane in the present document shall be superseded by 3GPP TS 29.281 [41].