3GPP TS 38.474 V15.0.0 (2018-01)Technical Specification3rd Generation Partnership Project;Technical Specification Group Radio Access Network; NG-RAN;F1 data transport(Release 15)The present document has been developed within the 3rd Generation Partnership Project (3GPP TM) and may be further elaborated for the purposes of 3GPP.The present document has not been subject to any approval process by the 3GPP Organizational Partners and shall not be implemented.This Specification is provided for future development work within 3GPP only. The Organizational Partners accept no liability for any use of this Specification.Specifications and Reports for implementation of the 3GPP TM system should be obtained via the 3GPP Organizational Partners Publications Offices.3GPP TS 38.474 V15.0.0 (2018-01)8Release 15KeywordsRadio, access3GPPPostal address3GPP support office address650 Route des Lucioles Sophia AntipolisValbonne FRANCETel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16Internethttp:/www.3gpp.orgCopyright NotificationNo part may be reproduced except as authorized by written permission.The copyright and the foregoing restriction extend to reproduction in all media. 2018, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC).All rights reserved.UMTS is a Trade Mark of ETSI registered for the benefit of its members3GPP is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational PartnersLTE is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational PartnersGSM and the GSM logo are registered and owned by the GSM AssociationContentsForeword41Scope52References53Definitions and abbreviations53.1Definitions53.2Abbreviations64Data Link Layer65F1 Interface user plane protocol65.1General65.2GTP-U65.3UDP/IP65.4Diffserv code point marking7Annex A (informative): Change history8ForewordThis Technical Specification has been produced by the 3rd Generation Partnership Project (3GPP).The contents of the present document are subject to continuing work within the TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an identifying change of release date and an increase in version number as follows:Version x.y.zwhere:xthe first digit:1presented to TSG for information;2presented to TSG for approval;3or greater indicates TSG approved document under change control.Ythe second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates, etc.zthe third digit is incremented when editorial only changes have been incorporated in the document.1ScopeThe present document specifies the standards for user data transport protocols and related signalling protocols to establish user plane transport bearers over the F1 interface. The F1 interface provides means for interconnecting a gNB-CU and a gNB-DU of a gNB within an NG-RAN, or for interconnection a gNB-CU and a gNB-DU of an en-gNB within an E-UTRAN.2ReferencesThe following documents contain provisions which, through reference in this text, constitute provisions of the present document.-References are either specific (identified by date of publication, edition number, version number, etc.) or nonspecific.-For a specific reference, subsequent revisions do not apply.-For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.13GPP TR 21.905: Vocabulary for 3GPP Specifications.23GPP TS 29.281: General Packet Radio System (GPRS) Tunnelling Protocol User Plane (GTPv1-U).3IETF RFC 768 (1980-08): User Datagram Protocol.4IETF RFC 2474 (1998-12): Definition of the Differentiated Services Field (DS Field) in the Ipv4 and Ipv6 Headers.5IETF RFC 2460 (1998-12): Internet Protocol, Version 6 (Ipv6) Specification.6IETF RFC 791 (1981-09): Internet Protocol.73GPP TS 38.300: NR; Overall description; Stage-2.83GPP TS 38.401: NG-RAN; Architecture Description.93GPP TS 37.340: NR; Multi-connectivity; Overall description; Stage-2.3Definitions and abbreviations3.1DefinitionsFor the purposes of the present document, the terms and definitions given in 3GPP TR21.9051 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in 3GPP TR21.9051.en-gNB: as defined in TS 37.340 9.F1: interface between a gNB-DU and a gNB-CU, providing an interconnection point between the gNB-DU and the gNB-CU. gNB-CU: as defined in TS 38.401 8.gNB-DU: as defined in TS 38.4