1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T G.8112/Y.1371 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1 (08/2017) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Packet over Transport aspects MPLS over Transport aspects SERIES Y:
2、GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS, NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES Internet protocol aspects Transport Interfaces for the MPLS transport profile layer network Amendment 1 Recommendation ITU-T G.8112/Y.1371 (2015) Amendment 1 ITU-T G-SERIES REC
3、OMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALL
4、IC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 D
5、IGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000
6、G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 Ethernet over Transport aspects G.8000G.8099 MPLS over Transport aspects G.8100G.8199 Synchronization, quality and availability targets G.8200G.8299 Service Management G.8600G.8699 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the
7、 list of ITU-T Recommendations. Rec. ITU-T G.8112/Y.1371 (2015)/Amd.1 (08/2017) i Recommendation ITU-T G.8112/Y.1371 Interfaces for the MPLS transport profile layer network Amendment 1 Summary Recommendation ITU-T G.8112/Y.1371 specifies the interfaces for the multi-protocol label switching transpor
8、t profile (MPLS-TP) layer network. The interfaces for the MPLS-TP layer network use various server layer networks, like the plesiochronous digital hierarchy (PDH), synchronous digital hierarchy (SDH), optical transport hierarchy (OTH) and the Ethernet MAC layer network (ETH). Amendment 1 avoids rede
9、fining terms already defined in Recommendations ITU-T G.8001/Y.1354 and ITU-T G.8101/Y.1355 by referencing these Recommendations. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.8112/Y.1371 2006-10-07 15 11.1002/1000/8783 1.1 ITU-T G.8112/Y.1371 (2006) Cor. 1 2007-01-09 15
10、 11.1002/1000/9006 2.0 ITU-T G.8112/Y.1371 2012-10-29 15 11.1002/1000/11772 2.1 ITU-T G.8112/Y.1371 (2012) Amd. 1 2014-04-04 15 11.1002/1000/12187 2.2 ITU-T G.8112/Y.1371 (2012) Cor. 1 2015-01-13 15 11.1002/1000/12385 3.0 ITU-T G.8112/Y.1371 2015-08-13 15 11.1002/1000/12547 3.1 ITU-T G.8112/Y.1371 (
11、2015) Amd. 1 2017-08-13 15 11.1002/1000/13315 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T G.8112/Y.1371 (2015)/Amd.1 (0
12、8/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible
13、for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T st
14、udy groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basi
15、s with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory
16、provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use
17、 of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no p
18、osition concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, pr
19、otected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No par
20、t of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.8112/Y.1371 (2015)/Amd.1 (08/2017) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 3 3.1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendatio
21、n . 3 4 Abbreviations and acronyms 4 5 Conventions 6 6 MPLS transport profile layer network interface structure 6 6.1 NNI basic signal structure 7 6.2 Information structure for the MPLS-TP network node interfaces 10 6.3 MPLS-TP labels . 17 6.4 MPLS-TP shim header . 17 7 Multiplexing/mapping principl
22、es 18 7.1 Mapping 18 7.2 MPLS-TP multiplex . 18 7.3 MPLS-TP tandem connection monitoring 18 8 Physical specification of the MPLS-TP interfaces . 18 Appendix I Example of layer networks in ETH UNI and MPLS-TP NNI . 19 Appendix II Bandwidth requirements for MPLS-TP transport 20 Rec. ITU-T G.8112/Y.137
23、1 (2015)/Amd.1 (08/2017) 1 Recommendation ITU-T G.8112/Y.1371 Interfaces for the MPLS transport profile layer network Amendment 1 Editorial note: This is a complete-text publication. Modifications introduced by this amendment are shown in revision marks relative to Recommendation ITU-T G.8112/Y.1371
24、 (2015). 1 Scope This Recommendation specifies the interfaces for the multi-protocol label switching transport profile (MPLS-TP) layer network, in particular the: encapsulation of MPLS-TP client signals into the MPLS-TP characteristic information that will be present on MPLS-TP network-to-network in
25、terface (NNI) links in the transport network; encapsulation of MPLS-TP characteristic information into the MPLS-TP link frames that will be present on MPLS-TP NNI links in the transport network; MPLS-TP layer network within the transport network and associated MPLS-TP multiplexing; MPLS-TP nested co
26、nnection monitoring per layer network level within the transport network; MPLS-TP operation, administration and maintenance (OAM) associated with nested connection monitoring in the transport network; encapsulation of MPLS-TP control plane information. The MPLS-TP network uses various server layer n
27、etworks like optical transport hierarchy (OTH), synchronous digital hierarchy (SDH), plesiochronous digital hierarchy (PDH) and Ethernet MAC layer network (ETH). The detailed requirements are specified in a number of ITU-T Recommendations, ANSI Standards, IEEE Standards and IETF RFCs, which are cite
28、d. This Recommendation specifies point-to-point label-switched paths (LSPs); point-to-multipoint LSPs are for further study. This Recommendation does not cover inter-operator control plane aspects of the MPLS-TP NNI. This Recommendation provides a representation of the MPLS-TP technology using the m
29、ethodologies that have been used for other transport technologies e.g., SDH, optical transport network (OTN) and Ethernet.1 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At
30、 the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed b
31、elow. A list of the currently _ 1 This Recommendation is intended to be aligned with the IETF MPLS RFCs normatively referenced by this Recommendation. 2 Rec. ITU-T G.8112/Y.1371 (2015)/Amd.1 (08/2017) valid ITU-T Recommendations is regularly published. The reference to a document within this Recomme
32、ndation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.704 Recommendation ITU-T G.704 (1998), Synchronous frame structures used at 1544, 6312, 2048, 8448 and 44 736 kbit/s hierarchical levels. ITU-T G.705 Recommendation ITU-T G.705 (2000), Characteristics of ple
33、siochronous digital hierarchy (PDH) equipment functional blocks. ITU-T G.707 Recommendation ITU-T G.707/Y.1322 (2007), Network node interface for the synchronous digital hierarchy (SDH). ITU-T G.709 Recommendation ITU-T G.709/Y.1331 (2012), Interfaces for the optical transport network. ITU-T G.832 R
34、ecommendation ITU-T G.832 (1998), Transport of SDH elements on PDH networks Frame and multiplexing structures. ITU-T G.951 Recommendation ITU-T G.951 (1988), Digital line systems based on the 1544 kbit/s hierarchy on symmetric pair cables. ITU-T G.7041 Recommendation ITU-T G.7041/Y.1303 (2011), Gene
35、ric framing procedure. ITU-T G.7043 Recommendation ITU-T G.7043/Y.1343 (2004), Virtual concatenation of plesiochronous digital hierarchy (PDH) signals. ITU-T G.7712 Recommendation ITU-T G.7712/Y.1703 (2010), Architecture and specification of data communication network. ITU-T G.8001 Recommendation G.
36、8001/Y.1354 (20132016), Terms and definitions for Ethernet frames over transport. ITU-T G.8012 Recommendation G.8012/Y.1308 (2004), Ethernet UNI and Ethernet NNI. ITU-T G.8040 Recommendation ITU-T G.8040/Y.1340 (2005), GFP frame mapping into Plesiochronous Digital Hierarchy (PDH). ITU-T G.8101 Recom
37、mendation G.8101/Y.1355 (20152016), Terms and definitions for MPLS transport profile. ITU-T G.8110.1 Recommendation ITU-T G.8110.1/Y.1370.1 (2011), Architecture of the Multi-Protocol Label Switching transport profile layer network. ITU-T G.8151 Recommendation ITU-T G.8151/Y.1374 (2015), Management a
38、spects of the MPLS-TP network element. ITU-T Y.1415 Recommendation ITU-T Y.1415 (2005), Ethernet-MPLS network interworking User plane interworking. ITU-Y Y.1711 Recommendation ITU-T Y.1711 (2004), Operation client layer network interface as specified in IETF RFC 5921 and IETF RFC 6215. The MPLS-TP l
39、ayer interface can be deployed as a network-to-network interface (NNI) and within the transport network. As described in IETF RFC 5921, the MPLS-TP layer network consists of the Transport Service layer and the Transport Path layer. The MPLS-TP NNI provides the interface between two MPLS-TP PEs and c
40、ould be used for the support of client layer connection services, i.e., the Transport Service layer and the connection within transport, i.e., Transport Path layer. The user-to-network interface (UNI) provides the interface for client services that are carried by MPLS-TP layers. UNIs are used for su
41、ch a service. The location of the UNI and NNI is illustrated in Figure 6-1. UNI functions are located at the customer edge (CE) and provider edge (PE). The UNI client side (UNI-C) is located and terminated at the CE and the UNI network side (UNI-N) is located and terminated at the PE. The functions
42、for UNI-C and UNI-N are described in IETF RFC 5921 and IETF RFC 6215. G . 8 1 1 - Y . 1 3 7 1 ( 1 2 ) _ F 6 - 12M PL S- T P PENNINNINNIU N I - N U N I - NCEU N I - C U N I - CCEUNI UNIM PL S- T P PEFigure 6-1 Locations of UNI and MPLS-TP NNI Rec. ITU-T G.8112/Y.1371 (2015)/Amd.1 (08/2017) 7 The MPLS
43、TP-NNI may be deployed as an intra-domain interface (IaDI) within a single administrative domain and as an inter-domain interface (IrDI) between two administrative domains as illustrated in Figure 6-2. G . 8 1 1 - Y . 1 3 7 1 ( 1 2 ) _ F 6 - 22M PL S- T P PE M PL S- T P PE M PL S- T P PENNI NNI NNI
44、 NNI NNI NNIU N I - N U N I - NCEU N I - C U N I - CCEUNI UNII a D I N N II a D I N N I I r D I N N IM PL S- T P PEFigure 6-2 Locations of client-UNI and MPLS-TP NNI UNI and MPLS-TP NNI can encompass multiple layer networks. Appendix I describes an example of the Ethernet as the client service. The
45、MPLS-TP NNI can be used to carry informational elements of three planes (Figure 6-3): data (or user) plane, optionally including a data communication network (DCN) supporting management plane and control plane communications; control plane (e.g., signalling and routing); management plane. G . 8 1 1
46、 Y . 1 3 7 1 ( 1 2 ) F 6 - 32T N E T N EM a na ge m e ntpl a neM a na ge m e ntpl a neC ont r olpl a neC ont r olpl a neD C NU s e r / da t apl a neU s e r / da t apl a neD C ND C N D C NNNIFigure 6-3 Three planes of MPLS-TP NNI Each NNI is divided into three plane-specific NNIs: NNID for the data
47、plane informational elements, including operation, administration and maintenance (OAM), which is terminated in the layers termination, adaptation and connection/flow forwarding functions; NNIC for the control plane informational elements; NNIM for the management plane informational elements. This R
48、ecommendation specifies NNID and NNIC as defined in IETF RFC 6215. In IETF RFC 6215, NNID and NNIC are represented as NNI (network-to-network interface) function. An NNI function is defined at the interface of an MPLS-TE PE node as described in Figure 2 of IETF RFC 6215. NNIC and NNIM realized via t
49、he DCN interface are described in ITU-T G.7712 and ITU-T G.8151, respectively. 8 Rec. ITU-T G.8112/Y.1371 (2015)/Amd.1 (08/2017) 6.1 NNI basic signal structure The basic structure is shown in Figure 6-4. The relationship between clients and MPLS-TP is described in IETF RFC 5921 and the example of the clients for pseudowire (PW) is described in IETF RFC 5960. Note that this Recommendation only describes Etherne
