1、 International Telecommunication Union ITU-T G.8113.1/Y.1372.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2012) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Packet over Transport aspects MPLS over Transport aspects SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERN
2、ET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Transport Operations, administration and maintenance mechanism for MPLS-TP in packet transport networks Recommendation ITU-T G.8113.1/Y.1372.1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND
3、 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 METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CAR
4、RIER 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 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.89
5、9 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.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 Ethernet over
6、Transport aspects G.8000G.8099 MPLS over Transport aspects G.8100G.8199Quality and availability targets G.8200G.8299 Service Management G.8600G.8699 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.8113.1/Y.1372.1 (11/2012) i Recommend
7、ation ITU-T G.8113.1/Y.1372.1 Operations, administration and maintenance mechanism for MPLS-TP in packet transport networks Summary Recommendation ITU-T G.8113.1/Y.1372.1 specifies mechanisms for user-plane operations, administration and maintenance (OAM) in multi-protocol label switching transport
8、profile (MPLS-TP) networks to meet the MPLS-TP OAM requirements defined in IETF RFC 5860. It also specifies the MPLS-TP OAM packet formats, syntax and semantics of MPLS-TP OAM packet fields. The OAM mechanisms defined in this Recommendation assume common forwarding of the MPLS-TP user packets and MP
9、LS-TP OAM packets. In transport networks, the OAM return path is always in-band. The MPLS-TP OAM mechanisms described in this Recommendation apply to co-routed bidirectional point-to-point MPLS-TP connections. Unidirectional point-to-point and point-to-multipoint MPLS-TP connections will be addresse
10、d in a future version of this Recommendation. This Recommendation is compliant with the transport profile of MPLS as defined by the IETF. In the event of a misalignment in MPLS-TP-related architecture, framework, and protocols between this ITU-T Recommendation and the normatively referenced IETF RFC
11、s, the RFCs will take precedence. History Edition Recommendation Approval Study Group 1.0 ITU-T G.8113.1/Y.1372.1 2012-11-20 15 ii Rec. ITU-T G.8113.1/Y.1372.1 (11/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunicatio
12、ns, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications
13、 on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid
14、 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 basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunicat
15、ion administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these manda
16、tory 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 of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws a
17、ttention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or ot
18、hers outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represe
19、nt the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.8113.1/Y.1372
20、.1 (11/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 3 5 Conventions 5 6 Functional components . 5 6.1 Maintenance entity (ME) 5 6.2 Maintenance entity group (MEG) 6 6
21、.3 MEG end points (MEPs) 6 6.4 MEG intermediate points (MIPs) . 8 6.5 Server MEP 10 7 OAM functions . 10 7.1 Identification of OAM packets from user-traffic packets 10 7.2 OAM functions specification . 11 8 OAM packet formats 15 8.1 Common OAM packets 15 8.2 OAM PDU formats based on ITU-T G.8013 16
22、8.3 Management communication channel (MCC) . 24 8.4 Signalling communication channel (SCC) . 24 9 MPLS-TP OAM procedures . 24 9.1 MPLS-TP OAM procedures based on ITU-T G.8013 PDUs . 24 Annex A MPLS-TP OAM for a packet transport network (PTN) applicability statement 33 Appendix I MPLS-TP network scen
23、arios . 34 I.1 MEG nesting example 34 Bibliography. 35 Rec. ITU-T G.8113.1/Y.1372.1 (11/2012) 1 Recommendation ITU-T G.8113.1/Y.1372.1 Operations, administration and maintenance mechanism for MPLS-TP in packet transport networks 1 Scope This Recommendation specifies mechanisms for operations, admini
24、stration and maintenance (OAM) for multi-protocol label switching transport profiles (MPLS-TPs) that can be applied in packet transport networks (PTN). It defines mechanisms for user-plane OAM in MPLS-TP networks to meet the MPLS-TP OAM requirements defined in IETF RFC 5860. It also specifies the MP
25、LS-TP OAM packet formats, syntax and semantics of MPLS-TP OAM packet fields. The OAM mechanisms defined in this Recommendation assume common forwarding of the MPLS-TP user packets and MPLS-TP OAM packets. In transport networks, the OAM return path is always in-band. The MPLS-TP OAM mechanisms descri
26、bed in this Recommendation are applicable in network scenarios, as described in Annex A, and apply to co-routed bidirectional point-to-point MPLS-TP connections. Unidirectional point-to-point and point-to-multipoint MPLS-TP connections will be addressed in a future version of this Recommendation. Th
27、is Recommendation provides a representation of the MPLS-TP technology using the methodologies that have been used for other transport technologies (e.g., synchronous digital hierarchy (SDH), optical transport network (OTN) and Ethernet).12 References The following ITU-T Recommendations and other ref
28、erences contain provisions which, through reference in this text, constitute provisions of this Recommendation. At 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 in
29、vestigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the
30、status of a Recommendation. ITU-T G.805 Recommendation ITU-T G.805 (2000), Generic functional architecture of transport networks. ITU-T G.806 Recommendation ITU-T G.806 (2004), Characteristics of transport equipment Description methodology and generic functionality. ITU-T G.826 Recommendation ITU-T
31、G.826 (2002), End-to-end error performance parameters and objectives for international, constant bit-rate digital paths and connections. ITU-T G.7710 Recommendation ITU-T G.7710/Y.1701 (2007), Common equipment management function requirements. ITU-T G.7712 Recommendation ITU-T G.7712/Y.1703 (2010),
32、Architecture and specification of data communication network. _ 1This ITU-T Recommendation is intended to be aligned with the IETF MPLS RFCs normatively referenced by this Recommendation. 2 Rec. ITU-T G.8113.1/Y.1372.1 (11/2012) ITU-T G.8010 Recommendation ITU-T G.8010/Y.1306 (2004), Architecture of
33、 Ethernet layer networks, plus Amendment 1 (2006). ITU-T G.8013 Recommendation ITU-T G.8013/Y.1731 (2011), OAM functions and mechanisms for Ethernet based networks. ITU-T G.8021 Recommendation ITU-T G.8021/Y.1341 (2010), Characteristics of Ethernet transport network equipment functional blocks. ITU-
34、T G.8110.1 Recommendation ITU-T G.8110.1/Y.1370.1 (2011), Architecture of MPLS Transport Profile (MPLS-TP) layer network. ITU-T M.20 Recommendation ITU-T M.20 (1992), Maintenance philosophy for telecommunication networks. ITU-T M.1400 Recommendation ITU-T M.1400 (2006), Designations for interconnect
35、ions among operators networks. IETF RFC 3031 IETF RFC 3031 (2001), Multiprotocol Label Switching Architecture. IETF RFC 3032 IETF RFC 3032 (2001), MPLS Label Stack Encoding. IETF RFC 4385 IETF RFC4385 (2006), Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN. IETF RFC 34
36、43 IETF RFC 3443 (2003), Time To Live (TTL) Processing in Multi-Protocol Label Switching (MPLS) Networks. IETF RFC 5462 IETF RFC 5462 (2009), Multiprotocol Label Switching (MPLS) Label Stack Entry: “EXP“ Field Renamed to “Traffic Class“ Field. IETF RFC 5586 IETF RFC 5586 (2009), MPLS Generic Associa
37、ted Channel. IETF RFC 5654 IETF RFC5654 (2009), Requirements of an MPLS Transport Profile. IETF RFC 5718 IETF RFC5718 (2010), An In-Band Data Communication Network For the MPLS Transport Profile. IETF RFC5860 IETF RFC5860 (2010), Requirements for Operations, Administration, and Maintenance (OAM) in
38、MPLS Transport Networks. IETF RFC 6371 IETF RFC6371 (2011), Operations, Administration and Maintenance Framework for MPLS-Based Transport Networks. 3 Definitions This Recommendation introduces terminology that is required to discuss the functional network components associated with OAM. These defini
39、tions are consistent with ITU-T G.805 terminology. 3.1 Terms defined elsewhere This Recommendation uses the following terms defined in ITU-T G.806: defect failure 3.2 Terms defined in this Recommendation This Recommendation defines the following term: 3.2.1 MPLS transport profile: A set of multi-pro
40、tocol label switching (MPLS) functions used to support packet transport services and network operations. Rec. ITU-T G.8113.1/Y.1372.1 (11/2012) 3 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: 1DM One-way Delay Measurement A Adaptation function ACH As
41、sociated Channel Header AIS Alarm Indication Signal AP Access Point APS Automatic Protection Switching C Customer CC Continuity Check CCM Continuity Check Message C-DCI Client - Defect Clear Indication CFI Client Failure Indication CSF Client Signal Fail CV Connectivity Verification DCC Data Communi
42、cation Channel DM Delay Measurement DMM Delay Measurement Message DMR Delay Measurement Reply DT Diagnostic Test ES Experimental Specific EXM Experimental OAM Message EXP Experimental EXR Experimental OAM Reply FC Frame Count G-ACh Generic Associated Channel GAL G-ACh Label IANA Internet Assigned Nu
43、mbers Authority ICC ITU-T Carrier Code ID Identifier IETF Internet Engineering Task Force IF Interface IO Intermediate Operator IP Intermediate Provider LBM Loopback Message LBR Loopback Reply LCK Locked Signal 4 Rec. ITU-T G.8113.1/Y.1372.1 (11/2012) LER Label Edge Router LM Loss Measurement LMM Lo
44、ss Measurement Message LMR Loss Measurement Reply LOC Loss Of Continuity LSE Label Stack Entry LSP Label Switched Path LSR Label Switch Router MCC Management Communication Channel ME Maintenance Entity MEG Maintenance Entity Group MEL MEG Level MEP MEG End Point MIP MEG Intermediate Point MMG Mismer
45、ge MPLS Multi-Protocol Label Switching MPLS-TP MPLS Transport Profile N Network NE Network Element Num Number O Operator OAM Operation, Administration and Maintenance OpCode Operations Code OSS Operations Support System OTN Optical Transport Network P Provider PD Packet Delay PDU Protocol Data Unit
46、PDV Packet Delay Variation PHB Per-Hop Behaviour PRBS Pseudo-Random Bit Sequence PSN Packet Switched Network PW PseudoWire PWE3 PseudoWire Emulation Edge-to-Edge RDI Remote Defect Indication RFC Requests for Comments Rx Receive Rec. ITU-T G.8113.1/Y.1372.1 (11/2012) 5 S Stack SCC Signalling Communic
47、ation Channel SDH Synchronous Digital Hierarchy Sk Sink SLA Service Level Agreement So Source SPME Sub-Path Maintenance Entity SRV Server TC Traffic Class TCM Tandem Connection Monitoring TLV Type, Length, and Value TrCP Traffic Conditioning Point TSB Telecommunication Standardization Bureau TST Tes
48、t TTL Time To Live Tx Transmit UNI User Network Interface UNL Unexpected (MEG) Level UNM Unexpected MEP UNP Unexpected Period UNPr Unexpected Priority VCCV Virtual Circuit Connectivity Verification VS Vendor-Specific VSM Vendor Specific (OAM) Message VSR Vendor Specific (OAM) Reply 5 Conventions The
49、 diagrammatic conventions for maintenance entity group end point (MEP) and MEG intermediate point (MIP) compound functions are those of ITU-T G.8010. The values of the OAM protocol data unit (PDU) fields are expressed in decimal format. 6 Functional components 6.1 Maintenance entity (ME) A maintenance entity (ME) can be viewed as the association between two MEG end points (MEPs) that applies maintenance and monitoring operations to a network connection or a tandem connec
