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.8121.2/Y.1381.2 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (04/2016) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Packet over Transport aspects MPLS over Transport aspects SERIES Y: GLOBAL I
2、NFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS, INTERNET OF THINGS AND SMART CITIES Internet protocol aspects Transport Characteristics of MPLS-TP equipment functional blocks supporting ITU-T G.8113.2/Y.1372.2 OAM mechanisms Recommendation ITU-T G.8121.2/Y.1381.2 I
3、TU-T G-SERIES RECOMMENDATIONS 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
4、SYSTEMS ON METALLIC 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 CHARACTERIS
5、TICS G.600G.699 DIGITAL 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 GENER
6、IC ASPECTS G.7000G.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, pl
7、ease refer to the list of ITU-T Recommendations. Rec. ITU-T G.8121.2/Y.1381.2 (04/2016) i Recommendation ITU-T G.8121.2/Y.1381.2 Characteristics of MPLS-TP equipment functional blocks supporting ITU-T G.8113.2/Y.1372.2 OAM mechanisms Summary Recommendation ITU-T G.8121.2/Y.1381.2 specifies both the
8、functional components and the methodology that should be used in order to specify multi-protocol label switching transport profile (MPLS-TP) layer network functionality of network elements based on the protocol neutral constructs defined in Recommendation ITU-T G.8121/Y.1381 and on the tools defined
9、 in Recommendation ITU-T G.8113.2/Y.1372.2. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T G.8121.2/Y.1381.2 2013-11-06 15 11.1002/1000/12018 2.0 ITU-T G.8121.2/Y.1381.2 2016-04-13 15 11.1002/1000/12806 Keywords Atomic functions, equipment functional blocks, MPLS, MPLS-TP,
10、MPLS-TP layer network, OAM. * 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.8121.2/Y.1381.2 (04/2016) FOREWORD The Internat
11、ional 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 for studying technical, opera
12、ting 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 study groups which, in turn, pr
13、oduce 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 basis with ISO and IEC. NOTE In t
14、his 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 provisions (to ensure, e.g.,
15、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 of such words does not sugge
16、st 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 position concerning the eviden
17、ce, 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, protected by patents, which may
18、 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 2016 All rights reserved. No part of this publication may be
19、reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.8121.2/Y.1381.2 (04/2016) 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 . 3 4 Abbreviations and acronyms 3 5
20、 Conventions 5 6 Supervision . 5 6.1 Defects 5 7 Information flow across reference points . 5 8 MPLS-TP processes 5 8.1 G-ACh process . 5 8.2 TC/Label processes 5 8.3 Queuing process . 5 8.4 MPLS-TP-specific GFP-F processes 5 8.5 CW processes . 5 8.6 OAM related processes used by server adaptation f
21、unctions . 6 8.7 OAM related processes used by adaptation functions 8 8.8 Proactive and on-demand OAM related processes . 9 8.9 Dataplane Loopback processes . 55 9 MPLS-TP layer functions . 55 9.1 Connection functions (MT_C) . 55 9.2 Termination functions 55 9.3 Adaptation functions 62 9.4 MT Diagno
22、stic functions 62 10 MPLS-TP to Non-MPLS-TP client adaptation functions . 73 11 Non-MPLS-TP server to MPLS-TP adaptation functions 73 Appendix I OAM process and sub-processes . 74 Appendix II SDL descriptions 75 Rec. ITU-T G.8121.2/Y.1381.2 (04/2016) 1 Recommendation ITU-T G.8121.2/Y.1381.2 Characte
23、ristics of MPLS-TP equipment functional blocks supporting ITU-T G.8113.2/Y.1372.2 OAM mechanisms 1 Scope This Recommendation describes both the functional components and the methodology that should be used in order to describe multi-protocol label switching transport profile (MPLS-TP) layer network
24、functionality of network elements; it does not describe individual MPLS-TP network equipment as such. This Recommendation provides protocol-specific extensions of the protocol-neutral constructs defined in ITU-T G.8121 to support the operation, administration and maintenance (OAM) tools defined in I
25、TU-T G.8113.2. This Recommendation provides a description of the MPLS-TP functional technology using the same methodologies that have been used for other transport technologies (e.g., synchronous digital hierarchy (SDH), optical transport network (OTN) and Ethernet)1. This Recommendation, along with
26、 ITU-T G.8121, specifies a library of basic building blocks and a set of rules by which they may be combined in order to describe digital transmission equipment. The library comprises the functional building blocks needed to specify completely the generic functional structure of the MPLS-TP layer ne
27、twork. In order to be compliant with this Recommendation, equipment needs to be describable as an interconnection of a subset of these functional blocks contained within this Recommendation. The interconnections of these blocks should obey the combination rules given. Not every atomic function defin
28、ed in this Recommendation is required for every application. Different subsets of atomic functions may be assembled in different ways according to the combination rules given in this Recommendation to provide a variety of different capabilities. Network operators and equipment suppliers may choose w
29、hich functions must be implemented for each application. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Re
30、commendations 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 below. A list of the currently valid ITU-T Recommendations is regula
31、rly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the 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 (2012), Char
32、acteristics of transport equipment Description methodology and generic functionality. ITU-T G.8101 Recommendation ITU-T G.8101/Y.1355 (2015), Terms and definitions for MPLS transport profile. 1 This ITU-T Recommendation is intended to be aligned with the IETF MPLS RFCs normatively referenced by this
33、 Recommendation. 2 Rec. ITU-T G.8121.2/Y.1381.2 (04/2016) 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.8113.2 Recommendation ITU-T G.8113.2/Y.1372.2 (2015), Operations, administration and mai
34、ntenance mechanisms for MPLS-TP networks using the tools defined for MPLS. ITU-T G.8121 Recommendation ITU-T G.8121/Y.1381 (2013), Characteristics of MPLS-TP equipment functional blocks. ITU-T Z.100 Recommendation ITU-T Z.100 (2011), Specification and Description Language Overview of SDL-2010. IETF
35、RFC 4379 IETF RFC 4379 (2006), Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures. IETF RFC 5880 IETF RFC 5880 (2010), Bidirectional Forwarding Detection (BFD). IETF RFC 5884 IETF RFC 5884 (2010), Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs). IETF RFC
36、 6370 IETF RFC 6370 (2011), MPLS Transport Profile (MPLS-TP) Identifiers. IETF RFC 6374 IETF RFC 6374 (2011), Packet Loss and Delay Measurement for MPLS Networks. IETF RFC 6375 IETF RFC 6375 (2011), A Packet Loss and Delay Measurement Profile for MPLS-Based Transport Networks. IETF RFC 6426 IETF RFC
37、 6426 (2011), MPLS On-Demand Connectivity Verification and Route Tracing. IETF RFC 6427 IETF RFC 6427 (2011), MPLS Fault Management Operations, Administration, and Maintenance (OAM). IETF RFC 6428 IETF RFC 6428 (2011), Proactive Connectivity Verification, Continuity Check and Remote Defect Indicatio
38、n for the MPLS Transport Profile. IETF RFC 6435 IETF RFC 6435 (2011), MPLS Transport Profile Lock Instruct and Loopback Functions, plus Errata 3429 (2013) and 4017 (2014). 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 access point: IT
39、U-T G.805 3.1.2 adapted information: ITU-T G.805 3.1.3 associated channel header: ITU-T G.8101 3.1.4 bottom of stack: ITU-T G.8101 3.1.5 characteristic information: ITU-T G.805 3.1.6 client/server relationship: ITU-T G.805 3.1.7 connection: ITU-T G.805 3.1.8 connection point: ITU-T G.805 3.1.9 expli
40、citly TC-encoded-PSC LSP: ITU-T G.8101 3.1.10 generic associated channel: ITU-T G.8101 Rec. ITU-T G.8121.2/Y.1381.2 (04/2016) 3 3.1.11 G-ACh label: ITU-T G.8101 3.1.12 label: ITU-T G.8101 3.1.13 label inferred PHB scheduling class LSP: ITU-T G.8101 3.1.14 label stack: ITU-T G.8101 3.1.15 label switc
41、hed path: ITU-T G.8101 3.1.16 label value: ITU-T G.8101 3.1.17 layer network: ITU-T G.805 3.1.18 matrix: ITU-T G.805 3.1.19 MPLS label stack: ITU-T G.8101 3.1.20 network: ITU-T G.805 3.1.21 network connection: ITU-T G.805 3.1.22 per-hop behaviour: ITU-T G.8101 3.1.23 reference point: ITU-T G.805 3.1
42、.24 subnetwork: ITU-T G.805 3.1.25 subnetwork connection: ITU-T G.805 3.1.26 termination connection point: ITU-T G.805 3.1.27 time to live: ITU-T G.8101 3.1.28 traffic class: ITU-T G.8101 3.1.29 trail: ITU-T G.805 3.1.30 trail termination: ITU-T G.805 3.1.31 transport: ITU-T G.805 3.1.32 transport e
43、ntity: ITU-T G.805 3.1.33 transport processing function: ITU-T G.805 3.1.34 unidirectional connection: ITU-T G.805 3.1.35 unidirectional trail: ITU-T G.805 3.2 Terms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: A
44、IS Alarm Indication Signal APS Automatic Protection Switching BFD Bidirectional Forwarding Detection CCCV Continuity Check and Connectivity Verification CC/CV Continuity Check or Connectivity Verification CoS Class of Service CSF Client Signal Fail 4 Rec. ITU-T G.8121.2/Y.1381.2 (04/2016) CV Connect
45、ivity Verification CW Control Word DLM Direct Loss Measurement DM Delay Measurement DSMap Downstream Mapping EMF Equipment Management Function FEC Forwarding Equivalence Class G-ACh Generic Associated Channel GAL G-ACh Label GFP Generic Framing Procedure ILM Inferred Loss Measurement LCK Locked LI L
46、ock Instruct LKR Lock Report LM Loss Measurement LStack Label Stack MCC Maintenance Communication Channel MEG Maintenance Entity Group MEP Maintenance entity group End Point MIP Maintenance entity group Intermediate Point MPLS Multi-Protocol Label Switching MPLS-TP Multi-Protocol Label Switching Tra
47、nsport Profile MT Multi-Protocol Label Switching Transport Profile MTDe MPLS-TP MEP Diagnostic function MTU Maximum Transmit Unit OAM Operation, Administration and Maintenance OOO Out Of Order PDU Protocol Data Unit PHB Per Hop Behaviour PM Performance Monitoring QTF Queriers Timestamp Format RDI Re
48、mote Defect Indication Req Request Resp Response RPTF Responders Preferred Timestamp Format RTF Responders Timestamp Format SCC Signalling Communication Channel Rec. ITU-T G.8121.2/Y.1381.2 (04/2016) 5 SQI Session Query Interval SSF Server Signal Fail TC Traffic Class TS Timestamp TSFmt Timestamp Fo
49、rmat TLV Type Length Value TTL Time-To-Live 5 Conventions The diagrammatic convention for connection-oriented layer networks described in this Recommendation is that of ITU-T G.805. 6 Supervision 6.1 Defects 6.1.1 Summary of entry/exit conditions for defects The defect entry and exit conditions are based on events. Occurrence or absence of specific events may raise or reset specific defects. The events used by this R
