1、 International Telecommunication Union ITU-T G.8113.1/Y.1372.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(08/2013) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Packet over Transport aspects MPLS over Transport aspects SERIES Y: GLOBAL INFORMATION INFRASTRUCT
2、URE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Transport Operations, administration and maintenance mechanism for MPLS-TP in packet transport networks Amendment 1 Recommendation ITU-T G.8113.1/Y.1372.1 (2012) Amendment 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISS
3、ION 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 METALLIC LINES G.300G.399 GE
4、NERAL 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 DIGITAL TERMINAL EQUIPM
5、ENTS 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.7000G.7999 PACKET OVER TRA
6、NSPORT ASPECTS G.8000G.8999 Ethernet over 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
7、-T G.8113.1/Y.1372.1 (2012)/Amd.1 (08/2013) i Recommendation ITU-T G.8113.1/Y.1372.1 Operations, administration and maintenance mechanism for MPLS-TP in packet transport networks Amendment 1 Summary Amendment 1 to Recommendation ITU-T G.8113.1/Y.1372.1 (2012) updates the abbreviations, acronyms and
8、references, adds text for a route tracing function in clause 7, and adds a new clause 10 on security. The global uniqueness consideration of IDs and the usage of GAL for PW are clarified, respectively, in clauses 8 and 7. History Edition Recommendation Approval Study Group Unique ID*1.0 ITU-T G.8113
9、.1/Y.1372.1 2012-11-20 15 11.1002/1000/113231.1 ITU-T G.8113.1/Y.1372.1 (2012) Amd. 1 2013-08-29 15 11.1002/1000/12032_ *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
10、.int/11.1002/1000/11830-en. ii Rec. ITU-T G.8113.1/Y.1372.1 (2012)/Amd.1 (08/2013) 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 Standa
11、rdization 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 on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), whi
12、ch 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 down in WTSA Resolution 1. In some areas of information technology which fall within I
13、TU-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 telecommunication administration and a recognized operating agency. Compliance with this Recommendati
14、on 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 mandatory provisions are met. The words “shall“ or some other obligatory language such as “m
15、ust“ 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 attention to the possibility that the practice or implementation of this Recommendation
16、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 others outside of the Recommendation development process. As of the date of approval of t
17、his 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 represent the latest information and are therefore strongly urged to consult the TSB patent da
18、tabase at http:/www.itu.int/ITU-T/ipr/. ITU 2014 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.1372.1 (2012)/Amd.1 (08/2013) iii Table of Contents Page 1) Clause 2, References . 1 2) Add
19、 the specification of “Route Tracing“ in clause 7 1 2.1) Table 7-1 . 1 2.2) Clause 7.2.1.2.3 2 3) Clause 8.2 . 2 4) Bibliography . 5 5) Clause 10, Security . 6 6) Usage of GAL for PW Modify the text in clause 7.1.2 . 6 7) Update abbreviations and acronyms . 7 7.1) Clause 4 7 7.2) Figure I.1 7 Rec. I
20、TU-T G.8113.1/Y.1372.1 (2012)/Amd.1 (08/2013) 1 Recommendation ITU-T G.8113.1/Y.1372.1 Operations, administration and maintenance mechanism for MPLS-TP in packet transport networks Amendment 1 1) Clause 2, References Add the following reference ISO 3166-1 ISO 3166-1:2013 alpha-2, Codes for the repre
21、sentation of names of countries and their subdivisions Part 1: Country codes. 2) Add the specification of “Route Tracing“ in clause 7 2.1) Table 7-1 Add the on demand “Route Tracing“ OAM item in Table 7-1: OAM functions. 7.2 OAM functions specification Table 7-1 OAM functions Application OAM functio
22、n Fault Management Pro-active Continuity check and connectivity verification (CC/CV) Remote defect indication (RDI) Alarm indication signal (AIS) Client signal fail (CSF)4On-demand Connectivity verification (CV) Route tracing (RT) Diagnostic test (DT) Locked signal (LCK)5Performance Management Pro-a
23、ctive Loss measurement (LM) Delay measurement (DM) On-demand Loss measurement (LM) Delay measurement (DM) Other Applications Automatic protection switching (APS) Management communication channel/Signalling communication channel (MCC/SCC) Vendor-specific (VS) Experimental (EXP) _ 4Client Signal Fail
24、(CSF) is called Client Failure Indication (CFI) in IETF RFC 5860. 5Locked Signal (LCK) is called Lock Reporting in IETF RFC 5860. 2 Rec. ITU-T G.8113.1/Y.1372.1 (2012)/Amd.1 (08/2013) 2.2) Clause 7.2.1.2.3 Add a new clause to specify “Route tracing“ in clause 7.2.1.2. 7.2.1.2 On-demand OAM functions
25、 for fault management 7.2.1.2.3 Route tracing Route tracing (RT) enables a MEP to discover the ordered sequence of MIPs (if any) and MEP(s) within a MEG. The Route tracing (RT) OAM function can be implemented using the LBM OAM PDU with the “Discovery ingress/node MEP/MIP“ and/or the “Discovery egres
26、s MEP/MIP“ TLVs in the target MEP/MIP ID TLV which are defined in clause 8.2.2. However detailed procedures for implementing the RT OAM function are for further study in this version of the Recommendation. 3) Clause 8.2 Add the globally uniqueness consideration of IDs used in ITU-T G.8113.1. 8.2 OAM
27、 PDU formats based on ITU-T G.8013 Insert a new paragraph after the first: This clause describes the use of the CC and ICC based MIP and MEP identifiers. MPLS-TP also supports IP-based formats for MIP and MEP identifiers6. The possible mixing of CC and ICC based formats and IP based formats within a
28、n operator domain is for further study. The encoding of the IP-based formats is also for further study. 8.2.1 Continuity check message (CCM) In order to perform pro-active connectivity verification, the CCM packet contains a globally unique identifier of the source MEP, which is the combination of a
29、 globally unique MEG ID with a MEP ID that is unique within the scope of the maintenance entity group. The generic format for MEG ID is defined in Figure A.1 of ITU-T G.8013. Different formats of MEG ID are allowed: the MEG ID format type is identified by the MEG ID Format field. The formats of both
30、 the ICC-based MEG ID, and the CC- and ICC-based global MEG ID are is defined in Annex A of ITU-T G.8013. Both of these This formats isare applicable to MPLS-TP Sections, LSPs and PWs. If a globally unique MEG ID is required the CC- and ICC-based MEG ID must be used. MPLS-TP supports also IP-based f
31、ormat for MEG ID. These formats are outside the scope of this version of the Recommendation.6_ 6The semantics for IP-based identifiers for MIP and MEP are defined in b-IETF RFC 6370. 6The IP-based format for MEG ID is under definition in IETF: see b-IETF tp-id. Rec. ITU-T G.8113.1/Y.1372.1 (2012)/Am
32、d.1 (08/2013) 3 8.2.2.1 Target and replying MEP/MIP ID TLVs The format of the target and replying MIP/MEP/MIP ID TLVs are shown in Figures 8-6 and 8-7. 1 2 3 4 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 11 Type (33) Length (25) ID Sub-Type 5 MEP/MIP Identifier (format is ID Sub-Ty
33、pe specific) 9 13 17 21 25 Figure 8-6 Target MEP/MIP ID TLV format 1 2 3 4 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 11 Type (34) Length (25) ID Sub-Type 5 MEP/MIP Identifier (format is ID Sub-Type specific) 9 13 17 21 25 Figure 8-7 Replying MEP/MIP ID TLV format Different format
34、s of MEP/MIP identifiers can be defined: the format type is described by the MEP/MIP ID sub-type field (see Table 8-4). Table 8-4 MEP/MIP identifier sub-type values ID Sub-Type MEP/MIP identifier name MEP/MIP identifier length 0x00 Discovery ingress/node MEP/MIP 0 0x01 Discovery egress MEP/MIP 0 0x0
35、2 ICC-based MEP ID 2 bytes 0x03 ICC-based MIP ID 16 4bytes 0x04-0xFF Reserved The “Discovery ingress/node MEP/MIP“ and the “Discovery egress MEP/MIP“ identifiers can only be used within the LBM PDU (and cannot appear in an LBR PDU) for discovering the identifiers of the MEPs or of the MIPs located a
36、t a given TTL distance from the MEP originating the LBM PDU. The format of the Target MEP/MIP ID TLV carrying a “Discovery ingress/node MEP/MIP“ is shown in Figure 8-8. 4 Rec. ITU-T G.8113.1/Y.1372.1 (2012)/Amd.1 (08/2013) 1 2 3 4 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 11 Type
37、 (33) Length (25) ID Sub-Type (0x00) 5 All-ZEROs 9 13 17 21 25 Figure 8-8 Target MEP/MIP ID TLV format for (Ddiscovery ingress/node MEP/MIP) The format of the Target MEP/MIP ID TLV carrying a “Discovery egress MEP/MIP“ is shown in Figure 8-9. 1 2 3 4 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8
38、 7 6 5 4 3 2 11 Type (33) Length (25) ID Sub-Type (0x01) 5 All-ZEROs 9 13 17 21 25 Figure 8-9 Target MEP/MIP ID TLV format for (Ddiscovery egress MEP/MIP) The format of the target or replying MEP/MIP ID TLV carrying an “ICC-based MEP ID“ is shown in Figure 8-10. 1 2 3 4 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2
39、 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 11 Type Length (25) ID Sub-Type (0x02) 5 MEP ID 9 All-ZEROs 13 17 21 25 Figure 8-10 Target or replying MEP/MIP ID TLV format for (ICC-based MEP ID) The MEP ID is a 16-bit integer value identifying the transmitting MEP within the MEG. The format of the target or reply
40、ing MEP/MIP ID TLV carrying an “ICC-based MIP ID“ is shown in Figure 8-11. Rec. ITU-T G.8113.1/Y.1372.1 (2012)/Amd.1 (08/2013) 5 1 2 3 4 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 11 Type Length (25) ID Sub-Type (0x03) 5 ITUCarrier Code (ICC) 9 Node_ID 13 Node_ID IF_Num 17 IF_Num
41、Country Code (CC) 21 All-ZEROs 25 Figure 8-11 Target or replying MEP/MIP ID TLV format for (ICC-based MIP ID) The ITU-T Carrier Code (ICC) is a code assigned to a network operator/service provider and maintained by the ITU-T Telecommunication Standardization Bureau (TSB) as per ITU-T M.1400. The ITU
42、 field in Figure 8-11 consists of between 1 and 6 left-justified characters with trailing NULLs completing the ICC field. For backward compatibility, in cases where global uniqueness is not required, the CC field may be All ZEROs. The Node_ID is a numeric identifier of the node where the MIP is loca
43、ted. Its assignment is a matter for the organization to which the ICC has been assigned, provided that uniqueness within that organization is guaranteed. The IF_Num is a numeric identifier of the access point (AP) toward the server layer trail, which can be either an MPLS-TP or a non-MPLS-TP server
44、layer, where a per-interface MIP is located. Its assignment is a matter for the node the MIP is located, provided that uniqueness within that node is guaranteed. Note that the value 0 for IF_Num is reserved to identify per-node MIPs. MPLS-TP supports also IP-based format for MIP and MEP identifiers.
45、 These formats are outside the scope of this version of the Recommendation.7The Country Code (alpha-2) is a string of 2 alphabetic characters represented with upper case letters (i.e., A-Z). The Country Code format is defined in ISO 3166-1. 8.2.2.2 Requesting MEP ID TLV The MEP ID and MEG ID carry t
46、he globally unique MEP ID as defined in clause 8.2.1. The globally unique identifier for a MEP can be provided by the combination of a globally unique MEG ID with a MEP ID as defined in clause 8.2.1. 4) Bibliography Replace b-IETF tp-id IETF draft-ietf-mpls-tp-identifiers-04 (2013), MPLS-TP Identifi
47、ers following ITU-T Conventions. http:/tools.ietf.org/html/draft-ietf-mpls-tp-itu-t-identifiers-04 with b-IETF RFC 6370 IETF RFC 6370 (2011), MPLS-TP Identifiers. _ 7The IP-based format for MIP and MEP identifiers are under definition in IETF: see b-IETF tp-id 6 Rec. ITU-T G.8113.1/Y.1372.1 (2012)/A
48、md.1 (08/2013) Add the following bibliographic entry: b-IETF RFC 6423 IETF RFC 6423 (2011), Using the Generic Associated Channel Label for Pseudowire in the MPLS Transport Profile (MPLS-TP). 5) Clause 10, Security Add a new clause 10 to describe security considerations. 10 Security According to clau
49、se 6.3 of this Recommendation packets originating outside the MEG are encapsulated by the MEP at the ingress and transported transparently through the MEG. This encapsulation significantly reduces the risk of an attack from outside the MEG. The MEP at the egress also prevents OAM packets from leaving a MEG. The use of the CV tool improves network integrity by ensuring traffic is not misconnected or mismerged between L
