1、 International Telecommunication Union ITU-T G.709/Y.1331TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2009) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments General SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEX
2、T-GENERATION NETWORKS Internet protocol aspects Transport Interfaces for the Optical Transport Network (OTN) Recommendation ITU-T G.709/Y.1331 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENER
3、AL 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 CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTIO
4、N 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 General G.700G.709Coding of voice and audio signals G.710G.729 Principal characteristics of primary m
5、ultiplex equipment G.730G.739 Principal characteristics of second order multiplex equipment G.740G.749 Principal characteristics of higher order multiplex equipment G.750G.759 Principal characteristics of transcoder and digital multiplication equipment G.760G.769 Operations, administration and maint
6、enance features of transmission equipment G.770G.779 Principal characteristics of multiplexing equipment for the synchronous digital hierarchy G.780G.789 Other terminal equipment G.790G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE
7、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 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendation
8、s. Rec. ITU-T G.709/Y.1331 (12/2009) i Recommendation ITU-T G.709/Y.1331 Interfaces for the Optical Transport Network (OTN) Summary Recommendation ITU-T G.709/Y.1331 defines the requirements for the optical transport module of order n (OTM-n) signals of the optical transport network, in terms of: op
9、tical transport hierarchy (OTH); functionality of the overhead in support of multi-wavelength optical networks; frame structures; bit rates; formats for mapping client signals. The first revision of this Recommendation includes the text of Amendment 1 (ODUk virtual concatenation, ODUk multiplexing,
10、backward IAE), extension of physical interface specification, ODUk APS/PCC signal definition and several editorial enhancements. The second revision of this Recommendation includes the text of Amendments 1, 2, 3, Corrigenda 1, 2, Erratum 1, Implementers Guide, support for an extended (unlimited) set
11、 of constant bit rate client signals, a flexible ODUk, which can have any bit rate and a bit rate tolerance up to 100 ppm, a client/server independent generic mapping procedure to map a client signal into the payload of an OPUk, or to map an ODUj signal into the payload of one or more tributary slot
12、s in an OPUk, ODUk delay measurement capability. History Edition Recommendation Approval Study Group 1.0 ITU-T G.709/Y.1331 2001-02-09 15 1.1 ITU-T G.709/Y.1331 (2001) Amend. 1 2001-11-29 15 2.0 ITU-T G.709/Y.1331 2003-03-16 15 2.1 ITU-T G.709/Y.1331 (2003) Amend. 1 2003-12-14 15 2.2 ITU-T G.709/Y.1
13、331 (2003) Cor. 1 2006-12-14 15 2.3 ITU-T G.709/Y.1331 (2003) Amend. 2 2007-11-22 15 2.4 ITU-T G.709/Y.1331 (2003) Cor.2 2009-01-13 15 2.5 ITU-T G.709/Y.1331 (2003) Amend. 3 2009-04-22 15 3.0 ITU-T G.709/Y.1331 2009-12-22 15 ii Rec. ITU-T G.709/Y.1331 (12/2009) FOREWORD The International Telecommuni
14、cation 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, operating and tariff q
15、uestions 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, produce Recommendat
16、ions 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 this Recommendatio
17、n, 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. interoperability or
18、 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 suggest that compliance
19、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 may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or ap
20、plicability 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 received notice of intellectual property, protected by patents, which may be required to implem
21、ent 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 2010 All rights reserved. No part of this publication may be reproduced, by any mea
22、ns whatsoever, without the prior written permission of ITU. Rec. ITU-T G.709/Y.1331 (12/2009) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms and definitions . 3 3.1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendation . 4 4 Abbreviations 4 5 Conventions 8 6 Optical transport netwo
23、rk interface structure . 9 6.1 Basic signal structure 9 6.2 Information structure for the OTN interfaces . 11 7 Multiplexing/mapping principles and bit rates . 15 7.1 Mapping 17 7.2 Wavelength division multiplex . 18 7.3 Bit rates and capacity 18 7.4 ODUk time-division multiplex . 22 8 Optical trans
24、port module (OTM-n.m, OTM-nr.m, OTM-0.m, OTM-0.mvn) 27 8.1 OTM with reduced functionality (OTM-0.m, OTM-nr.m, OTM-0.mvn) 28 8.2 OTM with full functionality (OTM-n.m) . 32 9 Physical specification of the ONNI 34 9.1 OTM-0.m 34 9.2 OTM-nr.m 34 9.3 OTM-n.m 34 9.4 OTM-0.mvn 34 10 Optical channel (OCh) 3
25、4 10.1 OCh with full functionality (OCh) . 34 10.2 OCh with reduced functionality (OChr) . 35 11 Optical channel transport unit (OTU) . 35 11.1 OTUk frame structure . 35 11.2 Scrambling 36 12 Optical channel data unit (ODUk) 37 12.1 ODUk frame structure 37 12.2 ODUk bit rates and bit rate tolerances
26、 . 37 13 Optical channel payload unit (OPUk) . 40 14 OTM overhead signal (OOS) . 40 15 Overhead description 41 15.1 Types of overhead 42 15.2 Trail trace identifier and access point identifier definition 43 iv Rec. ITU-T G.709/Y.1331 (12/2009) Page 15.3 OTS OH description . 45 15.4 OMS OH descriptio
27、n 46 15.5 OCh OH description . 46 15.6 OTUk/ODUk frame alignment OH description . 47 15.7 OTUk OH description 48 15.8 ODUk OH description 51 15.9 OPUk OH description . 65 16 Maintenance signals 67 16.1 OTS maintenance signals . 68 16.2 OMS maintenance signals 68 16.3 OCh maintenance signals . 68 16.
28、4 OTUk maintenance signals . 68 16.5 ODUk maintenance signals 70 16.6 Client maintenance signal . 71 17 Mapping of client signals . 72 17.1 OPUk client signal fail (CSF) . 72 17.2 Mapping of CBR2G5, CBR10G, CBR10G3 and CBR40G signals into OPUk 73 17.3 Mapping of ATM cell stream into OPUk (k=0,1,2,3)
29、 77 17.4 Mapping of GFP frames into OPUk . 78 17.5 Mapping of test signal into OPUk 79 17.6 Mapping of a non-specific client bit stream into OPUk . 81 17.7 Mapping of other constant bit-rate signals with justification into OPUk . 81 17.8 Mapping a 1000BASE-X and FC-1200 signal via timing transparent
30、 transcoding into OPUk . 93 17.9 Mapping a supra-2.488 CBR Gbit/s signal into OPUflex 96 18 Concatenation . 97 18.1 Virtual concatenation of OPUk 97 18.2 Mapping of client signals . 102 18.3 LCAS for virtual concatenation 110 19 Mapping ODUj signals into the ODTU signal and the ODTU into the HO OPUk
31、 tributary slots 111 19.1 OPUk tributary slot definition 111 19.2 ODTU definition 118 19.3 Multiplexing ODTU signals into the OPUk . 120 19.4 OPUk multiplex overhead and ODTU justification overhead . 128 19.5 Mapping ODUj into ODTUjk 139 19.6 Mapping of ODUj into ODTUk.ts 148 Annex A Forward error c
32、orrection using 16-byte interleaved RS(255,239) codecs 153 Rec. ITU-T G.709/Y.1331 (12/2009) v Page Annex B Adapting 64B/66B encoded clients via transcoding into 513B code blocks . 155 B.1 Transmission order . 155 B.2 Client frame recovery . 155 B.3 Transcoding from 66B blocks to 513B blocks . 155 B
33、.4 Link fault signalling . 159 Annex C Adaptation of OTU3 and OTU4 over multichannel parallel interfaces 160 Annex D Generic mapping procedure principles 163 D.1 Basic principle 163 D.2 Applying GMP in OTN 166 D.3 Cm(t) encoding and decoding . 169 D.4 CnD(t) encoding and decoding 173 Appendix I Rang
34、e of stuff ratios for asynchronous mappings of CBR2G5, CBR10G, and CBR40G clients with 20 ppm bit-rate tolerance into OPUk, and for asynchronous multiplexing of ODUj into ODUk (k j) 174 Appendix II Examples of functionally standardized OTU frame structures 180 Appendix III Example of ODUk multiplexi
35、ng . 183 Appendix IV Example of fixed stuff in OPUk with multiplex of lower-order ODUk signals . 185 Appendix V 186 Appendix VI ODUk multiplex structure identifier (MSI) examples 187 Appendix VII Adaptation of parallel 64B/66B encoded clients . 189 VII.1 Introduction 189 VII.2 Clients signal format
36、. 189 VII.3 Client frame recovery . 189 VII.4 Additions to Annex B transcoding for parallel 64B/66B clients 192 Appendix VIII Improved robustness for mapping of 40GBASE-R into OPU3 using 1027B code blocks 195 VIII.1 Introduction 195 VIII.2 513B code block framing and flag bit protection . 195 VIII.3
37、 66B block sequence check 196 Appendix IX Parallel logic implementation of the CRC-8 and CRC-5 201 Appendix X OTL4.10 structure 203 Appendix XI CPRI into LO ODU mapping 204 Appendix XII Overview of CBR clients into LO OPU mapping types 206 Bibliography. 207 Rec. ITU-T G.709/Y.1331 (12/2009) 1 Recomm
38、endation ITU-T G.709/Y.1331 Interfaces for the Optical Transport Network (OTN) 1 Scope The optical transport hierarchy (OTH) supports the operation and management aspects of optical networks of various architectures, e.g., point-to-point, ring and mesh architectures. This Recommendation defines the
39、interfaces of the optical transport network to be used within and between subnetworks of the optical network, in terms of: optical transport hierarchy (OTH); functionality of the overhead in support of multi-wavelength optical networks; frame structures; bit rates; formats for mapping client signals
40、. The interfaces defined in this Recommendation can be applied at user-to-network interfaces (UNI) and network node interfaces (NNI) of the optical transport network. It is recognized, for interfaces used within optical subnetworks, that aspects of the interface are optical technology dependent and
41、subject to change as technology progresses. Therefore, optical technology dependent aspects (for transverse compatibility) are not defined for these interfaces to allow for technology changes. The overhead functionality necessary for operations and management of optical subnetworks is defined. The s
42、econd revision of this Recommendation introduces: support for an extended (unlimited) set of constant bit rate client signals; a flexible ODUk, which can have any bit rate and a bit rate tolerance up to 100 ppm; a client/server independent generic mapping procedure to map a client signal into the pa
43、yload of an OPUk, or to map an ODUj signal into the payload of one or more tributary slots in an OPUk; ODUk delay measurement capability. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Reco
44、mmendation. 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 investigate the possibility of applying the most recent edition of the Recommendations and other refer
45、ences 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 status of a Recommendation. ITU-T G.652 Recommendation ITU-T G.652 (2009), Characteristics of a sing
46、le-mode optical fibre and cable. ITU-T G.653 Recommendation ITU-T G.653 (2006), Characteristics of a dispersion-shifted single-mode optical fibre and cable. ITU-T G.655 Recommendation ITU-T G.655 (2009), Characteristics of a non-zero dispersion-shifted single-mode optical fibre and cable. ITU-T G.69
47、3 Recommendation ITU-T G.693 (2009), Optical interfaces for intra-office systems. 2 Rec. ITU-T G.709/Y.1331 (12/2009) ITU-T G.695 Recommendation ITU-T G.695 (2009), Optical interfaces for coarse wavelength division multiplexing applications. ITU-T G.707 Recommendation ITU-T G.707/Y.1322 (2003), Netw
48、ork node interface for the synchronous digital hierarchy (SDH). ITU-T G.780 Recommendation ITU-T G.780/Y.1351 (2008), Terms and definitions for synchronous digital hierarchy (SDH) networks. ITU-T G.798 Recommendation ITU-T G.798 (2006), Characteristics of optical transport network hierarchy equipmen
49、t functional blocks, plus Amendment 1 (2008). 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 (2009), Characteristics of transport equipment Description methodology and generic functionality. ITU-T G.870 Recommendation ITU-T G.870/Y.1352 (2004), Terms and definitions for optical transport networks (OTN). ITU-T G.872
