1、 International Telecommunication Union ITU-T G.709/Y.1331TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (02/2012) 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 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 GENERAL CHA
3、RACTERISTICS 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 INTERCONNECTION WITH
4、 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 multipl
5、ex 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 maintenance
6、 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 AND PE
7、RFORMANCE 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 Recommendations. Rec
8、. ITU-T G.709/Y.1331 (02/2012) i Recommendation ITU-T G.709/Y.1331 Interfaces for the optical transport network 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: optical transp
9、ort 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 included the text of Amendment 1 (ODUk virtual concatenation, ODUk multiplexing, backward IAE), e
10、xtension of the physical interface specification, ODUk APS/PCC signal definition and several editorial enhancements. The second revision of this Recommendation included the text of Amendments 1, 2 and 3, corrigenda 1 and 2, Erratum 1, the Implementers Guide (2005), support for an extended (unlimited
11、) 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 payload of an OPUk, or to map an ODUj signal into the payload of one or more tributary
12、 slots in an OPUk and the ODUk delay measurement capability. The third revision of this Recommendation includes the text of Amendments 1 and 2, Corrigendum 1 and Erratum 1 to Recommendation ITU-T G.709/Y.1331 (2009) and support for more client signals. History Edition Recommendation Approval Study G
13、roup 1.0 ITU-T G.709/Y.1331 2001-02-09 15 1.1 ITU-T G.709/Y.1331 (2001) Amd.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) Amd.1 2003-12-14 15 2.2 ITU-T G.709/Y.1331 (2003) Cor.1 2006-12-14 15 2.3 ITU-T G.709/Y.1331 (2003) Amd.2 2007-11-22 15 2.4 ITU-T G.709/Y.133
14、1 (2003) Cor.2 2009-01-13 15 2.5 ITU-T G.709/Y.1331 (2003) Amd.3 2009-04-22 15 3.0 ITU-T G.709/Y.1331 2009-12-22 15 3.1 ITU-T G.709/Y.1331 (2009) Cor.1 2010-07-29 15 3.2 ITU-T G.709/Y.1331 (2009) Amd.1 2010-07-29 15 3.3 ITU-T G.709/Y.1331 (2009) Amd.2 2011-04-13 15 4.0 ITU-T G.709/Y.1331 2012-02-13
15、15 4.1 ITU-T G.709/Y.1331 (2012) Cor. 1 2012-10-29 15 4.2 ITU-T G.709/Y.1331 (2012) Amd. 1 2012-10-29 15 ii Rec. ITU-T G.709/Y.1331 (02/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communic
16、ation 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 on a worldwide basis. The W
17、orld 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 down in WTSA Resolution 1.
18、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 telecommunication administration and a rec
19、ognized 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 mandatory provisions are met. The
20、 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 attention to the possibility
21、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 others outside of the Recommen
22、dation 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 implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and ar
23、e therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2012 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.709/Y.1331 (02/2012) iii Table of Contents Pa
24、ge 1 Scope 1 2 References. 1 3 Definitions 3 3.1 Terms defined elsewhere 3 3.2 Terms defined in this Recommendation . 4 4 Abbreviations and acronyms 5 5 Conventions 9 6 Optical transport network interface structure . 10 6.1 Basic signal structure 10 6.2 Information structure for OTN interfaces . 12
25、7 Multiplexing/mapping principles and bit rates . 16 7.1 Mapping 18 7.2 Wavelength division multiplex . 19 7.3 Bit rates and capacity 19 7.4 ODUk time-division multiplex . 23 8 Optical transport module (OTM-n.m, OTM-nr.m, OTM-0.m, OTM-0.mvn) 31 8.1 OTM with reduced functionality (OTM-0.m, OTM-nr.m,
26、OTM-0.mvn) 31 8.2 OTM with full functionality (OTM-n.m) . 35 9 Physical specification of the ONNI 37 9.1 OTM-0.m 37 9.2 OTM-nr.m 37 9.3 OTM-n.m 37 9.4 OTM-0.mvn 37 10 Optical channel (OCh) 37 10.1 OCh with full functionality (OCh) . 37 10.2 OCh with reduced functionality (OChr) . 37 11 Optical chann
27、el transport unit (OTU) . 38 11.1 OTUk frame structure . 38 11.2 Scrambling 39 12 Optical channel data unit (ODUk) 39 12.1 ODUk frame structure 39 12.2 ODUk bit rates and bit-rate tolerances . 40 13 Optical channel payload unit (OPUk) . 42 14 OTM overhead signal (OOS) . 42 15 Overhead description 43
28、 15.1 Types of overhead 44 15.2 Trail trace identifier and access point identifier definition 45 iv Rec. ITU-T G.709/Y.1331 (02/2012) Page 15.3 OTS OH description . 47 15.4 OMS OH description 48 15.5 OCh OH description . 48 15.6 OTUk/ODUk frame alignment OH description . 49 15.7 OTUk OH description
29、50 15.8 ODUk OH description 53 15.9 OPUk OH description . 67 16 Maintenance signals 69 16.1 OTS maintenance signals . 70 16.2 OMS maintenance signals 70 16.3 OCh maintenance signals . 70 16.4 OTUk maintenance signals . 71 16.5 ODUk maintenance signals 71 16.6 Client maintenance signal . 73 17 Mappin
30、g of client signals . 73 17.1 OPUk client signal fail (CSF) . 74 17.2 Mapping of CBR2G5, CBR10G, CBR10G3 and CBR40G signals into OPUk 74 17.3 Mapping of ATM cell stream into OPUk (k=0,1,2,3) 78 17.4 Mapping of GFP frames into OPUk (k=0,1,2,3,4,flex) 79 17.5 Mapping of test signal into OPUk 80 17.6 M
31、apping of a non-specific client bit stream into OPUk . 81 17.7 Mapping of other constant bit-rate signals with justification into OPUk . 82 17.8 Mapping a 1000BASE-X and FC-1200 signal via timing transparent transcoding into OPUk . 95 17.9 Mapping a supra-2.488 CBR Gbit/s signal into OPUflex 97 17.9
32、.1 FC-400 and FC-800 99 17.9.2 FC-1600 99 18 Concatenation . 99 18.1 Virtual concatenation of OPUk 99 18.2 Mapping of client signals . 104 18.3 LCAS for virtual concatenation 112 19 Mapping ODUj signals into the ODTU signal and the ODTU into the HO OPUk tributary slots 112 19.1 OPUk tributary slot d
33、efinition 113 19.2 ODTU definition 121 19.3 Multiplexing ODTU signals into the OPUk . 123 19.4 OPUk multiplex overhead and ODTU justification overhead . 132 19.5 Mapping ODUj into ODTUjk 142 19.6 Mapping of ODUj into ODTUk.ts 151 Rec. ITU-T G.709/Y.1331 (02/2012) v Page Annex A Forward error correct
34、ion using 16-byte interleaved RS(255,239) codecs 162 Annex B Adapting 64B/66B encoded clients via transcoding into 513B code blocks . 164 B.1 Transmission order . 164 B.2 Client frame recovery . 164 B.3 Transcoding from 66B blocks to 513B blocks . 165 B.4 Link fault signalling . 170 Annex C Adaptati
35、on of OTU3 and OTU4 over multichannel parallel interfaces 171 Annex D Generic mapping procedure principles 174 D.1 Basic principle 174 D.2 Applying GMP in OTN 177 D.3 Cm(t) encoding and decoding . 180 D.4 CnD(t) encoding and decoding 184 Annex E Adaptation of parallel 64B/66B encoded clients . 185 E
36、.1 Introduction 185 E.2 Clients signal format . 185 E.3 Client frame recovery . 185 E.4 Additions to Annex B transcoding for parallel 64B/66B clients 188 Annex F Improved robustness for mapping of 40GBASE-R into OPU3 using 1027B code blocks . 191 F.1 Introduction 191 F.2 513B code block framing and
37、flag bit protection . 191 F.3 66B block sequence check 192 Appendix I Range 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) 197 Appendix II Examples of functionally sta
38、ndardized OTU frame structures 203 Appendix III Example of ODUk multiplexing . 206 Appendix IV Example of fixed stuff in OPUk with multiplex of lower-order ODUk signals . 208 Appendix V ODUk multiplex structure identifier (MSI) examples . 209 Appendix VI Parallel logic implementation of the CRC-8 an
39、d CRC-5 211 Appendix VII OTL4.10 structure 213 Appendix VIII CPRI into LO ODU mapping . 214 Appendix IX Overview of CBR clients into LO OPU mapping types . 218 Appendix X Overview of LO ODU into HO OPU mapping types 220 Appendix XI Derivation of recommended ODUflex(GFP) bit-rates and examples of ODU
40、flex(GFP) clock generation 222 XI.1 Introduction 222 XI.2 Tributary slot sizes . 222 vi Rec. ITU-T G.709/Y.1331 (02/2012) Page XI.3 Example methods for ODUflex(GFP) clock generation 223 Bibliography. 227 Rec. ITU-T G.709/Y.1331 (02/2012) 1 Recommendation ITU-T G.709/Y.1331 Interfaces for the optical
41、 transport network 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 interfaces of the optical transport network to be used withi
42、n 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. The interfaces defined in this Recommendation can be applied a
43、t 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 subject to change as technology progresses. Therefore, optical t
44、echnology 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 second revision of this Recommendation introduced: support for an
45、 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 payload of an OPUk, or to map an ODUj signal into the payload of o
46、ne or more tributary slots in an OPUk; ODUk delay measurement capability. The third revision of this Recommendation introduces the text of Amendments 1 and 2, Corrigendum 1 and Erratum 1 to Recommendation ITU-T G.709/Y.1331 (2009) and support for more client signals. 2 References The following ITU-T
47、 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 Recommendations and other references are subject to revision; users of this Recommendation
48、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 regularly published. The reference to a document within this Recommendation does not give it, a
49、s a stand-alone document, the status of a Recommendation. ITU-T G.652 Recommendation ITU-T G.652 (2009), Characteristics of a single-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. 2 Rec. ITU-T G.709/Y.1331 (02/2012) ITU-T G.655 Recommendation ITU-T G.655 (2009), Characteristics of a non-zero dispersion-shifted single-mode opti
