1、 International Telecommunication Union ITU-T G.798TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2012) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments Other terminal equipment Characteristics of optical transport network hierarchy equipment fun
2、ctional blocks Recommendation ITU-T G.798 ITU-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 CHARACTE
3、RISTICS 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 METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMI
4、SSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 General G.700G.709 Coding of voice and audio signals G.710G.729 Principal characteristics of primary multiplex equipment G.730G.739 Principal characteristics of second order multiplex equipment G.740G.7
5、49 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 features of transmission equipment G.770G.779 Principal characteristics of multiplexing equip
6、ment for the synchronous digital hierarchy G.780G.789 Other terminal equipment G.790G.799DIGITAL 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.60
7、00G.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. ITU-T G.798 (12/2012) i Recommendation ITU-T G.798 Characteristics of optical transport netwo
8、rk hierarchy equipment functional blocks Summary Recommendation ITU-T G.798 specifies both the components and the methodology that should be used in order to specify the optical transport network functionality of network elements; it does not specify individual optical transport network equipment. T
9、he components in this revision support ODU and client signal and server bit rates up to 100 Gbit/s. This includes the support of mapping and demapping of a multitude of client signals into carrier signals of various bit rates from STM1 as the SDH transport rate and 1GE for the data client rate, up t
10、o the transport of 100 Gbit/s Ethernet LAN signal rate. History Edition Recommendation Approval Study Group Unique ID*1.0 ITU-T G.798 2002-01-06 15 11.1002/1000/5604-en 1.1 ITU-T G.798 (2002) Amd. 1 2002-06-13 15 11.1002/1000/6057-en 2.0 ITU-T G.798 2004-06-13 15 11.1002/1000/7329-en 3.0 ITU-T G.798
11、 2006-12-14 15 11.1002/1000/8983-en 3.1 ITU-T G.798 (2006) Amd. 1 2008-12-12 15 11.1002/1000/9669-en 3.2 ITU-T G.798 (2006) Cor.1 2009-01-13 15 11.1002/1000/9647-en 4.0 ITU-T G.798 2010-10-22 15 11.1002/1000/10877-en4.1 ITU-T G.798 (2010) Cor. 1 2011-04-13 15 11.1002/1000/11117-en4.2 ITU-T G.798 (20
12、10) Amd. 1 2011-07-22 15 11.1002/1000/11116-en4.3 ITU-T G.798 (2010) Cor. 2 2012-02-13 15 11.1002/1000/11488-en4.4 ITU-T G.798 (2010) Amd. 2 2012-04-06 15 11.1002/1000/11487-en5.0 ITU-T G.798 2012-12-22 15 11.1002/1000/11778-en_ *To access the Recommendation, type the URL http:/handle.itu.int/ in th
13、e 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.798 (12/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications,
14、 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 on
15、 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 do
16、wn 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 telecommunication
17、 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 mandator
18、y 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 atte
19、ntion 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 other
20、s 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 implement this Recommendation. However, implementers are cautioned that this may not represent the
21、latest information and are therefore strongly urged to consult the TSB patent database 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.798 (12/2012) iii Ta
22、ble of Contents Page 1 Scope 1 2 References. 3 3 Definitions 6 3.1 Terms defined elsewhere 6 3.2 Terms defined in this Recommendation . 8 4 Abbreviations and acronyms 8 5 Methodology . 16 6 Supervision . 16 6.1 Alarm reporting control 16 6.2 Defects 17 6.3 Consequent actions . 26 6.4 Defect correlat
23、ions 26 6.5 Performance filters . 26 7 Information flow across reference points . 28 8 Generic processes . 28 8.1 Scrambling processes . 28 8.2 Alignment processes . 28 8.3 Signal quality supervision 32 8.4 BIP correction . 33 8.5 OTUk forward error correction (FEC) processing . 33 8.6 Trail trace i
24、dentifier (TTI) processing 33 8.7 Payload structure indication (PSI) acceptance processes . 34 8.8 Status information (STAT) acceptance process . 34 8.9 Generic AIS generation and detection 35 8.10 Generic layer fault processing 35 8.11 Optical signal processing 38 9 Optical transmission section (OT
25、S) layer functions . 39 9.1 Connection functions 40 9.2 Termination functions 40 9.3 Adaptation functions 47 10 Optical multiplex section (OMS) layer functions . 50 10.1 Connection functions 52 10.2 Termination functions 52 10.3 Adaptation functions 57 10.4 Sub-layer functions . 61 11 Optical physic
26、al section (OPS) layer functions 67 11.1 Connection functions 68 iv Rec. ITU-T G.798 (12/2012) Page 11.2 Termination functions 68 11.3 OPS0 to OChr adaptation function (OPS0/OChr_A) . 79 12 OCh (layer) functions . 90 12.1 Connection functions 92 12.2 Termination functions 96 12.3 Adaptation function
27、s 106 12.4 Layer functions . 119 13 OTU (layer) functions. 119 13.1 Connection functions 120 13.2 Termination functions 120 13.3 Adaptation functions 132 13.4 Sub-layer functions . 145 14 ODU (layer) functions 146 14.1 Connection functions 148 14.2 Termination functions 159 14.3 Adaptation functions
28、 166 14.4 COMMS functions . 265 14.5 Sub-layer functions . 274 14.6 Virtual concatenation functions 295 Annex A Optical section (OSx) and constant bit rate (CBRx) layer functions 335 A.1 Connection functions 335 A.2 Termination functions 335 A.3 Adaptation functions 339 Appendix I Applications and f
29、unctional diagrams . 343 I.1 Transparent CBRx tributary interface port with optional SDH RS non-intrusive monitor on OTN equipment 343 I.2 OTM-0.m tributary interface port on OTN equipment 344 I.3 Selectable CBRx/OTM-0.m tributary interface port on OTN equipment 346 I.4 OTM-0.m interface ports on no
30、n-OTN equipment 348 I.5 OTM-n.m interface port with 3-R regeneration functionality for an ODUk connection function 350 Appendix II TCM applications . 352 Appendix III Performance of processes 355 III.1 Introduction 355 III.2 OTUk frame alignment process 355 III.3 STAT acceptance process and related
31、defect detection (ODUkP/TdAIS, ODUkP/TdOCI, ODUkP/TdLCK, ODUkTdLTC, ODUkTdIAE) . 357 III.4 OTUkdIAE, OTUkdBDI, ODUkP/TdBDI detection . 358 III.5 PT acceptance process and ODUkPdPLM detection . 359 III.6 Generic AIS and OTUk AIS detection . 360 Rec. ITU-T G.798 (12/2012) v Page III.7 OTUkdBIAE and OD
32、UkTdBIAE detection process 361 Appendix IV TTI processing examples 363 IV.1 Example 1 . 363 IV.2 Example 2 . 364 Appendix V Client services of sub ODU1 rate mapping into OTN using higher order virtual container mapping . 368 V.1 Description of the application 368 V.2 ODUk/Sn compound function 370 V.
33、3 Migration from SDH towards OTN networking 371 Appendix VI OCH client mapping of pre-OTN signals . 373 VI.1 OCh to CBRx adaptation (OCh/CBRx_A) . 373 VI.2 OCh to GbE adaptation function (OCh/GbE_A) 375 VI.3 OCh to RSn adaptation (OCh/RSn_A) . 375 Bibliography. 379 vi Rec. ITU-T G.798 (12/2012) Intr
34、oduction This Recommendation forms part of a suite of Recommendations covering the full functionality of network equipment (e.g., ITU-T G.783, ITU-T G.705, ITU-T G.781, and ITU-T G.784) and follows the principles defined in ITU-T G.806. This Recommendation specifies a library of basic building block
35、s and a set of rules by which they may be combined in order to describe equipment used in an optical transport network. The library comprises the functional building blocks needed to specify completely the generic functional structure of the optical transport network. In order to be compliant with t
36、his Recommendation, the OTN functionality of any equipment which processes at least one of the OTN layers needs to be describable as an interconnection of a subset of the functional blocks contained within this Recommendation. The interconnections of these blocks should obey the combination rules gi
37、ven. The specification method is based on the functional decomposition of the equipment into atomic and compound functions. The equipment is then described by its equipment functional specification (EFS) which lists the constituent atomic and compound functions, their interconnection and any overall
38、 performance objectives (e.g., transfer delay, availability, etc.). Rec. ITU-T G.798 (12/2012) 1 Recommendation ITU-T G.798 Characteristics of optical transport network hierarchy equipment functional blocks 1 Scope This Recommendation covers the functional requirements of optical transport network f
39、unctionality within equipment. Some examples of this functionality are: optical transmission section termination and line amplification functionality optical multiplex section termination functionality optical channel termination functionality optical channel cross-connect functionality. This Recomm
40、endation uses the specification methodology defined in ITU-T G.806, in general for transport network equipment, and is based on the architecture of optical transport networks defined in ITU-T G.872 and the interfaces for optical transport networks defined in ITU-T G.709. The description is generic a
41、nd no particular physical partitioning of functions is implied. The input/output information flows associated with the functional blocks serve for defining the functions of the blocks and are considered to be conceptual, not physical. The OCh layer, as defined in ITU-T G.872, is divided into an OCh
42、layer, an OTU layer and an ODU layer with tandem connection sub-layers as defined in ITU-T G.709. The functionality defined in this Recommendation can be applied at user-to-network interfaces (UNIs) and network node interfaces (NNIs) of the optical transport network. It is recognized that for interf
43、aces used within optical subnetworks, aspects of the interface are optical technology dependent and subject to change as technology progresses. Therefore, optical-technology dependent aspects (for transverse compatibility) are not defined for functional blocks used for these interfaces to allow for
44、technology changes. The overhead processing functionality necessary for operations and management of optical subnetworks is defined. Not every functional block defined in this Recommendation is required for every application. Different subsets of functional blocks from this Recommendation and others
45、 (e.g., ITU-T G.783) may be assembled in different ways according to the combination rules given in these Recommendations to provide a variety of different capabilities. Network operators and equipment suppliers may choose which functions must be implemented for each application. The internal struct
46、ure of the implementation of this functionality (equipment design) need not be identical to the structure of the functional model, as long as all the details of the externally observable behaviour comply with the equipment functional specification (EFS). Equipment developed prior to the production o
47、f this Recommendation may not comply in all details with this Recommendation. Equipment which is normally stated to be compliant with this Recommendation may not fulfil all the requirements in the case that it is interworking with old equipment that is not compliant with this Recommendation. Figures
48、 1-1, 1-2 and 1-3 present the set of atomic functions associated with traffic signal transport. The functions for the processing of communication channels (COMMS) are not shown in these figures in order to reduce the complexity of the figures. For the COMMS functions, refer to the specific layer net
49、work descriptions. 2 Rec. ITU-T G.798 (12/2012) G.798-Amd.1(11)_F1-1OPSn OPSMnkOTM-nr.m/OTM-0.m signal OTM-0.mvn signalOPSn/OChr OPSM/OTUkOPSn/OChr OPSM/OTUkOPSn OPSMnkOChr OChrOCh_APOPSn_AP OPSM_APOPSn_TCP OPSMnk_TCPOChr_TCPOChr_CPOTUk_CPFigure 1-1 OTN atomic functions specific for the reduced functionality OTM-nr.m/ OTM-0.m and OTM-0.mvn interface G.798(10)_F1-2OChOChOChOMSn/OChOMSnOTM-n.m signalOTSn/OMSnOTSnOMSn/OChOMSnOTM-n.m signalOTSn/OMSn
