1、 International Telecommunication Union ITU-T G.798.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2013) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments Other terminal equipment Types and characteristics of optical transport network equipment R
2、ecommendation ITU-T G.798.1 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 CHARACTERISTICS OF INT
3、ERNATIONAL 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 TRANSMISSION MEDIA AN
4、D 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.749 Principal c
5、haracteristics 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 equipment for the s
6、ynchronous 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.6000G.6999 DATA
7、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.798.1 (01/2013) i Recommendation ITU-T G.798.1 Types and characteristics of optical transport netwo
8、rk equipment Summary Recommendation ITU-T G.798.1 provides an overview of the functions of optical transport network (OTN) equipment and examples of possible OTN equipment types based on the atomic functions specified in Recommendation ITU-T G.798. History Edition Recommendation Approval Study Group
9、 1.0 ITU-T G.798.1 2011-04-13 15 2.0 ITU-T G.798.1 2013-01-13 15 2.1 ITU-T G.798.1 (2013) Amd. 1 2013-08-29 15 Keywords Optical transport network. ii Rec. ITU-T G.798.1 (01/2013) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecom
10、munications, 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 telecommu
11、nications 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 Recommendations on these topics. The approval of ITU-T Recommendations is covered by the proce
12、dure 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 Recommendation, the expression “Administration“ is used for conciseness to indicate both a telec
13、ommunication 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 th
14、ese 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 with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS IT
15、U 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 applicability of claimed Intellectual Property Rights, whether asserted by ITU memb
16、ers 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 be required to implement this Recommendation. However, implementers are cautioned that this may no
17、t represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 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.
18、1 (01/2013) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 2 3.1 Terms defined elsewhere 2 4 Abbreviations and acronyms 3 5 Conventions 5 6 OTN layer hierarchy, domains, topology and connections 5 6.1 Network overview 5 6.2 Layer networks . 5 6.3 OTN OAM functions 8 7 Operations,
19、 administration, maintenance and provisioning . 9 7.1 OAM applications 9 7.2 TMN access 19 7.3 Timing function 20 7.4 Control plane access . 21 7.5 Connection management 21 8 Protection switching . 21 8.1 Linear protection 21 8.2 Shared ring protection 21 8.3 Shared mesh protection 21 9 Interface po
20、rts on optical transport network equipment . 21 9.1 I-NNI 21 9.2 E-NNI . 23 9.3 UNI . 25 10 Basic OTN equipment types . 25 10.1 3R regeneration compound function 26 10.2 OTN network termination unit (NTU) . 26 10.3 Wavelength add/drop multiplexer (WADM) . 27 10.4 Wavelength cross connect (WXC) . 27
21、10.5 Sub-wavelength cross connect (SWXC) 28 10.6 Optical amplifier . 30 10.7 Sub-wavelength add/drop multiplexer (SWADM) 30 11 OTN and packet transport network (PTN) hybrid equipment 30 Appendix I ODU multiplexing considerations . 32 Appendix II Examples of SNC protection implementation 33 II.1 Anal
22、ysis 33 iv Rec. ITU-T G.798.1 (01/2013) Page Appendix III OTN link and connection examples 37 Appendix IV Multi-layer OTM-n network node interface . 45 Appendix V Converged packet and optical transport equipment type . 46 Rec. ITU-T G.798.1 (01/2013) 1 Recommendation ITU-T G.798.1 Types and characte
23、ristics of optical transport network equipment 1 Scope This Recommendation provides an overview of the functions of optical transport network (OTN) equipment and examples of possible OTN equipment types. It does not define required OTN equipment types. The Recommendation is based on the OTN atomic f
24、unctions specified in ITU-T G.798. 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 Recommendations and othe
25、r 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 regularly published. The ref
26、erence to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.703 Recommendation ITU-T G.703 (2001), Physical/electrical characteristics of hierarchical digital interfaces. ITU-T G.707 Recommendation ITU-T G.707 (2007), Network n
27、ode interface for the synchronous digital hierarchy (SDH). ITU-T G.709 Recommendation ITU-T G.709/Y.1331 (2009), Interfaces for the optical transport network (OTN). ITU-T G.783 Recommendation ITU-T G.783 (2006), Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks. ITU-
28、T G.798 Recommendation ITU-T G.798 (2010), Characteristics of optical transport network hierarchy equipment functional blocks. 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 trans
29、port equipment Description methodology and generic functionality. ITU-T G.808.1 Recommendation ITU-T G.808.1 (2010), Generic protection switching Linear trail and subnetwork protection. ITU-T G.870 Recommendation ITU-T G.870/Y.1352 (2008), Terms and definitions for optical transport networks (OTN).
30、ITU-T G.872 Recommendation ITU-T G.872 (2001), Architecture of optical transport networks. ITU-T G.873.1 Recommendation ITU-T G.873.1 (2011), Optical Transport Network (OTN): Linear protection. ITU-T G.874 Recommendation ITU-T G.874 (2010), Management aspects of optical transport network elements. I
31、TU-T G.7710 Recommendation ITU-T G.7710/Y.1701 (2007), Common equipment management function requirements. 2 Rec. ITU-T G.798.1 (01/2013) ITU-T G.7712 Recommendation ITU-T G.7712/Y.1703 (2010), Architecture and specification of data communication network. ITU-T G.8012.1 Recommendation ITU-T G.8012.1/
32、Y.1308.1 (2012), Interfaces for the Ethernet transport network. ITU-T G.8021 Recommendation ITU-T G.8021/Y.1341.1 (2012), Types and characteristics of Ethernet transport network equipment. ITU-T G.8112 Recommendation ITU-T G.8112/Y.1371 (2012), Interfaces for the MPLS Transport Profile layer network
33、. ITU-T G.8121 Recommendation ITU-T G.8121/Y.1381 (2012), Characteristics of MPLS-TP equipment functional blocks. ITU-T G.8080 Recommendation ITU-T G.8080/Y.1304 (2006), Architecture for the automatically switched optical network (ASON). ITU-T I.112 Recommendation ITU-T I.112 (1984), Vocabulary of t
34、erms for ISDNs. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 adaptation function (A): ITU-T G.806. 3.1.2 compound function: ITU-T G.806. 3.1.3 connection function (C): ITU-T G.806. 3.1.4 defect: ITU-T G.806. 3.1.5 fault cause: ITU-T
35、G.806. 3.1.6 function: ITU-T G.806. 3.1.7 network: ITU-T G.805. 3.1.8 ODUk path (ODUkP): ITU-T G.870. 3.1.9 ODUk TCM (ODUkT): ITU-T G.870. 3.1.10 optical channel (OChr): ITU-T G.870. 3.1.11 optical channel data unit (ODUk): ITU-T G.870. 3.1.12 optical channel payload unit (OPUk): ITU-T G.870. 3.1.13
36、 optical channel transport unit (OTUkV): ITU-T G.870. 3.1.14 optical channel with full functionality (OCh): ITU-T G.870. 3.1.15 optical channel with reduced functionality (OChr): ITU-T G.870. 3.1.16 optical multiplex section (OMS): ITU-T G.872. 3.1.17 optical physical section of order n (OPSn): ITU-
37、T G.870. 3.1.18 optical supervisory channel (OSC): ITU-T G.870. 3.1.19 optical transmission section (OTS): ITU-T G.872. 3.1.20 optical transport hierarchy (OTH): ITU-T G.870. 3.1.21 optical transport module (OTM-nr.m): ITU-T G.870. Rec. ITU-T G.798.1 (01/2013) 3 3.1.22 optical transport network (OTN
38、): ITU-T G.870. 3.1.23 subnetwork connection (SNC): ITU-T G.805. 3.1.24 switching: ITU-T I.112. 3.1.25 trail termination function (TT): ITU-T G.806. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: ADM Add-Drop Multiplexer AIS Alarm Indication Signal AM
39、P Asynchronous Mapping Procedure BDI Backward Defect Indication BDI-O Backward Defect Indication Overhead BDI-P Backward Defect Indication Payload BEI Backward Error Indicator BIAE Backward Incoming Alignment Error BMP Bit-synchronous Mapping Procedure CBR Constant Bit Rate signal COMMS Communicatio
40、ns channel EEC Ethernet Equipment Clock E-NNI External Network Node Interface FDI Forward Defect Indication FDI-O Forward Defect Indicator Overhead FDI-P Forward Defect Indicator Payload GMP Generic Mapping Procedure HO High Order IAE Incoming Alignment Error I-NNI Internal Network Node Interface IP
41、 Internet Protocol LCK Locked indication LF Local Fault LO Low Order LOA Loss Of Alignment LOF Loss Of Frame LOFLANE Loss of Frame of logical Lane LOFLOM Loss Of Frame and Loss Of Multiframe LOL Loss of Lane Alignment LOM Loss of Multiframe 4 Rec. ITU-T G.798.1 (01/2013) LOR Loss of Recovery LOS Los
42、s Of Signal LOS-O Loss Of Signal Overhead LOS-P Loss Of Signal Payload LSP Label Switched Path MPLS-TP Multiprotocol Label Switching Transport Profile MSIM Multiplex Structure Identifier Mismatch OAM Operations, Administration and Maintenance OCh Optical Channel OCI Open Connection Indication ODU Op
43、tical Data Unit OH Overhead OLA Optical Line Amplifier OMS Optical Multiplex Section ONTU OTN Network Termination Unit OPS Optical Physical Section OTM Optical Transport Module OTN Optical Transport Network OTS Optical Transport Section OTU Optical Transport Unit PMI Payload Missing Indication PRC P
44、rimary Reference Clock PTN Packet Transport Network SEC SDH Equipment Clock SNC Subnetwork Connection SNC/S Subnetwork Connection protection with Sublayer monitoring SSU Synchronization Supply Unit STM-N Synchronous Transport Module, level N SWXC Sub-Wavelength Cross Connect TDM Time Division Multip
45、lexing TIM Trail trace Identifier Mismatch UNI User Network Interface VLAN Virtual Local Area Network VPN Virtual Private Network WADM Wavelength Add-Drop Multiplexer WDM Wavelength Division Multiplexing WXC Wavelength Cross Connect Rec. ITU-T G.798.1 (01/2013) 5 5 Conventions None. 6 OTN layer hier
46、archy, domains, topology and connections 6.1 Network overview Figure 6-1 shows a simplified view of an OTN network that consists of two optical domains (identified by the clouds) and showing different types of OTN equipment within those clouds. At the customer premises there may be client nodes, or
47、there may be a client node and an OTN network termination unit (ONTU). Within the service provider domains there are ONTUs, wavelength add-drop multiplexers (WADMs)/cross connects, sub-wavelength cross connects (SWXC), and optical line amplifiers (OLAs). G.798.1(13)_F6-1SWXCWADM/WXCDomain ASWXCONTUO
48、NTUCustomer premisesCustomerpremisesCustomerpremisesClientnodeClientnodeClientnodeSWXCDomain BONTUClientnodeCustomerpremisesWADM/WXCSWXCONTUWADM/WXCSWXCSWXCWADM/WXCOLAFigure 6-1 OTN network example 6.2 Layer networks ITU-T G.872 decomposes an OTN into four layers: optical channel (OCh), optical mult
49、iplex section (OMS), optical transport section (OTS), and physical media. In cases where there is a single wavelength, the OMS and OTS layers are collapsed into a single optical physical section (OPS). The OCh layer is further decomposed into digital section (optical transport unit (OTU) and digital path (optical data unit (ODU) sublayers. The ODU layer further supports time division multiplexing (TDM) of lower-speed OD
