1、 International Telecommunication Union ITU-T G.780/Y.1351TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (07/2010) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments Principal characteristics of multiplexing equipment for the synchronous digital hierar
2、chy SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Transport Terms and definitions for synchronous digital hierarchy (SDH) networks Recommendation ITU-T G.780/Y.1351 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND
3、 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 GENERAL CHARACTER
4、ISTICS 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 EQUIPMENTS G.700G.799
5、 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 characteristics of higher order multiplex equipment G.750G.759 Principal characteris
6、tics 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 synchronous digital hierarchy G.780G.789Other terminal equipment G.790G.799 DIGITAL
7、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 TRANSPORT ASPECTS G.8000G.8
8、999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.780/Y.1351 (07/2010) i Recommendation ITU-T G.780/Y.1351 Terms and definitions for synchronous digital hierarchy (SDH) networks Summary Recommendation ITU-T G.780/Y.1351 provides ter
9、ms, definitions and abbreviations used in synchronous digital hierarchy (SDH) Recommendations. Physical layer terminology, synchronization-related terminology, and terms applicable to multiple technologies in addition to SDH are not included. The goal of this Recommendation is to be a single normati
10、ve source for terms in this subject area. History Edition Recommendation Approval Study Group 1.0 ITU-T G.780 1994-11-01 15 2.0 ITU-T G.780 1999-07-02 15 3.0 ITU-T G.780/Y.1351 2004-07-22 15 3.1 ITU-T G.780/Y.1351 (2004) Amend. 1 2005-06-29 15 4.0 ITU-T G.780/Y.1351 2008-03-29 15 5.0 ITU-T G.780/Y.1
11、351 2010-07-29 15 Keywords Definitions, synchronous digital hierarchy (SDH), terminology. ii Rec. ITU-T G.780/Y.1351 (07/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technolog
12、ies (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 World Telecommun
13、ication 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. In some areas o
14、f 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 recognized operati
15、ng 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 words “shall“ o
16、r 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 that the practic
17、e 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 Recommendation developme
18、nt 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 not represent the latest information and are therefore
19、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 means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.780/Y.1351 (07/2010) iii CONTENTS Page 1 Scope 1 2 Refere
20、nces. 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms defined in this Recommendation . 3 4 Abbreviations and acronyms 14 Appendix I List of source Recommendations . 17 Rec. ITU-T G.780/Y.1351 (07/2010) 1 Recommendation ITU-T G.780/Y.1351 Terms and definitions for synchronous digital hierar
21、chy (SDH) networks 1 Scope This Recommendation contains a list of terms, definitions and abbreviations used in Recommendations dealing with synchronous digital hierarchy (SDH) networks. SDH terms specific to synchronization or physical layer or characteristics are not a part of this Recommendation.
22、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 other references are subject to revisio
23、n; 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 reference to a document within this Re
24、commendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.702 Recommendation ITU-T G.702 (1988), Digital hierarchy bit rates. ITU-T G.703 Recommendation ITU-T G.703 (2001), Physical/electrical characteristics of hierarchical digital interfaces. ITU-T G.707 Rec
25、ommendation ITU-T G.707/Y.1322 (2007), Network node interface for the synchronous digital hierarchy (SDH), including its amendments. ITU-T G.783 Recommendation ITU-T G.783 (2006), Characteristics of synchronous digital hierarchy (SDH) equipment functional blocks, plus Amendment 1 (2008) and Amendmen
26、t 2 (2010), Support for optical modules transporting 40 Gigabit/s signals via a multilane interface. ITU-T G.784 Recommendation ITU-T G.784 (1999), Synchronous digital hierarchy (SDH) management. ITU-T G.803 Recommendation ITU-T G.803 (2000), Architecture of transport networks based on the synchrono
27、us digital hierarchy (SDH). 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 (2006), Characteristics of transport equipment Description methodology and generic functionality. ITU-T G.826 Recommendation ITU-T
28、G.826 (2002), End-to-end error performance parameters and objectives for international, constant bit-rate digital paths and connections. ITU-T G.828 Recommendation ITU-T G.828 (2000), Error performance parameters and objectives for international, constant bit-rate synchronous digital paths. ITU-T G.
29、829 Recommendation ITU-T G.829 (2002), Error performance events for SDH multiplex and regenerator sections. ITU-T G.841 Recommendation ITU-T G.841 (1998), Types and characteristics of SDH network protection architectures. ITU-T G.842 Recommendation ITU-T G.842 (1997), Interworking of SDH network pro
30、tection architectures. 2 Rec. ITU-T G.780/Y.1351 (07/2010) ITU-T G.870 Recommendation ITU-T G.870/Y.1352 (2008), Terms and definitions for optical transport networks (OTN). ITU-T G.7712 Recommendation ITU-T G.7712/Y.1703 (2008), Architecture and specification of data communication network. ITU-T M.3
31、010 Recommendation ITU-T M.3010 (2000), Principles for a telecommunications management network. ITU-T X.710 Recommendation ITU-T X.710 (1997) | ISO/IEC 9595:1998, Information technology Open Systems Interconnection Common Management Information service. 3 Definitions 3.1 Terms defined elsewhere This
32、 Recommendation uses the following terms defined elsewhere: 3.1.1 Terms defined in ITU-T G.805: access point (AP) adaptation characteristic information (CI) connection connection point (CP) network connection (NC) subnetwork connection (SNC) trail trail termination function (TT) 3.1.2 Terms defined
33、in ITU-T G.806: alarm all ONEs defect failure function management information (MI) path process signal degrade (SD) signal fail (SF) 3.1.3 Term defined in ITU-T G.7712: embedded control channel (ECC) 3.1.4 Terms defined in ITU-T G.870: bridge head-end null signal switch Rec. ITU-T G.780/Y.1351 (07/2
34、010) 3 tail-end 3.1.5 Term defined in ITU-T M.3010: telecommunications management network (TMN) 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 active trail/path/section/SNC/NC: The trail/path/section/SNC from which the signal is selected by the protec
35、tion selector. 3.2.2 adapted information (AI): The information passing across an AP. 3.2.3 add traffic: Normal or extra traffic inserted into working, protection, or non-pre-emptible unprotected channels on the ring at a ring node. 3.2.4 add/drop multiplexer (ADM): Network element that provides acce
36、ss to all, or some subset of the constituent signals contained within an STM-N signal. The constituent signals are added to (inserted), and/or dropped from (extracted) the STM-N signal as it passes through the ADM. 3.2.5 administrative unit group (AUG): One or more administrative units occupying fix
37、ed, defined positions in an STM payload are termed an administrative unit group (AUG). An AUG-1 consists of a homogeneous assembly of AU-3s or an AU-4. 3.2.6 administrative unit-n (AU-n): An administrative unit is the information structure which provides adaptation between the higher order path laye
38、r and the multiplex section layer. It consists of an information payload (the higher order virtual container) and an administrative unit pointer which indicates the offset of the payload frame start relative to the multiplex section frame start. Two administrative units are defined. The AU-4 consist
39、s of a VC-4 plus an administrative unit pointer which indicates the phase alignment of the VC-4 with respect to the STM-N frame. The AU-3 consists of a VC-3 plus an administrative unit pointer which indicates the phase alignment of the VC-3 with respect to the STM-N frame. In each case, the administ
40、rative unit pointer location is fixed with respect to the STM-N frame. 3.2.7 administrative unit-n (AU-n) pointer: An administrative unit pointer which indicates the offset of the payload frame start relative to the multiplex section frame start. See ITU-T G.707. 3.2.8 agent: Part of the management
41、application function (MAF) which is capable of responding to network management operations issued by a manager and may perform operations on managed objects, issuing events on behalf of managed objects. The managed objects can reside within the entity or in another open system. Managed objects from
42、other open systems are controlled by a distant agent, via a local manager. All SDH network elements (S.NEs) will support at least an agent. Some S.NEs will provide managers and agents (being managed). Some S.NEs (e.g., regenerators) will only support an agent. 3.2.9 alarm indication signal (AIS): A
43、code sent downstream in a digital network as an indication that an upstream failure has been detected and alarmed. It is associated with multiple transport layers. NOTE See ITU-T G.707 for specific AIS signals. 3.2.10 asynchronous interface: These interfaces provide an output signal with a frequency
44、 that is not traceable to a primary reference clock (PRC) and that meets the frequency offset requirements given in ITU-T G.703. 3.2.11 automatic protection switching (APS): Autonomous switching of a signal between and including two MSn_TT, Sn_TT, or Sm_TT functions, from a failed working trail/SNC
45、to a 4 Rec. ITU-T G.780/Y.1351 (07/2010) protection trail/SNC and subsequent restoration using control signals carried by the K-bytes in the MSOH, HO POH, or LO POH. 3.2.12 automatic protection switching (APS) controller: That part of a node that is responsible for generating and terminating informa
46、tion carried in the APS protocol and implementing the APS algorithm. 3.2.13 automatic protection switching (APS) request: That set of signals into an APS controller that determines its behaviour. An APS request can be either an externally initiated command or an automatically initiated command. 3.2.
47、14 automatically initiated command: An APS request that is initiated by any one of the following: 1) multiplex section performance criteria; 2) local equipment performance criteria; or 3) received bridge requests. 3.2.15 auto-provisioning: The assignment of values to parameters within a network elem
48、ent, without those values being specifically entered externally by a user. 3.2.16 background block error (BBE): An errored block not occurring as part of an SES. 3.2.17 background block error ratio (BBER): The ratio of BBE in available time to total blocks in available time during a fixed measuremen
49、t interval. The count of total blocks excludes all blocks during SESs. 3.2.18 bidirectional protection switching: A protection switching architecture in which, for a unidirectional failure (i.e., a failure affecting only one direction of transmission), both directions (of the “trail“, “subnetwork connection“, etc.), including the affected direction and the unaffected direction, are switched to protection. 3.2.19 bidirectional ring: In a bidirect
