1、 AMERICAN NATIONAL STANDARD FOR TELECOMMUNICATIONS ATIS-0300231.02.2003(R2007) DS1 Layer 1 In-Service Digital Transmission Performance Monitoring ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for th
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9、rpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken perio
10、dically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Notice of Disclaimer Revision T1.231-1997) American National Standard for Telecommunicat
11、ions DS1 Layer 1 In-Service Digital Transmission Performance Monitoring Secretariat Alliance for Telecommunications Industry Solutions Approved October 22, 2003 American National Standards Institute, Inc. Abstract This standard provides performance monitoring functions and requirements applicable to
12、 DS1 digital transmission signals. This standard provides functional requirements to support maintenance and is not meant to be an equipment specification. This standard is one of a set of standards which are applications utilizing the common criteria as specified in T1.231-2003. ATIS-0300231.02.200
13、3 ii Foreword The information contained in this Foreword is not part of this American National Standard (ANS) and has not been processed in accordance with ANSIs requirements for an ANS. As such, this Foreword may contain material that has not been subjected to public review or a consensus process.
14、In addition, it does not contain requirements necessary for conformance to the standard. This American National Standard is one of a series of maintenance operations standards developed by Technical Subcommittee T1M1 of Committee T1 - Telecommunications. Committee T1 standards serve the public throu
15、gh improved understanding between carriers, end-users, and manufacturers. This standard specifies a basic set of monitoring requirements, and provides criteria that are common to a set of standards, the T1.231 series, which define applications for a specific level in the digital hierarchy. The docum
16、ents, which are included in the T1.231 series (at the time that this document is approved), are listed below: T1.231-2003, Digital Hierarchy Layer 1 In-Service Transmission Performance Monitoring. T1.231.01-2003,DSL Layer 1 In-Service Transmission Performance Monitoring. T1.231.02-2003, DS1 Layer 1
17、In-Service Digital Transmission Performance Monitoring. T1.231.03-2003, DS3 Layer 1 In-Service Digital Transmission Performance Monitoring. T1.231.04-2003, SONET Layer 1 In-Service Digital Transmission Performance Monitoring. T1.231.05-200x, OTN Layer 1 In-Service Transmission Performance Monitoring
18、. (This standard is not yet approved.) This particular standard will be useful to anyone engaged in the design, provisioning, or operation of telecommunications equipment or services utilizing DS1 digital transmission technology. The standard establishes uniform and consistent performance monitoring
19、 functions and requirements applicable to Layer1 DS1 digital transmission signals. This standard is intended to be a living document, subject to revision and updating as warranted by advances in digital transmission technology Compliance with the standard should provide uniform and consistent measur
20、ement parameters and techniques for DS1 circuits, facilities, and networks. In some cases, location-oriented options are needed to ensure compatibility: this need for options is imposed by significant differences between network providers as well as between network elements Requirements are designat
21、ed by the word shall while recommendations utilize the word should. Requirements specify the minimum acceptable functionality for effective performance monitoring in a network element; recommendations identify functionality that may enhance performance monitoring capabilities for some users. There i
22、s one annex in this standard, which is informative and is not considered part of the standard. Suggestions for the improvement of this standard will be welcome They should be sent to the Alliance for Telecommunications Industry Solutions, 1200 G Street, NW, Suite 500, Washington, DC, 20005. This sta
23、ndard was processed and approved for submittal to ANSI by Accredited Standards Committee on Telecommunications, T1. Committee approval of the standard does not necessarily imply that all members voted for its approval. At the time it approved this standard, the T1 Committee had the following members
24、: E.R. Hapeman, T1 Chair W.R. Zeuch, T1 Vice-Chair J.A. Crandall, T1 Director S.M. Carioti, T1 Disciplines S.D. Barclay, T1 Secretary C.A. Underkoffler, T1 Chief Editor T. Malpass, T1M1 Technical Editor EXCHANGE CARRIERS Organization Represented Name of Representative AT It describes the functions r
25、elated to the collection, storage, thresholding, and reporting of performance monitoring information; and It establishes the performance monitoring functions that may be used at network interfaces between telecommunication carriers, at network boundaries, and at customer premises to permit compatibl
26、e maintenance operations. Although this standard establishes ranges over which transmission performance can be measured, it does not establish any requirements or guidelines for levels of performance. This standard refers to other American National Standards that address digital transmission and per
27、formance criteria. 2 Normative references The following standards contain provisions, which through reference in this text constitute provisions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to ag
28、reements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. T1.102-1993 (R1999), Digital hierarchy Electrical interfaces1. 1This document is available from the Alliance for Telecommunications I
29、ndustry Solutions, 1200 G Street N.W., Suite 500, Washington, DC 20005. ATIS-0300231.02.2003 2 T1.217-1991 (R2003), Integrated Services Digital Network (ISDN) Management - Primary Rate Physical Layer.1T1.231-2003, Digital Hierarchy Layer 1 In-Service Digital Transmission Performance Monitoring.1T1.4
30、03-1999, Network and Customer Installation Interface DS1 Electrical Interface.13 Definitions and Acronyms 3.1 Definitions 3.1.1 alarm indication signal (AIS): A signal transmitted in lieu of the normal signal to maintain transmission continuity and to indicate to the receiving equipment that there i
31、s a transmission interruption located either at the equipment originating the AIS signal or upstream of that equipment. 3.1.2 alarm indication signal - customer installation (AIS-CI): An AIS signal which carries a special signature defined in T1.403-1999 to indicate that the transmission interruptio
32、n has originated in the customer installation (CI). 3.1.3 alarm/status monitoring: Surveillance based monitoring process where information pertaining to failure events on a transmission entity is communicated. 3.1.4 application specific (A): A descriptor, applied to a monitoring capability, indicati
33、ng that the capability shall be provided when a particular performance monitoring application (as defined in this standard) is implemented. 3.1.5 bidirectional path: A pair of unidirectional paths, where each source is physically collocated with a path sink. Note that path sources may set far-end pe
34、rformance monitoring indications based on information provided by the collocated path sink. 3.1.6 layer 1: The physical layer of the Open Systems Interconnection model. 3.1.7 optional (O): A descriptor, applied to a monitoring capability, indicating that the capability may or may not be provided in
35、a performance monitoring implementation. 3.1.8 path: A logical connection between the point at which a standard frame format for the signal at the given rate is assembled (i.e., path source), and the point at which the standard frame format for the signal is disassembled (i.e., path sink). 3.1.9 pay
36、load: That portion of the total bitstream not specifically reserved for overhead functions. 3.1.10 performance monitoring (PM): The process of continuous collection, analysis, and reporting of performance data associated with a transmission entity. 3.1.11 protection switching (PS): A feature of a tr
37、ansmission entity that enables data on a failed facility to be moved to an alternate facility. This feature may be either revertive or nonrevertive. 3.1.12 protection switching - revertive: An arrangement that, upon restoral of the regular line, the service is automatically switched back from the pr
38、otection line to the regular line. 3.1.13 protection switching - nonrevertive: An arrangement that, upon restoral of the regular line, the service will not automatically switch back from the protection line. This process is used to prevent further service interruptions that may be caused by the swit
39、ch. 3.1.14 remote alarm indication (RAI): A signal transmitted in the outgoing direction when a terminal determines that specific defects have persisted long enough to declare a received signal failure. The RAI terminology is in widespread industry use, replacing an earlier term (yellow alarm). 3.1.
40、15 remote alarm indication signal - customer installation (RAI-CI): An RAI signal which carries a special signature defined in T1.403-1999 to indicate that the received signal failure has originated in the customer installation (CI). 3.1.16 requirement (R): A descriptor, applied to a monitoring capa
41、bility, indicating that the capability must be provided in all performance monitoring implementations to meet this standard. 3.1.17 surveillance: Non-intrusive monitoring of digital signals in real time to recognize performance degradations and failures. 3.1.18 testing: The process of verifying and
42、isolating failures or performance degradations by subjecting network elements to predetermined inputs (e.g., quasi-random test signals) and measuring the resulting response. ATIS-0300231.02.2003 3 3.1.19 unidirectional path: A path that logically connects a single path source with the associated pat
43、h sink. 3.2 Acronyms and 2. The extended superframe format (ESF). A DS1 path termination is the point where its frame format is generated and transmitted, or received and decoded. For more details about DS1 line and path formats, see T1.102-1993 (R1999) and T1.403-1999. 4.1 Abbreviations and Convent
44、ions All the primitives, parameters, failures, and other indicators and signals defined in this standard are abbreviated to simplify the text. The abbreviations are included with the definitions in the appropriate clauses of this standard. In many cases, the same general name (e.g., code violation,
45、errored second, etc.) applies to all entities for a particular digital signal. The identification of the entity is determined by the suffix applied to the abbreviation of the general name. A dash followed by an “L“ indicates the Line entity, and a “P“ indicates the Path entity. Items defined for nea
46、r-end monitoring have no additional suffixes, while far-end items append “FE“ to the entity suffix. For example, ES-P designates near-end Errored Seconds at the path layer, while ES-PFE designates the same parameter for the far-end. NP and NPFE indicates a network path used to differentiate failures
47、 and errors between the CI and network. 4.2 Performance Primitives Table 1 and Table 2 summarize the performance primitives that are judged to be useful for in-service performance monitoring. DS1 primitives and are described below. Support of the primitives in a network element is indicated in the t
48、able as: required (R), application specific (A), or optional (O). (See also T1.231-2003.) ATIS-0300231.02.2003 5 4.2.1 Performance anomalies 4.2.1.1 Line anomalies 4.2.1.1.1 Bipolar violation (BPV) A BPV is the occurrence of a pulse of the same polarity as the previous pulse. 4.2.1.1.2 Excessive zer
49、os (EXZ) An EXZ for an AMI-coded signal is the occurrence of more than fifteen consecutive zeros. An EXZ for a B8ZS-coded signal is the occurrence of more than seven consecutive zeros. 4.2.1.2 Path anomalies 4.2.1.2.1 Cyclic redundancy check (CRC-6) error A CRC-6 error primitive applies only to DS1 Extended Superframe Format (ESF) paths. It is the occurrence of a received CRC-6 code that is not identical to the corresponding locally calculated code. 4.2.1.2.2 Frame bit error (FE) An FE primitive, also referred to as Frame Synchronization Bit Error, app
