1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU M.2130 (02/2000) SERIES M: TMN AND NETWORK MAINTENANCE: INTERNATIONAL TRANSMISSION SYSTEMS, TELEPHON E CI RCU ITS, TELEGRAPHY, FACS I M I LE AND LEASED CIRCUITS International transport network Operational pro
2、cedures for the maintenance of the transport network ITU-T Recommendation M.2130 (Formerly CCITT Recommendation) ITU-T M-SERIES RECOMMENDATIONS TMN AND NETWORK MAINTENANCE: INTERNATIONAL TRANSMISSION SYSTEMS, TELEPHONE CIRCUITS, TELEGRAPHY, FACSIMILE AND LEASED CIRCUITS Introduction and general prin
3、ciples of maintenance and maintenance organization International transmission systems International telephone circuits Common channel signalling systems International telegraph systems and phototelegraph transmission International leased group and supergroup links International leased circuits Mobil
4、e telecommunication systems and services International public telephone network International data transmission systems M. 1 0-M.299 M.300-M.559 M.560-M.759 M.760-M.799 M.800-M.899 M.900-M.999 M. 1000-M. 1099 M.1100-M.1199 M. 1200-M. 1299 M. 1300-M.1399 Designations and information exchange M.1400-M
5、.1999 u u International transport network M.2000-M.2999 Telecommunications management network M.3000-M.3599 Integrated services digital networks Common channel signalling systems M.3600-M.3999 M.4000-M.4999 For further details, please re$er to the list of ITD-T Recommendations. ITU-T Recommendation
6、M.2130 Operational procedures for the maintenance of the transport network Summary This ITU-T Recommendation specifies the operational procedures that two international maintenance organizations have to follow in case of failure or degradation of the transport network: paths, section or synchronizat
7、ion. These procedures are required in order to: localize and clear the fault, permit protectionheversibility and facilitate restoration and return to the original configuration. The maintenance procedures in this ITU-T Recommendation defines reference points requiring information to be exchanged bet
8、ween maintenance organizations of involved Network Operators/Service Providers. Source ITU-T Recommendation M.2130 was revised by ITU-T Study Group 4 (1997-2000) and approved under the WTSC Resolution 1 procedure on 4 February 2000. Keywords Degradation, failure, fault, maintenance, path, procedure,
9、 protection, restoration, reversibility, section. ITU-T M.2130 (02/2000) 1 FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T
10、 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 Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for stu
11、dy 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 WTSC Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a
12、collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or i
13、mplementation 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 development pro
14、cess. 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, implementors are cautioned that this may not represent the latest information and are therefore strong
15、ly urged to consult the TSB patent database. o ITU 2001 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing fi-om ITU. 11 ITU-T M.2130 (02/2000) CONTE
16、NTS 1 2 3 4 5 5.1 5.2 5.3 5.4 5.5 5.6 Scope . References . Terms and definitions . Abbreviations Reference cases . No recovery mechanisms Automatic protection (revertive) . The (revertive) protection failed Automatic protection (non-revertive) . The (non-revertive) protection failed . Manual protect
17、ion . Restoration plans . 5.5.1 Automatic restoration 5.5.2 Manual restoration . Extraneous events . 5.2.1 5.2.2 The (revertive) protection succeeded . 5.3.1 5.3.2 The (non-revertive) protection succeeded . Annex A . Synchronization faults . Appendix I . Bibliography . ITU-T M.2130 (02/2000) Page 1
18、1 2 2 2 3 3 3 4 4 4 5 5 6 6 6 7 14 14 . 111 Introduction This ITU-T Recommendation specifies the operational procedures to manage faults occurring without recovery mechanisms, with automatic protection (revertive and non-revertive) or manual protection. It also covers the operational procedure for r
19、estoration plan. iv ITU-T M.2130 (02/2000) ITU-T Recommendation M.2130 Operational procedures for the maintenance of the transport network 1 Scope This ITU-T Recommendation covers PDH and SDH international paths, sections and synchronization. A brief description of maintenance procedures is provided
20、. These maintenance procedures follow the approach expressed in ITU-T Recommendations M.20 2 and M.21 3, the PDH and SDH paths and sections maintenance procedures expressed in ITU-T Recommendations M.2 1 O0 and M.2 1 O 1 7, the SDH paths and sections recovery procedures expressed in ITU-T Recommenda
21、tion M.2102 SI, PDH and SDH maintenance procedures expressed in ITU-T Recommendation M.2120 9. Synchronization faults usually result in degradation rather than unavailability of the supported trails. The relevant maintenance procedure is detailed in Annex A. The following six cases are addressed: 1)
22、 no recovery mechanisms; 2) automatic protection (revertive); 3) automatic protection (non revertive); 4) manual protection; 5) restoration plans (automatic restoration revertive, automatic restoration non revertive, 6) extraneous events. The relevant flow charts are provided. manual restoration); 2
23、 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 revision
24、; all 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. 11 ITU-T Recommendation G.8 10 (1996),
25、Deflnitions and terminoloa for synchronization networks. 2 CCITT Recommendation M.20 (1 992), Maintenance philosophy for telecommunication networks. 3 CCITT Recommendation M.2 1 (1 992), Maintenance philosophy for telecommunication services. 4 ITU-T Recommendation M.60 (1 993), Maintenance terminolo
26、a and deflnitions. 5 ITU-T Recommendation M. 1400 (1997), Designations for international networks. 6 ITU-T Recommendation M.2 100 (1995), Performance limits for bringing-into-service and maintenance of international PDHpaths, sections and transmission systems. ITU-T M.2130 (02/2000) 1 7 81 ITU-T Rec
27、ommendation M.2 101 (2000), Performance limits and objectives for bringing- into-service and maintenance of international SDHpaths and multiplex sections. ITU-T Recommendation M.2 102 (2000), Maintenance thresholds and procedures for recovery mechanisms brotection and restoration) of international S
28、DH VC trails baths) and multiplex sections. ITU-T Recommendation M.2120 (2000), PDH path, section and transmission system and SDHpath and multiplex section fault detection and localization procedures. 9 3 Terms and definitions This ITU-T Recommendation uses terms defined in ITU-T Recommendations M.2
29、0 2, M.60 4, M.2100 6, M.2101 7 and M.2102 SI. 4 Abbreviations This ITU-T Recommendations uses the following abbreviations: ACK APS FS GPS IB ICPCE IDTC IG IPCE MTIE NACK os PCE PDH SASE SDH ssu TDEV Acknowledgement Automatic Protection Switch Frontier Station Global Positioning System International
30、 Border Inter-country Path Core Element International Digital Transmission Centre International Gateway International Path Core Element Maximum Time Interval Error Negative Acknowledgement Operations System Path Core Element Plesiochronous Digital Hierarchy Stand Alone Synchronization Equipment Sync
31、hronous Digital Hierarchy Synchronization Supply Unit Time Deviation 5 Reference cases In all cases below, a path or section between two points under the jurisdiction of Control Stations A and B respectively is assumed. For the purposes of the following discussions, the direction of transmission fro
32、m B to A is considered. A disturbance in this transmission has taken place. Synchronization faults usually result in degradation rather than unavailability of the supported trails. The relevant maintenance procedure is detailed in Annex A. 2 ITU-T M.2130 (02/2000) A general description of mandatory
33、information to be exchanged (e.g. ITU-T Recommendation M.1400 5 designation of the path or section, other information (e.g.: equipment facility), APS event time stamp etc.) follows. 5.1 No recovery mechanisms The procedures to be applied are shown in Figures 1, 2, 3 and 4. The acceptable, degraded a
34、nd unacceptable states and relevant thresholds are defined in ITU-T Recommendations M.2 1 O0 61 and M.2101 7. In particular: - the degradation procedures normally involve the count of relevant events and the measurement of their duration. Additionally, taking into consideration that specific mainten
35、ance degradation processes also involve commercial aspects (e.g. extra costs for the possible withdrawal of the degraded path or section fiom service), their establishment is completely left to agreements among all involved Network Operators/Service Providers; in all Figures fiom 1 to 4, every refer
36、ence to “acceptable performance“ implies the use of the BIS Performance after Repair limits as defined in ITU-T Recommendations M.2 1 O0 6 and M.2101 7. 5.2 Automatic protection (revertive) 5.2.1 The (revertive) protection succeeded Control Station A acknowledges the activation of the protection and
37、 agrees with Control Station B to begin the process of fault diagnosis to understand the reason for the recovery initiation with the goal of returning to the original configuration. In this case Control Station A shall send, at least, the following information to Control Station B: a) b) c) request
38、for diagnosis. The fault shall be repaired in a fixed time window. If this window is exceeded, an escalation procedure, if it exists, shall be activated. Thus, it is necessary to discover the reason of the failure analysing the network configuration. In particular it is necessary to find out if the
39、fault is located in the IPCE or in the ICPCE. If the faulty element is found in the IPCE the maintenance organization involved clears it and the control station responsible communicates to the other control station: a) b) If the faulty element is located in the ICPCE, the two control stations cooper
40、ate to locate and repair the fault. Return to the original configuration will take place as specified in ITU-T Recommendation M.2102 SI. If the return to the original configuration does not occur, then either the normal is non working, in which case the procedure described in this subclause should b
41、e restarted, or there is some other problem which needs investigation. ITU-T Recommendation M. 1400 5 designation of the path or section; time1 of the recovery initiation; the cause of the fault; the date and time for returning to the original configuration. Wherever, in this ITU-T Recommendation, d
42、ate and time are referred, the time is intended to be UTC (Universal Coordinated Time). ITU-T M.2130 (02/2000) 3 5.2.2 The (revertive) protection failed Control Station A detects the failure in the recovery mechanism and agrees with Control Station B to begin the process of fault diagnosis with the
43、goal to recover the transmission capacity as soon as possible, by any means possible. In this case Control Station A shall send, at least, the following information to Control Station B: a) b) request for diagnosis. The fault shall be repaired in a fixed time window. If this window is exceeded, an e
44、scalation procedure, if it exists, shall be activated. Thus, it is necessary to discover the reason of the failure analysing the network configuration. In particular it is necessary to find out if the fault is located in the IPCE or in the ICPCE. If the faulty element is found in the IPCE the mainte
45、nance organization involved clears it and the control station responsible communicates to the other control station: a) b) If the faulty element is located in the ICPCE, the two control stations cooperate to locate and repair the fault. ITU-T Recommendation M. 1400 5 designation of the path or secti
46、on; the cause of the fault; the date and time for returning to the original configuration. 5.3 Automatic protection (non-revertive) 5.3.1 The (non-revertive) protection succeeded Control Station A acknowledges the activation of the protection and agrees with Control Station B to begin the process of
47、 fault diagnosis to understand the reason for the recovery initiation with the goal of returning to the original configuration. In this case Control Station A shall send, at least, the following information to Control Station B: a) b) c) request for diagnosis. The fault shall be repaired in a fixed
48、time window. If this window is exceeded, an escalation procedure, if it exists, shall be activated. Thus, it is necessary to discover the reason of the failure analysing the network configuration. In particular it is necessary to find out if the fault is located in the IPCE or in the ICPCE. If the f
49、aulty element is found in the IPCE the maintenance organization involved clears it and the Control Station responsible communicates to the other Control Station: a) b) If the faulty element is located in the ICPCE, the two control stations cooperate to locate and repair the fault. Once the fault is repaired, the Control Station responsible for the repair communicates to the other the cause of the failure and the date and time of the fault clearing. Thereafter the two entities negotiate a BIS test according to ITU-T Recommendation M.2100 6 o
