1、INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE MAINTENANCE: ISDN M.3605 (1 0/92) APPLICATION OF MAINTENANCE PRINCIPLES TO STATIC MULTIPLEXED ISDN BASIC RATE ACCESS I Recommendation M.3605 CCITT RECflN*M.3bOS 92 Y8b2.591 0579337 T83 FOREWO
2、RD The CCIT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCIT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecomm
3、unications on a worldwide basis. The Plenary Assembly of CCIT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid
4、down in CCIT Resolution No. 2 (Melbourne, 1988). Recommendation M.3605 was revised by Study Group IV and was approved under the Resolution No. 2 procedure on the 5th of October 1992. CCIIIT NOTE In this Recommendation, LV expression “Administration” is used for conciseness to indicate m th a telecom
5、munication administration and a recognized private operating agency. O ITU 1993 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 microfii, without permission in writing from the ITU. CCITT
6、 RECMN*M.3605 92 I 4862533 0579138 91T I Recommendation M.3605 APPLICATION OF MAINTENANCE PRINCIPLES TO STATIC MULTIPLEXED ISDN BASIC ACCESS (Melbourne 1988 as Rec. 1.605; revised and renumbered in 1992) Abstract This Recommendation defines capabilities and functions used by the network to maintain
7、static multiplexed ISDN basic rate access. Keywords - ISDN; - maintenance: - subscriber access; - V4 interface. 1 Scope of application This Recommendation covers the maintenance of the static multiplexed basic rate access, controlled by the network, and describes the operations and maintenance aspec
8、ts of the V4 interface. The V4 interface is defined in Recommendation Q.512 7. The specification of the operations and maintenance aspects of the V4 interface is the subject of this Recommendation. This Recommendation follows the maintenance principles as defined in RecommendationM.20 i and applies
9、to the basic rate access connected to the exchange via a static multiplexer. The principle of controlled maintenance is applied for maintaining the static multiplexed basic rate access. Controlled maintenance is a method of sustaining a desired technical performance by the systematic application of
10、supervision, testing and performance sampling in order to minimize preventive maintenance and to reduce corrective maintenance. 2 Network configuration for maintenance activities Figure 1M.3605 shows the general reference configuration of the static multiplexed basic rate access, connected via a dig
11、ital link to the Exchange Termination (ET). 3 Relationship to the maintenance of the basic rate access The same principles as given in Recommendation M.3603 5 for the ISDN basic rate accesses directly connected to the local exchange, should be applied. Therefore, the NT1 and LT for the basic rate ac
12、cesses connected via a basic rate access static multiplexer to the local exchange must have the same functions as NTl and LT for the basic rate accesses connected directly to the local exchange. The loopback mechanism must be implemented according to Recommendation M.3603 5. Recommendation M.3605 (1
13、0/92) 1 CCITT RECMN*flm3b05 92 48b259L 0579339 5b = 4 - TO403390-9ZdO 1 T II ! :!- ! II T II + ! ! II Basic rate access static muitiplexer v4 v4 ! Digital link II (Notes 1, 2) II II II II Confiauration to be maintained Local exchange Note 1 - The digital link, as defined in Recommendation G.701 2, c
14、an make use of a variety of transmission techniques and media complying with Recommendations G.703 3 and G.701 4. Note 2 - The digital link may not be present (Co-located configuration). FIGURE 1/M.3605 Equipment configuration for maintenance of the static multiplexed basic rate access In order to s
15、upport these principles, operation and maintenance information has to be exchanged between the digital section for the ISDN basic rate access and the exchange termination (ET). This information is conveyed in the CV1-channel, which is defined in Recommendation Q.512 7. This CV1-channel is shown in F
16、igure 2M.3605. Basic rate access static muitiplexer Local exchange T I I 11 v4 ! Digital link I I II II vt I Configuration to be maintained FIGURE 2/M.3605 Information exchange between the digital section for the ISDN basic rate access and the local exchange termination (ET) 2 Recommendation M.3605
17、(10D2) CCITT RECMN*Mg3b05 92 m 4b2593 0579340 578 M The functions which are allocated within this CV1-channel are defined in Recommendation G.960 8 on the digital section for the ISDN basic rate access. These functions can be classified according to - activatioddeactivation procedures; - error and s
18、tatus reporting to the ET; - fault localization within the digital section for the ISDN basic rate access; - conveyance of control information from the ET to the digitai section of the ISDN basic rate access. 4 Maintenance of the digital Link and basic rate access static multiplexer 4.1 Fault detect
19、ion Unlike the ISDN basic rate access, the digital link and basic rate access static multiplexer are always in the active state (as seen by the exchange). Continuous automatic supervision, supervising the correct functioning of layer 1 up to the basic rate access static multiplexer, is operating. Th
20、is supervision is called continuous automatic supervision on layer 1. 4.1.1 Functions applied to the ET The functions which are allocated to the ET are listed below: - - - detection of AIS; - detection of RAI; - - CRC code generation; - RAI generation; - - - - AIS generation. The implementation of t
21、hese functions should be the same as for the ET in the ISDN primary rate access, as detection of loss of incoming signal; detection of loss of frame alignment: generation of the frame signal; CRC monitoring of the incoming signai (basic rate access static multiplexer to the ET); detection of CRC err
22、or information; CRC error reporting (ET to the basic rate access static multiplexer) (optionai); defined in Recommendation M.3604 6 for the exchange termination (ET). 4.1.2 Functions applied to the basic rate access static multiplexer The functions which are allocated to the basic rate access static
23、 multiplexer are listed below: - - - detection of AIS; - detection of RAI; - - CRC code generation: - detection of loss of incoming signal; detection of loss of frame alignment; generation of the frame signal; CRC monitoring of the incoming signal (network to basic rate access static multiplexer) an
24、d detection of CRC error information (if provided from the ET); CRC error reporting (basic rate access static multiplexer to the ET). - The implementation of these functions should be the same as for the NT2 in the primary rate access, as defined in Recommendation M.3604 6. Recommendation M.3605 (10
25、192) 3 CCITT RECNNxN.3605 92 4Bb2593 05793i13 404 M In addition, the following functions are allocated to the basic rate access static multiplexer: - sending of AIS on the V4 interface, in case of a defect in the basic rate access static multiplexer between the Vi reference point and the V4 interfac
26、e of the static multiplexer; signalling to ail the basic rate accesses the condition “out of service due to failure”, in the case of a defect occurring in the basic rate access static multiplexer, between the Vi reference point and the V4 interface of the static multiplexer, and in the digital link.
27、 - 4.1.3 Functions allocated to the digital links The functions, which are allocated to the digital links are: - - detection of loss of incoming signal on either end and within the digital link; generation and transmission of AIS within the digital link. 4.2 System protection When a fault is detecte
28、d in the digital link or basic rate access static multiplexer, which has an adverse effect on the availability and/or functionality of all the ISDN basic rate accesses, all the ISDN basic rate accesses connected via this digital link and basic rate access static multiplexer are considered to be “out
29、 of service due to failure” and call attempts may be rejected. When a fault is detected in the digital link or basic rate access static multiplexer, which has an adverse effect on the availability and/or functionality of only one basic rate access, then this particular basic rate access is considere
30、d to be “out of service due to failure” and call attempts may be rejected. 4.3 Fault information When a fault is detected in the basic rate access static multiplexer or digital links, this should be reported to the OAMC by a message. 4.4 Fault localization When a fault is detected in the digital lin
31、k, additional information for fault localization may be required from other network management entities. 4.5 Logistic delay time See Recommendation M.20 i. 4.6 Fault correction See Recommendation M.20 i. 4.1 Verification The verification that the fault has been corrected is performed on demand of th
32、e OAMC. 4.8 Restoration After a fault has been rectified and the correct operation of all the accesses verified (during which time the accesses will be in either the “out of service due to failure” or “degraded transmission” conditions), the accesses shall be returned to the “in service” condition.
33、The mechanisdprocedure for returning the accesses to the “in service” condition (e.g. automatic or manual) is not a subject of this Recommendation. 4.9 Overall pe formance measurements See Recommendation M.3603 5 for the performance related to the digital section of the basic rate access, and Recomm
34、endation M.3604 6 for the V4 digital section. 4 Recommendation M.3605 (10/92) CCITT RECMN*M=3605 92 D 4862591 0579342 340 M References il CCITT Recommendation M.20 Maintenance philosophy for telecommunications network. 121 CCIT Recommendation G.701 Vocabulary of digital transmission and multiplexing
35、, and pulse code modulation (PCM) terms. i31 CCIT Recommendation G.703 PhysicaWeEectrical Characteristics of hierarchical digital interfaces. 41 CCITT Recommendation G.704 Functional characteristics of interfaces associated with network nodes. 51 CCIT Recommendation M.3603 Application of maintenance
36、 principles to ISDN basic rate access. 61 CCITT Recommendation M.3604 Application of maintenance principles to ISDN primary rate access. 171 CCITT Recommendation Q.5 12 Exchange interfaces for subscriber access. i81 CCIT Recommendation G.960 Digital section for ISDN basic rate access. Recommendation M.3605 (10/92) 5 CCITT RECMN*M*3605 92 D 4862593 0579143 287 D Printed in Switzerland Geneva. 1993
