1、 STD-ITU-T RECMN I-bOL-ENGL 1988 m ?+8b2591 Ob30877 O77 m INTERNATIONAL TELECOMMUNICATION UNION I ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU INTEGRATED SERVICES DIGITAL NETWORK (ISDN) MAINTENANCE PRINCIPLES 1.601 GENERAL MAINTENANCE PRINCIPLES OF ISDN SUBSCRIBER ACCESS AND SUBSCRIBER INST
2、ALLATION ITU-T Recommendation 1.601 (Extract from the Blue Book) NOTES 1 ITU-T Recommendation 1.601 was published in Fascicle 111.9 of the BZue Book. This file is an extract from the Blue Book. While the presentation and layout of the text might be slightly different from the Blue Book version, the
3、contents of the file are identical to the Blue Book version and copyright conditions remain unchanged (see below). 2 telecommunication administration and a recognized operating agency. In this Recommendation, the expression “Administration” is used for conciseness to indicate both a O ITU 1988, 1993
4、 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 from the ITU. Recommendation 1.601 GENERAL MAINTENANCE PRINCIPLES OF ISDN SUBSCRIBER ACCESS AND S
5、UBSCRIBER INSTALLATION (Melbourne, 1988) 1 Scope of application 1.1 This Recommendation outlines the general aspects and principles relating to the reference configurations and general architecture for each kind of subscriber access (basic, primary, multiplexed, higher rate) and associated subscribe
6、r installations. This is given in terms of the function groupings and the interconnecting communication parties. Loopback definitions and their locations used in this Recommendation are also given. 1.2 Recommendation 1.602 is concerned with the maintenance of the ISDN subscriber installation. The ma
7、intenance principles are given in a general way for functions which are dependent on the design of NT2 and TE and more precisely where it impacts directly on the S or T interface (i.e. in relation to Recommendations 1.430, 1.431). These functions are supervised and/or controlled by the subscriber in
8、stallation. The ISDN management protocols which provide this activity are contained in Recommendation Q.940 on ISDN user-network management and maintenance protocols. 1.3 A common format with other similar Recommendations, in conformance with Recommendation M.20, is used. Recommendation 1.603 descri
9、bes maintenance for the network portion of the ISDN basic access (144 kbit/s). The functions performed by the digital transmission section and the exchange termination (ET) are identified. These functions are supervised and/or controlled by the network or Administration (see 3 3.3 of Recommendation
10、1.601). 1.4 1544 kbit/s) following the same principles as given in Recommendation 1.603. Recommendation 1.604 describes maintenance of the network portion of the ISDN primary access (2048 and The functions provided by the digital transmission section and the exchange termination (ET) are identified.
11、 The functions are supervised and/or controlled by the network or Administration. 1.5 Recommendations 1.603 and 1.604 when common mechanisms are applied. Recommendation 1.605 describes the maintenance of a multiplexed basic rate system. Reference is made to The functions performed by the digital sec
12、tion of the ISDN basic rate access, the basic access multiplexer, the digital link, and the exchange termination (ET) are identified. These functions are supervised and/or controlled by the network or Administration. 2 Objectives In order to try and meet overall objectives, a number of points have b
13、een identified for Administrations and i) to detect fault conditions, identify the failed maintenance entity, take system protection actions, inform the maintenance staff of Administrations; ii) to incorporate facilities to enable the failure to be located by the maintenance staff, so that failure c
14、orrection is achievable by a single attendance to the failed location; iii) to provide an appropriate maintenance organization and levels of staffing, so as to achieve goals for out- of-service repair times; maintenance service providers (see 3 3.2.2.3): Fascicle III.9 - Rec. 1.601 1 STD*ITU-T RECMN
15、 ImbOL-ENGL 1988 m 48b257L Ob30880 bbL m iv) to incorporate facilities to allow clear differentiation of failures between the subscriber installation and the network; v) to incorporate facilities to allow clear differentiation between failures and normal subscriber activities. 3 Network reference mo
16、del 3.1 ISDN subscriber access ana installation configuration Figure M.601 shows the simplified ISDN subscriber access and installation configuration (based on The definitions contained in this figure are the ones used in the 1.600-Series Recommendations. Recommendations 1.41 1 and 4.512). TE1 I Dig
17、ital section (Note 2) (Note 1) ISDN subscriber access 4 MQ37U4I Note 1 - The NT2 functional grouping may be null. In this case the S and T reference points are coincident. Note2 - The ISDN subscriber access contains a digital section which can use a variety of transmission techniques and may also in
18、clude a regenerator. The digital section could be a basic rate section, a primary rate section, or a multiplexed basic rate section. FIGURE 1D.601 Simplified ISDN subscriber access and installation configuration (based on Recommendations 1.411 and 4.512) 3.2 Network configuration ana definition for
19、maintenance activities 3.2.1 Network configuration Figure 2A.601 is the basis for the general maintenance principles of the ISDN access and subscriber installation. i; I Subscriber insta I lation ISDN I l I Configuration to be maintained I I+ #! lD2.86 SAMC Subscriber access maintenance centre SIME
20、Subscriber installation maintenance entity MSP Maintenance service provider Note - In the case where the subscriber installation does not contain a NT2, the S and T reference points are coincident FIGURE 2/1.601 Reference configuration for maintenance activities 2 Fascicle m.9 - Rec. 1.601 STD-ITU-T
21、 RECMN I-bO1-ENGL 1988 m Lib2591 Ob30881 5T8 3.2.2 Definitions 3.2.2.1 Subscriber Access Maintenance Centre (SAMC) A SAMC represents a group of functions, network equipment elements and staff controlled by the Administration, which together have the responsibility and capability for maintenance func
22、tions and maintenance actions within the subscriber access, such as defined in Figure 2I.60 1. The equipment and functions may be centralized or distributed in the network, local exchange and subscriber access. The architecture of the SAMC and its internal interface(s) between SAMC staff equipment(s
23、) is presented in 9 3.4. Conceptually, the SAMC is considered to be a single functional entity within an ISDN, as seen by the subscriber. 3.2.2.2 Subscriber Instailation Maintenance Entity (SIME) A SIME represents a group of dedicated functions contained within the functional groups (as specified in
24、 Recommendation 1.41 1) of the subscriber installation which have the following purposes, e.g.: - - - interaction with the (human) user; handling of the maintenance protocol from the subscriber installation and/or maintenance service provider; control of internal testing and maintenance mechanisms.
25、It is considered that the functions of the SIME may be distributed throughout layers 1-3 and managementmaintenance entities, including NTl functions in some applications. However, the precise architecture and protocol of the SIME is not a subject of this Recommendation. 3.2.2.3 Maintenance Service P
26、rovider (MSP) The MSP represents a group of functions, equipment and maintenance staff, which together have the responsibility for maintaining a subscriber installation or a part of the subscriber installation. A MSP cannot control the maintenance functions of the subscriber access. If authorized, i
27、t can request an SAMC to perform these functions. Agreement and responsibility for maintenance between the subscriber and the MSP for each part or parts of the subscriber installation should be made at the time of subscription to the maintenance service (this may take the form of a commercial contra
28、ct). In any case, provision to allow a customer to change the maintenance service provider(s) is recommended. The subscriber may choose not to make such an agreement with the MSP. Maintenance service providers can be: - private providers; - the Administration. Note - A subscriber can act as his own
29、MSP. A private maintenance service provider external to ISDN is connected to the ISDN via a recommended T reference point. An Administrations maintenance service provider may be connected to the ISDN via a recommended T reference point or via an interface which is internal (outside the scope of this
30、 Recommendation) to the ISDN. More than one MSP may have the responsibility to maintain one subscriber installation. The responsibility for maintaining each equipment shall be unique. Other interfaces are for further study. If authorized, the MSP can invoke maintenance function in the SIME. It is th
31、e sole responsibility of a subscriber installation and not of the network to ensure that an unauthorized MSP cannot get access to maintenance functions in the subscriber installation. 3.3 Communication configurations 3.3.1 General The presentation of the relationships between the functional blocks S
32、AMC, SIME and MSP and the Fascicle m.9 - Rec. 1.601 3 configurations to be maintained have been completed by figures showing the various communication paths. Subscriber installation r-3G-I The communication paths are shown by bold lines within the Figures 3h.60 1 to 7A.601. I T I SIT 1 1 I MSP I 3.3
33、.2 Communication configuration for maintenance of a subscriber access by the SAMC Subscriber installation /SIME Figure 3/1.60 1 shows the communication configuration between the subscriber access and the SAMC. T 1 I I FIGURE 3/1.601 Communication configuration for the maintenance of a subscriber acc
34、ess by the SAMC 3.3.3 Communication conjguration for maintenance of a Subscriber access by a SAMC requested by an MSP Figure 4/1.601 shows the communication configuration between an MSP and a SAMC that allows the MSP to request maintenance information and actions related to the subscriber access. I:
35、 v Test requestlresponse access Cornmu- nication path SAMC Test requestlresponse I Configuration 1 I I to be maintained I TL1OWfO.M I I Note 1 - Test request and/or response are made by normal calls or automatic procedures after authorization. Protocols for the automatic procedure are to be defined.
36、 The MSP has no direct control over subscriber access maintenance. The SAMC tests the subscriber access according to other sections of this Recommendation. Note 2 - A subscriber may act as his own MSP, requesting the SAMC to perform tests on his own subscriber access. FIGURE 4/1.601 Communication co
37、nfiguration for maintenance of a subscriber access by an SAMC requested by an MSP 4 Fascicle IiI.9 - Rec. 1.601 - STD-ITU-T RECMN I-bol-ENGL 1788 m i.Ib259l Ob30883 370 3.3.4 Communication configuration for maintenance of a subscriber installation by an MSP within the ISDN Figure 5h.601 shows the co
38、mmunication configuration between an MSP within the ISDN and the subscriber installation. Communication Subscriber installation ISDN Subscriber access I I I i Configuration I to be maintained ! Ti802080-86 Note - In same countries the subscriber installation is allowed to control certain maintenance
39、 functions in the subscriber access without authorization of an SAMC. FIGURE 5/1.601 Communication configuration for maintenance of a subscriber installation by an MSP with the ISDN 3.3.5 Communication conjguration for maintenance of a subscriber installation by an MSP connected to the ISDN via an S
40、 or T reference point Figure 6A.601 shows the communication configuration between an MSD at reference point S or T and the subscriber installation. I I Communication path T1802090-86 Note - In some countries the subscriber installation is allowed to control certain maintenance functions in the subsc
41、riber access without authorization of an SAMC. FIGURE 6/1.601 Communication Configuration for maintenance of a subscriber installation by an MSP connected to the ISDN via an S or T reference point Fascicle III.9 - Rec. 1.601 5 STD*ITU-T RECMN 1-bol-ENGL 1988 98b257L Ob3088Li 207 M T 1 Subscriber ins
42、tallation 3.4 Management configurations 3.4.1 Relationships Network Subscriber access In Figure 7i.601 the communication relationships between the management entities required to support the functions in this series of Recommendations are given. It does not imply any physical model of the network. N
43、ote I - As shown here, only the relationships are indicated since the interface is outside the scope of this Recommendation. Note 2 - In this case the subscriber is acting as his own MSP. Note 3 - The OAMC acts as the communication agent for the SAME. FIGURE 7/1.601 Communication relationships The c
44、onnections shown in Figure 7h.601 represent the allowed communication paths that use the protocol architecture defmed in Recommendation 4.940. These communications are subject to security procedures implemented by the receiver of the message. The subscriber access maintenance entity (SAME) controls
45、the subscriber access maintenance functions and provides communications for such activities. The SAMC functions might be distributed. The operations administration and maintenance centre (OAMC) consists of a group of functions and staff. In the context of this Recommendation the OAMC is responsible
46、for the communication with, and the controlling of, the subscriber access maintenance functions as provided by the SAME. The OAMC may also be responsible for the communication with, and the controlling of, other maintenance functions as provided by other management entities. Such functions are outsi
47、de the scope of this Recommendation. Therefore, the SAMC can be considered as the grouping of the SAME, communication path and part of the OAMC. 3.4.2 Security provisions To facilitate maintenance procedures and failure localization, management entities responsible for different control domains may
48、communicate. However, since management and maintenance information is of critical importance to system integrity, access to management functions and information is subject to prior authorization and security restrictions. The security restrictions are enforced by the recipient of the maintenance req
49、uest and may include requirements for user authentication (identification), the use of passwords and/or limited access based on the originating call. 6 Fascicle lII.9 - Rec. 1.601 The use of adequate security mechanisms is especially important in the case of the OAMC since maintenance functions for many users may be affected by unauthorized access. 3.5 Maintenance conditions for an ISDN subscriber access In general, a subscriber access can be considered to be in one of the following conditions for the purpose of explanation of the relationship between maintenance
