1、INTERNATIONAL TELECOMMUNICATION UNION lTU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Maintenance principles 1.61 O (02/99) B-ISDN operation and maintenance principles and functions ITU-T Recommendation 1.61 O (Previously CCllT Recommendation) GENE
2、RAL STRUCTURE Terminology 1.1 10-1.1 19 Description of ISDNs 1.120-1.129 General modelling methods 1.130-1.139 Telecommunication network and service attributes 1.140-1.149 General description of asynchronous transfer mode 1.150-1.199 Scope 1.200-1.209 General aspects of services in ISDN 1.210-1.219
3、Common aspects of services in the SDN I .220-1.229 Bearer services supported by an ISDN 1.230-1.239 Teleservices supported by an SDN I .240-1.249 Supplementary services in ISDN 1.250-1.299 Network functional principles 1.310-1.319 Reference models 1.320-1.329 Numbering, addressing and routing I .330
4、-1.339 Connection types 1.340-1.349 Performance objectives 1.350-1.359 Protocol layer requirements 1.360-1.369 General network requirements and functions 1.370-1.399 Application of I-series Recommendations to ISDN user-network interfaces I .420-1.429 , Layer 1 Recommendations I .430-1.439 Layer 2 Re
5、commendations I .440-1.449 Layer 3 Recommendations I .450-1.459 Multiplexing, rate adaption and support of existing interfaces 1.460-1.469 Aspects of ISDN affecting terminal requirements I .470-1.499 INTERNETWORK INTERFACES 1.500-1.599 SERVICE CAPABILITIES OVERALL NETWORK ASPECTS AND FUNCTIONS ISDN
6、USER-NETWORK INTERFACES I I 1.730-1.739 Transport functions 1.740-1.749 Management of ATM equipment 1.750-1.799 For further details. please refer to ITU-T List of Recommendations. B-ISDN OPERATION AND MAINTENANCE PRINCIPLES AND FUNCTIONS Summary This Recommendation “B-ISDN operation and maintenance
7、principles and functions“ describes the set of functions required to operate and maintain the physical layer and ATM layer aspects of the B-ISDN for permanent, semi-permanent, reserved and on-demand virtual connections. The functions of the layers above the ATM layer are not considered. For a detail
8、ed description of the maintenance mechanisms and functions at the physical layer, the appropriate ITU-T Recommendations need to be considered depending on the transmission system in use(e.g. SDH,PDH). For maintenance purposes F4 and F5 flows are defined at the ATM layer covering the VP and VC level,
9、 respectively. Both flows are bidirectional and follow the same physical route as the user-data cells, thus constituting an in-band maintenance flow. Besides the vertical subdivision into F4 and F5 levels a “horizontal“ partition also exists: both flows can either cover the entire virtual connection
10、 (end-to-end flow) or only parts of the virtual connection (segment flow). Dedicated OAM cells with pre-assigned VCI and PT1 values are used to implement the F4 and F5 flows at segment or end-to-end levels. This Recommendation specifies the purpose and the realization (using different OAM cell types
11、) of the following functions: 1) Fault management, using AIS, RDI, CC and LB cells. 2) Performance management, using FPM and BR cells. 4) System management cells for use by end-systems only. 3) Activation/deactivation of PM and/or CC, using activatioddeactivation cells. In addition, the coding of th
12、e APS cell used for providing ATM protection switching is specified. Source ITU-T Recommendation 1.6 1 O was revised by ITU-T Study Group 13 (1 997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 26th of February 1999. FOREWORD ITU (International Telecommunication Union) is t
13、he United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standa
14、rdizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by t
15、he Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. l. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation the term recognized operating
16、agency (ROA) includes any individual, company, corporation or governmental organization that operates a public correspondence service. The terms Administration, ROA and public correspondence are defined in the Constitution of the ITU (Geneva, 1992). INTELLECTUAL PROPERTY RIGHTS The ITU draws attenti
17、on to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or othe
18、rs outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU had 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
19、 the latest information and are therefore strongly urged to consult the TSB patent database. O lTU 1999 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 wr
20、iting from the ITU. 1 2 3 4 5 5.1 5.2 5.3 6 6.1 6.2 7 7.1 7.2 7.3 8 8.1 8.2 8.3 9 9.1 CONTENTS Scope References Definitions Abbreviations . OAM principles Network configuration for maintenance activities . Relation with the Telecommunications Management Network (TMN) . Management of the information
21、produced by OAM fnctions OAM levels and flows OAM levels in the B-ISDN Relationship of OAM functions with the B-ISDN models . 6.2.1 B-ISDN Protocol Reference Model (PM) 6.2.2 ATM transport network model Mechanisms to provide OAM flows Physical layer mechanisms . 7.1.1 SDH-based transmission systems
22、7.1.2 Cell-based transmission systems . 7.1.3 PDH-based transmission systems ATM layer mechanism . 7.2.1 F4 flow mechanism . 7.2.2 F5 flow mechanism . Association of the OAM mechanisms with the transport functions . OAM functions of the physical layer OAM flows in some physical configurations . OAM
23、functions . 8.2.1 OAM functions supported solely by the flows F1 to F3 . 8.2.2 OAM functions with regard to the system management . Additional OAM functions . 8.3.1 LCD events 8.3.2 UNEX events . OAM functions of the ATM layer OAM flows in some physical configurations . Pages 1 1 2 4 7 7 7 8 10 10 1
24、0 10 10 11 11 12 13 13 13 14 16 17 17 18 18 19 19 19 19 19 20 20 9.2 10 10.1 10.2 10.3 10.4 10.5 10.6 STD 1TU“I RECMN IObLO-ENGL OAM functions . 9.2.1 OAM functions for VPC (F4 flow) . 9.2.2 OAM functions for the VCC (F5 flow) . 9.2.3 Activatioddeactivation procedures . ATM layer OAM cell format Com
25、mon OAM cell fields Specific fields for fault management cell . 10.2.1 AIS/RDI fault management cell 10.2.2 Continuity check fault management cell . 10.2.3 Loopback cell Specific fields for performance management cell 10.3.1 Forward performance monitoring cell . 10.3.2 Backward reporting cell Specif
26、ic fields for activatioddeactivation cell . Specific fields for system management cell . Specific fields for APS cell Annex A . Guidance on estimating VPCNCC outages Annex B - SDLs for activatioddeactivation using OAM cells . Annex C - Procedures to be performed when receiving LB cells . C.l Case of
27、 seg-LB cells C.2 Case of e-t-e-LB cells Appendix I - Examples of OAM cell error detection codes Appendix II II . 1 Processes applicable to forward performance monitoring cells . II . 1 . 1 Forced insertion . II . 1.2 Non forced insertion II.2 Process applicable to backward reporting cells II.2.1 Fo
28、rced insertion . II.2.2 Non forced insertion Appendix III - Use of segment loopback cells for localizing failures . 1II.l Description of failure types which may be observed at the ATM layer level . III.2 Loopback techniques applicable for segment loopback cells . III.2.1 Basic principle of the singl
29、e loopback technique III.2.2 Basic principle of the multiple loopback technique Pages 20 20 30 37 39 40 42 42 43 43 44 44 45 46 48 48 48 49 63 63 64 67 67 67 67 68 69 69 70 70 70 71 71 72 Pages Examples of use of segment loopback cells for localizing failures occurring at the VPNC layer levels . III
30、.3.1 Case of Point-to-Point VPCNCC . III.3.2 Case of point-to-multipoints VPCNCC . Appendix IV . OAM hierarchical levels and their relationship with the functional model ofG.805 . Appendix V . Use of an ID in the segment CC cell V . 1 Basic concepts V.2 Defect conditions V.3 CC ID source/sink functi
31、ons . V.4 SESATM estimation V.5 Backwards compatibility V.6 Connection identification for the purposes of through-path monitoring 72 72 75 75 77 77 77 77 78 78 78 Recommendation 1.61 O B-ISDN OPERATION AND MAINTENANCE PRINCIPLES AND FUNCTIONS (Geneva, 1991; revised Helsinki, 1993; revised in 1995 an
32、d 1999) 1 Scope The scope of this Recommendation is to identi fnctions required to operate and maintain the physical layer and ATM layer aspects of the B-ISDN. The functions apply to the Virtual Path (W) and Virtual Channel (VC) connections that may be routed through the B-ISDN. The mechanisms, ncti
33、ons and protocols as described in this Recommendation apply to all types of ATM connections, i.e. permanent, semi-permanent, reserved and switched virtual connections unless otherwise stated. However, the need for reduced and/or additional Operation and Maintenance (OAM) functionality for switched v
34、irtual connections is for further study. The nctions of the layers above the ATM layer are not considered but are for further study. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommend
35、ation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other refere
36、nces listed below. A list of the currently valid ITU-T Recommendations is regularly published. ITU-T Recommendation E. 164 (1997), The international public telecommunication numberingplan. CCITT Recommendation G.702 (1 988), Digital hierarchy bit rates. ITU-T Recommendation G.707 (19961, Network nod
37、e inter$ace for the Synchronous Digital Hierarchy (SDH). ITU-T Recommendation G.783 (1 997), Characteristics of Synchronous Digital Hierarchy (SDH) equipment functional blocks. ITU-T Recommendation G.784 (1994), Synchronous Digital Hierarchy (SDH) management. ITU-T Recommendation G304 (1998), ATM ce
38、ll mapping into Plesiochronous Digital Hierarchy (PDH). ITU-T Recommendation G.805 (1999, Generic functional architecture of transport networks. ITU-T Recommendation G.832 (1998), Transport of SDH elements on PDH networks: Frame and multiplexing structures. ITU-T Recommendation 1.3 1 1 (1 996), B-IS
39、DN general network aspects. CCITT Recommendation 1.32 1 (1 991), B-ISDN protocol reference model und its application. STD-ITU-T RECMN 1-bBO-ENGL B999 m qBb259B Ubb32LB 51T m ITU-T Recommendation 1.326 (1995), Functional architecture of transport networks based on ATM. ITU-T Recommendation 1.356 (1 9
40、96), B-ISDNA TM layer cell transfer performance. ITU-T Recommendation 1.357 (1 996), B-ISDN semi-permanent connection availability. ITU-T Recommendation 1,361 (1 999), B-ISDNATM layer specification. ITU-T Recommendation 1.371 (1996), Trafic control and congestion control in B-ISDN. ITU-T Recommendat
41、ion 1.432.1 (1999), B-ISDN user-network interface - Physical layer specification: General characteristics. ITU-T Recommendation 1.432.2 (1999), B-ISDN user-network interface - Physical layer specifcation: 155 520 kbith and 622 080 kbith operation. ITU-T Recommendation 1.432.4 (1999), B-ISDN user-net
42、work interjace - Physical layer specification: 51 840 kbit/s operation. ITU-T Recommendation 1.630 (1999), ATMprotection switching. ITU-T Recommendation 1.732 (1996), Functional characteristics ofATM equipment. ITU-T Recommendation 1.75 1 (1 996), Asynchronous transfer mode management of the network
43、 element view. CCITT Recommendation M.20 (1 992), Maintenance philosophy for telecommunications networks. ITU-T Recommendation M.301 O (1996), Principles for a telecommunications management network. CCITT Recommendation M.3600 (1992), Principlesfor the management ofISDNs. Definitions This Recommenda
44、tion defines the following terms: 3.1 backward direction: The backward direction is opposite to the forward direction. 3.2 Connection Points (CPs): (see Note 1 in 3.21) Reference points which are defined along a network connection defined at a given network layer. CPs defined at the ATM layer along
45、a VPC (or VCC) are located at the ingress and egress of an ATM network element (or customer equipment), where VP (or VC) link termination functions operate. 3.3 Connection Point Identifier (CPID): Identifier of a given CP along a VPC or VCC. Different values are intended to be used for identifying t
46、he ingress and egress of a given ATM network element. 3.4 defect: (see Note 2 in 3.21) Interruption of the capability of a transport entity (e.g. network connection) to transfer user or OAM information. Examples of defects are loss of signal, LCD, LOC at the VP (or VC) layer. 3.5 egress: The egress
47、point of an ATM network element is illustrated in Figure O. ingress O egress - direction of a connection T1314050-98 Figure OA.610 - Usage of ingress and egress terms in Recommendation 1.610 3.6 failure: (see Note 2 in 3.21) Termination of the capability of a transport entity to transfer user or OAM
48、 information. A failure can be caused by a persisting defect. 3.7 forward direction: The forward direction is the direction followed by the monitored user cells flow. 3.8 ingress: The ingress point of an ATM network element is illustrated in Figure O. 3.9 link connection: Definition is provided in R
49、ecommendation G.805. As an example, a VP link connection is delimited by the CPs located in two consecutive ATM network elements operating at VP level. 3.10 Maintenance Entity (ME): (see Note 2 in 3.21) MES are defined at the physical and ATM layers in order to provide the means to detect maintenance events (e.g. defects, failures, performance impairments) occumng within the part of the telecommunication network delimited by the ME boundaries. MES have an interface with the Telecommunications Management Network (TMN) to convey maintenance information to the Operation Sys
