1、INTERNATIONAL TELECOMMUNICATION UNIONITU-T I.732TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU(10/2000)SERIES I: INTEGRATED SERVICES DIGITALNETWORKB-ISDN equipment aspects ATM equipmentFunctional characteristics of ATM equipmentITU-T Recommendation I.732(Formerly CCITT Recommendation)ITU-T I-SERIES R
2、ECOMMENDATIONSINTEGRATED SERVICES DIGITAL NETWORKGENERAL STRUCTURETerminology I.110I.119Description of ISDNs I.120I.129General modelling methods I.130I.139Telecommunication network and service attributes I.140I.149General description of asynchronous transfer mode I.150I.199SERVICE CAPABILITIESScope
3、I.200I.209General aspects of services in ISDN I.210I.219Common aspects of services in the ISDN I.220I.229Bearer services supported by an ISDN I.230I.239Teleservices supported by an ISDN I.240I.249Supplementary services in ISDN I.250I.299OVERALL NETWORK ASPECTS AND FUNCTIONSNetwork functional princip
4、les I.310I.319Reference models I.320I.329Numbering, addressing and routing I.330I.339Connection types I.340I.349Performance objectives I.350I.359Protocol layer requirements I.360I.369General network requirements and functions I.370I.399ISDN USER-NETWORK INTERFACESApplication of I-series Recommendati
5、ons to ISDN user-network interfaces I.420I.429Layer 1 Recommendations I.430I.439Layer 2 Recommendations I.440I.449Layer 3 Recommendations I.450I.459Multiplexing, rate adaption and support of existing interfaces I.460I.469Aspects of ISDN affecting terminal requirements I.470I.499INTERNETWORK INTERFAC
6、ES I.500I.599MAINTENANCE PRINCIPLES I.600I.699B-ISDN EQUIPMENT ASPECTSATM equipment I.730I.739Transport functions I.740I.749Management of ATM equipment I.750I.759Multiplexing aspects I.760I.769For further details, please refer to the list of ITU-T Recommendations.ITU-T I.732 (10/2000) iITU-T Recomme
7、ndation I.732Functional Characteristics of ATM equipmentSummaryITU-T I.731 and I.732 describe the functional requirements to enable the interoperability betweenATM network elements. The detailed characteristics of ATM equipment, or equipment containingATM aspects, are contained in this Recommendatio
8、n. The companion Recommendation, ITU-TI.731, provides introductions and covering terms and concepts that did not easily fit into the structureof this Recommendation. ITU-T I.731 introduces the functional model used in thisRecommendation.The functional model approach used in this Recommendation is de
9、rived from ITU-T G.805. It is alsoused by other technologies such as SDH equipment, PDH equipment and optical networking. Thisallows for equipment with multiple technologies to be easily defined by selecting the appropriatefunctional blocks.Annex D defines the atomic functions used in the TP Converg
10、ence, ATM VP and VC LayerNetworks and their associated adaptation functions.SourceITU-T Recommendation I.732 was revised by ITU-T Study Group 15 (1997-2000) and approved bythe World Telecommunication Standardization Assembly (Montreal, 27 September 6 October 2000).ii ITU-T I.732 (10/2000)FOREWORDThe
11、 International Telecommunication Union (ITU) is the United Nations specialized agency in the field oftelecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ ofITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recomm
12、endationson them with a view to standardizing telecommunications on a worldwide basis.The World Telecommunication Standardization Assembly (WTSA), which meets every four years,establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on thesetopics.The approv
13、al of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.In some areas of information technology which fall within ITU-Ts purview, the necessary standards areprepared on a collaborative basis with ISO and IEC.NOTEIn this Recommendation, the expression “Administration“ i
14、s used for conciseness to indicate both atelecommunication administration and a recognized operating agency.INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation mayinvolve the use of a claimed Intellectual Property Right. ITU t
15、akes no position concerning the evidence,validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or othersoutside of the Recommendation development process.As of the date of approval of this Recommendation, ITU had not received notice of intellectual proper
16、ty,protected by patents, which may be required to implement this Recommendation. However, implementors arecautioned that this may not represent the latest information and are therefore strongly urged to consult theTSB patent database. ITU 2001All rights reserved. No part of this publication may be r
17、eproduced or utilized in any form or by any means,electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU.ITU-T I.732 (10/2000) iiiCONTENTSPage1 Scope 12 References 13 Abbreviations, Terms and Definitions . 33.1 Abbreviations . 33.2 Definitions 54 Gener
18、al functional description of the ATM equipment 54.1 Transfer functions. 74.1.1 Physical layer 74.1.2 ATM Layer 84.1.3 ATM Adaptation Layer (AAL) . 134.1.4 Signalling ATM Adaptation Layer (SAAL) . 134.2 Layer Management functions . 134.3 Coordination functions . 134.4 Guidelines for using the Table s
19、tructure and corresponding functional descriptions 135 Transfer functions and Layer Management functions 205.1 Section/Path Adaptation, Section Termination and Lower Layer Functions . 205.1.1 SDH 155.52 Mbit/s Interface 205.1.2 SDH 622.08 Mbit/s Interface 205.1.3 SDH 2488.32 Mbit/s Interface 205.1.4
20、 SDH 9953.28 Mbit/s Interface 205.1.5 PDH based interfaces 205.1.6 Cell-based UNI 205.1.7 ATM 25 Mbit/s interface. 215.1.8 IMA interface 215.1.9 xDSL interfaces. 215.2 Transmission Path Trail Termination function (TP_TT) . 215.3 Transmission Path/Virtual Path Adaptation function (TP/VP_A) . 215.3.1
21、TP/VP_A (B to A). 215.3.2 TP/VP_A (A to B) for SDH and PDH 255.4 VP Traffic Management function (VPTM) 275.4.1 VP usage measurement . 285.4.2 VP UPC/NPC (B to A only) 285.4.3 Traffic shaping 295.4.4 EFCI setting. 295.4.5 Resource management. 29iv ITU-T I.732 (10/2000)Page5.5 VP OAM functions. 295.5.
22、1 F4 OAM functions (B to A) between VPTM and VP_C 295.5.2 F4 OAM functions (A to B) between VPTM and VP_C 305.6 VP Connection function (VP_C) 305.7 VP Connection End point Loopback function (VPLB_TT). 305.8 VP Trail Termination function (VP_TT) 305.9 Virtual Path/Virtual Channel Adaptation function
23、(VP/VC_A). 305.9.1 VP/VC_A (B to A) 305.9.2 VP/VC_A (A to B) 315.10 VC Traffic Management function (VCTM) . 325.10.1 VC usage measurement. 335.10.2 VC UPC/NPC (B to A only) . 335.10.3 Traffic shaping 345.10.4 EFCI setting. 345.10.5 Resource management. 345.11 VC OAM functions 345.11.1 F5 OAM functio
24、ns (B to A) between VCTM and VC_C . 345.11.2 F5 OAM functions (A to B) between VCTM and VC_C . 355.12 VC Connection function (VC_C). 355.13 VC Connection End point Loopback function (VCLB_TT) 355.14 VC Trail Termination function (VC_TT). 355.15 ATM Adaptation Layer function (AAL) 365.15.1 Discard of
25、 end-to-end and segment F5 OAM cells. 365.15.2 AAL functional modelling 365.15.3 Service Specific Coordination functions. 366 Coordination Function (CoF) . 367 CAC and resource control functions 367.1 ATM resource requests to be processed by an ATM equipment . 367.1.1 Establishing or releasing a VP
26、or VC connection . 367.1.2 Modification of the traffic characteristics of an established VP or VCconnection . 377.2 General ATM equipment features for processing an ATM resource request. 387.2.1 Processing of resource request messages 387.2.2 CAC function 387.3 Management, signalling, RM application
27、s. 397.4 Detailed description of the CAC function 397.4.1 Service Acceptance Control SAC . 427.4.2 Equipment Admission Control (EAC) function 45ITU-T I.732 (10/2000) vPage7.5 Processing steps of an ATM resource request 477.5.1 Request to establish or release an ATM VP or VC connection 477.5.2 Reques
28、t to modify the traffic characteristics of an existing ATM VP orVC connection. 477.6 Method for reducing outages on resource modification. 48Annex A Relationship between B-ISDN PRM and I.326 representations of an ATM NE 48Annex B Examples of ATM equipment. 49Annex C Correspondence between I.732 and
29、I.751 models. 51Annex D Library of Atomic Functions. 51D.1 Definitions, abbreviations and symbols . 51D.1.1 Definitions. 51D.1.2 Abbreviations 51D.1.3 Symbols and diagrammatic conventions. 54D.1.4 Introduction . 54D.2 Transmission Path to ATM Virtual Path Adaptation Functions 57D.2.1 S3 Path Adaptat
30、ion Functions. 57D.2.2 S4 Path Adaptation Functions. 67D.2.3 S4-nc Path Adaptation Functions 77D.2.4 Cell-Based Adaptation Functions 86D.2.5 P12s Path Adaptation Functions . 87D.2.6 P31s Path Adaptation Functions . 96D.3 ATM Virtual Path Layer Network Functions. 105D.3.1 ATM Virtual Path Connection
31、Function VP_C 114D.3.2 ATM Virtual Path Trail Termination Functions . 120D.3.3 ATM Virtual Path Monitoring Functions 128D.3.4 ATM Virtual Path Segment Functions 134D.3.5 ATM Virtual Path Traffic Management Functions. 148D.3.6 ATM Virtual Path Loopback Functions 152D.3.7 ATM Virtual Path Linear Trail
32、 Protection Functions . 171D.4 ATM Virtual Path to ATM Virtual Channel Adaptation Functions. 173D.4.1 ATM Virtual Path to ATM Virtual Channel Adaptation Source FunctionVP/VC_A_So 173D.4.2 ATM Virtual Path to ATM Virtual Channel Adaptation Sink FunctionVP/VC_A_Sk 176D.5 ATM Virtual Channel Layer Netw
33、ork Functions 179D.5.1 ATM Virtual Channel Connection Function VC_C . 187D.5.2 ATM Virtual Channel Trail Termination Functions . 193vi ITU-T I.732 (10/2000)PageD.5.3 ATM Virtual Channel Monitoring Functions . 201D.5.4 ATM Virtual Channel Segment Functions 207D.5.5 ATM Virtual Channel Traffic Managem
34、ent Functions. 222D.5.6 ATM Virtual Channel Loopback Functions 225D.5.7 ATM Virtual Channel Linear Trail Protection Functions. 239D.6 ATM Virtual Channel to ATM Client Adaptation Functions 241D.6.1 ATM Virtual Channel to ATM Client Adaptation Source VC/XXX_A_So 241D.6.2 ATM Virtual Channel to ATM Cl
35、ient Adaptation Sink VC/XXX_A_Sk 242Appendix I Functional requirements for ABR transfer capability . 243I.1 Location in I.732 Model . 243I.2 Transfer Functions 243I.3 Report to Layer Management. 244I.4 Control from Layer Management. 244I.5 Layer Management Functions 244I.5.2 BECN Function. 244ITU-T
36、I.732 (10/2000) viiIntroductionThe B-ISDN Protocol Reference Model described in ITU-T I.321 partitions ATM equipment into auser (transfer) plane, a layer management plane, a plane management and a control plane.The user and control planes are decomposed into a Physical Layer, ATM Layer, ATM Adaptati
37、onLayer and higher level functions. The plane management may not be layered.Further decomposition of the layers is possible in order to define additional functions which can begrouped to provide a logical description of any ATM equipment. The ATM layer may bedecomposed into the Virtual Path and Virt
38、ual Channel layers. The physical layer may bedecomposed into a number of path and section layers depending on the transport technologyemployed.Within each layer of the Transfer and Layer Management Planes, the management and processing ofuser information may be described in terms of three functions.
39、 These support the termination of layerspecific information, adaptation of information between layers, and connection. This methodologyprovides a logical description of equipment which is aligned with the network level view of ATMtransport contained in ITU-T I.326 and G.805.ITU-T I.732 (10/2000) 1IT
40、U-T Recommendation I.732Functional characteristics of ATM equipment1ScopeThe purpose of this Recommendation is to describe the functional requirements to enableinteroperability between ATM Network Elements (NEs). The description must be precise enough toenable interoperability, but be generic so as
41、to not constrain implementation.This Recommendation provides a detailed description of the functional requirements identified inITU-T I.731.This Recommendation makes references to other existing Recommendations where they containdetailed descriptions or specifications for a function to avoid duplica
42、tion of work. ThisRecommendation provides the basis for defining in detail an ATM NE.2 ReferencesThe following ITU-T Recommendations and other references contain provisions which, throughreference in this text, constitute provisions of this Recommendation. At the time of publication, theeditions ind
43、icated were valid. All Recommendations and other references are subject to revision; allusers of this Recommendation are therefore encouraged to investigate the possibility of applying themost recent edition of the Recommendations and other references listed below. A list of the currentlyvalid ITU-T
44、 Recommendations is regularly published.1 ITU-T G.703 (1998), Physical/electrical characteristics of hierarchical digital interfaces.2 ITU-T G.707/Y.1322 (2000), Network node interface for the synchronous digital hierarchy(SDH).3 ITU-T G.783 (2000), Characteristics of synchronous digital hierarchy (
45、SDH) equipmentfunctional blocks.4 ITU-T G.784 (1999), Synchronous digital hierarchy (SDH) management.5 ITU-T G.804 (1998), ATM cell mapping into plesiochronous digital hierarchy (PDH).6 ITU-T G.805 (2000), Generic functional architecture of transport networks.7 ITU-T I.326 (1995), Functional archite
46、cture of transport networks based on ATM.8 ITU-T G.832 (1998), Transport of SDH elements on PDH networks Framing andmultiplexing structures.9 ITU-T G.957 (1999), Optical interfaces for equipments and systems relating to thesynchronous digital hierarchy.10 ITU-T I.731 (2000), Types and general charac
47、teristics of ATM equipment.11 ITU-T I.211 (1993), B-ISDN service aspects.12 ITU-T I.311 (1996), B-ISDN general network aspects.13 ITU-T I.321 (1991), B-ISDN protocol reference model and its application.14 ITU-T I.353 (1996), Reference events for defining ISDN and B-ISDN performanceparameters.15 ITU-
48、T I.356 (2000), B-ISDN ATM layer cell transfer performance.2 ITU-T I.732 (10/2000)16 ITU-T I.361 (1999), B-ISDN ATM layer specification.17 ITU-T I.363.1 (1996), B-ISDN ATM Adaptation Layer specification: Type 1 AAL.18 ITU-T I.363.2 (1997), B-ISDN ATM Adaptation layer specification: Type 2 AAL.19 ITU
49、-T I.363.3 (1996), B-ISDN ATM Adaptation Layer specification: Type 3/4 AAL.20 ITU-T I.363.5 (1996), B-ISDN ATM Adaptation Layer specification: Type 5 AAL.21 ITU-T I.371 (2000), Traffic control and congestion control in B-ISDN.22 ITU-T I.432.1 (1999), B-ISDN user-network interface Physical layer specification:General characteristics.23 ITU-T I.432.2 (1999), B-ISDN user-network interface Physical layer specification:155 520 kbit/s and 622 080 kbit/s operation.24 ITU-T I.432.3 (1999), B-ISDN user-ne
