1、STD*ITU-T RECMN 1.3b3-3-ENGL L99b D 48b259L 0b35004 243 INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STAN DARD I ZATI O N SECTOR OF ITU 1.363.3 (08/96) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Overall network aspects and functions - Protocol layer requirements B-ISDN ATM Adapta
2、tion Layer specification: Type 314 AAL ITU-T Recommendation 1.363.3 (Previously CCITT Recommendation) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services- STD-ITU-T RECMN 1-3b3.3-ENGL 197b = YBb257L Ob35005 LAT ITU-T I-SERIES RECOMMENDATIO
3、NS INTEGRATED SERVICES DIGITAL NETWORK ;ENERAL STRUCTURE Terminology Description of ISDNs General modelling methods Telecommunication network and service attributes General description of asynchronous transfer mode Scope General aspects of services in ISDN Common aspects of services in the ISDN Bear
4、er services supported by an ISDN Telecervices supported by an ISDN Supplementary services in ISDN Network functional principles Reference models Numbering, addressing and routing Connection types Performance obiectives SERVICE CAPABILITIES 3VERALL NETWORK ASPECTS AND FUNCTIONS I. 100-I. 199 1.110-1.
5、119 I. 120-1.129 I. 130-1.139 I. 140-1.149 I. 150-1.199 I .200-1.299 1.200-1.209 I .2 1 0-1.21 9 1.220-1.229 1.230-1.239 1.240-1.249 I .250-1.299 1.300-1.399 I. 3 1 0-1.3 1 9 I .320-1.329 1.330-1.339 1.340-1.349 1.350-1.359 Protocol layer requirements 1.3604.369 General network requirements and func
6、tions Application of 1-series Recommendations to ISDN user-network interfaces Layer 1 Recommendations Layer 2 Recommendations Layer 3 Recommendations Multiplexing, rate adaption and support of existing interfaces Aspects of ISDN affecting terminal requirements ISDN USER-NETWORK INTERFACES INTERNETWO
7、RK INTERFACES MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS ATM equipment Management of ATM equipment 1.370-1.399 I .400-1.499 1.420-1.429 1.430-1.439 1.440-1.449 1.450-1.459 1.460-1.469 1.470-1.499 1.500-1.599 I .600-1.699 I .700-1.799 I .730-1.749 1.750-1.799 For further details, please refer to
8、 ITU-T List of Recommendations. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECOMMENDATION 1.363.3 B-ISDN ATM ADAPTATION LAYER SPECIFICATION: TYPE 3/4 AAL Summary The ATM Adaptation Layer (AAL) type 314 enhances the service pr
9、ovided by the ATM layer to support functions required by the next higher layer. This AAL performs functions required by the user, control and management planes and supports the mapping between the ATM layer and the next higher layer. The AAL type 3/4 supports the non-assured transfer of user data fr
10、ames. An internal mulitplexing function allows the establishment of several concurrent AAL type 3/4 user connections on one ATM connection. On each such connection, the data sequence integrity is maintained and transmission errors are detected. Two new appendices describe the multiplexing AAL type 3
11、14 connections on an ATM connection using the Multiplexing Identification (MID) field and one procedure for dynamic MID allocation. Source ITU-T Recommendation 1.363 was prepared by the ITU-T Study Group XVIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). The current revisio
12、n which lead to different ITU-T Recommendations (e.g. ITU-T Recommendation 1.363.3 for the AAL type 3/4) for the different AAL types was prepared and approved by the ITU-T Study Group 13 (1993-1996) on 27th of August 1996. I Keywords I Asynchronous Transfer Mode (ATM), ATM Adaptation Layer (AAL), Br
13、oadband Integrated I Services Digital Network (B-ISDN). COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesFOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. Th
14、e ITU Telecommunication Standardization Sector (IT-T) is a permanent organ of the ITU. The IT-T 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
15、Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the IT-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resoluti
16、on No. 1. 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 expression “Administration“ is used for conciseness to indicate both a telecommunication administration
17、 and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS The ITU draws attention 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 applicab
18、ility of claimed Intellectual Property Rights, whether asserted by IT members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the ITU hadhad not received notice of intellectual property, protected by patents, which may be required to im
19、plement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O ITU 1997 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any mea
20、ns, electronic or mechanical, including photocopying and microfilm, without permissioh in writing from the ITU. Recommendation L363.3 (08/96) I1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesSTD-ITU-T RECMN 1.3b3-3-ENGL L99b 48b259L O
21、b35008 777 = 1 2 3 5 6 7 7.1 7.2 7.3 8 8.1 8.2 9 9.1 9.2 10 10.1 10.2 CONTENTS Scope Normative references Definitions Abbreviations . Conventions Framework of AAL type 3/4 Service provided by the Common Part ofthe AAL type 3/4 . Primitives for the AAL type 3/4 . Primitives for the CPCS of the AAL ty
22、pe 3/4 7.2.1 Primitives for the data transfer service 7.2.2 Primitives for the abort service . Primitives for the SAR sublayer of the AAL type 3/4 . 7.3.1 Primitives for the data transfer service 7.3.2 Primitives for the abort service . Interaction with the management and control plane . Management
23、plane Control plane Functions. structure and coding of the AAL type 314 Segmentation and Reassembly (SAR) sublayer . 9.1.1 Functions of the SAR sublayer 9.1.2 SAR-PDU structure and coding Convergence Sublayer (CS) . 9.2.1 Functions, structure and coding for the CPCS Procedures Procedures of the SAR
24、sublayer . 1 O . 1.1 State variables of the SAR sublayer at the sender side . 1 O . 1.2 Procedures of the SAR sublayer at the sender side . 1 O . 1.3 State variables of the SAR sublayer at the receiver side . 1 O . 1.4 Procedures of the SAR sublayer at the receiver side . Procedures ofthe CPCS for t
25、he message mode service . 10.2.1 State variables of the CPCS at the sender side 10.2.2 10.2.3 State variables of the CPCS at the receiver side . 10.2.4 Procedures ofthe CPCS at the receiver side . Procedures of the CPCS at the sender side for the message mode service . Recommendation 1.363.3 (08196)
26、 Page 1 1 1 1 3 3 5 6 6 6 7 7 8 8 8 8 8 8 8 8 9 12 12 16 16 16 16 18 18 20 20 20 21 21 iii COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services10.3 Procedures of the CPCS for the streaming mode service . Annex A . Details of the data unit n
27、aming convention . Annex B . General framework ofthe AAL type 3/4 . B . 1 Message segmentation and reassembly B.2 B.3 B.4 B.5 PDU headers. trailers and terminology . SAR and CPCS format . Relation of the MID field to the SN field and BtagEtag fields . Examples of the segmentation and reassembly proc
28、ess . Annex C . Functional model for the AAL type 314 Annex D . SDL diagrams for the SAR and the CPCS of the AAL type 314 D.l SDL for the SAR sublayer D . 1.1 The SAR sender D . 1.2 The SAR receiver SDL for CPCS procedures D.2.1 The CPCS sender D.2.2 The CPCS receiver D.2 Appendix I . Multiplexing A
29、AL type 3/4 connections on an ATM connection using the MID field I . 1 Introduction 1.2 Multiplexing configurations . Point-to-point AAL connection on a point-to-multipoint ATM connection . Point-to-point AAL connection on a multipoint-to-multipoint ATM- connection . Point-to-multipoint AAL connecti
30、on on a point-to-multipoint ATM- connection . Point-to-multipoint AAL connection on a multipoint-to-multipoint ATM- connection . 1.2.1 1.2.2 1.2.3 1.2.4 1.2.5 Point-to-point AAL connection on a point-to-point ATM connection . Page 24 25 27 27 27 28 30 30 32 34 34 34 35 43 43 44 48 48 49 49 51 52 52
31、52 iv Recommendation 1.363.3 (08/96) . COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services STD-ITU-T RECMN I.3b3.3-ENGL 199b H Lib2571 Ob35010 5Li7 m Recommendation 1.363.3 B-ISDN ATM ADAPTATION LAYER SPECIFICATION: TYPE 3/4 AAL (Geneva, 1
32、996) 1 Scope This Recommendation describes the AAL type 314 and the interactions between the AAL type 3/4 Common Part and the next higher layer, and the AAL type 3/4 Common Part and the ATM layer, as well as AAL type 3/4 Common Part peer-to-peer operations. This Recommendation is applicable to equip
33、ment to be attached to a B-ISDN User Network Interface (UNI) or B-ISDN Network Node Interface (“I) when the services of the AAL type 3/4 are to be supported. 2 Normative references The following ITU-T Recommendations and other references contain provisions which, through reference in this text, cons
34、titute provisions of this Recommendation. 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 t
35、he Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. i 2 ITU-T Recommendation X.200 (1 994), Information technology - Open Systems 3 ITU-T Recommendation X.2 1 O (1 993), Information technology - Open Systems ITU-T Recommen
36、dation 1.361 (1999, B-ISDNATM layer specijcation. Interconnection - Basic Reference Model: The Basic Model. Interconnection - Basic Reference Model: Convention for the definition of OSI services. 3 Definitions This Recommendation is based upon the concepts developed in Recommendations X.200 2 and X.
37、210 3. Details of the data unit naming convention used in this Recommendation can be found in Annex A. 4 Abbreviations This Recommendation uses the following abbreviations: AAL ATM Adaptation Layer AAL-SAP AAL Service Access Point AAL-SDU AAL Service Data Unit AL Alignment ATM Asynchronous Transfer
38、Mode ATM-SDU ATM Service Data Unit BASize Buffer Allocation Size Recommendation 1.363.3 (08/96) 1 - COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesBOM Btag CEP COM CPCS CPCS-IDU CPCS-PDU CPCS-SDU CPI CRC cs EOM Etag ID Length LI LSB M
39、MID ML MM MSB “I PAD QOS RS SAR SAR-PDU S AR-SDU I SM SN sscs S SC S -PDU SSM ST UNI Beginning of Message Beginning Tag Connection Endpoint Continuation of Message Common Part Convergence Sublayer CPCS Interface Data Unit CPCS Protocol Data Unit CPCS Service Data Unit Common Part Indicator Cyclic Re
40、dundancy Check Convergence Sublayer End of Message End Tag Interface Data Length of CPCS-PDU Payload Length Indication Least Significant Bit More Multiplexing Identification Maximum Length Message Mode Most Significant Bit Network Node Interface Padding Quality of Service Reception Status Segmentati
41、on and Reassembly (Sublayer) SAR Protocol Data Unit SAR Service Data Unit Streaming Mode Sequence Number Service Specific Convergence Sublayer SSCS Protocol Data Unit Single Segment Message Segment Type User Network Interface I Recommendation 1.363.3 (08/96) 2 COPYRIGHT International Telecommunicati
42、ons Union/ITU TelecommunicationsLicensed by Information Handling Services STD-ITU-T RECMN 1.3b3.3-ENGL L77b D 4862571 Ob35012 31T 5 Conventions The AAL type 3/4 receives from the ATM layer the information in the form of a 48-octet ATM Service Data Unit (ATM-SDU). The AAL passes to the ATM layer info
43、rmation in the form of a 48-octet ATM-SDU. The primitives between the ATM layer and the AAL type 3/4 are defined in Recommendation 1.361 i. 6 The Convergence Sublayer (CS) has been subdivided into the Common Part CS (CPCS) and the Service Specific CS (SSCS) as shown in Figure 1. The CPCS and the SAR
44、 sublayer are called the “Common Part of the AAL type 3/4“. Further clarification can be found in Annex B. Framework of AAL type 314 SAP Service specific CS (may be null) Common Pari CS I SAR (common) TI 33-95 * L u L L SAP cs Convergence Sublayer CPCS Common Party Convergence Sublayer SAR Segmentat
45、ion and Reassembly Sublayer SAP Service Access Point SSCS Service Specific Convergence Sublayer Figure 1D.363.3 - Structure of the AAL type 3/4 Different SSCS protocols, to support specific AAL services, or groups of services, may be defined. The SSCS may also be null, in the sense that it only prov
46、ides for the mapping of the equivalent primitives of the AAL to those of the CPCS and vice versa. SSCS protocols are specified in separate Recommendations. The AAL type 3/4 provides the capabilities to transfer the AAL-SDU fi-om one AAL-SAP to another AAL-SAP through the ATM network (see Figure 2).
47、The AAL users will have the capability to select a given AAL-SAP associated with the QOS required to transport that AAL-SDU (for example, delay and loss sensitive QOS). The AAL type 3/4 in non-assured operation provides the capability to transfer the AAL-SDUs from one AAL-SAP to more than one AAL-SA
48、P through the ATM Network (see Figure 3). Recommendation 1.363.3 (08196) 3 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services STD-ITU-T RECMN 1-3b3.3-ENGL 199b 48b2591 Ob35013 25b AALSAP AAL-SAP AAL ATM however, this option is for further
49、 study. - NOTE - If assured operations are required, they must be provided by the SSCS or by higher layers. The CPCS has the following service characteristics: - Non-assured transfer of user data frames with any length measured in octets from 1 to 65 535 octets and with the possibility of further extension (how much it can be extended is for further study). One or more “CPCS connections“ may be established between two CPCS peer entities utilizing one ATM connection (no switching of CPCS connections will be supported). The maximum number of CPC
