1、INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU 1.364 (0299) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Overall network aspects and functions - Protocol layer requirements Support of the broadband connectionless data bearer service by the B-ISDN ITU-T R
2、ecommendation 1.364 (Previously CCITT Recommendation) ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERALSTRUCTURE Terminology Description of ISDNs General modelling methods Telecommunication network and service attributes General description of asynchronous transfer mode Scop
3、e General aspects of services in ISDN Common aspects of services in the ISDN Bearer services supported by an ISDN Teleservices supported by an ISDN Supplementary services in ISDN Network functional principles Reference models Numbering, addressing and routing Connection types Performance objectives
4、Protocol layer requirements General network requirements and functions Application of I-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 affect
5、ing terminal requirements SERVI CE CAPABILITIES OVERALL NETWORK ASPECTS AND FUNCTIONS ISDN USER-NETWORK INTERFACES INTERNETWORK INTERFACES MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS ATM equipment Transport functions Management of ATM equipment 1.110-1.119 I. 120-1.129 I. 1 304.139 I. 140-1.149
6、I. 150-1.199 1.200-1.209 1.210-1.219 1.220-1.229 1.230-1.239 1.240-1.249 1.250-1.299 I .3 1 04.3 1 9 1.320-1.329 I. 3304.339 1.340-1.349 1.350-1.359 1.360-1.369 1.370-1.399 1.420-1.429 1.430-1.439 1.440-1.449 1.450-1.459 I .460-1.469 I .470-1.499 1.500-1.599 1.600-1.699 I .730-l. 739 I .740-1.749 1.
7、750-1.799 For further details, please refer to ITU-T List of Recommendations STD-ITU-T RECMN 1.3b4-ENGL 1999 4862593 Ohb05h0 825 II ITU-T RECOMMENDATION 1.364 SUPPORT OF THE BROADBAND CONNECTIONLESS DATA BEARER SERVICE BY THE B-ISDN Summary This Recommendation describes the support of the Broadband
8、Connectionless Data Bearer Service (BCDBS) by the B-ISDN. It describes the framework for network support of BCDBS and the protocols used at the user interface and network interface. This Recommendation relates to the direct provision of the BCDBS as defined in Recommendation 1.2 1 1 using connection
9、less service functions. However, aspects of this Recommendation can be applied also to the indirect provision of the BCDBS. Source ITU-T Recommendation 1.364 was revised by ITU-T Study Group 13 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 15th of February 1999. Recom
10、mendation 1.364 (02/99) 1 STD-ITU-T RECMN 1.3b4-ENGL 1999 48b259L Ohb05bL 7bL M FOREWORD ITLJ (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU.
11、 The ITU-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 Standardization Conference (WTSC), which meets every four years, establishes the topi
12、cs for study by the ITU-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 Resolution No. 1. In some areas of information technology which fall within ITU-T?s purview,
13、 the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation the term recognized operating agency (ROA) includes any individual, company, corporation or governmental organization that operates a public correspondence service. The terms Administration,
14、ROA and public correspondence are defined in the Constitution of the ITU (Geneva, 1992). 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 p
15、osition concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the IT had received notice of intellectual property, pro
16、tected by patents, which may be required to implement 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 1999 All rights reserved. No part of this publication may be re
17、produced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. II Recommendation 1.364 (02/99) - STD-ITU-T RECMN 1.364-ENGL 1999 4862591 0660562 bTB CONTENTS 1 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.
18、1 1 2.12 3 3.1 3.2 Scope Framework for the provision of the Broadband Connectionless Data Bearer Service by the B-ISDN Definition of the Broadband Connectionless Data Bearer Service by the B-ISDN . 2.1.1 Group addressing . Functional architecture . Connectionless server functional description . Inte
19、rfaces 2.4.1 Connectionless Access Interface (CLAI) 2.4.2 Connectionless Network Interface (CLNI) . Connections Protocols . Numbering and addressing . 2.7.1 Individual Address (IA) 2.7.2 Group Address (GA) . 2.7.3 Nested Group Address (NGA) Traffic aspects . 2.8.1 Access class enforcement Operations
20、 and maintenance . 2.9.1 Identification of OAM information flow 2.9.2 OAM-supported functions . 2.9.3 OAM mechanisms . 2.9.4 Operations . Network charging capabilities Interworking with non-B-ISDN connectionless data protocols . Interworking with connection-oriented data services . Layer service and
21、 functions provided by the Connectionless Layer Layer service provided by the Connectionless Layer . 3.1.2 Definition of parameters Connectionless Layer functions for user data transport . . 3.1.1 Description of primitives . 3.2.1 Preservation of CLL-SDUs . 3.2.2 Addressing . 3.2.3 Transit operator
22、selection 3.2.4 QOS selection Recommendation 1.364 (02/99) Page 1 1 1 2 2 4 6 6 9 11 12 12 12 12 12 13 13 14 14 16 16 17 17 17 17 17 17 18 18 19 19 19 19 19 . 111 STDeITU-T RECMN 1.3b4-ENCL 1999 m 4862592 0hb0563 534 m 3.3 4 Protocol for the support of the Broadband Connectionless Data Bearer Servic
23、e by the B-ISDN at the UNI . 4.1 Protocol stack . 4.2 4.3 Connectionless Layer functions for CL-OAM data transport Layer service expected from the AAL CLNAP protocol data unit structure and encoding 4.3.1 4.3.2 4.3.3 4.3.4 4.3.5 4.3.6 4.3.7 4.3.8 4.3.9 4.3.10 4.3.1 1 4.3.12 Destination- Address Sour
24、ce- Address . Higher-Layer-Protocol-Identifier (HLPI) PAD-Length CRC Indication Bit (CIB) . Header Extension Length (HEL) . Reserved Header extension . User-Information . PAD . CRC . Quality of Service (QOS) 4.4 Procedures 5 Protocol for the support of the Broadband Connectionless Data Bearer Servic
25、e by the B-ISDN at the NNI . 5.1 Scope 5.2 Protocol stack . 5.4.1 5.4.2 5.4.3 5.4.4 5.4.5 5.4.6 5.4.7 5.4.8 5.4.9 5.4.10 5.4.1 1 5.4.12 5.3 5.4 Layer service expected from the AAL CLNIP Protocol Data Unit structure and encoding Destination Address (DA) . Source Address (SA) . Protocol Identifier (PI
26、) PAD length Quality of Service (QOS) CRC Indication Bit (CIB) . Header Extension Length (HEL) . NGID . Reserved Header Extension HE Post-PAD User-information . Page 19 19 19 20 20 21 21 22 22 22 22 22 22 23 23 23 23 23 23 23 24 24 26 26 27 27 27 27 27 27 28 28 28 28 28 iv Recommendation 1.364 (02/9
27、9) STDoITU-T RECMN 1.3bY-ENGL 1999 m YBb2591 0bb0564 430 W 5.5 6 6.1 6.2 7 7.1 7.2 7.3 7.4 Error conditions 5.5.1 In the case of encapsulation . 5.5.2 In the case of non-encapsulation . Mapping between CLNAP and CLNIP Application rules for encapsulation and non-encapsulation . Encapsulatioddecapsula
28、tion and non-encapsulation mechanisms . 6.2.1 Derivation of the encapsulating CLNIP-PDU fields . 6.2.2 Derivation of the non-encapsulating CLNIP-PDU fields Group Addressed PDU handling Definitions 7.1.1 Group Address Agent (GAA) 7.1.2 Nested Group Address Agent (NGAA) . 7.1.3 Architectural codigurat
29、ions for Group Addressing Centralized database approach . Adding a new member to the group Centralized database in conjunction with NGAAs . Centralized database in conjunction with one level of NGAAs 7.2.1 Transport mechanism 7.2.2 7.3.1 7.3.2 Centralized database approach in conjunction with multip
30、le levels of NGAAs 7.3.3 Partial resolution before the GAA . Combination of group address resolution mechanism . Annex A . Encoding of the Destination Address field and Source Address field Appendix I . List of acronyms Appendix II . SDL diagrams . II . 1 11.2 11.3 General description . Interaction
31、between CLNAP entity and CLLR - - point-to-point information transfer; - multicast information transfer; - addresses based on E. 164 numbering; address screening supplementary service for point-to-point and multicast information transfer; - network capabilities for charging; - - quality of service p
32、arameters. intenvorking to other connectionless and connection-oriented data services; O Recommendation 1.2 1 1 which describes connectionless data service aspects. Recommendation 1.21 1 identifies two configurations, Type (i) and (ii) to support connectionless data service. In Type (i), a Connectio
33、nless Service Function (CLSF) is installed outside the B-ISDN. In Type (ii), a CLSF is installed within the B-ISDN, which handles routing of data to be transferred based on connectionless techniques. a Recommendation 1.327 which describes “higher layer capabilities“ for the support of services (e.g.
34、 connectionless service) and gives functional architectural models for the cases mentioned above. 0 Recommendation 1.363.3 which specifies AAL type 3/4. This Recommendation relates to Type (ii) (direct) provision of the BCDBS, using B-ISDN connectionless service functions. However, aspects of this R
35、ecommendation can be applied to some Type (i) provision of BCDBS. This Recommendation describes the framework for network support of the BCDBS and the protocols used to support it. 2 Framework for the provision of the Broadband Connectionless Data Bearer Service by the B-ISDN 2.1 This definition is
36、provided by Recommendation F.8 12 in conjunction with this Recommendation. Definition of the Broadband Connectionless Data Bearer Service by the B-ISDN Recommendation 1.364 (02/99) 1 STD.1TU-T RECflN 1.3bV-ENGL 1qqq Y862591 Obb05bb 243 2.1.1 Group addressing Group addressing is a mechanism used for
37、multicast communication (see clause 2R.8 12). Multicast information transfer allows a user to send a CLNAP-PDU to the network which delivers the same CLNAP-PDU to several intended recipients. The network shall deliver one and only one copy of a group addressed CLNAP-PDU (GAP) across each of the CLAI
38、s associated with the individual addresses represented by the group address (i.e. each CLAI associated with multiple destination addresses will receive a single copy from the network). The GAP shall not be copied back to the originating CLAI. Any recipient of a GAP may make use of the destination gr
39、oup address carried by that GAP to multicast to the recipients of the GAP (but excluding himself). Non-members of a group address may send GAPS to that group. As a result of address screening, some of the copies of the GAP may not be delivered; all other copies should be delivered. The service provi
40、der is responsible for assigning group addresses and ensuring that each GA (Group Address) identifies uniquely only one set of individual addresses. GAS can be distinguished from individual addresses by the address type. 2.2 Functional architecture The provision of the BCDBS by the B-ISDN is realize
41、d by means of ATM switched capabilities and Connectionless Service Functions (CLSF). The ATM switched capabilities support the transport of connectionless data units in B-ISDN between specific functional groups CLSF able to handle the connectionless protocol and to realize the adaptation of the conn
42、ectionless data units into ATM cells to be transferred in a connection-oriented environment. The CLSF functional groups may be located outside B-ISDN, in a Private Connectionless Network or in a Specialized Service Provider, or inside B-ISDN. The relevant reference configuration for the provision of
43、 the BCDBS by the B-ISDN is depicted in Figure 1. 2 Recommendation 1.364 (02/99) m ATM switched T1818040-92 CLSF Connectionless Service Function M, P, S, T Reference point Figure 1D.364 - Reference configuration for the provision of the CL data service in B-ISDN The ATM switched capabilities are per
44、formed by the ATM nodes (ATM switchlcross-connect) which realize the ATM transport network. The CLSF functional group terminates the B-ISDN connectionless protocols and perfoms functions for the adaptation of the connectionless protocol including preservation of PDU sequence integrity to the intrins
45、ically connection-oriented ATM layer protocol. The connectionless functions are those related to the layer directly above the AAL denoted Connectionless Layer (CLL) and performed by the Connectionless Network Access Protocol (CLNAP), Connectionless Network Interface Protocol (CLNIP) and related Rout
46、ing and Relaying (CLLR 4 Recommendation 1.364 (02/99) STDeITU-T RECMN 1.364-ENGL 1999 4862573 Obb0569 TCZ R - Connectionless Service Handling Functions (CLHF) which include all the service-specific functions required for the support of the BCDBS by the B-ISDN. In general they are related to network
47、integrity issues (e.g. address validationscreening, access class enforcement) and to relaying issues (e.g. routing, group address handling); Control Functions (CTF) are related to connectiodresource handling and service processing; the information necessary to effect control over the communication r
48、esources in the server can be exchanged with other network elements through signalling or management protocols. Operation and Maintenance (OAM) functions. r-+ I I l I l l l I I I I E El 4- QI .g 01 ci -1 I I _- E _-_-_-_ Connectionless Service Handling Functions specific functions I- l I I _-_-_-_ C
49、ontrol Functions Connection this network can be different from the network where the GAP originated and from the network resolving the GA. (The resolution function provides, for a given GA or NGA, the list of addresses of all the members and/or NGAs in the case of a GA using NGAs.) The type of address used for an NGA is the same as the one defined for a GA. An NGA is globally unique. A given NGA associated with a GA cannot be reused for another GA in order to allow independent evolution of the two GAS. An NGA shall not be used in a CLN
