ITU-T X 34-1996 Access to Packet Switched Data Transmission Services Via B-ISDN - Series X Data Networks and Open System Communication Public Data Networks - Interfaces《通过B-ISDN接入分.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU x.34 (1 0196) SERIES X: DATA NETWORKS AND OPEN SYSTEM COMMUNICATION Public data networks - Intedaces Access to packet switched data transmission services via B-ISDN ITU-T Recommendation X.34 (Previously “CCIl

2、T Recommendation”) STD-ITU-T RECMN X-3Li-ENGL 177b m Lib2591 b22509 7bT M ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS AND OPEN SYSTEM COMMUNICATION x. 1-x.19 Services and facilities Transmission, signalling and switching Network aspects Maintenance Administrative arrangements Model and notation Ser

3、vice definitions Connection-mode protocol specifications Connectionless-mode protocol specification PICS proformas Protocol Identification Security Protocols Layer Managed Objects Conformance testing General Satellite data transmission networks MESSAGE HANDLING SYSTEMS DIRECTORY OS1 NETWORKING AND S

4、YSTEM ASPECTS Networking Efficiency Naming, Addressing and Registration Abstract Syntax Notation One (ASN. 1) Systems Management framework and architecture Management Communication Service and Protocol Structure of Management Information Management functions )PEN SYSTEM INTERCONNECTION NTERWORKING B

5、ETWEEN NETWORKS OS1 MANAGEMENT SECURITY OS1 APPLICATIONS Commitment, Concurrency and Recovery Transaction processing Remote operations OPEN DISTRIBUTED PROCESSING X.50-X.89 X.90-X. 149 X.150-X.179 X.180-X. 199 X.200-X.299 X.200-X.209 X.210-X.219 X.220-X.229 X.230-X.239 X.240-X.259 X.260-X.269 X.270-

6、X.279 X.280-X.289 X.290-X.299 x.300-x.399 X.300-X.349 X.350-X.399 X .400-X .499 X.500-X.599 X.600-X.699 X.600-X.629 X.630-X.649 X.650-X.679 X.680-X.699 X.700-X. 799 X.700-X.709 X.7 10-X.7 19 X.720-X.729 X.730-X.799 X.800-X. 849 X.850-X.899 X.850-X.859 X.860-X.879 X.880-X.899 X.900-X.999 For further

7、details, please refer to ITU-T List of Recommendatiom. STD-ITU-T RECMN X.34-ENGL L9fb 48b2571 0622530 4L FOREWORD The IT-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The -T is responsible for studying technical, operating and t

8、ariff questions and issuing Recommen- dations 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 topics for study by the -T Study Groups which, in their turn, produ

9、ce 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 (Helsinki, March 1-12, 1993). IT-T Recommendation X.34 was prepared by IT-T Study Group 7 (1993-1996) and was approved under the WTSC Resolut

10、ion No. i procedure on the 5th of October 1996. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. All rights reserved. No part of this publication may be reproduced or utilized i

11、n any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. Recommendation X.34 (10/96) I CONTENTS Page . 1 SCOPE 1 2 References 1 . 3 Terms and definitions 2 4 Abbreviations . 2 5 General service aspects 3 6 Reference confi

12、gurations . 3 6.1 Configuration when accessing PSPDN via a B-ISDN 4 6.2 Configuration when accessing the packet switched data transmission services of an ISDN via a B-ISDN 5 . 7 Service aspects . 5 7.1 General 5 7.2 Service characteristics . 6 7.3 User access capabilities 8 8 Addressing and routing

13、aspects 8.1 Outgoing calls . 8.1.1 Access unit selection . 8.1.2 Addressing scheme . 8.2 Incoming calls . 8.2.1 Access unit selection . 8.2.1.1 Access unit selection by PSPDN (Type A) . 8.2.1.2 Access unit selection by ISDN (Type B) 8.2.2 Addressing scheme . 8.2.3 Called TEIx.25 DEcTA interface sele

14、ction . 8 8 8 8 8 8 9 9 9 9 9 Interworking with dedicated networks . 9 9 9.1 General 9.2 Access to PSDTS via a B-ISDN 10 . 10 Procedures 10.1 General 10.2 Procedures 10.2.1 Outgoing call . 10.2.1.1 Outgoing ATM switched virtual channel connection . 10.2.1.2 Outgoing X.25 virtual call setup and relea

15、se 10.2.2.1 Incoming ATM switched virtual channel connection . 10.2.2.2 Incoming X.25virtual call setup and release ATM switched virtual channel connection clearing . 10.3.1 Clearing initiated by the WX.25 DTE+TA . 10.3.2 Clearing initiated by the PSDTS AU 10.4 ATM switched virtual channel connectio

16、n clear collision 10.5 Restart procedures 10.6 Handling of error conditions . 10.7 10.2.2 Incoming call 10.3 ATM PVC management procedure 10 10 10 10 11 11 11 11 12 12 12 12 12 12 13 13 11 Recommendation X.34 (10/96) STD-ITU-T RECMN X*ILi-ENGL 177b = Lidb2571 Ob22512 254 11 Terminai adaptor function

17、alities 11.1 General 1 1.2 Access to PSDTS via a B-ISDN . 11.2.1 Physical interfaces Layer 2 adaption . 11.2.4 Signalling 11.2.4.2 Incoming call 1 1.2.4.3 Call clearing 1 1.2.5 Synchronization 11.2.6 Maintenance Annex A - The mappings 4.2931 cause field to Recommendation X.25 . 11.2.2 Rate adaption

18、1 1.2.3 11.2.4.1 Outgoing call . Appendix1 . I . 1 1.2 1.3 Example of sequence diagrams . Example sequence diagrams . Key to the figures Example of sequence diagrams . Recommendation X.34 (10/96) . Page 14 14 14 14 14 14 16 16 18 19 20 20 20 21 21 21 22 . 111 STD-ITU-T RECMN X-34-ENGL L97b 48b257L 0

19、b22523 190 SUMMARY This Recommendation defines services available and signalling procedures operated at the SBITB reference point of a B-ISDN for access to packet switched data transmission service via the B-ISDN. iv Recommendation X.34 (10196) STD-ITU-T RECMN X-34-ENGL 199b m YBb257L Ob225LY O27 M

20、Recommendation X.34 ACCESS TO PACKET SWITCHED DATA TRANSMISSION SERVICES VIA B-ISDN (Geneva, 1996) 1 SCOPE This Recommendation defines the procedures of access to PSDTS via a B-ISDN. It includes two cases; a) PSPDN provides the PSDTS. b) ISDN provides the PSDTS. 2 References The following I-T Recomm

21、endations and other references contain provisions which, through reference in this text, constitute 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

22、 therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of Currently valid IT-T Recommendations is regularly published. CCIT Recommendation E.164 (1991), Numberingplan for the ISDN era. ITU-T Recommenda

23、tion E. 166K. 122 (1996), Numbering plan interworking for E. I64 and X 121 numbering plans. -T Recommendation 1.21 1 (1993), B-ISDN service aspects. ITU-T Recommendation 1.36 1 (1993, B-ISDN ATM layer speclfication. -T Recommendation 1.362 (1993). B-ISDN ATM adaptation layer (AAL)functional descript

24、ion. ITU-T Recommendation 1.363 (1993), B-ISDN ATM adaptation layer (AAL) specication. ITU-T Recommendation 1.41 3 (1993), B-ISDN user-network interface. ITU-T Recommendation 1.430 (1 993, Basic user-network interface - Layer 1 specification. IT-T Recommendation 1.43 1 (1 993), Primary rate user-net

25、work interface - Layer 1 specification. ITU-T Recommendation 1.432 (1993), B-ISDN user-network interface - Physical layer specification. ITU-T Recommendation 1.580 (1995). General arrangements for interworking between B-ISDN and 64 Kbit/s based ISDN. IT-T Recommendation 4.21 10 (i994), B-ISDN ATM ad

26、aptation layer - Service Specific Connection Oriented Protocol (SSCOP). ITU-T Recommendation Q.2130 (1994), B-ISDN signalling ATM adaptation layer - Service specijic coordination function for support of signalling at the user-network interface (SSCF at UNI). ITU-T Recommendation 1.6 10 ( 1993, B-ISD

27、N operation and maintenance principles andfunctions. 1 Recommendation X.34 (10196) STDmITU-T RECMN X.W-NGL 19Tb m qBb2591 Ob22515 Tb3 M IT-T Recommendation 4.293 1 (1993, Broadband Integrated Services Digital Network (B-ISDN) - Digital Subscriber Signalling System No. 2 (OSS 2) - user network - inte

28、rface (vrur) layer 3 specification for basic caWconnection control. IT-T Recommendation X.l (1996), International user classes of service in, and categories of access to, public data networks and Integrated Services Digital Networks (ISDNs). IT-T Recommendation X.25 (1996). Interface between Data Te

29、rminal Equipment TE) and Data Circuit- terminating Equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit. ITU-T Recommendation X.31 (1995), Support ofpackt mode terminal equipment by an ISDN. IW-T Recommendation X.32 (1996), Interface b

30、etween Data Terminal Equipment (DTE) and Data Circuit- terminating Equipment CE) for terminals operating in the packet mode and accessing a packet switched public data network through a public switched telephone network or an integrated services digital network or a circuit switchedpublic data netwo

31、rk. IT-T Recommendation X.75 (1996), Packet switched signalling system between public networks providing data transmission services. IT-T Recommendation X.121 (1996), International numberingplan for public data networks. -T Recommendation X.2 13 (1995), Information technology - Open Systems Intercon

32、nection - Network service definition. ITU-T Recommendation 1.365.4 (1996), Service specific convergence sublayer for HDLC applications. Terms and definitions For the purposes of this Recommendation, the following definition applies. 3.1 HDLC applications SSCS (HDLC Appiications Service Specific Conv

33、ergence Sublayer, see Recommendation 1.365.4): HDLC Applications SSCS is used at the TE and AU for interworking between AAL and X.25 LAPB. 4 Abbreviations For the purposes of this Recommendation, the following abbreviations are used. AAL ATM Adaptation Layer ATM Asynchronous Transfer Mode AU Access

34、Unit BCOB B-ET B-ISDN Broadband ISDN B-NT B-TA CH Cell Handler CPCS Common Part Convergence Sublayer CPCS-CI CPCS-Congestion Indication Broadband Connection Oriented Bearer class Exchange Terminal for Broadband ISDN Network Termination for Broadband ISDN Terminai Adaptor for Broadband ISDN CPCS-LP C

35、PCS-Loss Priority CPCS-UU CPCS-User to User indication DNIC Data Network Identification Code DTE Data Terminal Equipment ISDN Integrated Services Digital Network 2 Recommendation X.34 (lO96) STD.ITU-T RECMN XD 34-ENGL L99b m 4b2571hZZ5lb 9TT IWF NT PH PMBS PSPDN PSDTS PVC QOS sscs svc TA TE VCI VPCI

36、 Interworking Function Network Termination Packet Handler Packet Mode Bearer Service Packet Switched Public Data Network Packet Switched Data Transmission Services Permanent Virtual channel Connection Quality of Service Service Specific Convergence Sublayer Switched Virtual channel Connection Termin

37、al Adapter Terminal Equipment Virtual Channel Identifier Virtual Path Connection Identifier 5 General senice aspects Packet Switched Data Transmission Services (PSDTSs) are provided by Packet Switched Public Data Networks (PSPDNs) or by Integrated Services Digital Networks (ISDNs). These PSDTSs may

38、be accessed by users of Broadband ISDNs (B-ISDNs). This Recommendation defines the aspects of packet switched data transmission services provided by a PSPDN or an ISDN to the users of B-ISDN in accordance with the services defined in Recommenda- tions 1.211 and X.l. This Recommendation defines the p

39、rocedures at the user-network interface of a B-ISDN to access packet switched data transmission services provided by a PSPDN or an ISDN in alignment with Recommenda- tions Q.293 1 and X.25. This Recommendation defines the procedures at the user-network interface of a B-ISDN to access packet switched

40、 data transmission services provided by a PSPDN or an ISDN in alignment with Recommenda- tions 1.432,1.361,1.362,1.363 , Q.2110 and 4.2130. This Recommendation defines the Terminal Adaptation functions to adapt existing X.25 terminals for use at the user-network interface of a B-ISDN in order to acc

41、ess packet switched data transmission services provided by a PSPDN or an ISDN. a) b) c) d) 6 Reference configurations There are two reference configurations: Type A: Access to the Packet Switched Data Transmission Service (PSDTSs) provided by a Packet Switched Public Data Network (PSPDN) using the B

42、-ISDN. Access to the PSDTS provided by an ISDN using the B-ISDN. Type B: In the configurations given below, a Terminal Equipment TE) with X.25 and ATM capabilities is equivalent to a combination consisting of an X.25 Data Terminal Equipment (DE) and a Terminal Adapter TA) with ATM capabilities. NOTE

43、 1 -ATM capabilities are in accordance with Recommendations 1.361. 1.362, 1.363, 1.432, Q.2110 and Q.2130 for TEsfAs attached to a B-ISDN. In this Recommendation, every reference to the combination of an X.25 DTE and its TA should always be considered as being applicable to a TE with X.25 and also T

44、A and TE should support AAL type 5 function (CPCS+HDLC Applications SSCS) to convey X.25 frames. (See Recommendation 1.365.4). NOTE 2 - Use of AAL type 1 with HDLC framing instead of AAL type 5 should not be precluded. Recommendation X.34 (10/96) 3 STD.ITU-T RECMN X-3Li-ENGL Lq7b W Li8b2571 Ob22517

45、83b II I I I I II TE R aB I In case AAL type 5 is used, AAL type 5 message mode service will be available. The functionality of the HDLC Applications SSCS only provides for the mapping of the equivalent primitives of AAL to CPCS and vice versa. The CPCS-UNITDATA primitive parameters should be set by

46、 SSCS as specified in 7.4D.365.4. AU 6.1 Configuration when accessing PSPDN via a B-ISDN This configuration (Figure 6-1) refers to the case where the PSDTS provided by a PSPDN is accessed using the B-ISDN. In this case, a TEK25 DTE+TA accesses the PSDTS of the PSPDN by means of an ATM virtual channe

47、l connection established through the B-ISDN. The ATM virtual channel connection is routed, within the B-ISDN, to an access port of the PSPDN referred to as “Access Unit (AU)”. An ATM virtual channel connection is set up to/from an AU port. An AU supports the possible path setting-up functions for La

48、yer 1 and possible rate adaptation between the PSPDN and the B-ISDN. An AU also supports the necessary processing functions for ATM virtual channel connections and X.25 virtual calls. The-same AAL as that of TESTAS are also applicable for AU. NOTE 1 -The PSDTS may be provided by physically the same

49、network as B-ISDN. It is important to note that the procedures for accessing PSDTS through a B-ISDN user-network interface are inde- pendent of where the service provider chooses to locate the AU function. The AU function, logically belonging to the PSPDN. may physically be located either in the PSPDN or in the B-ISDN. II ! 1 Reference point II AU Access Unit DTE Data Terminai Equipment TA TE Terminal Adapter lor Broadband ISDN Terminal Equipment with ATM capabilities (see text) NOTES 1 2 ATM demand channel connection. 3 The AU logically bel